Cooley's Cyclopædia of Practical Receipts and Collateral Information in the Arts, Manufactures, Professions, and Trades..., Sixth Edition, Volume I (part 2 of 10)

Preface

The design of the present work is briefly, but not completely expressed in its title-page. Independently of a reliable and comprehensive collection of formulæ and processes in nearly all the industrial and useful arts, it contains a description of the leading properties and applications of the substances referred to, together with ample directions, hints, data, and allied information, calculated to facilitate the development of the practical value of the book in the shop, the laboratory, the factory, and the household. Notices of the substances embraced in the Materia Medica of our national pharmacopœias, in addition to the whole of their preparations, and numerous other animal and vegetable substances employed in medicine, as well as most of those used for food, clothing, and fuel, with their economic applications, have been included in the work. The synonymes and references are other additions which will prove invaluable to the reader. Lastly, there have been appended to all the principal articles referred to brief, but clear, directions for determining their purity and commercial value, and for detecting their presence and proportions in compounds.

The sources from which I have derived the vast mass of materials forming this volume are such as to render it deserving the utmost confidence. I have invariably resorted to the best and latest authorities, and have consulted almost innumerable volumes, both British and foreign, during its compilation. Secondary channels of information have been scarcely ever relied on when original authorities were within my reach. A large portion of the work has been derived from my personal experience and observations in the departments of applied chemistry and hygiene, and from the processes of various laboratories and manufactories, many of which I can the more confidently recommend from having either inspected or witnessed their employment on an extensive scale. The indiscriminate adoption of matter, without examination, has been uniformly avoided, and in no instance has any formula or process been admitted into this work, unless it rested on some well-known fact of science, had been sanctioned by usage, or come recommended by some respectable authority. The settlement of doubtful or disputed points has often occupied me a greater number of hours, and not unfrequently a greater number of days, than that of the lines of letter-press which convey the results to the public. In all cases precedence has been given to the standard formulæ of our national pharmacopœias, and to those processes which long experience, or well-conducted experiments, have shown to be the most successful, profitable, and trustworthy. In general, the sources of information have been indicated, for the purpose of enabling the reader to form a better estimation of their value. Whenever this is not the case, in reference to borrowed formulæ and data, the omission has arisen from the impossibility of determining to whom the merit is justly due.

I have endeavoured as much as possible, in the present work, to avoid confusion of the medical weights with those commonly used in trade and commerce——an attempt which, so far as I am aware, has not been successfully carried out in any other quarter. For this purpose I determined to entirely abandon the usual arbitrary signs or characters employed to represent the divisions of the apothecaries’ pound, and to distinguish the two weights from each other, by simply printing, in different type, the plain English names and abbreviations representing their several denominations. The medical signs for the imperial gallon and its subdivisions have also been abandoned for their common English names. It would have afforded me pleasure to have reduced all the quantities to one uniform standard, had it been practicable, or, in all cases, advisable.

Under the names of most of the leading diseases that could be profitably noticed in the present work, such explanations and directions have been given as accord with the prevailing opinions and practice of the faculty at the present day. These, when judiciously applied, will prove invaluable to emigrants, travellers, voyagers, and other parties beyond the reach of legitimate medical assistance; and, under opposite circumstances, will, in general, enable those who have the care of the sick the better to second and carry out the instructions and efforts of the physician for the benefit of their charge. Here, however, it may be useful to repeat the cautions given in other parts of this volume, as to the impropriety of unnecessarily meddling with the healing art, or neglecting a prompt application to a duly qualified practitioner, in all cases demanding either medical or surgical aid. It is an indubitable fact that the best efforts of the inexperienced and uninitiated in the mysteries of medical science must be always enormously behind those of parties whose whole lives and study have been devoted to the subject.

The nature of a condensed alphabetical arrangement not permitting numerous articles to come under distinct heads, or to be referred to under all their synonymes, the casual reader may often be led to suppose that this book is most deficient where in reality it is the most copious. In general I have attempted, as much as possible, to bring together subjects of a closely allied character, and compounds which are analogous to each other, either in constitution or the mode of their preparation. Thus, most of the formulæ for Mixtures, Ointments, Pills, &c., follow in alphabetical order the general articles under these heads; whilst those for the Oxides, Salts, &c., follow the names of their respective bases. In like manner, a notice of a number of preparations will be found included in that of their principal ingredients. The names under which the leading substances appear are generally those which are most familiar to well-informed practical men, and which have commonly reference to either their acknowledged chemical constitution, or to some long-known and easily recognised quality. The following extract conveys an important lesson on this subject, with which I perfectly agree:——“We have been unwilling to make any unnecessary changes in the nomenclature of substances whose names are sanctioned by the usage of the present day; for these names have been, for the most part, rightly assigned by our predecessors, or confirmed by lapse of time. We are indeed aware that every improvement in the knowledge of things ought to be embodied in their names; but we must be careful, in selecting or forming these names, not to make those points appear certain and established which are as yet doubtful, for it is safer to be in the rear than advance of natural history.”[1]

[Footnote 1: Preface to the Ph. L., 1851.]

I have exerted myself to the utmost to ensure the accuracy and completeness of this volume, but I feel conscious that, after all my efforts for this purpose, some errors have crept into it, that many subjects which deserve insertion in it have been omitted, and that many others have been either imperfectly or too briefly noticed. “Yet these failures, however frequent, may,” I trust, “admit of extenuation and apology. To have attempted much is always laudable, even where the enterprise is above the strength that undertakes it. To rest below his aim is incident to every one whose fancy is active, and whose views are comprehensive; nor is any man satisfied with himself because he has done much, but because he conceives little.” When I commenced this work I resolved to leave nothing within its legitimate limits unexamined or unelucidated; and I flattered myself with a prospect of the hours which I should thus “revel away” in a pursuit so congenial to my desires——“the treasures with which I expected every search into those neglected mines to reward my labour——and the triumph with which I should display my acquisitions to mankind.” But these were the dreams of a poet, doomed at last to wake a “Cyclopædist”. The long task which I had undertaken soon exhibited its truly onerous character, and daily grew in urgency, until that which promised to be a pleasure had been transformed into an exhausting and continuous labour. At first, a sacrifice of the hours of leisure only seemed necessary to the undertaking——next, those assigned to professional and business avocations were demanded, and absorbed; but, ere long, one by one, the hours usually devoted to repose were sucked into the insatiable vortex, until the bright beams of the rising sun not unfrequently illumined the lamp-lit study or the gloomy laboratory, and surprised the author, no longer an enthusiast, at his still-enduring task. But long ere this I had learned that to carry out my original resolutions in all their completeness and entirety was impossible, and “that to pursue perfection was, like the first inhabitants of Arcadia, to chase the sun, which, when they had reached the hill where he had seemed to rest, was still at the same distance from them.”[2] All I can further say in reference to this point is simply to assure the reader that three of the elements usually deemed essential to give value to a technological work——viz. zeal, industry, and capital——have not been wanting in the production of the present one;——the first two depending on the author, and the other chiefly on the liberality and enterprise of the publisher.

[Footnote 2: Dr Samuel Johnson’s Preface to his English Dictionary.]

As heretofore, I beg to solicit my readers to apprise me of any inaccuracies or omissions in this volume which may come beneath their notice. I shall also thankfully receive any hints or suggestions tending to the improvement of future editions of this work. Such communications, to be useful, must, however be written on only one side of the paper. Parties who may thus kindly afford me assistance will, in due course, have their services publicly acknowledged; and their names and addresses, unless when otherwise requested, will be published in full.

I have endeavoured to render the present volume as self-explanatory as possible, and, in general, have appended ample directions to the several formulæ and processes that seemed to me likely to cause embarrassment to those inexpert in chemical manipulation; but should any party find it otherwise, I shall be happy to reply, gratuitously, to any reasonable questions tending to elucidate the difficulty.

In conclusion, I may add that, having now for nearly a quarter of a century devoted my attention to the applications of chemistry in most of the useful arts and manufactures, both British and foreign, and in sanitation, I am in possession of many valuable processes and formulæ, hitherto wholly unknown, or but partially developed, with various improved plans of factories, laboratories, ventilation, &c., which the limits of this work will not permit me to describe in its pages, but on which I should be happy to communicate with parties interested in the same. Persons desirous of establishing any new branch of manufacture, or of improving an existing one, or of determining the purity or value of articles of food, wines, liqueurs, medicines, &c., or of obtaining formulæ or processes which are not contained in this work, may, in like manner, have their wishes complied with, by enclosing to me samples, or the requisite information.

ARNOLD J. COOLEY.

NAMES OF THOSE WHO HAVE CONTRIBUTED TO, OR ASSISTED IN THE REVISION OF, THIS EDITION

JOHN ATTFIELD, Ph.D., F.I.C., F.C.S., Professor of Practical Chemistry to the Pharmaceutical Society of Great Britain.

J. WORTLEY AXE, P.C.V.M.S., Professor of Histology in the Royal Veterinary College.

LLOYD BULLOCK, F.I.C., F.C.S.

E. L. BARRET, B.Sc., F.I.C., F.C.S.

E. CANTON, F.R.C.S., Surgeon to Charing Cross Hospital.

SPENCER COBBOLD, M.D., F.R.S., Professor of Parasitology and Botany in the Royal Veterinary College.

STEPHEN DARBY, F.C.S.

DR DE VRIJ, of the Hague.

JOHN GARDNER, F.I.C., F.C.S.

WILLIAM HARKNESS, F.I.C., F.C.S., F.R.M.S., Assistant Chemist in the Laboratory of the Inland Revenue Department, Somerset House.

C. W. HEATON, F.I.C., F.C.S., Lecturer on Chemistry at the Charing Cross Hospital.

EDMUND NEISON, F.I.C., F.C.S.

WILLIAM PRITCHARD, Professor of Anatomy in the Royal Veterinary College.

A. E. SANSOM, M.D. Lond., M.R.C.P., Physician to the Royal Hospital for Diseases of the Chest.

J. B. SIMONDS, Principal of, and Professor of Pathology in, the Royal Veterinary College.

JOHN SPILLER, F.I.C., F.C.S.

JOHN STENHOUSE, LL.D., F.R.S., formerly Lecturer on chemistry in St. Bartholomew’s Hospital.

ABBREVIATIONS, ETC., USED IN THIS WORK

These, for the most part, consist of the first syllable, or the initial letter or letters of the words they stand for. As Prep., preparation; Pur., purity; Purif., purification; Obs., observations; Var., varieties, &c.——Ph., stands for pharmacopœia; B. P., for British Pharmacopœia; Ind. Ph., for Indian Pharmacopœia; Cod., for Codex.——L., E., D., P., U. S., &c., associated with the last two abbreviations, are the initial letters of the cities and countries which produced the respective works; as, London, Edinburgh, Dublin, Paris, United States, &c. When no dates are given, the last editions of the pharmacopœias are referred to.

lb., oz., dr., respectively represent the pound, ounce, and drachm (1/8 oz.), AVOIRDUPOIS WEIGHT. This is the only weight employed in the British and last Dublin Pharmacopœias.

lb., oz., dr., and gr., refer to the pound, ounce, drachm, and grain, APOTHECARIES’ or TROY WEIGHT.

The word ‘drop’ in all cases indicates a measured drop or minim.

The names of individuals which appear in this work are those to whom the immediately attached information or formula is usually attributed, or on whose recommendation or authority it has been selected.

′ denotes the accented vowel or syllable.

′′ that the following consonant coalesces with the preceding letter in utterance.

† that the name or the definition to which it is attached is ‘obsolete,’

* that the name or the definition to which it is attached is ‘obsolescent,’ little used, or objectionable.

‡ that the name or the definition to which it is attached is ‘colloquial,’ or popular, or used only in trade.

§ that the name or the definition to which it is attached is ‘vulgar,’

A CYCLOPÆDIA OF PRACTICAL RECEIPTS, PROCESSES, AND COLLATERAL INFORMATION

A——ABBREVIATION

=A-, ab-, abs-.= [L.] In composition, from, denoting distance, departure, separation, or opposition; as in aberration, abstraction, abnormal, &c.

=A-, an-.= [Gr.] In composition, no, not, without, denoting the absence or loss of some quality or thing; as in achromatic, anhydrous, amorphous, &c.

=AB′ACA= (kăh). A species of vegetable fibre, of several varieties, obtained in the Philippine Islands, and remarkable for its brilliancy, strength, and durability. The finer kinds are woven into muslins, and other delicate fabrics; the coarser are formed into mats, cordage, and sail-cloth. It has been recently employed in Paris for the manufacture of various articles of furniture and dress; including bonnets, tapestry, carpets, network, hammocks, &c. The fibre, and fabrics made of it, may be bleached and dyed in a similar manner to flax and linen.

=ABATTOIR=. A public slaughter-house for cattle, &c., usually erected within the walls or precincts of a continental town or city.

=ABBREVIATION=. One or more of the earlier letters of a word used to express the whole.

1. Abbreviations in general use:——

A.B., Bachelor of Arts. A.D., In the year of our Lord. A.I.C., Associate of the Institute of Chemistry. A.I.C.E., Associate of the Institute of Civil Engineers. A.M., Master of Arts.——Before noon. A.R.A., Associate of the Royal Academy. B.A., Bachelor of Arts. Bart., Baronet. B.C., Before Christ. B.D., Bachelor of Divinity. B.Sc., Bachelor of Science. C.B., Companion of the Bath. C.E., Civil Engineer. C.S., Civil Service. D.C.L., Doctor of Civil Laws. D.D., Doctor of Divinity. D.G., By the Grace of God. Dr., Doctor.——Debtor. D.Sc., Doctor of Science. D.V., God willing. Ed., Editor, or Edition. e.g., for example. F.C.P., Fellow of the College of Preceptors. F.C.S., Fellow of the Chemical Society. F.G.S., Fellow of the Geological Society. F.I.C., Fellow of the Institute of Chemistry. F.L.S., Fellow of the Linnean Society. F.R.A.S., Fellow of the Royal Astronomical Society. F.R.C.P., Fellow of the Royal College of Physicians. F.R.C.S., Fellow of the Royal College of Surgeons. F.R.G.S., Fellow of the Royal Geographical Society. F.R.S., Fellow of the Royal Society. F.R.S.E., Fellow of the Royal Society of Edinburgh. H.M.S., Her Majesty’s Ship. H.R.H., His (or Her) Royal Highness. i.e., That is. Inst., Instant (the present month). I.H.S., Jesus the Saviour of Man. K.B., Knight of the Bath. K.C.B., Knight Commander of the Bath. K.G., Knight of the Garter. Knt., Knight. K.St.P., Knight of St. Patrick. K.T., Knight of the Thistle. L.A.C., Licentiate of the Apothecaries’ Company. Lat., Latitude. L.D., Licentiate in Dentistry. LL.D., Doctor of Laws. L.M., Licentiate in Midwifery. Loc. cit., The part referred to. Lon. or Long., Longitude. M.A., Master of Arts. M.B., Bachelor of Medicine. M.C., Master of Surgery.——Master of the Ceremonies. M.C.P., Member of the College of Preceptors. M.D., Doctor of Medicine. M.I.B.A., Member of the Institute of British Architects. M.R.C.P., Member of the Royal College of Physicians. M.R.C.S., Member of the Royal College of Surgeons. M.R.C.V.S., Member of the Royal College of Veterinary Surgeons. M.R.I., Member of the Royal Institution. M.R.I.A., Member of the Royal Irish Academy. MS., Manuscript. MSS., Manuscripts. Mus. Doc., Doctor of Music. N.B., Mark well. Nem. con., Without opposition. O.H.M.S., On Her Majesty’s service. Op. cit., The work quoted. Per cent. (often expressed by the sign %), By the hundred. Ph.D., Doctor of Philosophy. P.M., Afternoon. Prox., The next (month). P.S., Postscript. Q.C., Queen’s Counsel. Qy. (?), Query, Question. R.A., Royal Academician——Royal Artillery. R.E., Royal Engineers. R.H.A., Royal Horse Artillery. R.M., Royal Marines. R.N., Royal Navy. Tr., Translator. Ult., The last (month). v. or vide, See. W.S., Writer to the Signet. &, ampersand, and. &c., et cetera, And so on.

2. Abbreviations used in Prescriptions:——

A. aa., ana (Greek), of each. Equally by weight or measure. Abdom., abdomen, the abdomen, the belly. Abs. febr., absente febre, fever being absent. Ad 2 vic., ad secundum vicem, to the second time; or _ad duas vices_, for two times. Ad gr. acid., ad gratam aciditatem, to an agreeable acidity. Ad def. animi, ad defectionem animi, to fainting. Ad del. an., ad deliquium animi, to fainting. Ad libit., ad libitum, at pleasure. Add., adde, or addantur, add, or let them be added; addendus, to be added. Adjac., adjacens, adjacent. Admov., admove, admoveatur, admoveantur, apply, let it be applied, let them be applied. Ads. febre, adstante febre, while the fever is present. Alter. hor., alternis horis, every other hour. Alvo adstr., alvo adstrictâ, when the bowels are confined. Aq. astr., aqua astricta, frozen water. Aq. bull., aqua bulliens, boiling water. Aq. com., aqua communis, common water. Aq. fluv., aqua fluviatilis, river water. Aq. mar., aqua marina, sea water. Aq. niv., aqua nivalis, snow water. Aq. pluv., aqua pluviatilis, or pluvialis, rain water. Aq. ferv., aqua fervens, hot water. Aq. font., aqua fontana, or aqua fontis, spring water. Bis ind., bis in dies, twice a day. Bib., bibe, drink. BB., Bbds., Barbadensis, Barbadoes, as aloë Barbadensis. B.M., balneum mariæ, or balneum maris, a warm-water bath. B. P., or B. Ph., British Pharmacopœia. But., butyrum, butter. B.V., balneum vaporis, a vapour bath. Cærul., cæruleus, blue. Cap., capiat, let him (or her) take. Calom., calomelas, calomel, subchloride of mercury. C. C., cornu cervi, hartshorn; it may also signify cucurbitula cruenta, the cupping-glass with scarificator. C.C.U., cornu cervi ustum, burnt hartshorn. Cochleat., cochleatim, by spoonfuls. Coch. ampl., cochleare amplum, a large (or table) spoonful; about half a fluid ounce. Coch. infant., cochleare infantis, a child’s (or tea) spoonful. Coch. magn., cochleare magnum, a large spoonful. Coch. med., cochleare medium, } a middling or moderate spoonful; that is, Coch. mod., cochleare modicum,} a dessert-spoonful——about two fluid drachms. Coch. parv., cochleare parvum, a small (or tea) spoonful; it contains about one fluid drachm. Col., cola, strain. Col., colatus, strained. Colet., coletur, colat., colatur, let it be strained; colaturæ, to the strained liquor. Colent., colentur, let them be strained. Color., coloretur, let it be coloured. Comp., compositus, compounded. Cong., congius, a gallon. Cons., conserva, conserve; also (imperat. of conservo) keep. Cont. rem., or med., continuentur remedia, or medicamenta, let the remedies, or the medicines, be continued. Coq., coque, boil; coquantur, let them be boiled. Coq. ad med. consumpt., coque or _coquatur ad medietatis consumptionem_, boil, or let it be boiled to the consumption of one half. Coq. S. A., coque secundum artem, boil according to art. Coq. in S. A., coque in sufficiente quantitate aquæ, boil in a sufficient quantity of water. Cort., cortex, bark. C. v., cras vespere, to-morrow evening. C. m. s., cras mane sumendus, to be taken to-morrow morning. C. n., cras nocte, to-morrow night. Crast., crastinus, for to-morrow. Cuj., cujus, of which. Cujusl., cujuslibet, of any. Cyath. theæ, cyatho theæ, in a cup of tea. Cyath., cyathus, vel, a wine-glass; from an ounce and half... C. vinar., cyathus vinarius; to two ounces and half. Deaur. pil., deaurentur pilulæ, let the pills be gilt. Deb. spiss., debitur spissitudo, due consistence. Dec., decanta, pour off. Decub. hor., decubitûs horâ, at the hour of going to bed, or at bedtime. De d. in d., de die in diem, from day to day. Deglut., deglutiatur, let it be swallowed. Dej. alv., dejectiones alvi, stools. Det., detur, let it be given. Dieb. alt., diebus alternis, every other day. Dieb. tert., diebus tertiis, every third day. Dil., dilue, dilutus, dilute (thin), diluted. Diluc., diluculo, at break of day. Dim., dimidius, one half. D. in 2 plo., deter in duplo, let it be given in twice the quantity. D. in p. æq., dividatur in partes æquales, let it be divided in equal parts. D. P., directione propria, with a proper direction. Donec alv. bis dej., donec alvus bis dejecerit, until the bowels have been twice opened. Donec alv. sol. fuer., donec alvus soluta fuerit, until the bowels have been loosened. Donec dol. neph. exulav., donec dolor nephriticus exulaverit, until the nephritic pain has been removed. D., dosis, a dose. Eburn., eburneus, made of ivory. Ed., edulcorata, edulcorated. Ejusd., ejusdem, of the same. Elect., electuarium, an electuary. Enem., enema, a clyster. Exhib., exhibeatur, let it be administered. Ext. sup. alut. moll., extende super alutam mollem, spread upon soft leather. F., fac, make; fiat, fiant, let it be made, let them be made. F. pil., fiant pilulæ, let pills be made. Fasc., fasciculus, a bundle. Feb. dur., febre durante, during the fever. Fem. intern., femoribus internis, to the inside of the thighs. F. venæs., fiat venæsectio, let venesection be performed. F. H., fiat haustus, let a draught be made. Fict., fictilis, earthen. Fil., filtrum, a filter. Fist. arm., fistula armata, a clyster-pipe and bladder fitted for use. Fl., fluidus, fluid. F. L. A., fiat lege artis, let it be made by the rules of art. F. M., fiat mistura, let a mixture be made. F. S. A., fiat secundum artem, let it be made according to art. Gel. quav., gelatina quavis, in any jelly. G. G. G., gummi guttæ gambæ, gamboge. Gr., granum, a grain; grana, grains. Gr. vj pond., grana sex pondere, six grains by weight. Gtt., gutta, a drop; guttæ, drops. Gtt. quibusd., guttis quibusdam, with some drops. Guttat., guttatim, by drops. Har. pil. sum. iij, harum pilularum sumantur tres, of these pills let three be taken. H. D., or hor. decub., horâ decubitûs, at bedtime. H. P., haustus purgans, purging draught. H. S., horâ somni, at the hour of going to sleep. Hor. un. spætio, horæ unius spatio, at the expiration of one hour. Hor. interm., horis intermediis, in the intermediate hours. Hor. 11mâ mat., horâ undecimâ matutinâ, at 11 o’clock in the morning. Ind., indies, daily. In pulm., in pulmento, in gruel. Ind. Ph., Indian Pharmacopœia. Inf., infunde, infuse. Inj. enem., injiciatur enema, let a clyster be thrown up. Jul., julepus, julapium, a julep. Kal. ppt., kali præparatum, prepared kali (potassæ carbonas). Lat. dol., lateri dolenti, to the affected side. M., misce, mix; mensurâ, by measure; manipulus, a handful; minimum, a minim. Mane pr., mane primo, early in the morning. Man., manipulus, a handful. Min., minimum, a minim, the 60th part of a drachm measure. M. P., massa pilularum, a pill mass. M.R., mistura, a mixture. Mic. pan., mica panis, crumb of bread. Mitt., mitte, send; mittantur, let them be sent. Mitt. sang. ad [oz]xij, mitte sanguinem ad [oz]xij, take blood to twelve ounces. Mod. præscr., modo præscripto, in the manner directed. Mor. dict., more dicto, in the way ordered. Mor. sol., more solito, in the usual way. Ne tr. s. num., ne tradas sine nummo, do not deliver it without the money. No., numero, in number. N. M., nux moschata, a nutmeg. O., octarius, a pint. Ol. lini s. i., oleum lini sine ligné, cold-drawn linseed oil. Omn. hor., omni horâ, every hour. Omn. bid., omni biduo, every two days. Omn. bih., omni bihorio, every two hours. O. M., or omn. man., omni mane, every morning. O. N., or omn. noct., omni nocte, every night. Omn. quadr. hor., omni quadrante horæ, every quarter of an hour. O. O. O., oleum olivæ optimum, best olive oil. Ov., ovum, an egg. Oz., the ounce avoirdupois. P. æ., part. æqual., partes æquales, equal parts. P. d., per deliquium, by deliquescence. Past., pastillus, a pastil, or ball of paste. P., pondere, by weight. Ph. D., Pharmacopœia Dubliniensis. Ph. E., Pharmacopœia Edinensis. Ph. L., Pharmacopœia Londinensis. Ph. U. S., Pharmacopœia of the United States. Part. vic., partitis vicibus, in divided doses. Per. op. emet., peractâ operatione emetici, the operation of the emetic being over. Pocul., poculum, a cup. Pocill., pocillum, a small cup. Post sing. sed. liq., post singulas sedes liquidas, after every loose stool. Ppt., præparata, prepared. P. r. n., pro re nata, occasionally. P. rat. ætat., pro ratione ætatis, according to the age. Pug., pugillus, a pinch, a gripe between the thumb and the two first fingers. Pulv., pulvis, pulverizatus, a powder, pulverised. Q. l., quantum lubet, } as much as you Q. p., quantum placet,} please. Q. s., quantum sufficiat, as much as may suffice. Quor., quorum, of which. Q. V., quantum vis, as much as you will. Red. in pulv., redactus in pulverem, reduced to powder. Redig. in pulv., redigatur in pulverem, let it be reduced into powder. Reg. umbil., regio umbilici, the umbilical region. Repet., repetatur, or repetantur, let it, or them, be repeated. S. A., secundum artem, according to art. Scat., scatula, a box. S. N., secundum naturam, according to nature. Semidr., semidrachma, half a drachm. Semih., semihora, half an hour. Sesunc., sesuncia, half an ounce. Sesquih., sesquihora, an hour and a half. Si n. val., si non valeat, if it does not answer. Si op. sit, si opus sit, if it be necessary. Si vir. perm., si vires permittant, if the strength allow it. Signat., signatura, a label. Sign. n. pr., signetur nomine proprio, let it be written upon, let it be signed with the proper name (not the trade name). Sing., singulorum, of each. S. S. S., stratum super stratum, layer upon layer. Ss., semi, a half. St., stet, let it stand; stent, let them stand. Sub fin. coct., sub finem coctionis, towards the end of boiling, when the boiling is nearly finished. Sum. tal., sumat talem, let the patient take one such as this. Summ., summitates, the summits or tops. Sum., sume, sumat, sumatur, sumantur, take, let him or her take, let it be taken, let them be taken. S. V., spiritus vini, spirit of wine. S. V. R., spiritus vini rectificatus, rectified spirit of wine. S. V. T., spiritus vini tenuis, proof spirit. Tabel., tabella, a lozenge. Temp. dext., tempori dextro, to the right temple. T. O., tinctura opii, tincture of opium. T. O. C., tinctura opii camphorata, camphorated tincture of opium. Tra., tinctura, tincture. Ult. præscr., ultimo præscriptus, last prescribed. U. S. Ph., United States’ Pharmacopœia. V. O. S., vitello ovi solutus, dissolved in the yolk of an egg. Vom. urg., vomitione urgente, the vomiting being troublesome. V. S. B., venæsectio brachii, bleeding from the arm. Zz., zingiber, ginger.

See FORMULA, PRESCRIPTIONS, SYMBOLS, &c.

=ABDO′MEN.= [Eng., Fr., L.] In anatomy, the belly, or lower belly; the great cavity of the body extending from the thorax, or chest, to the bottom of the pelvis. It contains the stomach, intestines, liver, spleen, kidneys, bladder, &c.; and in the female, the uterus, ovaria. &c.

=AB′ERNE′THY MEDICINES.= These originally consisted of a calomel pill, and subsequently of a mercurial or ‘blue’ pill, to be taken over-night, followed by an aromatised black draught in the morning. The quantity of either of the former, for an adult, was about 3 gr. to 3-1/2 gr., increased a little in bulk by the addition of some liquorice powder; that of the latter, from 1 to 1-1/2 fl. oz. As, however, when frequently taken, these pills sometimes occasioned salivation, which proved prejudicial to their sale, a little compound extract of colocynth (Ph. L., 1836) was introduced into their composition, by which this objection was obviated. Ultimately, their composition was settled at 3 gr. of mercurial pill, and 2 gr. of compound extract of colocynth; and these proportions are still followed as the best by those who prepare and sell them. Persons who object to black draught, will find a dose of castor oil, or of any other mild purgative medicine that may be more agreeable to them, equally efficacious.

The occasional use of these medicines seldom fails to prove highly beneficial to the plethoric, bilious, and dyspeptic. In ordinary cases of constipation, headache, &c., arising from deranged stomach or liver, wherein the administration of mercurials is not contra-indicated, they will be found of great service. It need scarcely be added that these medicines are named after Mr Abernethy, the celebrated surgeon, who is said to have frequently employed them in his practice.

=ABERRA′TION.= [Eng., Fr.] Syn. ABERRA′TIO, L. A wandering or deviation from the usual course, or from the normal condition. In optics, the deviation of the rays of light from the true focus, when inflected by a lens or speculum. This arises from a difference in the physical nature of the rays, from the figure of the lenses or specula, or from the nature of the materials of which the media traversed are composed. See ACHROMATISM, LENS, &c.

=Aberration of mind.= Mental alienation or wandering; insanity. A term frequently applied, in familiar language, to a mild form of incipient insanity or dementia, which is more or less occasional or continued, trifling or severe, according to circumstances. The studious, nervous, slothful, and those who are engaged in sedentary occupations and spend much of their time in ill-ventilated apartments, or who indulge in irregular or vicious habits, as well as ‘fast livers,’ are the most liable to this affection. It also frequently arises from disordered physical health.

Treat., &c. Change of scene, out-door exercise, agreeable company, pleasing and continued mental occupation, and due attention to diet, clothing, ventilation, &c., with the judicious use of some mild aperient medicine and tepid bathing, will generally alleviate, and frequently effect a cure. For the prevention of its accession, or its recurrence, care should be taken to promote the general health, and also, where necessary, to elevate the spirits and to divert the mind.

=ABLU′TION.= [Eng., Fr.] Syn. ABLU′TIO, L. In a general sense, washing, cleansing, or purification by water.

=Ablution.= In hygiène and the toilet, a washing of the whole body, or any part of it. The value of frequent and copious affusions of pure water to the surface of the body is well known. During life, the skin is continually subjected to abrasion, and the processes of reproduction and decay, by which the cuticle, its exterior portion, is being constantly thrown off as effete and useless matter, in the shape of very minute scales or dust. This, mingling with the oily and saline products of the skin, acquires sufficient adhesiveness to attach itself to the surface of the body and clothing, as well as to attract the waste particles of the dress, and the dust and soot floating in the atmosphere. In this way, if occasional ablutions be not had recourse to, the channels of perspiration will become choked, and the clothing itself rendered unwholesome and unfit for use. The consequence of the pores of the skin being obstructed is impeded transpiration, by which its functions, as a respiratory organ, are interfered with or suspended. This adhering pellicle of refuse matter also acts as an irritant, and forms a favorable medium for the absorption, and the transmission into the body, of effluvia, miasmata, poisonous gases, and the infectious and contagious matters of disease. “The greater part of (contagious) poisons are conveyed to us through the external surface of our bodies; and it is fully proved that poison, already communicated, has been by cleanliness removed, before it could actually produce any bad effects. I here allude, in particular, to frequent washing, bathing, rinsing the mouth, combing and brushing the hair, and often changing the linen, clothing, and bedding.” (Hufeland.) Such are the immediate effects of neglected ablution of the skin; the further consequences are of an equally serious character. The blood being deprived of one of its sources of oxygen, and one of the outlets for its carbon, the functions of nutrition become imperfect, and the animal temperature lessened. The matters which would be thrown out of the system in the form of perspiration are retained, and must be eliminated by other channels. The lungs, the kidneys, the liver, and the bowels, are each, in their turn, overtasked to perform the functions of another organ. The oppressed viscera suffer from exhaustion, and incipient disease soon follows. Their particular offices are languidly performed, the equilibrium of health is disturbed, and skin diseases, or consumption, diarrhœa, dropsy, liver-complaints, visceral obesity, or some other serious diseases of the vital organs, ensue. When it is added, that no dirty or imperfectly washed skin can long continue healthy, and ceasing to be healthy must also cease to be agreeable and beautiful, the argument in favour of the daily use of water of good quality to the whole surface of the body, when possible, will surely be complete. The inculcation of habits of personal cleanliness cannot be too forcibly emphasized. The fact, however, cannot be overlooked, that in order to introduce habits of cleanliness amongst the poorer classes, a plentiful supply of water, combined with cheap baths, are requisite. Every officer of health should inquire into the amount as well as the character of the water supply in the district over which he has supervision. The body should be washed all over every morning with either cold or lukewarm water and soap. This custom is more necessary for workmen employed in laborious and dirty occupations than for those who live sedentary lives; but all people perspire, and from every drop of perspiration the water evaporates, and leaves a fraction of solid matter on and around the pores that excrete the perspiration. If this solid matter be not washed off, it accumulates and may derange the health. Instances have occurred in which persons suffering from extensive bodily burns have died, not from the effect of the injury, but from the destruction of the pores or excreting vessels, with which the skin is covered. It is well, therefore, to bear in mind that a dirty skin does not always come from without, but also from within. Cold ablution, that has been so indiscriminately recommended, is not half so efficacious, nor so safe, as lukewarm. The German aurists ascribe the presence of the large amount of deafness in England to our habit of washing the head and ears each morning with cold water.

=Ablution.= In medicine, the washing the body, externally, as by bathing; or internally, by diluting drinks. In ancient medicine, according to Galen, internal ablution was accomplished by the use of profuse libations of milk-whey; an object now aimed at, by the hydropathists, by the copious administration of pure cold water. To neglect the daily ablution of an infant is to discard one of the greatest aids to its healthy development and physical wellbeing. That disregard of this precaution is a fertile source of most of the skin diseases that affect infants and children there seems little question about amongst medical men. Water at a temperature ranging from 80° to 90° F. should always be used. Mr Chevasse, in his ‘Counsel to a Mother,’ is emphatic in his advocacy of rain water. He also advises the employment of Castile soap, and of glycerine soap, should there be any excoriation of the skin. Of course the same remarks apply to children as to infants, with this difference, that the ablution is to be performed with water a few degrees colder; and both infants and children should be rubbed dry with a dry soft towel. There are doubtless many persons who deem themselves cleanly washed, if in addition to their hands and arms, neck and face, undergoing duly daily ablution, they wash their feet once a week. These individuals cannot reflect that, because of their less exposure to the depurating influence of the atmosphere, the feet require to be more frequently washed than either the hands or face. See BATHING, BATHS, HYDROPATHY, &c.

=ABNORM′AL.= [Eng., Fr.] Syn. ABNOR′MIS, L. In medicine and the collateral sciences, contrary to, or without system or rule; irregular; deformed; unnatural. In a diseased or unhealthy state.

=ABORTION IN COWS.= Abortion is the expulsion of the contents of the pregnant womb before the full period of gestation is complete, and occurs much more frequently in cows than in any other of the lower animals. Abortion is often induced by shocks and injuries, feeding on ergotised grasses, but more commonly by causes which are less obvious. Thus, bad smells, pasturing on flooded meadows, rich and stimulating food, and even association with other cows while aborting, are among the exciting causes of this malady. The premonitory signs are an irritable excited state of the animal, a discharge from the vagina, looseness and fulness of the external organs of generation, and, occasionally, sudden enlargement of the udder. These symptoms may continue for several days, and, if noticed before straining or other signs of calving have appeared, the animal should be copiously bled and placed in a comfortable loose-box, kept as quiet as possible, moderately supplied with soft laxative food, and, if the bowels be costive, with a pound or two of treacle daily. Powerful purgatives are too irritant, and must, therefore, be studiously avoided. Two ounces of laudanum, with the same quantity of sweet spirits of nitre, should be given twice a day until all danger is over. To prevent the continuance and spread of the evil, place the cow by herself as soon as she aborts; remove and bury the fœtus beyond the reach of other cows; feed off the cow, if practicable, but if she be again bulled, it ought not to be for several weeks, and until the period of heat is passing off; remove all disagreeable smells, and see that the remainder of the herd are moderately fed and carefully watched, so that the earliest symptoms of abortion may be noticed.

=ABRA′SION.= [Eng., Fr.] Syn. ABRA′SIO, L. The rubbing or wearing down of surfaces by friction. In the arts, the reduction or figuration of materials by the use of an abrasive tool, or grinder, of which the effective portion is an exact counterpart of the form to be produced.

=Abrasion.= In numismatics, the ‘wear and tear,’ or waste of the substance of coins, in the pocket and circulation. It forms a large item in the expense of a metallic currency. The means employed to obviate, or to reduce it, consist in either alloying the metal to render it tougher and harder, or raising the borders so as to lessen the surface exposed to friction. In well-formed coin both methods are adopted.

=Abrasion.= In pathology and surgery——1. A superficial removal or injury of the skin by fretting or friction.

Treat., &c. When the injured surface is large, or exposed, it should be protected from dirt and further injury, by applying a piece of lint or soft linen rag, covered with spermaceti cerate, or some other simple ointment; over which a piece of strapping, or bandage of any sort, may be placed to keep it on. In many cases, a piece of common sticking-plaster will be found quite sufficient.

2. A very superficial ulceration or excoriation of the intestinal or other mucous membrane. Treat. Aperients of castor oil, demulcents, and a light nutritious diet. See EXCORIATIONS.

=ABRUS PRECATORIUS.= (Ind. Ph.) Indian Liquorice Plant. Habitat. Tropical portions of both hemispheres, Officinal part. The root (Abri Radix, Indian Liquorice). Occurs in pieces of various lengths, from 1/2 to 1 inch in diameter; pale brown externally, yellowish internally; inodorous, taste sweetish and mucilaginous, much resembling officinal liquorice root. Properties and uses. Similar to those of liquorice, for which it forms an excellent substitute. Preparation. EXTRACT OF ABRUS (Extractum Abri). Prepared as Extractum Glycyrrhizæ.

=ABSCESS.= A formation of matter or pus, resulting from inflammation, either acute or chronic. The symptoms are pain, swelling, heat, and redness, a conical projection on the swelling, often with a white point at the apex. Abscess or suppuration may come on any part of the body. When the local inflammation does not yield to cold lotions, apply poultices; a pledget of lint dipped in cold water and kept moist by means of oil-silk; a slice of bread softened with boiling water or milk, or linseed meal, make the best poultices. Should the pain be severe add laudanum, and additionally rub it round the swelling. Or apply common white paint by laying it on gently with a brush, or else tincture of marigold or arnica in the same manner. Chronic abscesses in the glands in the neck are usually scrofulous, and should be opened. Abscesses in the breast should not be opened too early, or others are formed. Those in the gums may be cut early, not so if in the tonsils. After opening with a needle or lancet-point external abscesses, continue to poultice till the hardness disappears, then dress with spermaceti ointment spread on lint. When the abscess is of a dangerous nature, lose no time in consulting a medical practitioner.

Treatment for horses and cattle. Mr Finlay Dun prescribes fomentations, poultices, counter-irritants, the knife, cauterisation, carbolic-acid dressing, stimulating injections, and the administration of sulphites and chlorate of potash.

=ABSINTHE.= [Fr.] ABSINTHIUM, L.; WORMWOOD, E.; WERMUTH, G. This article is met with in commerce in the form of the dried herb with the flowers of Artemisia Absinthium, having a whitish-grey appearance, a soft feel, an aromatic and unpleasant odour, and an extremely bitter and aromatic flavour. The plant is indigenous, and grows in thickets, in mountainous districts, and on waste ground. Its odour is due to its containing an essential oil; its bitterness is referable to absinthin, a crystallisable principle which may be extracted from the herb by water or spirit. The name absinthe is also given to an intoxicating liqueur which is extensively drunk on the Continent, and which unfortunately appears to be rapidly attracting consumers in this country. The remarks on this subject by Blyth in his admirable ‘Dictionary of Hygiène’ are so pregnant with important facts that they will be here produced verbatim et literatim. “An analysis recently made at the Conservatoire des Arts shows that absinthe now contains a large quantity of antimony, a poison which cannot fail to add largely to the irritant effects necessarily produced on the alimentary canal and liver by constant doses of a concentrated alcoholic liquid. And we have recently received the results of some experiments made by M. Magnan, of Paris. By means of successive distillations he has been able to isolate various products——(1) a blue oil; (2) a yellowish oil; (3) an oxygenated substance. There was besides a yellowish residue left in the glass. These various substances were tried on animals; ten grammes of the yellow sediment given to a small dog produced no effect; thirty centigrammes of the blue oil produced from eight to ten epileptiform attacks. The oxygenated product proved, however, the most powerful toxic agent. Fifteen centigrammes of it, injected into the veins of a large dog, caused the most violent epileptic attacks, which followed in rapid succession, and ended in death. There was an extraordinary rise of temperature, from 39° to 42° Centigrade, and the post mortem showed various apoplectic centres. Dr Decaisne regards the terrible evil of this almost universal absinthe-drinking as the greatest national calamity that has ever befallen France, and has made an eloquent appeal to the Government to strike at once a decisive blow at the trade in this liqueur. Originally the only important ingredient in its composition besides alcohol was the essential oil of absinthium or wormwood; and though this without doubt added something to the mischievous effects of the liqueur, it would be impossible to trace to it, or to the other comparatively trivial ingredients, the more serious of the special results which are now observed to occur to victims of absinthe, though the habitual drinking even in small doses of good absinthe is believed by Dr Decaisne, sooner or later, to produce disorders in the animal economy. Now various deleterious substances are added, the most important of these being antimony. As at present constituted, therefore, and especially when drunk in the disastrous excess now common in Paris, and taken, as it frequently is, on an empty stomach, absinthe forms a chronic poison of almost unequalled virulence, both as an irritant to the stomach and bowels, and also as a destroyer of the nervous system. The effect of absinthe is to produce a superabundant activity of the brain, a cerebral excitement, which at first is agreeable; intoxication comes on rapidly; the head swims, and the effect produced is nearly the same as that of poisoning by a narcotic, which certainly does not occur with an equal dose of brandy. With the absinthe-drinker, as with the opium-eater, the excitement the spirit produces diminishes daily in intensity. Each day he is obliged to augment the dose in order to bring himself up to the right pitch. The diseases brought on by the excessive drinking of ardent spirits are produced with greater rapidity by the use of absinthe.” The amount of absinthe consumed in London has during the last few years been enormously on the increase. See LIQUEURS.

=ABSINTHIN.= C_{16}H_{22}O_{5}. The bitter principle of wormwood (Artemisia absinthium). A hard crystalline solid, having an intensely bitter taste; slightly soluble in water, very soluble in alcohol, less so in ether. Its physiological effects resemble those of extract of wormwood. Dose. 1/2 gr. to 2 gr., or more; in dyspepsia; as a stomachic, to promote the appetite, &c.; as a substitute for quinine in intermittents; and in worms.

=ABSINTH′IUM.= [L.] See ABSINTHE.

=ABSOLUTE.= Syns. ABSOLUTUS, L.; ABSOLU, Fr.; UNDEBINGT, G. In chemistry, pure, unmixed; as absolute alcohol, pure spirit of wine, i.e. free from water.

=ABSORBED′= (-sorbd′). Syn. CHILLED; ABSORBÉ, Fr. In painting, a term among French connoisseurs, to represent that state of a picture in which the oil has sunk into the canvas or ground, leaving the colours ‘flat,’ and the touches indistinct. The remedy consists in rubbing the surface of the picture, previously well cleaned, with a soft sponge dipped in a little drying oil, and after some days varnishing it; when it should be kept in a warm room until perfectly dry.

=ABSORB′ENT.= Syn. ABSORB′ENS, L.; ABSORBANT, Fr.; ABSORBIREND, Ger. Imbibing; that imbibes or sucks up; variously applied in science and art. (See below.)

=Absorbent Ground.= In painting, a picture-ground prepared wholly or chiefly in distemper or water colour, in order that the redundant oil in the colours subsequently applied may be immediately ‘absorbed,’ by which expedition is permitted, and brilliancy imparted to them.

=Absorbent Surfaces.= In the arts, these are usually rendered non-absorbent, preliminary to their being bronzed, gilded, painted, or varnished, by giving them one, or more, coats of thin size, so as to destroy their porosity; care being taken to allow each coat to become thoroughly dry before the application of the next one; and also, finally, to remove any unabsorbed excess of size from the surface, by means of a sponge dipped in warm water. This applies to ALABASTER, PAPER, WOOD, PLASTER CASTS, &c.; and to WALLS and CEILINGS which are not exposed to the weather, and which there is not time to prepare with drying oil. See BRONZING, MAPS, VARNISHING, &c.

Absorption and consequent adherence in porous moulds, as those of plaster, are usually prevented by thoroughly saturating the pores of the mould with melted tallow, or a mixture of tallow and bees’ wax; or for delicate objects or the electrotype, with white wax. The ‘dry moulds’ are either heated before the application of these substances, or they are boiled in them; any portion that may finally remain unabsorbed, being carefully removed with cotton-wool or a soft rag. Another method is to wash the moulds over two or three times with drying oil, or to boil them in it; after which they must be exposed to the air for some days, to dry and harden. Before being used for plaster, composition, &c., the surface of these prepared moulds require to be slightly moistened with sweet oil.

Plaster moulds are generally prepared for sulphur, wax, and gutta percha casts, by simply placing them (upright) with the back immersed in a little water, contained in any shallow vessel, as a saucer or plate; and letting them remain there until moisture begins to appear on the surface. The materials to be cast, or moulded, should then be used at the lowest possible temperature, to prevent the formation of air-bubbles.

The adherence of wax or mixtures containing it, and of gutta percha, is best prevented by moistening the surface of the mould (whether of plaster, metal, or gutta percha), immediately before use, with soft soap reduced to the consistence of thin cream with water. See CASTS, MOULDS, ELECTROTYPE, &c.

=ABSORB′ENTS.= In anatomy and physiology, two distinct sets of small, delicate, transparent vessels, which imbibe or suck up fluid substances, and convey them to the blood. They are termed lacteals or lymphatics; the former take up the chyme from the alimentary canal, the latter pervade almost every part of the body in which they absorb lymph.

=Absorbents.= In botany and vegetable physiology, the origins of the different vessels constituting the vascular tissue, as they are found in the root, where they imbibe or suck up the nutritive fluids from the soil. See PLANTS and VEGETABLES.

=Absorbents.= In agriculture and chemistry, substances which possess the power of withdrawing moisture from the atmosphere; as soils, argillaceous earths, &c. Also (but less frequently) substances which neutralise acids; as chalk, lime, and magnesia. Absorbents differ from ‘deliquescent salts’; the latter attract moisture and dissolve in it; whilst the former merely suck it into their pores, as a sponge does water. See ABSORPTION.

=Absorbents.= Syn. ABSORBEN′TIA, L. In medicine and pharmacy, substances which remove acidity from the stomach and bowels. Of these the principal are——magnesia, carbonate and bicarbonate of magnesia, prepared chalk, and the carbonates and bicarbonates of potash, soda, and ammonia. The first four are popularly called earthy absorbents; and the others, alkaline absorbents. See ANTACIDS.

The following absorbent mixtures are taken from Dr Kirby’s valuable work, ‘Selected Remedies’:

1. Infusion of rhubarb, 1-1/2 oz.; compound spirit of ammonia, 1-1/2 dr.; compound infusion of gentian to 6 oz. Two tablespoonfuls to be taken 3 times a day.

2. Bicarbonate of potash, 1-1/2 dr.; syrup, 2 drs.; compound spirit ammonia, 1-1/2 dr.; compound infusion of gentian to 6 oz. Two tablespoonfuls to be taken 3 times a day.

3. Bicarbonate of soda, 1-1/2 dr.; spirits of chloroform, 1-1/2 dr.; infusion of calumba to 6 oz. Two tablespoonfuls to be taken 3 times a day.

=ABSORP′TION.= [Eng., Fr.] Syn. ABSORP′TIO, L.; EINSAUGUNG, Ger. The act or the power of absorbing, in various applications. (See below.)

=Absorption.= In agriculture, the power possessed by soils of absorbing moisture from the atmosphere. The more a soil is divided by labour and vegetation, the greater is its absorbent power, and, consequently, its fertility. Indeed, the latter chiefly depends on its capacity for imbibing moisture, and may be illustrated by reference to recent and disintegrated lava. (Leslie.) The finely divided state, most penetrable by the delicate fibres of plants, appears to derive its superior power of acting on atmospheric vapour from the augmentation of its surface and the multiplication of its points of contact. (Ure.) This method of increasing the fertility of a soil is well known to scientific farmers, and seldom neglected by them. (Loudon.) That soil must be regarded as the most fertile which possesses this power in the greatest degree. Garden-mould has the highest absorbent power of any mineral substance. (Leslie.)

Process of ascertaining the ABSORBENT POWER OF SOILS, and other substances. Thoroughly dry the article by the suitable application of a heat not exceeding 212° Fahr., continued for several hours, and transfer it, while still warm, into a clean dry phial furnished with a perfectly tight ground-glass stopper. When cold, quickly and cautiously introduce it, along with a delicate hygrometer, into a large wide-mouthed glass bottle, the atmosphere of which has been previously rendered as damp as possible, by suspending a piece of moistened rag or filtering paper in it. It must now be kept closed for some hours, when the hygrometer will indicate the degree of dryness of the enclosed air, and, consequently, the absorbent power of the substance examined.

Obs. Experiments of this nature are only relatively correct, and must be performed under exactly similar circumstances, to furnish reliable comparative results. The whole process, in each case, must be as similar as careful manipulation can possibly make them. With this reserve, they will be found invaluable to the agriculturist.

=Absorption.= In chemistry the passage of gases and vapours into liquid and solid substances. Thus, water absorbs the oxygen of the air, lime absorbs water, charcoal absorbs ammoniacal and other gases.

=Absorption.= In medicine and toxicology, see MEDICINES and POISONS.

=Absorption.= In perfumery, see ENFLEURAGE.

=Absorption.= In physics, see HEAT, LIGHT, REFRIGERATION, &c.

=Absorption.= In physiology (animal and vegetable), the function of sucking, or taking up, of appropriate substances, by the ‘absorbent vessels.’ It is one of the chief vital functions, the primary object of which is to convey to the circulatory organs the proper supply of the materials necessary for the support and growth of the body; and subsequently, to remove and convey to these organs its effete and useless portions, in order to their ultimate elimination from the system.

=Absorption.= In surgery, the natural process by which tumours and their contents, morbid growths, and, sometimes, even healthy glands, &c., are gradually taken up and disappear, by the action of the ‘absorbents.’

=Absorption= (of Surfaces, Moulds, &c). See ABSORBENT SURFACES.

=ABSTERG′ENTS.= Syn. ABSTERGEN′TIA, L. In medicine and pharmacy, substances which cleanse or clear away foulness from the surface of the body or sores; as soap, lotions, &c. See DETERGENT, which has a nearly similar meaning, and is in more general use.

=AC′ARI= (-rī). [L.; prim. Gr.] Syn. ACAR′IDANS; ACAR′IDES (dēz); ACARID′IÆ. (-e-ē). In entomology, a division of arachnidans, including the mite and tick. All the species are either microscopic or extremely minute, and possess such tenacity of life as to resist for some time the action of boiling water, and to live with comparative impunity in alcohol. Leuwenhoek had one that lived eleven weeks glued on its back to the point of a needle, without food. The following are well known——ACARUS AUTUMNA′LIS, the harvest-bug or wheal-worm; A. DOMES′TICUS, the domestic tick; A. DYSENTE′RIÆ, the dysentery-tick; A. FARI′NÆ, the meal mite (fig. a); A. RI′′CINUS (rĭc-), the dog-tick; A. SAC′CHARI, the sugar-mite (fig. b); A. SI′′RO, the cheese-mite (fig. c); A. SCABIE′I, the itch-insect (fig. d).

The irritation of the skin, caused by these vermin, may be relieved by a lotion of equal parts of sal volatile and water; and they may be destroyed by tobacco water, or a lotion or ointment of stavesacre. See ITCH, MANGE, PARASITES, PEDICULI, SCAB, &c.

=Acarus Farinæ=, or meal-mite (fig. a). This insect is found only in damaged flour, and is more frequently met with in the flour of the leguminosæ (beans, peas) than in that of the gramineæ (wheat, rye, oat).

Now and then a single acarus may occasionally be found in good flour, but even one should be regarded with suspicion, and the flour should afterwards be frequently examined to see if they are increasing.

=Acarus Sacchari=, or sugar-mite (fig. b).

Most of the brown sugars of commerce are infested by this pest, which is of a size sufficiently large to be visible to the naked eye. The following method of proceeding will lead to its detection:

Dissolve 2 or 3 teaspoonfuls of sugar in a large wineglass of tepid water, and let the solution remain for an hour or so, at the expiration of which time the acari may be found, some on the surface of the liquid, some attaching themselves to the sides of the glass, and some at the bottom, mixed up with the copious and dark sediment, made up of fragments of cane, woody fibre, grit, dirt, and starch granules, which usually subside on dissolving even a small quantity of sugar in hot water. When first hatched this acarus is hardly visible.

Acari of all sizes——that is, in all stages of growth——may be met with in most samples of sugar.

Dr Hassall, in seventy-two samples of sugar which he examined, found sixty-nine containing them.

=Acarus Siro=, the cheese-mite (fig. c). The dry and powdery parts of decayed cheese, which by careful watching may very frequently be seen in movement, consist almost wholly of this insect and their eggs in different stages of development. The cheese-mite can hardly be seen without the aid of the microscope. They are very tenacious of life, even when kept without food. Mr Blyth says that under these circumstances “it is no uncommon sight to see them killing and devouring each other; and that cheese is rapidly destroyed by them; they crumble it into minute pieces, and emit a liquid substance which causes the decayed parts to spread speedily.” They may be destroyed by being exposed to a strong heat, or by putting the cheese for a short time in whisky.

=Acarus Scabiei=, the itch-insect (fig. d). The parasitic character of the disease known as the itch was first demonstrated by Dr Bononio, who on turning out the contents of one of the little bladders that show themselves between the fingers of those affected with the complaint, and placing the fluid under the microscope, discovered a minute animal, very nimble in its movements, covered with short hairs, having a short head, a pair of strong mandibles or cutting-jaws, and eight legs, terminating in remarkable appendages, each provided with a sucker and setæ.

It has no eyes; but when disturbed it quickly draws in its head and feet, and then somewhat resembles the tortoise in appearance, its march being precisely the same. It usually lays sixteen eggs, which are carefully deposited in furrows under the skin, and ranged in pairs; these are hatched in about ten days.

“To find the itch-insect,” says Mr Jabez Hogg, “the operator must carefully examine the parts surrounding each pustule; he will then see a red line or spot communicating with it; this part, and not the pustule, must be probed with a fine-pointed instrument. The operator must not be disappointed by repeated failures.”

=ACCIDENT′AL COLOURS.= See COLOURS (Complementary).

=ACCIDENTS.= Black eye. Bathe the eye frequently with a soft piece of linen rag dipped in a lotion composed of one part of tincture of arnica and seven parts of water.

Burns and Scalds. Refer to BURNS and SCALDS.

Charcoal, combustion of, poisoning by. Refer to CARBONIC ANHYDRIDE.

Choking, or suffocation from substances sticking in the throat. Refer to CHOKING.

Cut Finger. Refer to CUTS.

Precautions against Fires. Refer to FIRES.

Precautions against Lightning. To take refuge under a tree during a thunderstorm accompanied by lightning is to expose oneself to a double danger——firstly, because by keeping the clothes dry these are prevented becoming the non-conductors they would be if damp; and secondly, because the tree, serving as a point of attraction for the lightning, conducts it to the ground, and in doing so frequently rends the trunks or branches, and kills any person or animal who happens to be close to, or in contact with, it at the time.

Never, therefore, if overtaken by a storm of thunder and lightning fly to the dangerous cover of a tree, pillar, hay-rick, wall, or hedge, but seek shelter in the nearest dwelling; or if this is not at hand, get to a part of the road or field where there is no object to attract the lightning, and there remain till the storm has expended itself. Also avoid particularly the proximity of iron gates, palisades, bronze statues, bell wires, iron railings, and such like. When in the house, do not sit or stand near the windows, doors, or walls, but place yourself in the middle of the room, unless there should be a lamp or chandelier hanging from the ceiling. Franklin recommends persons to keep away from the neighbourhood of fireplaces.

Treatment of persons struck by lightning. In case of any person being struck by lightning, immediately strip the body and throw bucketsful of cold water over it for ten or fifteen minutes; continued frictions and inhalations of the lungs must also be employed, and electricity should be tried if it be possible.

=Accidents by Poison.= The means to be adopted in cases where poison is taken, if the poison be known, are embodied in the antidotes, which will be found given in this volume under the respective poisons.

Under all circumstances, however, medical aid should be sought as expeditiously as possible, since many of the antidotes themselves being of a dangerous, if not poisonous, character, should only be administered under medical supervision. Pending the arrival of the doctor, no time should be lost in giving an emetic, consisting of a teaspoonful of flour of mustard in half a pint of warm water, supplemented by copious draughts of warm water, and tickling the throat with the finger if necessary.

Fish poisoning. It is a not unfrequent occurrence to find fish when eaten giving rise to a species of poisoning of a more or less violent form, such as a sense of weight at the stomach, accompanied with nausea, vertigo, headache, heat about the head and eyes, pains in the stomach, thirst, and often an eruption of the skin resembling nettle-rash. These symptoms may be sometimes due to the nature of the fish itself; sometimes to its being in a state unfit to be taken as food, as, for instance, when it is in a stale or decomposing condition; and occasionally to the peculiarity of constitution of those who partake of it, even if in a perfectly fresh condition. Whenever any of the symptoms above described follow from eating fish, an emetic of mustard and water (a teaspoonful of mustard in half a pint of water) should be administered. If subsequently a rash should appear, it would be well to take a dose of brisk purgative medicine, and, if necessary, a few doses of carbonate of soda 3 or 4 times during the day.

Poisonous Mushrooms. The same treatment should be followed as for fish. With some people the edible mushroom acts as a poison.

Sinks. See that these be securely trapped, and in the event of any unpleasant smell from them, pour down some disinfectant, such as chloride of lime, carbolic acid, or Condy’s fluid. The foul emanations from a sink ought to be regarded as of a most dangerous and pestilential nature.

=Accidents to Children.= Many, if not most, of the casualties to which children are exposed are given above, together with the best course to be pursued in the event of their being overtaken by any of them. There are, however, a few forms of disaster which seem more especially peculiar to children. Of these we may select——

Swallowing a piece of broken glass. In this case avoid giving purgatives, but give solid farinaceous food, so as to envelope the glass and enable it to pass through the bowels without causing injury by coming in contact with them.

Swallowing a coin. Give a dose or two of castor oil, and examine the stools until the coin is perceived.

A small coin sticking in the windpipe. Seize the child by the legs, letting his head hang downwards, then administer several brisk blows on the back with the palm of the hand, when very frequently the coin will be coughed out of the mouth and on to the floor. If this plan do not succeed, send immediately for medical aid.

=ACCLI′MATE=, or =ACCLI′MATISE=. In botany and zoology, to inure a plant or animal to a climate to which it is not indigenous. When so inured it is said to be ACCLIMATED. In medicine, to habituate the body to a foreign climate, so that it may not be peculiarly liable to its endemic diseases; or to become so habituated. Thus, a person who has resided several years at New Orleans without an attack of yellow fever, or having had an attack has satisfactorily recovered, is said to be ACCLI′MATISED.

=ACCOM′PANIMENTS.= In cookery and housekeeping, see TRIMMINGS.

=ACCUMULA′TION.= [Eng., Fr.] Syn. ACCUMULA′TIO, L. In medicine, a term applied when the effects of the first dose of any substance still continue when the second is administered (accumulation of action); or when several doses of insoluble substances remain inactive in the system until their energy is developed by chemical influence (accumulation of doses). See MEDICINES, POISONS, &c.

=ACEPH′ALANS.= Syn. ACEPH′ALA, CUV. In malacology, a class of aquatic mollusca, having no apparent head, but a mouth between the folds of their mantle. Several of them, as the oyster, cockle, mussel, scallop, &c., are consumed for food.

=ACERB′ITY.= Syn. ACERB′ITAS, L.; ACERBITÉ, Fr.; HERBIGKEIT, Ger. In chemistry, &c., sourness, with bitterness and astringency, or harshness. See CIDER, FRUIT, WINE, &c.

=ACERBO’S ANTI-RHEUMATIC AND ANTI-CATARRH OIL.= For various horse diseases. Gum euphorbium, 10 parts; absolute alcohol, 10 parts; olive oil, 80 parts. Digest in a warm-water bath for 24 hours, then boil until all the spirit has evaporated, and, when cold, strain through cotton. (Hager.)

=ACER′IDES.= Plasters that do not contain wax.

=ACES′CENT.= Syns. ACES′CENS, L.; ACESCENT, AIGRELET, Fr.; SÄURLICH, Ger. In chemistry, &c., growing sour; slightly tart or acid; having a tendency to sourness, or to run into the acetic fermentation, as wine, beer, malt-wort, &c. Hence, ACES′CENCE or ACES′CENCY (acescen′tia, L.; acescense, aigreur, Fr.; säurlichkeit, Ger.), the tendency to become slightly acid, or the quality of being so. See ACETIFICATION, MALT-LIQUORS, WINE, WORT, &c.

=ACETA′′RIOUS= (-tāre′-e-ŭs). Used for salads (as plants); relating to salads (which see).

=AC′ETATE= (ăs′-). Syn. ACE′TAS, L.; ACETATE, Fr.; ESSIGSÄURE SALZE, Ger. In chemistry, a salt consisting of C_{2}H_{3}O_{2} (sometimes called the acid-radical of the acetates) with hydrogen, a metal, or a compound basic radical; e.g.,

Hydrogen acetate (acetic acid) HC_{2}H_{3}O_{2} Potassium acetate KC_{2}H_{3}O_{2} Lead (plumbic) acetate Pb(C_{2}H_{3}O_{2})_{2} Ammonium acetate NH_{4}C_{2}H_{3}O_{2} Salts of acetic acid (HC_{2}H_{3}O_{2}) with the alkaloids are likewise termed acetates; e.g., Morphia acetate C_{17}H_{19}NO_{3} . C_{2}H_{4}O_{2}

Prep. That of the commercial acetates, and of many others, is noticed under the respective metals. In general, they may all be formed by direct solution of the carbonate, hydrate or oxide of the metal whose acetate it is desired to form, in dilute acetic acid; or from a solution of an acetate and of another salt of the metal, by double decomposition. In either case, the resulting solution must be carefully evaporated by a gentle heat, and, where possible, crystallised.

Prop., &c. All the neutral acetates, except those of molybdenum and tungsten, are more or less soluble in water, several so much so as to be uncrystallizable; many dissolve in alcohol; they suffer decomposition at a dull red heat, and by distillation, at that temperature, yield acetone and water, or acetone and acetic acid, and leave a carbonaceous residuum; at a full red-heat, those of potassium, sodium, barium, strontium, calcium, and magnesium, are converted into carbonates, whilst the other metallic acetates leave behind the pure metal, or its oxide. The aqueous solutions of the alkaline acetates soon turn mouldy and suffer decomposition. No more of them should, therefore, be dissolved at once than is required for immediate use.

Char., tests, &c. The acetates are known——1. By evolving fumes of acetic acid, recognisable by its peculiar and characteristic odour, on the addition of strong sulphuric acid:——2. By evolving the vapour of acetic ether (known by its peculiar and agreeable odour) when heated with a mixture of about equal parts of concentrated sulphuric acid and alcohol.

=AC′ETATED= (ăs′-). In chemistry and pharmacy, combined or impregnated with acetic acid or vinegar.

=ACE′TIC.= Syn. ACE′TICUS, L.; ACÉTIQUE, Fr. Of or relating to vinegar; made with acetic acid, as perfumes, &c. (See below.)

=ACETIC ACID.= HC_{2}H_{3}O_{2}. Syn. PYROLIG′NEOUS ACID (pure); ACID OF VINEGAR; ACIDUM ACE′TICUM, L.; ACIDE ACETIQUE, Fr.; ACIDO ACETICO, It.; ESSIGSÄURE, Ger.; AZYNZUUR, Dut.; EISEL, Sax. When free from water it crystallises on cooling, and is distinguished as——ACETIC HYDRATE, HY′DRATED ACETIC ACID, MONOHY′DRATED A. A., GLA′CIAL A. A., MONOHYDRATED A. A., ACE′TUM GLACIA′LE, ACIDUM ACE′TICUM G., L., &c. the sour principle of vinegar.

Var. Commercial acetic acid is found under the form of the pure acid of the chemist and pharmaceutist (glacial and dilute), and of vinegar, of which there are several varieties, which are noticed under their respective heads.

Sources. Fermented liquors; the vinegars of commerce; alcoholic liquors; wood, from which it is obtained, as pyroligneous acid, by distillation; the commercial acetates of soda, potassa, lime, lead, copper, &c. The pure acetic acid of the chemist and of commerce is almost wholly obtained from the acetates, either by the action of a strong acid, which seizes on the base, setting the acid free; or, by dry distillation, in which the high degree of heat employed separates the acetic acid from the base in the form of vapour. It is also obtained by the oxidation of alcohol.

Prep. The following are the principal processes at present adopted to obtain pure acetic acid:——

1. From the Acetates in the moist way:——

a. From ACETATE OF SODA:——

1. Commercial acetate of soda (i.e., the ‘pure acetate’ of the pyroligneous acid works), in crystals, is put into the body of a stout copper still, and a deep cavity being made in the centre of the mass, about 35% of sulphuric acid of a sp. gr. of not less than 1·84 is poured in; the walls of the cavity are then thrown in upon the acid, and the whole briskly agitated, for a very short time, with a large wooden spatula; the head of the still is next luted on, and the distillation conducted at a gentle heat, the receiver being changed as soon as the distillate begins to acquire a slight empyreumatic odour. The product, when the process is well managed, is an almost colourless acid of the sp. gr. of fully 1·05, containing about 40% of glacial acid, or between 34% and 35% of anhydrous acid. Any trace of colour or empyreuma is removed by agitation with some well-washed and recently ignited vegetable charcoal, or with a very small quantity of recently ignited purified animal charcoal, and subsequently passing it through a prepared calico bag-filter; or by allowing it to stand, for about a fortnight, in barrels containing some beech-wood chips; after which it is ready for sale, either as the ordinary acetic acid or pure pyroligneous acid of commerce, or (on dilution, &c.) as vinegar.

2. The acid of sp. gr. 1·05 (obtained as above) is distilled with fused chloride of calcium, the distillate being run into a refrigerator; the crystals that form are drained at a temperature below 40° or 45° Fahr., and after removal to a warmer temperature, where they liquefy, and agitation with a little peroxide of lead, are submitted to a second distillation, as before; and this is repeated until the whole of the acid crystallises at 51° Fahr. The product is the glacial acetic acid of commerce.

Obs. The above are the processes usually adopted, on the large scale, in this country.

3. (M. Mollerat’s process——without distillation.) Pure commercial acetate of soda, in coarse powder, is placed in a hard glazed stoneware or glass pan or receiver set in a cool situation, and 35% or 36% of concentrated sulphuric acid, of the sp. gr. 1·843, added, in such a manner that the acid may flow under the powder, and little heat be generated by the operation; the whole is then allowed to remain in contact (covered) for some hours, when crystalline grains of sulphate of soda are found covering the bottom and sides of the vessel, and hydrated acetic acid, partly liquid and partly in crystals, the upper portion. The temperature being now slightly raised to a point just sufficient to cause the liquefaction of the crystals of acetic acid (i.e., to from 62° to 65° Fahr.), the fluid is poured off, and a very small quantity of pure acetate of lime added to it gradually, until it ceases to yield any trace of free sulphuric acid on evaporation. After sufficient repose it is carefully decanted for use. An excellent commercial strong acetic acid is thus obtained, without distillation, owing to the insolubility of sulphate of soda in acetic acid; and from which glacial acid may be procured by refrigeration. If, however, the process be badly managed, or the proportions of the ingredients be not carefully observed, the product will be contaminated with either a little sulphuric acid or saline matter. It is also important to the success of this process that it be performed in a cool apartment, and in well-cooled vessels. Perfectly pure acetic acid may easily be obtained by rectification from this acid. The above plan of superseding a troublesome distillation is one of the greatest improvements yet introduced into the manufacture of acetic acid.

4. (Liebig’s process.) Pure acetate of soda, thoroughly dried and finely powdered, 3 parts, is placed in a capacious retort, and pure concentrated sulphuric acid, 9·7 parts, poured over it through the tubulature. One eighth of the acetic acid passes over by the heat developed by the reaction of the ingredients. The heat of a sand bath is next applied and continued until the contents of the retort become quite liquid. The distillate, carefully rectified, yields two parts of pure acid, containing only 20 per cent. of water. On exposing the latter portion which comes over in a closed vessel to a temperature below 40° Fahr., crystals of hydrated acetic acid are deposited. The weaker, or liquid portion, being poured off, the crystals are again melted and re-crystallised by cooling. The crystals of the last operation, separated from the liquid, and carefully drained in a cool and closed vessel, are perfectly pure hydrated acetic acid.

Obs. The above is an excellent process for obtaining a chemically pure acid. The excess of sulphuric acid left from the process may be recovered by distillation; or the whole residuum may be employed in a second distillation with fresh acetate.

Although a retort is recommended by Liebig for the distillation, and is usually adopted, on the small scale, for the purpose, a flask closed by a cork perforated by two tubes, as exhibited by the engr., will be found more convenient and safe; as the product is then less likely to be contaminated by the ‘spirting’ of the ingredients over the brim of the vessel. The heat of a diffused gas-flame may also be often advantageously substituted for a sand bath.

b. From ACETATE OF POTASH:——

1. Acetate of potash (fused and powdered) is placed in a still, or other suitable vessel, and 50% of the strongest sulphuric acid (‘oil of vitriol’ of fully 1·84 sp. gr.) being added, the mixture is distilled to dryness, as before. The product is 50 to 51% of the weight of the acetate employed, with a sp. gr. of about 1·0735 to 1·074, containing about 66% of anhydrous acetic acid, or nearly 80% of ordinary glacial acid. By rectification from a little dried acetate of lead a perfectly pure acid of almost any strength may be obtained. The ingredients are nearly in equiv. proportions.

c. From ACETATE OF LEAD:——

1. (Ure.) Take of dried acetate of lead, 4 parts; strongest oil of vitriol, 1 part. Distil slowly to dryness. Nearly equal to the last.

2. (Liebig.) Acetate of lead, 3 parts; sulphuric acid, 8 parts; as before.

3. (Dollfuss’ Concentrated Acetic Acid.) Take of dried acetate of lead, 12 oz.; sulphuric acid, 6 oz.; distil 7 ounces.

d. From ACETATE OF LIME:——

1. (Christl.) Raw acetate or pyrolignate of lime (prepared by Völckel’s process), 100 parts, is mixed with hydrochloric acid (20° Baumé, or sp. gr. 1·1515), 120 parts; and after 12 hours, distilled in a copper vessel, with a gradually applied heat. The product is 100 parts or lbs. of acetic acid of 8° Baumé (sp. gr. 1·0556), containing about 47% of hydrated acid, only slightly coloured and empyreumatic, fit for various manufacturing purposes. The advantage of this process is the low price of hydrochloric acid, and the product not being contaminated with sulphuric or sulphurous acid.

Obs. It will be found that pyrolignate of lime generally contains 60% to 70% of neutral acetate; but should it contain either more or less, a proportionate quantity must be employed. When the proper proportions are used the distillate gives only a scarcely perceptible turbid cloud when tested with nitrate of silver. If the hydrochloric acid used has the sp. gr. 1·16, a less quantity being employed, the product will have the sp. gr. of 1·058 to 1·061, and will then contain from 48 to 51% of the monohydrate, or 41 or 42% of anhydrous acetic acid. The resin sometimes found floating on the mixed ingredients should be carefully removed, by skimming, before distillation.

As acid of the above strength is rarely required, and as the distillation is more easily conducted when the ingredients are less concentrated, a little water may be conveniently added either before or towards the end of the distillation. Hence the following proportions have been recommended:——

2. (Völckel.) Acetate of lime (as last), 100 parts; hydrochloric acid (sp. gr. 1·16), 90 to 95 parts; water, 25 parts; mix, and proceed as before. Prod. 96 to 98 parts of an excellent acid, well adapted to trading purposes, having a sp. gr. about 1·050, and containing nearly 40% of hydrated acetic acid. It has been correctly remarked, that the acetic acid produced with hydrochloric acid is always of better quality than that produced with sulphuric acid; being not only less coloured, but also entirely free from sulphurous acid. The distillation uniformly proceeds with ease and regularity, and the whole of the acetic acid passes over between 212° and 248° Fahr.; by which the danger of contamination with other products, resulting from a high degree of heat, is obviated.

3. An Acetic acid sufficiently strong and pure for many ordinary purposes may be obtained without distillation, by pouring strong sulphuric acid, 60 parts, diluted with water, 5 parts, on well-dried acetate of lime, 100 parts; digesting, with occasional agitation in a close vessel, decanting the clear liquid, and straining the remainder.

II. From the Acetates by dry distillation with a sulphate:——

a. From ACETATE OF LEAD:——

1. Acetate of lead (dried), 5 parts; and sulphate of iron (gently calcined), 2 parts; are separately powdered; and after thorough mixture, carefully distilled, by the heat of a sand bath, into a well-cooled receiver. An economical process for a strong acid, under certain circumstances; but one now seldom adopted.

2. (Bardollier’s Strong Acetous acid.) Dried acetate of lead, 10 oz.; calcined green vitriol, 12 oz.; as the last.

b. From the ACETATES OF COPPER:——By substituting acetate or diacetate of copper, in equiv. proportions, or better with excess of the sulphate. Seldom used.

c. From ACETATE OF POTASH, as the last.

III. From the Acetates per se:——

a. From ACETATE OF COPPER:——AROMATIC V.†; SPIRIT OF VERDIGRIS†; SPIRITUS VEN′ERIS†, L.; ESPRIT DE VENUS, Fr.; ACIDUM ACE′TICUM, (Ph. L. 1787.) Process. Carefully dry crystallised verdigris (diacetate of copper) by a very gentle heat, and introduce it into a large stoneware retort (see engr.), the bottom of which has been previously coated with a mixture of clay and horse-dung, to render it more capable of standing the fire. Next place it in a suitable furnace, and connect it, by an adapter, with 3 or 4 double tubulated globes, the last of which must be furnished with a vertical tubulature, to which a double Welter’s safety-tube should be adapted; the other end being immersed in a basin half-filled with distilled vinegar or water, while the funnel portion communicates with the atmosphere. Then place each globe in a basin of water, kept cool by a stream constantly passing through it; and cover the upper portion with cloths kept continually wet with cold water. After 15 or 20 hours, fire may be applied, and must be so regulated that the drops follow each other with considerable rapidity from the end of the adapter, whilst the bubbles of air cause no inconvenience at the other end of the apparatus. If otherwise, the fire must be damped a little. The operation should be continued, and the fire gradually increased, until vapour ceases to come over, known by the globes gradually cooling, notwithstanding the heat of the furnace. The operation being concluded, the whole may be allowed to cool, and the acid collected preparatory to rectification. This may be effected in a similarly arranged apparatus, except that it must be wholly of glass; and the retort should not be much more than half-filled. The operation must now be very carefully conducted, and discontinued before barely the whole of the acid has distilled over; as the last portion is apt to injure the flavour and colour of the rest. The first portions which come over are very weak, and should be kept separate, until the sp. gr. reaches to about 1·372, when the receiver should be changed, and the product collected in separate portions, as noticed below.

Obs. Good diacetate of copper yields, by careful management, at a temperature of 400° to 560° Fahr., fully one half its weight of a greenish-coloured acid, of the sp. gr. of about 1·061, containing above 50% of hydrated acetic acid, or 43% of anhydrous acid. 20 lbs. of the ordinary acetate yields 9-3/4 lbs. of this rough acid, leaving a residuum of about 6-1/2 lbs. of metallic copper mixed with a little charcoal, in the retort; the remainder (nearly 2/10ths of the acid in the acetate) being decomposed by the heat, and lost. This 9-3/4 lbs. of crude acid yields by rectification, and dividing the products, 1/2 lb. of acid of the sp. gr. 1·023; 3 lbs. of the sp. gr. 1·042; and 6 lbs. of the sp. gr. 1·065; exclusive of a little acetone which comes over with it. In the first distillation, the strongest acid is found in the third receiver, and the weakest in the first. The acid obtained in this way is always accompanied with a little fragrant pyro-acetic spirit; which renders it preferable for aromatic vinegar and perfumery. It dissolves camphor, resins, and essential oils with facility. This is one of the oldest methods of obtaining glacial acetic acid, and the product is still preferred for some purposes. It is the RADICAL VINEGAR of the alchemists, and it is that which is preferred by the perfumers. Well-dried acetate of lead, or of iron, as well as several other acetates, may be substituted for acetate of copper in the above process; but are less economical and convenient. In all cases, great care must be taken to avoid over-firing, as thereby the quantity obtained is lessened, and the quality injured. The residuum of the distillation is pyrophoric and frequently inflames spontaneously, on exposure to the air. Due caution must be therefore observed regarding it.

IV. From Wood, by dry distillation. See PYROLIGNEOUS ACID. The preparation of the purified acid, by converting it into an acetate, and subsequent distillation with a strong acid, is noticed above.

V. From Alcohol. (ALCOHOL VINEGAR, GERMAN ACETIC ACID.) In a bell-glass, or an oblong glass case, perforated shelves are arranged, a few inches apart, one above another, on which are placed a number of small flat dishes of porcelain, earthenware, or wood. These dishes are filled with spirit of wine or dilute alcohol; and over each is suspended a watch-glass or capsule containing a portion of platinum-black; the whole being arranged so that the platinum-black and the surface of the alcohol are not more than 1-1/2 to 2 inches apart. Strips of porous paper are next so hung in the case, that their bottom edges are immersed in the spirit, to promote evaporation; and lastly, the apparatus, loosely covered, is set in a light place at a temperature of from 70° to 90° Fahr.——the sunshine, when convenient. In a short time the temperature of the platinum rises, and the formation of acetic acid begins; and the condensed vapour trickles down the sides of the glass and collects at the bottom of the case, whence it is removed once or twice a day. (See engr.) The product of a case of twelve cubic feet content, with 7 or 8 oz. of platinum-powder, is capable of producing daily, if well managed, nearly 1·31 lb. of hydrated acetic acid from 1 lb. of absolute alcohol; 25 lbs. of platinum-powder and 300 lbs. of alcohol will, in like manner, furnish a daily supply of nearly 350 lbs. of pure acid, and of other strengths in proportion. Theoretically, the product should be 130 parts of the hydrated acid for every 100 parts of alcohol consumed; but this is never quite obtained in practice, owing to a small portion of the alcohol mixing with the newly formed acid, and escaping decomposition; and from another small portion of both the alcohol, and of the newly formed aldehyd, being carried off by the air that permeates the apparatus. The platinum-powder does not waste, and the most inferior spirit may generally be employed.

Rationale. In this process, the alcohol (as in other cases of acetification) is first converted into aldehyd; and this, as rapidly as formed, absorbs oxygen and passes into hydrated acetic acid. The simultaneous formation of aldehyd during the oxygenation of that already formed, may be detected by its odour.

Obs. During the mutual action of the platinum-black and the vapour of alcohol, the temperature increases, and continues to do so until all the oxygen contained in the air enclosed in the case is consumed, when the acetification stops. On opening the case for a short time, to admit of a fresh supply of air, the operation recommences, thus showing its dependence on the oxygen of the atmosphere. For this transmutation, 100 grains of alcohol require 71 grains (equal to 200 cubic inches) of oxygen, or about 1000 cubic inches of atmospheric air. To render the process continuous and rapid, a fresh supply of air must, therefore, be constantly provided. This may be effected by either having a loosely covered opening at the top of the case, and several much smaller ones near its lower part; or (and preferably) by means of two small glass tubes passing through the lid or cover, one of which terminates just below the point of insertion, whilst the other divides into branches which reach to within a short distance from the bottom, as shown in the engraving. In this way a very slow current of fresh air will always be kept up in the apparatus.

In practice, we find, that by loosely spreading the platinum-black on pieces of platinum-gauze, and supporting these on small tripods or bars of glass or porcelain (or even wood), the watch-glasses and their troublesome suspension may be dispensed with; as also may be the strip of porous paper, provided a temperature of not less than 90° Fahr. be maintained in the case or acetifier, which may easily be done by the application of artificial heat in the absence of sunshine. On the large scale, a case of wood with a glass roof, or even a well-seasoned cask or vat may be employed, in which case the temperature of the apparatus must be kept up either by means of steam-pipes or flues, or by the supply of warm air. On the small scale, a hand bell-glass placed on a dish, with a single watch-glass or piece of platinum-gauze, and a single capsule containing alcohol, may be used, provided the bell-glass be supported on three very small wedges, to admit of a supply of air. A modification of this is sometimes employed, in which the alcohol is supplied, in drops, to the platinum-black, by means of a long, tubular funnel passing through the mouth of the bell-glass, and having its lower extremity drawn to a very fine point, as shown in the engr. To ensure success, the platinum-black should be either fresh-prepared, or recently washed and very gently heated, before placing it in the acetifier. Spongy platinum, though ordered by many chemical compilers, does not answer well for this process.

By the above elegant and economical process, perfectly pure acetic acid of considerable strength may be produced from even impure alcohol; but it is impossible in this way to obtain a concentrated acid without a subsequent operation, because the action of platinum-black on absolute alcohol, or even on strong alcohol, is so violent that the platinum soon begins to glow, and inflammation ensues. Unfortunately the revenue laws of this country, until lately, stood in the way of the adoption of this beautiful process, unless duty-paid alcohol or methylated spirit be employed; but there is no statute that prevents an individual employing pure spirit, of any strength, on the small scale, for private consumption. In Germany, and in the United States of America, vinegar is manufactured on this plan, and from the low price of crude alcohol there, it will no doubt prove ultimately to be the cheapest source of both pure acetic acid and culinary vinegars.

VI. Miscellaneous Formulæ:——

1. An excellent acetic acid, of considerable strength, may be made by soaking fresh-burnt and perfectly dry charcoal in common vinegar, and then subjecting it to distillation. The water comes over first, and on increasing the heat, the acid follows. Vinegar-bottoms and waste vinegar may be used.

2. By exposing vinegar, or dilute acetic acid, to the air in very cold weather, or to freezing mixtures, the water separates in the form of ice, and the strong acetic acid may be obtained by draining it into suitable glass vessels, observing to do so at a temperature sufficiently low to keep the water solid. Said to answer well in cold climates.

3. Acetic acid containing 20% of water may be deprived of a good deal of its superfluous water by standing over dry sulphate of soda. (Liebig.) It may then be used either with or without distillation.

4. Acetic acid, of ordinary strength, may be concentrated to any degree, by rectification once, or oftener, from dry acetate of potash or soda, rejecting the first and last portions. The same acetate may be used repeatedly. The temperature need not exceed 400°, and must not rise above 570° Fahr.

ACETIC ACID. (B. P.) Syn. ACIDUM ACETICUM. Water mixed with 33% of hydrated acetic acid. Prepared by distilling acetate of soda with sulphuric acid. Colourless sour liquid. Sp. gr. 1·044.

Prop. Pure hydrated acetic acid is a thin, colourless liquid above 62 Fahr.; at 50° to 55° it crystallises in large, brilliant, colourless, transparent needles and plates, and even at 60° if a crystal of the acid be dropped in; at 40° it is a solid crystalline mass. Sp. gr.——liquid, 1·063 (Mollerat) to 1·0635 (Mohr);[3]——crystallised, 1·135 at 55° Fahr. (Ure). Odour, intensely pungent when concentrated, but grateful, fragrant, and refreshing, when diffused; taste, intensely sour and acrid, becoming agreeable and refreshing, on sufficient dilution with water; volatile; inflammable, burning with a white flame; vapour of boiling acid highly combustible; dissolves camphor, resins, gum resins, volatile oils, gelatin, gliadin, coagulated albumen, and fibrin (as muscle or the crassamentum of the blood); it coagulates casein, but not liquid albumen (as the serum of the blood and white of egg): miscible with alcohol, ether, and water in all proportions; boils at 248° Fahr.;[4] and is decomposed at a red heat. Its salts are called ACETATES (which see).

[Footnote 3: 1·064——H. M. Witt (Ure’s ‘Dict., of Arts, M. & M.,’ 5th ed.); 1·063 to 1·065——Muspratt (‘Chemistry, Theor. & Prac.,’ p. 2); 1·06296——Pereira (4th ed.); 1·0629——Brande; 1·062——Ure; 1·057——Berzelius (‘Jahr. ber.,’ xvi, 192):——variations evidently arising from difference of purity in the acid examined, or from difference of temperature. The sp. gr. 1·080, with other numbers given by Prof. Lehmann (‘Chemistry,’ Day’s Transl.), is probably a misprint.]

[Footnote 4: This is the boiling-point given by the best authorities, and confirmed by Gerhardt (‘Chimie Organique,’ i, 718). Ure made it 230°(an error corrected in 5th ed.), Lehmann says 243·140, and others give it at 235°, 240°, &c. An acid of about 80% (sp. gr. 1·073 to 1·0743), its maximum density, boils at 219° to 220° Fahr.]

Char., Tests, &c.——1. Free acetic acid reddens litmus paper, like the other acids; and may be readily recognised by its odour and volatility:——2. Sesquichloride of iron being added, and the acid then nearly saturated with ammonia, the fluid acquires a deep dark-red colour.

Estim. See ACETIMETRY. Organic mixtures that cannot be thus tested, or from which the acid cannot be obtained by simple distillation, may be neutralised, if acid, with carbonate of lime, boiled for a few minutes, cooled, filtered, the lime precipitated with dilute sulphuric acid, and the whole submitted to distillation, when the acid contents of the distillate may be estimated as above.

Pur. By heat, it escapes (entirely) in vapour; nothing is precipitated on the addition of either hydrosulphuric acid, nitrate of silver, or chloride of barium. Sometimes it is contaminated with sulphurous acid, which may be recognised by putting a fluid drachm of the acid, mixed with an ounce of distilled water and half a drachm of pure hydrochloric acid, also a few pieces of granulated zinc, into a flask. While effervescence continues suspend a slip of white blotting-paper, moistened with solution of sub-acetate of lead, in the upper part of the flask above the liquid, for about five minutes. The paper should not be discoloured, and thus indicate the absence of sulphurous acid.

Adult. The acetic acid of the shops is chiefly adulterated with water. Sulphurous acid and lead are accidental contaminations; that of the latter often reaches 2%, making the acid poisonous.

Phys. eff., &c. In its concentrated state it is a corrosive and an acrid poison. Taken internally, it acts by dissolving the animal tissues, and by thus destroying the organisation causes death, like the other acids. In the dilute form it acts as a stimulant, rubefacient, alterative, refrigerant, and escharotic.

Uses. Acetic acid is much employed by the chemist and pharmaceutist, in the manufacture of various preparations, and in analysis; by the perfumer, in the composition of several of his most refreshing and agreeable scents; and in medicine, as an antiseptic, stimulant, rubefacient, alterative, refrigerant, and escharotic. Acetic acid (B. P.) applied by means of a piece of rag tied to the end of a small stick, is a nearly certain cure for ring-worm and scaldhead——one or two applications generally effecting a cure, and the severe smarting it causes is only of short duration; as a caustic, it removes warts and corns; a piece of lint or blotting-paper wetted with it and applied to the skin (evaporation being prevented), forms a useful extemporaneous blister. It was once employed as a disinfectant; but is now only used as a fumigation, to disguise the unpleasant smell of the sickroom and crowded assemblies. It is a popular refreshing scent in faintings, asphyxia, and nervous headache; and is a valuable rubefacient, astringent, and local stimulant. It is also used as a rubefacient and caustic in veterinary practice.

In the arts, the commercial acid (pure pyroligneous acid) is used by the engraver to etch his plates; as an antiseptic in pickling and preserving animal and vegetable substances used as food, and anatomical preparations; in dyeing and calico printing, and in the manufacture of medicated vinegars and other pharmaceutical preparations.

In the dilute state, its properties and applications are similar to those of ordinary vinegar, and are noticed under that head.

Poisoning from acetic acid is rare. When concentrated, it is capable, by its corrosive and solvent action, of perforating the coats of the stomach and digestive canal; and it colours the mucus of these organs by the chemical action it exerts upon the blood. Vinegar in an excessive quantity acts in a similar way, but in a slighter degree. The treatment and antidotes are similar to those directed in cases of poisoning by the other acids. See POISONS.

Duty, Excise, &c. See VINEGAR.

Gen. commentary. Acetic acid, on the large scale, is principally prepared from acetate of soda, which yields by a comparatively inexpensive, and not a difficult operation, an acid sufficiently strong and pure for commercial purposes, without the necessity of rectification. In this process shallow vessels of wood or of copper formed without rivets or solder (except silver solder) in those parts exposed to the action of the acid, are generally employed for the purpose of the distillation. A coil of drawn copper pipe, heated by steam having a pressure of 30 to 40 lbs. to the inch, traverses the bottom of the apparatus, to impart the necessary heat. The refrigerator consists of well-cooled earthenware, Berlin ware, or glass vessels; and the adopter pipe is also of the same materials. Another common form, which is even still more convenient, is a stout copper still, furnished with a cast-iron jacket to hold high-pressure steam, the usual refrigeratory being employed. In a few instances the space between the still and jacket is filled with sand, oil, tallow, or fusible metal; in which case the apparatus is set in brickwork, and heated by a naked fire. Stills of earthenware are also frequently employed; and even worms and condensers of silver, or silvered copper, are sometimes used, and with advantage. With a leaden worm the product is always contaminated with a little of that metal; the efforts of the manufacturer to the contrary, by the exclusion of air, and by rejecting the first and last portions of the distillate, only lessening and not preventing this evil. A lute (if any) composed of linseed meal and water, with or without a little powdered plaster of paris, may be employed; but flat bands and short tubes of well-seasoned vulcanised india rubber are infinitely more convenient and efficacious. The ingredients being placed in the still, and well but hastily stirred together with a wooden spatula, the head is luted on, and the distillation soon afterwards commenced. The chief care now should be to increase the heat gradually as the distillation proceeds; and when a steam-heat is not used, to carefully avoid over-firing, particularly towards the close of the operation. A little acetic ether is added by some manufacturers. In this way 4 lbs. of acid of the sp. gr. 1·050, is obtained for every 3 lbs. of acetate of soda employed. Should rectification be had recourse to, the addition of about 2 or 3% of bichromate of potash, peroxide of manganese, or red oxide of lead, will remove empyreuma, if present. The first of these substances is the most effective; the power of the others being in the order in which they are printed. In distilling the weaker acids and vinegars, it is found useful to add from 25 to 30% of chloride of sodium, which, by raising the boiling-point of the liquid, allows the acid the more freely to pass over (Stein); but this addition proves disadvantageous when any sulphuric acid is present, in which case sulphate of soda may be employed instead. If this addition be not made, the whole of the acid cannot be obtained without distillation to dryness, and the generation of empyreuma.

On the small scale, glass retorts are usually directed to be used, but glass alembics or flasks are more convenient and safe, as already noticed. In the preparation of the pure acid, care should be taken that the acetate of soda does not contain common salt, as the carbonate of soda prepared by calcination, and frequently used to form the acetate, is generally contaminated with it, and yields up its hydrochloric acid or chlorine during the process of distillation, thus vitiating the product. In all the methods given the product becomes more concentrated in proportion to the dryness of the acetate and the strength of the oil of vitriol or muriatic acid employed. By using the one dry, and the other concentrated, glacial acid may always be obtained by collecting separately the last two fifths that come over, and submitting this to refrigeration.

According to Melsens, pure GLACIAL ACETIC ACID is most advantageously obtained by distilling pure and dry acetate of potash with an excess of strong and moderately pure acetic acid, rejecting that which first passes over.

Acetate of soda may be safely dried at a temperature of 400° to 450°, provided care be taken to avoid ignition from contact with sparks. A less heat is, however, quite sufficient to drive off the whole of its water of crystallisation. It is known to be dry by its assuming the appearance of a smooth oily liquid whilst hot. If, whilst heated, it emits fumes, it is suffering decomposition. The same applies to the other commercial acetates. Crystallised acetate of soda loses about 2/5ths of its weight by thorough drying.

When acetate of soda and sulphuric acid are the ingredients employed in the production of acetic acid, sulphate of soda is formed, which, in the large way, the chemist returns to the manufacturer of acetate of soda (i. e. to the pyroligneous acid maker), who employs it in the decomposition of fresh acetate or pyrolignite of lime. In this way the same soda-salt is employed over and over again, acting merely as the vehicle for the separation of the crude acetic acid in the solid form, and its easy and cheap transportation from one point to another. This ingenious method of mutual assistance resulting from the application of chemical science to provide for the wants of everyday life, offers some explanation of the extraordinarily low price at which acetic acid may now be purchased.

The acetic acid of commerce (pure pyroligneous acid) is almost wholly obtained from the acetates of soda and lime. The principal supply of crude acetate (pyrolignite) of soda is from America, Norway, and Sweden; but much is also obtained from our home manufactories. See ACETIFICATION, ACETIMETRY, FERMENTATION, PYROLIGNEOUS ACID, SODIUM, (Acetate of), VINEGAR, &c.

More recently, acetic acid has been obtained by decomposing with hydrochloric acid the double salt of chloride of calcium and acetate of lime, mentioned by Fritzsche (‘Ann. de Poggend,’ xxviii, 123). For this purpose, solutions of acetate of lime and chloride of calcium are mixed and evaporated, the combined salts readily crystallising in large needles. These are freed from the mother-liquor and distilled with common muriatic acid.

The acid furnished by this method requires redistillation, and is, moreover, contaminated with some of the fatty products always present in the crude pyrolignite.

=Anhydrous Acetic Acid.= Syn. ACETIC ANHYDRIDE. Acetic acid deprived of the elements of water.

Acetic Acid. Water. Acetic Anhydride. 2C_{2}H_{4}O_{2} - H_{2}O = C_{4}H_{6}O_{3}.

=Aromat′ic Acetic Acid.= Syn. AROMATIC VINEGAR; A. SPIRIT OF V.; ACIDUM ACE′TICUM AROMAT′ICUM, L.——Prep. 1. (Ph. E. 1839.) Dried rosemary and origanum, of each 1 oz.; lavender flowers, 1/2 oz.; bruised cloves, 1/2 dr.; acetic acid (sp. gr. 1·068), 1-1/2 pint; macerate for 7 days, express, and filter. A fragrant and refreshing perfume. Omitted in Ph. E. 1841 and P. B. 1867.

2. (Ph. E. 1817.) As the last, but using distilled vinegar instead of the strong acid of the Pharmacopœia. Inferior.

3. (P. Cod. 1839) Camphor, 2 oz.; oil of lavender, 10 gr.; oil of cinnamon, 20 gr.; oil of cloves, 30 gr.; concentrated acetic acid, 1 pint. Very fragrant and refreshing.

4. (Ph. Bor. 1847; Cod. Med. Hamb. 1845.) Oil of cloves, 1 dr.; oils of lavender and citron, of each 2 scrup.; oils of bergamot and thyme, of each 1 scrup.; oil of cinnamon, 10 drops; strongest acetic acid, 1 oz.; mix. Limpid; yellow-brown; highly fragrant and refreshing. See ACETIC ACID (Camphorated), and VINEGAR (Aromatic).

=Beaufoy’s Acetic Acid.= A superior commercial acetic acid (i. e. purified pyroligneous acid), having a sp. gr. of about 1·044; or containing about 28% of real acetic acid, or 32 to 33% of the hydrated acid. Same strength, &c., as ACETIC ACID P. B.

=Cam′phorated Acetic Acid.= Syn. CAMPHORATED VINEGAR; ACIDUM ACE′TICUM CAMPHORA′TUM, L.——Prep. 1. (Ph. E. 1841.) Camphor, 1/2 oz.; pulverise it by means of a few drops of spirit of wine, and then dissolve it in acetic acid (Ph. E.), 6-1/2 fl. oz.

2. (Ph. D. 1850.) Camphor, 1 oz.; rectified spirit, 1 fl. dr.; pulverise, and dissolve in strong acetic acid (acid. acet. fort. Ph. D.), 10 fl. oz.

Obs. This preparation is intended as a substitute for the aromatic acetic acid of the shops and previous pharmacopœias. It is also useful as an embrocation, in rheumatism and neuralgia; as an extemporaneous vesicant and counter-irritant; and as a fumigation in fevers, &c.

=Dilute′ Acetic Acid.= Syn. ACIDUM ACETICUM DILU′TUM, L. Acetic acid, 1 pint; distilled water, 7 pints; mix, Sp. gr. 1·006. One fluid ounce corresponds to 16 grains of anhydrous acid (3·63 per cent.).

=Glacial Acetic Acid.= Syn. ACIDUM ACETICUM GLACIALE. Acetate of soda, 20 oz., is liquefied by a gentle heat, stirred till it becomes pulverulent, and then further heated until it fuses; it is at once removed from the fire, and, when cool, the mass is broken up, placed in a 3-pint stoppered retort connected with a Liebig’s condenser, and then treated with sulphuric acid, 8 fl. oz. When the distillation slackens heat is to be applied, and the process continued until 6 fl. oz. of acetic acid have passed over. If a little of the product strikes a blue colour when mixed with a solution of iodate of potassium containing mucilage of starch, the whole product must be agitated with perfectly dry black oxide of manganese, 1/4 oz., and redistilled. Sp. gr. 1·065; contains 85% of anhydrous acid.

=ACETIC ANHYDRIDE.= See ANHYDROUS ACETIC ACID.

=ACETICA.= [L.] Medicated vinegars.

=ACETIDUX, Dr DELFER’S.= Made by Döllinger, of Berlin. For the radical and painless removal of warts, corns, hard skin, &c. A solution of 5 grms. of chromic acid in 15 grms. of water. (Schädler.)

=ACETIFICATION.= Syn. ACETIFACIO, L.; ACETIFICATION, Fr.; ESSIGMACHEN, EINSAÜERN, Ger. In chemistry, the act or process of converting into vinegar; also the state of undergoing such conversion.

Acetic acid is produced either by the partial dehydrogenation and subsequent oxidation of bodies containing its elements, or by their destructive distillation. The first is effected——by their exposure, in a finely divided state, to the action of air or atmospheric oxygen, as in the quick process of making vinegar; or——by submitting them, in combination with ferments, to contact with a free supply of atmospheric air, as in the old field process of making vinegar; or——by exposure to the direct action of chemical or mechanical oxidizing agents, as condensed air (platinum-black process), chromic and nitric acid, &c. In general, it is alcohol more or less dilute, particularly as it exists in fermented liquors, which is thus converted into acetic acid. In the second process (destructive distillation), wood is the substance usually employed, and heat is the agent which develops the acid.

The conversion of alcohol into acetic acid is not immediate and direct. The atmospheric oxygen first oxidises two atoms of its hydrogen, aldehyd and water being formed; and this aldehyd uniting with one atom of oxygen produces one molecule of ACETIC ACID. The changes are represented in the following equations:——

Alcohol. Oxygen. Aldehyd. Water. =1.= C_{2}H_{6}O + O = C_{2}H_{4}O + H_{2}O

Aldehyd. Oxygen. Acetic Acid. =2.= C_{2}H_{4}O + O = HC_{2}H_{3}O_{2}

After the first formation of aldehyd, the two processes, unless artificially checked, go on simultaneously, as long as any undecomposed alcohol is present.

The conversion of alcohol into acetic acid, although greatly accelerated by the presence of nitrogenised organic matter (according to Mulder, of a fungus——the Mycoderma Vini or Vinegar Plant), is rather a case of eremacausis (slow combustion) than of fermentation. Acetification effects combination, as shown by the foregoing equations, whereas fermentation resolves complex bodies into simpler ones, e.g. sugar into alcohol and carbonic anhydride. Moreover, the presence of ferments is not essential to the change, since pure alcohol becomes acetified when exposed to the oxidising agents already named.

Another remarkable distinction between acetification and fermentation is, that the former requires the continued presence of atmospheric oxygen; whilst the vinous fermentation after being once established, proceeds perfectly without it.

During the oxidation of the alcohol of vegetable solutions, some of the other organic matters present also suffer change. A white gelatinous mass (mother of vinegar)[5] is commonly deposited; but this is a secondary result of the process, and not, as formerly supposed, one essential to it. In ordinary cases acetification occurs only at or near the surface of the liquid; which accounts for the length of time required for the operation under the old process of ‘fielding,’ and the shorter time in which it is accomplished by the improved process of Mr Ham. It proceeds favorably at temperatures ranging from 60° to 90° Fahr.; and most rapidly at 95° Fahr. (Liebig). In the ‘quick process’ of making vinegar a temperature of 90° to 92° is generally aimed at; but it often rises to 100°, or even to 105°, Fahr. As the temperature falls acetification proceeds more slowly, and at 46 to 50° Fahr. it ceases altogether (Liebig).

[Footnote 5: It has generally been asserted that this substance contains vibriones, and other low forms of organised life; but Mulder describes it, under the name mycoderma aceti, as a plant of the order ‘fungi.’ It is formed at the expense of the constituents of the vinegar, and often causes whole vats of it to pass into water.]

Aldehyd (see above) is an exceedingly volatile substance, and easily dissipated by a slight heat. It is, therefore, of the highest importance to duly regulate the temperature, as well as the supply of air, during acetification. In the ‘quick process’ of making vinegar the loss from this cause is always considerable, and often very great. This loss may be diminished by passing the heated air, as it escapes from the acetifier, through a porcelain or silvered copper worm or refrigerator, set in a chamber containing water of a temperature not higher than 40° to 45° Fahr.; the connection being made at the lower end of the worm, whilst the upper end is open to the air. On the small scale, as in the platinum-black process, the loss may be almost entirely prevented by causing the upper air tube to pass through a vessel containing ice or a freezing mixture; or by uniting it with the lower end of a Liebig’s condenser.

In liquors undergoing the vinous fermentation, a portion of the newly formed alcohol is invariably acetified whenever the temperature rises above 51° Fahr.; and at a higher temperature, this proceeds with a rapidity often highly injurious to the quality of the liquor. In this way there is frequently a useless loss of the alcohol, which is rendered more apparent by the incipient, and sometimes the actual, souring of the liquor.

=ACETIM′ETRY=. Syn. ACETOM′ETRY; ACÉTOMÉTRIE, Fr.; ACETIME′TRIA, &c., L. The art or process of determining the quantity of pure acetic acid in vinegar, or in any other liquid. The plans generally adopted for this purpose are——

I. From the saturating power of the acid, as in the common methods of acidimetry:——

1. The molecular weight of commercially pure bicarbonate of potash, in crystals, being 100, whilst that of absolute acetic acid is 60, it is evident that every ten grains of the bicarbonate will exactly equal 6 grains of the acid. To apply this practically, we have only to exactly neutralise 100 gr. of the vinegar or solution under examination with the bicarbonate, observing the usual precautions; then, as 10 is to 6, so is the number of grains used, to the per-centage strength required. In this, as in other like cases, it is convenient to form a test-solution with the bicarbonate, by dissolving it in sufficient water to fill the 100 divisions of any simple form of ‘acidimeter,’ as a, b, or c; when the quantity of the solution, and, consequently, of the salt used, may be read off at once from the graduated portion of the tube. Still greater accuracy may be obtained by dissolving the bicarbonate in exactly 1000 gr. of distilled water contained in a ‘Schuster’s alkalimeter,’ previously very carefully weighed; in which case each grain of the test-solution will indicate 1/10th of a grain, or 0·1% of absolute acetic acid, whilst every 10 grains will be equal to 1 grain, or 1%.

The test-solution may also be prepared from bicarbonate of soda, or from the carbonates of soda or potash, care being taken that the quantity of the salt dissolved be in proportion to its molecular weight.

2. (Brande.) A small piece of white marble, clean and dry, is weighed, and then suspended by a silk thread in a weighed sample (say 100 or 1000 grs.) of the vinegar or acid under examination; the action being promoted by occasionally stirring the liquid with a glass rod, until the whole of the acid is saturated, as shown by no further action on the marble being observable on close inspection. The marble is then withdrawn, washed in distilled water, dried and weighed. The loss in weight which it has sustained will be nearly equal to the acetic acid present, or strictly, as 50 (marble) to 60 (absolute acetic acid). The only precautions required are, to avoid striking the piece of marble with the rod whilst stirring the solution, or causing loss of substance in it after its withdrawal; and to allow ample time for the action of the acid on it. If the sample consists of strong acid, it should be diluted with twice or thrice its weight of water before suspending the marble in it.

3. (Ure.) 100 grains of the sample under examination is slightly reddened with tincture of litmus, and ammonia of the sp. gr. 0·992 is added drop by drop (from an acetimeter holding 1000 water-gr. measure, divided into 100 divisions) until precise neutralisation is effected, indicated by the blue colour of the litmus being restored. The number of the divisions of the acetimeter used, multiplied by 60, and the first two right-hand figures of the product cut off as decimals, gives a number which represents the exact quantity of absolute acetic acid in the sample. In practice, it is found more convenient to keep the test-ammonia ready tinged with litmus.

The mode of estimating the per-centage of acetic acid in beers, when finding their original gravities, is a slight modification of the above. A test-solution of ammonia is prepared of such a strength that a given bulk of it will exactly neutralise one per cent. of absolute acetic acid in an equal bulk of beer, so that, if 100 fluid grains of the solution are sufficient to neutralise the acid in 1000 fluid grains of beer, such beer contains one tenth per cent. of acid. A solution of ammonia, diluted with distilled water until it has the sp. gr. ·9986 at 60°, is of the exact strength required.

An acetimeter holding 1000 grains, and graduated downwards to 100 equal divisions, is filled to 0 of the scale with the test-ammonia, which is then added, drop by drop, to 1000 measured grains of the beer, until neutralisation takes place. Every division of the acetimeter (corresponding to ten fluid grains), so emptied, indicates ·01 per cent. of acetic acid in the beer. The progress of the neutralisation is tested from time to time with a slip of reddened litmus paper, which should be suffered to become faintly blue before ceasing to add the ammonia. By this method the exact per-centage of absolute acetic acid in any sample may be accurately determined. The only precaution necessary is to be certain that the ‘test-ammonia’ has the required sp. gr. (·9986). Test-solutions may also be prepared with pure potash or pure soda.

II. From the specific gravity of the liquid after it has been neutralised with hydrate of lime:——

Common hydrate of lime (freshly slaked lime), in powder, is added gradually to the sample under examination, until it is saturated, when the sp. gr. of the resulting clear solution of acetate of lime is taken by Taylor’s ACETIMETER. This instrument is so adjusted and graduated as to float at the mark on the stem called ‘proof,’ in a solution containing 5% of absolute acetic acid (No. 24 vinegar). For vinegars stronger than proof small weights are provided, each of which indicates an additional 5 per cent. To ascertain the per-centage of real acid, 5% must therefore be added to the acetimeter number. Thus, without being loaded, the instrument, floating at the ‘proof mark,’ indicates a vinegar of 5%; with one weight, a vinegar of 10%; with two weights, 15%, and so on. According to this system of notation, each 5% is called a ‘vinegar.’ An acid of 10% is said to contain two vinegars; one of 15%, three vinegars, &c. It is also common to speak of the degrees of the acetimeter as proof or over-proof. Thus, No. 24 vinegar is said to be proof; one of 5 acetimeter degrees, 5 over-proof; one of 10 degrees, 10 over-proof, &c. For malt and wine vinegars, which contain gluten and mucilage, this method is not strictly accurate, as a portion of these substances escapes precipitation by the lime, and consequently alters the specific gravity. A small weight marked ‘M’ is generally supplied with the acetimeters for trying such vinegars.

III. From the specific gravity:——

The sp. gr. of the sample (carefully determined by any of the usual methods) is sought in one of the following Tables, when the corresponding per-centage content of acetic acid is at once seen.

This method furnishes reliable results only with pure, or nearly pure solutions which do not contain much above 50% of glacial acid, or which have a sp. gr. not higher than 1·062. It is also more to be depended on for weak solutions than strong ones. By carefully diluting a strong acid with an equal weight, or twice or thrice its weight of water, and allowing the mixture to again acquire its normal temperature, the sp. gr. may be taken as a guide in all cases in which great accuracy is not required. When such dilution is made it only becomes necessary to multiply the indication furnished in the Tables by 2, 3, or 4, as the case may be. As, however, authorities are not agreed as to the precise sp. gr. of the monohydrate or glacial acid, and of its solutions, extreme accuracy must not be expected by this method.

TABLE I.——Adapted to the Specific Gravities of common vinegar. By Messrs J. and P. TAYLOR.

per sp. gr. cent. 1·0085 contains of anhydrous or real acetic acid 5 1·0170 ” ” 10 1·0257 ” ” 15 1·0320 ” ” 20 1·0470 ” ” 30 1·0580 ” ” 40

TABLE II.——Exhibiting the quantity of ABSOLUTE or GLACIAL ACETIC ACID (HC_{2}H_{3}O_{2}), in acetic acid of successive strengths. By Mr COOLEY.

+---------+-------+---------+-------+---------+-------+---------+-------+ |Absolute | |Absolute | |Absolute | |Absolute | | | Acetic |Sp. Gr.| Acetic |Sp. Gr.| Acetic |Sp. Gr.| Acetic |Sp. Gr.| | Acid, | | Acid, | | Acid, | | Acid, | | |per cent.| |per cent.| |per cent.| |per cent.| | +---------+-------+---------+-------+---------+-------+---------+-------+ | Pure | | | | | | | | | acid, | | 75 |1·0731 | 49 |1·0593 | 23 |1·0320 | | or 100 |1·0630 | 74 |1·0732 | 48 |1·0582 | 22 |1·0311 | | 99 |1·0648 | 73 |1·0728 | 47 |1·0568 | 21 |1·0292 | | 98 |1·0663 | 72 |1·0721 | 46 |1·0557 | 20 |1·0275 | | 97 |1·0677 | 71 |1·0718 | 45 |1·0553 | 19 |1·0264 | | 96 |1·0685 | 70 |1·0713 | 44 |1·0544 | 18 |1·0253 | | 95 |1·0696 | 69 |1·0711 | 43 |1·0535 | 17 |1·0241 | | 94 |1·0704 | 68 |1·0708 | 42 |1·0525 | 16 |1·0229 | | 93 |1·0708 | 67 |1·0702 | 41 |1·0518 | 15 |1·0218 | | 92 |1·0715 | 66 |1·0701 | 40 |1·0513 | 14 |1·0200 | | 91 |1·0721 | 65 |1·0693 | 39 |1·0502 | 13 |1·0173 | | 90 |1·0726 | 64 |1·0692 | 38 |1·0492 | 12 |1·0172 | | 89 |1·0729 | 63 |1·0685 | 37 |1·0482 | 11 |1·0161 | | 88 |1·0730 | 62 |1·0679 | 36 |1·0473 | 10 |1·0150 | | 87 |1·0731 | 61 |1·0675 | 35 |1·0460 | 09 |1·0131 | | 86 |1·0732 | 60 |1·0672 | 34 |1·0449 | 08 |1·0121 | | 85 |1·0733 | 59 |1·0665 | 33 |1·0439 | 07 |1·0102 | | 84 |1·0734 | 58 |1·0662 | 32 |1·0425 | 06 |1·0085 | | 83 |1·07343| 57 |1·0653 | 31 |1·0413 | 05 |1·0071 | | 82 |1·0735 | 56 |1·0645 | 30 |1·0402 | 04 |1·0057 | | 81 |1·0738 | 55 |1·0641 | 29 |1·0392 | 03 |1·0042 | | 80 |1·0743 | 54 |1·0632 | 28 |1·0380 | 02 |1·0025 | | 79 |1·0742 | 53 |1·0628 | 27 |1·0364 | 01 |1·0012 | | 78 |1·0740 | 52 |1·0616 | 26 |1·0352 | Pure |1·0000 | | 77 |1·0739 | 51 |1·0610 | 25 |1·0341 | water. | | | 76 |1·0736 | 50 |1·0602 | 24 |1·0330 | | | +---------+-------+---------+-------+---------+-------+---------+-------+

Concluding remarks. Before applying the above processes, account should be taken of any mineral acid which may be present in the sample, such being not unfrequently added to vinegar to impart artificial strength; and in those depending on the sp. gr., gum, gluten, &c., must also be allowed for. The methods depending on the saturating power of the acid will be found appropriate to acetic acid of all strengths, when unadulterated with the mineral acid. The method based on the sp. gr. is also very convenient, and is sufficiently accurate for distilled vinegars and for pure acids of moderate strength.

It is found that the decimal fraction of the sp. gr. of pure or nearly pure vinegar is doubled by its conversion into acetate of lime. Thus, 1·0085 in vinegar becomes 1·0170 when converted into a solution of acetate of lime. In malt vinegar, however, 0·005 may be deducted from the sp. gr. for mucilage and gluten. The quantity of foreign matter present in vinegar may therefore be approximatively ascertained, by deducting the decimal of the sp. gr. of the solution of acetate of lime from double that of the decimal part of the sp. gr. of the vinegar. Thus:——the sp. gr. of a sample of vinegar being 1·014, and after saturation with hydrate of calcium 1·023, the sp. gr. of the pure vinegar would be 1·009, and that due to foreign matter ·005. For——

·028 - ·023 = ·005

and——

1·014 - ·005 = 1·009

The reason why proof-vinegar is called, in commerce, No. 24, is that 1 fl. oz. of it requires exactly 24 gr. of pure anhydrous carbonate of soda to neutralise it. Weaker vinegars are represented in the same ‘notation’ by the Nos. 22, 20, 18, &c., according to their respective strengths estimated by their saturating power.

=ACETINE.= An essence for the removal of corns. Concentrated vinegar (1·04 sp. gr.) slightly tinged with fuchsine, 15 grms. (Hager.)

=ACETINE, HOCHSTETTER’S.= Prepared by J. C. F. Witte, Berlin. A remedy for corns, warts, and hard skin. Diluted vinegar, coloured with blue carmine, 16 grms. (Schälder.)

=ACETOLATS.= [Fr.] Syn. ESPRITS ACÉTIQUES. In French pharmacy, medicated vinegars obtained by distillation.

=ACETOLES.= [Fr.] In French pharmacy, medicated vinegars obtained by maceration.

=ACETOUS FERMENTATION.= See ACETIFICATION.

=ACETUM.= [L.] Vinegar.

=ACETYL.= Syn. ACETYLE. A name originally given to a hypothetical body, having the formula C_{2}H_{3}, and regarded by Berzelius as the radical of the acetates and their congeners. The acetyl of Gerhardt (C_{2}H_{3}O) is, however, according to that chemist, the true radical of the acetates. Williamson, in order to remove the confusion of terms occasioned by the application of the same name to compounds of different composition, proposed the title of othyl for the radical C_{2}H_{3}O.

=ACHAR.= See PICKLES.

=ACEIILE′INE= (-kĭl-). A peculiar bitter principle obtained from achillé a millefolium (Linn.), or yarrow.

=A′CHOR=, (-kŏr). [Gr.] See SCALD-HEAD.

=ACHROMAT′IC= (ăk-ro-). Syn. ACHROMATIQUE, Fr. In optics, devoid of colour; bodies that transmit light without decomposition, and consequently, without the formation of coloured rings or fringes; applied to compound lenses, prisms, &c., and to instruments fitted with them.

=ACRO′MATISM.= Syn. ACHROMATISME, Fr. In optics, the state of being achromatic; the absence of coloured fringes in the images of objects seen through a lens or prism.

Light is not homogeneous, but decomposable by refraction, absorption, or reflection, into coloured rays of unequal refrangibility. A ray of white light, in passing through a glass prism, is entirely separated into the coloured rays forming the ‘prismatic spectrum,’ and when it passes through a lens, an analogous resolution into coloured rays still occurs, though not so readily observed, and that to an extent often incompatible with distinct vision. Now, if a convex lens be regarded as a number of prisms united by their bases round a common centre, and a concave lens, as a similar number of prisms with their apices in contact, the action of lenticular and prismatic glasses on light will be reduced to a common principle. A beam of light thrown on a simple converging lens not only suffers refraction at the spherical surface (SPHERICAL ABERRATION), but the different coloured rays of which it is composed, from the causes mentioned, being unequally bent or refracted, diverge from their original course (CHROMATIC ABERRATION), forming as many foci on the axis of the lens as there are colours, and fall separately, instead of together, on the eye or object which receives them. Hence arise the coloured fringes or halos that surround objects viewed through ordinary glasses, and which form the great impediments to the construction of perfect lenses. This effect, like the refractive power and focal distance, varies in degree in different diaphanous substances.

The correction of the chromatic aberration of lenses is commonly effected by combining two, or more, made of materials possessing different ‘dispersive’ powers. Thus, the spectrum formed by flint glass is longer than that formed by crown glass, for the same deviation. When the two are combined, so as to form a compound lens, the one tends to correct the ‘dispersion’ of the other. On this principle ACHROMATIC GLASSES are generally formed in this country. A convex lens of crown glass is combined with a weaker concave lens of flint glass, the latter counteracting the dispersion of the former, without materially interfering with its refractive power. The resulting combination is not absolutely achromatic, but is sufficiently so for all ordinary purposes. According to Dr Blair, a compound lens perfectly achromatic for the intermediate, as well as for the extreme rays, may be made by confining certain fluids, as hydrochloric acid, between two lenses of crown glass. In order to produce nearly perfect achromatism in the object-glasses of telescopes, microscopes, cameras, &c., a concave lens of flint glass is commonly placed between two convex lenses of crown or plate glass, the adjacent surfaces being cemented with the purest Canada balsam, to prevent the loss of light by reflection from so many surfaces.

Obs. The production of perfect achromatism in lenses is a subject not less fraught with difficulty than with practical importance to the astronomer, the mariner, the microscopist, and the photographer; and it has hence engaged the attention of the leading mathematicians and artists of Europe up to the present time. All the larger object-glasses lately manufactured are said to consist of only two lenses; the resulting achromatism proving sufficiently exact for all useful purposes. Those of recent production have come chiefly from the workshops of Dollond, of London, and the opticians of Bavaria and Switzerland. The achromatism of prisms depends upon the same principles, and it is effected in the same way as that of lenses.

=ACIC′ULAR.= Needle-shaped; slender or sharp pointed; spicular; in botany, applied to leaves, and in chemistry, to crystals. The last are also sometimes termed ACIC′ULÆ.

=ACID=, Syn. ACIDUM, L.; ACIDE, Fr.; ACIDO, Ital.; SÄURE, G. In familiar language, any substance possessing a sour taste. In chemistry, substances are said to be acid, or to have an acid reaction, when they are capable of turning blue litmus red. In chemistry, also, the term acid is applied to a very large class of compounds containing hydrogen (hydrogen salts), and in which one or more atoms of that element may be replaced by an equivalent quantity of a metal or other basic radical; e.g.——

1. The one atom of hydrogen in hydrochloric acid (HCl) may be replaced by sodium, producing the salt sodium chloride (NaCl).

2. The one atom of hydrogen in nitric acid (HNO_{3}) may be replaced by silver, producing the salt silver nitrate (AgNO_{3}).

3. One atom of hydrogen in acetic acid (HC_{2}H_{3}O_{2})[6] may be replaced by the basic radical ammonium (NH_{4}), producing the salt ammonium acetate (NH_{4}C_{2}H_{3}O_{2}).

[Footnote 6: Symbols indicating the number of atoms of replaceable hydrogen occupy the foremost position in the formulæ of acids, as shown in the text.]

Acids which, like those mentioned in the foregoing examples, contain one atom of replaceable hydrogen are called monobasic; those which contain two such atoms (e.g. sulphuric acid, H_{2}SO_{4}; tartaric acid, H_{2}C_{4}H_{4}O_{6}),[7] dibasic; those which contain three such atoms (e.g. phosphoric acid, H_{3}PO_{4}; citric acid, H_{3}C_{6}H_{5}O_{7}),[7] tribasic; and so on with acids of higher basicity. Acids of greater basicity than unity are frequently termed polybasic.

[Footnote 7: See footnote, p. 26.]

Besides containing replaceable or basic hydrogen, acids are further characterised by the property of combining with alkaloids to form salts; e.g.——

Sulphuric Acid. Quinia. H_{2}SO_{4} + 2C_{24}H_{24}N_{2}O_{2} =

Quinia Sulphate. (C_{20}H_{24}N_{2}O_{2}){2} . H{2}SO_{4}

Acetic Acid. Morphia. HC_{2}H_{3}O_{2} + C_{17}H_{19}NO_{3} =

Morphia Acetate. C_{17}H_{19}NO_{3} . HC_{2}H_{3}O_{2}

=Dibasic Acids.= See ACID.

=Fatty Acids.= Acids separable from fats or oils; e.g. stearic acid, oleic acid, butyric acid, &c.

=Inorganic Acids.= Same as MINERAL ACIDS (which see).

=Mineral Acids.= Acids chiefly or wholly derived from the mineral kingdom. In medicine, sulphuric, hydrochloric, and nitric acids, are commonly so called.

=Monobasic Acids.= See ACID.

=Organic Acids.= Acids formed by, or derived from organic substances; e.g. acetic acid, tartaric acid, uric acid, &c.

=Polybasic Acids.= See ACID.

=Pyro-acids.= Acids resulting from the decomposition by heat of other acids, e.g. gallic acid, when heated, yields pyro-gallic acid.

=Tribasic Acids.= See ACID.

=ACIDIFICA′TION.= [Eng., Fr.] Syn. ACIDIFICA′TIO, L. In chemistry, the act, process, or state of acidifying, or of making, becoming, or impregnated with acid.

=ACIDIM′ETER.= Syn. ACIDOM′ETER; ACIDIME′TRUM, &c., L.; ACIDIMÈTRE, Fr. An instrument or apparatus employed in acidimetry.

The ordinary acidimeters of the chemist are small tubes, constructed to hold exactly 1000 grains of distilled water, at 60° Fahr., within the limits of their scale, which is accurately graduated into 100 divisions. They are used to contain the alkaline solutions (TEST-LIQUORS, NORMAL or STANDARD SOLUTIONS) employed in the following processes.

Beaumé’s Acidimeter, and others of the same class, are HYDROMETERS, and are described under that ‘head.’

=ACIDIM′ETRY.= Syn. ACIDOM′ETRY; ACIDIME′TRIA, &c., L.; ACIDIMÉTRIE, Fr. The estimation of the strength or quantity of acid, in a free state, contained in any liquid. It is the reverse of ‘alkalimetry.’ Acidimetrical assays are understood to refer to the relative strengths of the same acids (i. e., the quantity of real acid of the same kind contained in the solutions examined), and not to the comparative strengths of acids of different composition or names.

Acidimetrical processes. These are founded chiefly on the capacity of the acids to saturate the bases; and, in some of the liquid acids, on the specific gravity.

a. VOLUMETRICALLY:——

1. The sample of the acid to be examined (100 gr., or any convenient aliquot part thereof) is placed in a suitable glass vessel, and if it be one of the stronger acids, diluted with six or eight times its weight of water, or if solid (as oxalic, or citric acid), dissolved in a like quantity. This liquid is then exactly neutralised with an alkali.

This point is usually determined, by the addition of a small quantity of litmus solution, which turns just blue when the solution is neutralised, but when a carbonate is used for the alkaline solution, the acid must be boiled a short time after each addition to expel the carbonic acid. The quantity of the alkaline solution consumed for this purpose represents an equivalent quantity of acid, and thus gives us the acid content of the sample under examination. The common practice is to dissolve one equivalent of the alkaline test in grains or grammes in water, and to make up the solution to exactly 1000 parts by measure (i. e., 1000 ‘water-grains’ or grammes), so as to accurately fill the 100 divisions of an acidimeter; when the quantity, in grains or grammes, of the sample tested, bears the same proportion to the equivalent number of the acid under examination, that the number of acidimeter divisions of the test-liquor consumed bear to the per-centage of acid sought. Thus:——suppose 50 gr. of a sample of sulphuric acid take 25 acidimeter divisions (300 parts or water-grains measure) of the test-liquid to neutralise it, what is its content of real acid?

The equivalent of sulphuric acid is 49 (half its atomic weight); so, by the rule of proportion,

50 : 49 :: 25 : 24-1/2

It therefore contains 24-1/2 parts of real sulphuric acid, in 50.

If the 1000 parts or grain-measures, instead of the number of the acidimeter divisions, be taken for the calculation, it will, of course, be necessary to point off the first right-hand figure of the result as a decimal. Thus; repeating the above example——

50 : 49 :: 250 : 24·5

Or, since the equivalent of the test-liquid is 100, it will bear the same proportion to the equiv. of the acid examined as the number of the acidimeter divisions of the test-liquid consumed in neutralising 100 gr., do to the per-centage sought. Thus:——50 gr. of hydrochloric acid take 45 acidimeter divisions to effect neutralisation, what is its real strength?——The equiv. of hydrochloric acid is 36·5: therefore——

100 : 36·5 :: 45 : 16·425%

and, since only 50 gr. (instead of 100 gr.) were examined——

16·425 × 2 = 32·85%

Some operators prefer employing 100 gr. instead of the equivalent weights of the given tests in making their test-solutions, in which case each gr. or 1000th part represents 1/10th, and each acidimeter degree 1 gr. of the alkali or carbonate employed; when a similar proportion will obtain to that first above given.

In technical analysis it is more convenient if the number of acidimeter divisions of the ‘test-liquid’ consumed express the per-centage strength of the acid, without further calculation. For this purpose the number of grains of the acid taken for the assay should correspond to the equivalent number of such acid (see Table I, below); or to some convenient aliquot part of it, as the 1/2, 1/4, 1/5, or 1/10th; the per-centage answer, in the last case, being doubled, quadrupled, &c., according to the aliquot part taken. The reason of this is obvious.

For the test-solutions, ammonia, and the dry and crystallised carbonates and bicarbonates of potash and soda, are used, and are made by dissolving in water their constituents except ammonia, of which 1000 grains, or one litre, of solution of specific gravity 0·992 contains exactly one equivalent.

53 grains (or grammes) of pure anhydrous carbonate of soda, prepared by gradually heating to redness the crystallised salt, constitute one equivalent (half the atomic weight), and 69 grains (or grammes) of pure dry carbonate of potash. Of the crystallised salt 143 grains of carbonate of soda will be required, and 84 grains (grammes) of the crystallised bicarbonate of soda, and 100 of the crystallised bicarbonate of potash. Occasionally solutions containing in one thousand parts, 50 of pure carbonate of lime or chalk, or 28 of pure caustic lime, are used.

Besides these, a process known as Kiefer’s is practised, and an ammoniacal solution of oxide of copper is employed as the ‘test-liquor,’ and the ‘point of neutralisation’ is known by the turbidity observed as soon as the free acid present is completely saturated.

The normal solution or test-liquor is prepared by adding to an aqueous solution of sulphate of copper, pure ammonia water, until the precipitate, which at first forms, is just redissolved, carefully avoiding excess. Or better, by adding a rather strong solution of sulphate of copper, to a quantity of a rather strong solution of ammonia containing exactly 17 gr., or one equiv. of pure ammonia, as long as the precipitate which forms is redissolved on agitation; the resulting liquid being afterwards diluted with pure distilled water, until it accurately measures 1000 water-grains, or fills 100 divisions of an acidimeter, at 60° Fahr. In either case, the strength of the resulting ‘test-solution’ must be carefully determined by means of standard sulphuric acid, and adjusted, if necessary.

This method answers well with all the stronger acids (excepting oxalic acid), even when dilute; and it has the advantage of not being affected by the presence of a neutral metallic salt with an acid reaction, as sulphate of copper, or of zinc.

Besides this process a solution of lime in sugar may be used, as proposed by M. Peligot, and made as follows:——

Pure caustic lime is carefully slaked by sprinkling with water, and 50 grains (or grammes), made up by water to a milky solution, and 100 grains of pure sugar candy dissolved in 1000 grains of water, are added, and the whole well shaken. It is allowed to settle in a closed bottle, and the clear solution poured off and diluted, until 1000 grains neutralise exactly 100 grains of pure hydrochloric acid of sp. gr. 1·1812. Of course it only answers with acids whose calcium salts are readily soluble in water.

b. GRAVERMETRICALLY:——

The test-liquors or standard solutions of the above methods are made up so as to weigh exactly 1000 grains, instead of to ‘measure’ 100 acidimeter divisions. Every grain of the test-liquor thus represents 1/10th gr. of alkali; and every 10 gr., 1 gr. of alkali; or respectively, 1/10th per cent. and 1 per cent. The vessel used for containing the solutions is carefully weighed whilst empty, and 1000 gr. being placed in the opposite scale, the test-solution, containing exactly one equivalent of base, is poured in, and the whole made up with distilled water (if necessary) so as to restore the balance to an equilibrium. After the process of neutralisation, the acidimeter, with its contents, is again placed in the scales; its previous weight still remaining there. The number of grains required to restore the equilibrium of the balance (i.e., the loss of weight), gives the exact weight of the test-liquor consumed. In all other respects the process is the same as in the ‘volumetrical method’ already described.

Another method for estimating the strength of the sample of acid is by weighing the amount of carbonic acid expelled during saturation. (Method of Fresenius and Will.) This depends on the weight of gaseous carbonic acid which a given weight of the acid-sample under examination is capable of expelling from pure bicarbonate of soda (or of potash), which is estimated by the loss of weight in the acidimeter, or apparatus, after the gas, rendered perfectly dry by passing through sulphuric acid, has escaped into the air.

TABLE I.——Weights of the respective acids equivalent to the given weight of the principal bases, hydrogen being taken as unity.

{51 Acetic acid (anhydrous). {60 ” ” (crystallised or glacial). {99 Arsenious acid (dry). {35 Boracic acid (anhydrous). 17 gr. of pure ammonia.[8] } {62 ” ” (crystallised). 31 ” anhydrous soda.[9] } {22 Carbonic acid (dry). 40 ” hydrate of soda.[9] } {67 Citric acid (crystallised). 53 ” dry carbonate of soda.[10] } {85 Gallic acid (dried at 212°). 143 ” crystallised carbonate of } {94 ” ” (crystallised). soda.[11] } {127-1/2 Hydriodic acid (dry or gaseous). 84 ” crystallised bicarbonate } {27 Hydrocyanic acid (anhydrous). of soda. } {36-1/2 Hydrochloric acid (dry or gaseous). 47 ” anhydrous potassa.[9] } {109 ” ” (liquid, sp. gr. 1·162). 56 ” hydrate of potassa.[9] } are {166-1/2 Iodic acid. 69 ” dry carbonate of potassa.[10]} exactly {54 Nitric acid (anhydrous). 100 ” crystallised bicarbonate } neutralised {63 ” ” (liquid, monohydrated, sp. gr. of potassa. } by { 1·517 to 1·521). 50 ” {pure chalk. } {67-1/2 ” ” (liquid, sesquihydrated, sp. gr. {pure marble. } { 1·5033 to 1·504). 28 ” pure caustic lime. } {72 ” ” (liquid, binhydrated, sp. gr. 37 ” hydrate of lime (fresh). } { 1·486). 44 ” dry carbonic acid (when } {90 ” ” (liquid, sp. gr 1·42). the bicarbonate of } {36 Oxalic acid (anhydrous). potassa or soda is } {63 ” ” (crystallised). used for testing in } {72 Phosphoric acid (anhydrous). the process of Fresenius } {81 ” ” (glacial). and Will). } {50 Succinic acid (dry or anhydrous crystals). 22 ” dry carbonic acid (when } {59 ” ” (ordinary crystals). a dry carbonate is } {40 Sulphuric acid (anhydrous). used). } {49 ” ” (liquid, monohydrated, sp. { gr. 1·8485). {75 Tartaric acid (crystallised). {212 Tannic acid (carefully dried).

[Footnote 8: 1000 water-grains measure of pure liquor of ammonia, sp. gr. 0·992, contains exactly 17 gr., or 1 equiv. of pure gaseous ammonia. A standard liquor of this strength may be most conveniently prepared by cautious dilution of a stronger solution, until a hydrostatic bead, corresponding to the sp. gr., floats indifferently in the middle of the new solution, at 60° Fahr. By keeping two hydrostatic beads in the solution——the one made barely to float, and the other barely to sink——we shall always be able to detect any change of strength or temperature which it may suffer; since the “loss of a single hundredth part of a grain of ammonia per cent., or the difference of a single degree of heat, will cause the beads to” vary their positions. To preserve its integrity it must be kept in a well-stoppered bottle. (See below.)]

[Footnote 9: These substances, as well as ‘test-solutions’ containing them, must be perfectly free from carbonic acid, and must be carefully preserved to prevent the absorption of carbonic acid from the atmosphere. Mohr states that a dilute solution of either of them is best preserved in a flask or bottle well closed with a cork fitted with a small bulb tube (resembling a chloride of calcium tube), filled with a finely triturated mixture of sulphate of soda and caustic lime, and bearing a very thin open tube in the exit aperture. Fresenius, and most other foreign chemists, prefer ‘test-solutions’ of pure soda. With test-solutions containing caustic alkalies, exact neutralisation of an acid is not only more easily effected, but more readily perceived, particularly when either solution is tinted with litmus.]

[Footnote 10: Prepared by gradually heating the pure crystallised carbonate to redness. From being uniform in composition, and easily procured or prepared, they are much employed; preference being usually given to the soda-salt.]

[Footnote 11: The crystals must be free from attached water, but not the least effloresced.]

Oper. A determined amount of the acid under examination is accurately weighed into the flask A (see engr.); and if it be a concentrated acid, or a solid, it is mixed with or dissolved in 6 or 8 times its weight of water. The little glass tube (e) is then nearly filled to the brim with pure bicarbonate of soda, in powder, and a fine silken thread is tied round the neck of the tube, by means of which it can be lowered down into the flask (A), so as to remain perpendicularly suspended when the cork is placed in the latter; the cord being held between the cork and the mouth of the flask. The flask (B) is next about half filled with oil of vitriol, and the tubes being arranged in their places, as represented in the engr.; and time having been allowed for the mixture of acid and water to cool completely, after the increase of heat caused by mixing, the whole apparatus is very accurately weighed. The cork in the flask (A) is then slightly loosened, so as to allow the little tube containing the bicarbonate of soda to fall into the acid, and is again instantly fixed AIR-TIGHT in its place. The evolution of carbonic acid now commences, and continues until the acid in the flask (A) is neutralised. When this takes place, which is easily seen by no bubbles being emitted on shaking the apparatus, the flask (A) is put into hot water (120° to 130° Fahr.), and kept there, with occasional agitation, until the renewed evolution of gas has completely ceased. The little wax stopper is then taken off the tube (a), the apparatus taken out of the hot water, wiped dry, and suction applied, by means of a perforated cork, or a small india-rubber tube, and the mouth, to the end of the tube (d), until the sucked air no longer tastes of carbonic acid. The whole is then allowed to become quite cold, when it is replaced in the balance (the other scale still containing the original weights), and weights added to restore the equilibrium.

The loss of weight represents the exact quantity of dry carbonic anhydride, or anhydrous carbonic acid gas, that has been expelled from the bicarbonate of soda, by the action of the acid in the sample examined.

The quantity of real acid it contained is then deduced by the following calculation:——One equivalent of gaseous carbonic anhydride, or anhydrous carbonic acid (= 44) bears the same proportion to one equivalent of the acid in question, as the amount of the carbonic anhydride expelled does to the amount of the acid sought. Thus, suppose a dilute sulphuric acid expels 3 gr. of carbonic anhydride, the arrangement is——

44 : 49 :: 3 : 3·349

Consequently the sample operated on contained 3·5 (nearly) grains of true sulphuric acid.

Instead of the above calculation, we may multiply the weights of the respective acids required to expel 1 gr. of carbonic acid (as exhibited in the following table) by the number of gr. of dry carbonic acid evolved during the above operation. The product represents the per-centage strength, when 100 gr. of the acid have been examined. When only 50, 25, 20, or 10 gr. have been tested, this product must, of course, be doubled, quadrupled, &c., as the case may be.

TABLE II.

Multipliers. Acetic acid (anhydrous) 1·159 ” ” (hydrated or glacial) 1·364 Citric acid (crystallised) 1·523 Hydrochloric acid (dry or gaseous) ·829 ” ” (sp. gr. 1·16) 2·478 Nitric acid (anhydrous) 1·227 ” ” (sp. gr. 1·5) 1·523 ” ” (sp. gr. 1·42) 2·045 Oxalic acid (crystallised) 1·432 Sulphuric acid (anhydrous) ·909 ” ” (sp. gr. 1·8485) 1·114 Tartaric acid (anhydrous) 1·500 ” ” (crystallised) 1·705

Even this easy calculation may be avoided, in technical analysis, by simply taking for the assay such a weight of the respective acids as is capable of disengaging exactly 10 gr. of dry carbonic acid from the bicarbonate. In this case, the loss of weight in grains, from the operation, multiplied by 10, at once indicates the exact per-centage strength sought. The proper weight of any acid to be taken to give per-centage results is found by simply dividing ten times the equiv. of that acid by 44. For, taking sulphuric acid as an example,

as—— 44: 49 :: 10 : 11·1318

or 11·13 nearly.

On this principle are obtained the weights to be taken, as given in——

TABLE III.

Grains. Acetic acid (anhydrous) 11·59 ” ” (hydrated or glacial) 13·64 Citric acid (crystallised) 15·23 Hydrochloric acid (dry or gaseous) 8·29 ” ” (sp. gr. 1·16) 24·78 Nitric acid (anhydrous) 12·27 ” ” (sp. gr. 1·5) 15·23 ” ” (sp. gr. 1·42) 20·45 Oxalic acid (crystallised) 14·32 Sulphuric acid (anhydrous) 9·09 ” ” (sp. gr. 1·845) 11·14 Tartaric acid (anhydrous) 15·00 ” ” (crystallised) 17·05

2. A convenient modification of the preceding method of acidimetry consists in using the common apparatus figured in the margin and employing fused chloride of calcium to dry the evolved carbonic acid gas, instead of concentrated sulphuric acid. The mode of conducting the process and obtaining the results is precisely the same as in that last explained, and need not, therefore, be repeated. In this case, however, suction must be applied to the small tube (g), instead of (d) in the accompanying engraving.

Obs. These methods, though apparently complicated, are not difficult to perform, when once well understood. The application of heat after the completion of the operation is indispensable, as, if it were neglected, from 0·3 to 0·4 of a gr. of carbonic acid would be retained in the liquid. The bicarbonate of soda must be pure, and perfectly free from any neutral carbonate or sesquicarbonate of soda. To ensure this, the bicarbonate of commerce is reduced to a uniform powder, put into a glass jar, and covered with its own weight of cold distilled or rain water, and allowed to stand for twenty-four hours, with frequent stirring. It is then placed upon a funnel, the tube of which is stopped with loose cotton, so as to allow the lye to drain off. It is next washed several times with small quantities of cold distilled or rain water, and after being dried by pressure between some sheets of blotting-paper, without the aid of heat, is kept for use in a well-closed glass bottle. Before use, it may be tested to ascertain its purity. If pure, it neither reddens turmeric paper, nor gives a brick-red precipitate with a solution of bichloride of mercury. Pure bicarbonate of potassa may be used instead of bicarbonate of soda; but in either case it is always proper to use an excess, so as to leave some undecomposed carbonate after the operation has ended. The presence of a little sodium chloride or sulphate in the bicarbonate will not interfere in the least, but the absence of every trace of neutral carbonate is a sine quâ non.

The two above methods of estimating the amount of acid are only superior to the generally used methods first described, when the presence of colouring matter interferes with the reaction of the litmus used to show the point of neutralisation.

Observations. When great accuracy is required in conducting the neutralisation of the solution in estimating volumetrically with litmus as an indicator, it is proper to prepare and keep standard solutions of sulphuric acid and oxalic acid, with which occasionally to try the alkaline test-liquor. The only difficulty in the process is to avoid over-saturation of the acid-sample. Great care must be taken not to exceed the precise point of neutralisation of the acid. After adding each portion of the test-liquor, the solution should be well stirred up, and as soon as the effervescence becomes languid the greatest caution must be observed in adding more. The proper point is arrived at when the liquor ceases to redden litmus, and does not alter the colour of turmeric paper; if it turns the latter brown, too much of the test-liquid has been added, and the operation becomes useless. Towards the end of the experiment, when great precision is required, a gentle heat may be applied, in order to expel the free carbonic acid in the liquor; but otherwise this is unnecessary. The peculiar soapy odour gradually acquired by the liquor as it nears saturation will materially assist the operator when testing vinegars, and some of the other vegetable acids. A good method is to tint either the acid-sample or the test-liquid with a few drops of litmus, as noticed under ACETIMETRY; when the reddish shade will gradually deepen into ‘purple,’ or the purple into ‘red,’ as the point of saturation is approached; and the blue colour will be perfectly restored as soon as this point is reached. Dr Ure recommends keeping the ammonia-test ready tinged with litmus, and the same applies to other test-liquors.

In commerce, the strength of acids is frequently reckoned with reference to a standard, termed 100 acidimetric degrees. This is taken from the circumstance that 91 gr. of commercial oil of vitriol, of a sp. gr. of 1·845, exactly saturate 100 gr. of dried carbonate of soda. An acid requiring only 35, 50, or any other number of grains of the carbonate to saturate it, is in like manner termed of so many degrees strong; the number of grains representing in each case an equal number of degrees. This method originated with the French chemists, and though only conventional, and principally confined to commercial purposes, is especially adapted to practical men but little conversant with chemistry, yet very ready in retaining or calculating anything on the centesimal scale, from its similarity to monetary language and reckoning.

=ACID′ITY.= Syn. ACID′ITAS, L.; ACIDITÉ, Fr.; SÄURE, Ger. In chemistry, the state of being acid. In physiology, &c., the impression given to the organs of taste by tart or acid substances. Sourness. See FERMENTATION, MALT-LIQUORS, WINES, &c.

=Gas′tric Acidity.= Acidity of the stomach; a common and well-known symptom of weak or disordered digestion.

Treat., &c. Small doses of absorbents or antacids, three or four times daily, to which some tonic bitter, as calumba, cascarilla, chamomile, gentian, or orange-peel, may be added. Stomachic stimulants, as capsicum, ginger, mustard, or wine, &c., taken with, or after, meals, are also useful. The diet should be light and nutritious; and acescent vegetables, over-ripe fruit, and weak new beer or other liquors avoided as much as possible. The bowels should be kept regular, but not open, by the occasional use of mild aperients, as rhubarb, aloes, castor oil, senna, or mercurial pill, or compounds containing them. Excessive looseness or diarrhœa may be checked by a few doses of carbonate of soda, chalk-mixture, or astringents.

In INFANCY this affection is usually accompanied by restlessness, continual crying, drawing up of the legs forcibly towards the body, hiccups, vomiting, diarrhœa, sour eructations, griping pains, green stools, and debility; often followed, when the irritation is considerable, by convulsions. The treatment consists in relieving the bowels of all offending matter by a few doses of rhubarb-and-magnesia. The looseness or diarrhœa may be checked by a few small doses of carbonate of soda or chalk mixture; or better, in an infant which is fed by lime-water (1 or 2 fl. oz.) mixed with as much milk. Two or three drops of caraway, cinnamon, dill, or peppermint water, on sugar (not with the food) will tend to promote the expulsion, and prevent the undue generation of gases. The flatulence usually disappears with the acidity. The occasional administration of 1 to 3 gr. of quicksilver-with-chalk (‘grey powder’), will frequently remove the complaint, and prevent its recurrence, when all other means fail. The diet of both nurse and infant should be carefully regulated.

See ANTACIDS, DYSPEPSIA, &c.

Treatment for Horses. Alkalies, their carbonates and bicarbonates; alterative doses of aloes with alkalies; chalk, carbonate of magnesia; mineral acids; bismuth, arsenic, nux vomica, or strychnia.

=ACIDS, EFFECTS OF, ON VEGETATION.= This subject has been ably investigated of recent years by Dr Angus Smith and Mr Rothwell, and the practical importance of their labours is shown by the circumstance that an Act of Parliament passed in 1875 renders it penal for the proprietors of alkali works to condense not less than 95 per cent. of the hydrochloric acid evolved in the process of manufacturing ‘soda,’ also to allow air, smoke, or chimney gases to escape into the atmosphere containing more than one fifth of a grain of hydrochloric acid per cubic foot. Every owner of an alkali work is likewise required to ‘use the best practical means of preventing the discharge into the atmosphere of all other noxious gases arising from such work, or of rendering such gases harmless when discharged.’

The injurious effects of acids on vegetation are indicated chiefly by the shrivelled-up appearance which the leaves of herbage, trees, &c., exhibit in the vicinity of chemical works in which the condensation of noxious gases (hydrochloric acid, sulphurous acid, sulphuric acid, sulphuretted hydrogen, nitric acid, and oxides of nitrogen and chlorine) is not effectually carried out. According to Mr Rothwell, ‘in fields exposed to acid vapours handfuls of dead grass may be pulled up in the spring, smelling strongly of the vapour, and that trees, under similar influences, become bark-bound.’

The following is a list of trees arranged in the order of their susceptibility. (Rothwell.)

Forest Trees. Larch, spruce fir, Scotch fir, black Italian poplar, Lombardy poplar, ash, oak, elm, birch, alder, sycamore.

Fruit Trees. Damson, greengage, Halewood plum, Jacob plum, pears, apples, cherries.

Shrubs, Evergreens, and Wild Plants. British laurels, Portugal laurels, Aucuba Japonica, Barberry evergreen, hazel, guelder rose, sloe thorn, hawthorn, raspberries, gooseberries, blackberries, gorse, hollies.

Farm Crops. Potatoes, mangel, white clover and rhubarb, red clover, trefoil, rye-grass, wheat, oats, barley, common turnips, swedes.

Second list of Plants affected by Noxious Vapours, mixing the classes according to the effects produced on each.

I. Fern——only in the summer.

Scotch firs, spruce, and larches——a little in winter.

Clover (white and red), trefoil, rye-grass, poplars, hawthorn, potatoes——receive damage in winter to roots.

II. Wheat receives some damage in winter.

Oats in May, when in the grass state, soon receive damage.

Barley, mangel, common turnips, rhubarb.

III. Laurels (British and Portugal), aucubas, yews, holly, gorse——receive damage in winter, but more in summer.

Old grass meadows and pastures receive much damage in winter.

IV. Ashes, oaks, hazels, horse-chestnuts, walnuts, Spanish chestnuts, sloe thorn.

V. Swedish turnip and cabbages, damson, other fruit trees, beech, elm, birch, alder, sycamores.

=ACIDULÆ.= [L. pl.] In medicine, mineral waters rich in carbonic acid.

=ACIDULATED=. Syn. ACIDULATUS, L.; ACIDULÉ, Fr. Blended or flavoured with an acid; made slightly sour. See KALI (Acidulated), DROPS, LOZENGES, &c. In chemistry, the addition of an acid to a neutral or alkaline liquid until it reddens blue litmus paper.

=ACIDUM.= [L.] An acid.

=ACNE.= [Syn. PIMPLED FACE.] There are two forms of this affection. 1st. In young persons of both sexes; generally in phlegmatic habits. The disease shows itself by hard pimples, with a small black spot on the apex, unaccompanied with redness or inflammation at first, but after a while they become red and inflamed, and sometimes suppurate, with a greasy look of the skin between them. In this form of acne the black spots should be picked out with a needle or a small pair of tweezers. A long piece of thick matter, like a worm, is extracted; but is no worm. Afterwards wash the face with water in which a small piece of Quillar bark has been steeped, or with bitter almond emulsion, or borax, one drachm, water 4 oz. When there is no inflammation, use Eau de Cologne, or a few drops of oil of rosemary dissolved in spirit of wine, taking a small dose of magnesia in the morning, or milk of sulphur daily. When the pimples are very sluggish the cautious application of tincture of iodine, or of ointment of nitrate of mercury, will be found serviceable.

2nd. Arises from intemperance. In this case a gradual change of habits is essential. The use of soap should be avoided, and recourse had to warm fomentations of slippery elm, or thin oat gruel. The following should be applied to the pimples:——Cold cream, 1 oz., Goulard’s extract 20 drops, mixed together; or lemon juice diluted, or solution of borax in water. The internal administration of the mineral acids combined with bitter tonics, or small doses of iodide of potassium, will be found effectual.

Treatment. Fomentations, poultices, chloride of zinc solution externally; sulphur and alteratives internally.

=ACOLOGY=. Syn. In medicine, the doctrine of, or a discourse on, remedies or the materia medica.

=ACONITE.= (-nite). Syn. ACON′ITUM, L.; ACONIT, Fr.: AKONITUM, EISENHUT, STURMHUT, Ger. Monkshood; wolfsbane. In botany, a genus of exogenous plants. Nat. ord., Ranunculaceæ; Sex. syst., Polyandria Trigynia. They are characterised by showy purple or yellow helmet-shaped flowers growing in panicles, deeply cut leaves, and perennial (usually) tap-shaped or tapering roots. The whole plant is highly poisonous, the roots being more poisonous than the leaves. In medicine and materia medica, the plant Aconitum Napellus (which see).

Symptoms. Numbness and tingling in the mouth and throat, which are parched; followed by giddiness, dimness of sight, and (sometimes) delirium, but seldom complete coma; there is numbness and tingling of the limbs, a loss of power in the legs, (in some cases) frothing at the mouth, severe abdominal pains, nausea, vomiting, and diarrhœa; tremors or twitchings of the voluntary muscles, (sometimes) convulsions (in animals, but not in man); sharp cries; pupil (generally) dilated, very rarely contracted; pulse fitful and sinking; skin cold and livid; difficulty of breathing; general prostration; loss of sensation or feeling, insensibility, general trembling, fainting, and sudden death. The eyes are often glaring; and, in some cases, the patient is completely paralysed, yet retains consciousness to the last. The case generally proves fatal in from 1 to 8 hours. If it last beyond this period there is hope of recovery. (Fleming.)

Antidotes. Ammonia, or brandy, with artificial respiration if necessary: cold affusion and friction, with warm towels to the back and limbs. See ALKALOIDS.

=ACONITE LEAVES= (B. Ph.). Syn. ACONITI FOLIA, L. The fresh leaves and flowering tops of aconitum napellus, Linn., gathered when about one third of the flowers are expanded, from plants cultivated in Britain.

Char. Leaves smooth, palmate, divided into five deeply cut wedge-shaped segments; excizing slowly, when chewed, a sensation of tingling. Flowers numerous, irregular, deep blue, in dense racemes.

Prep. Extractum aconiti.

=ACONITE ROOT.= (B. Ph.). Syn. ACONITI RADIX, L. The dried root of aconitum napellus. Imported from Germany, or cultivated in Britain, and collected in the winter or early spring before the leaves have appeared.

Prep. Aconitia, the active principle; Linimentum Aconiti, 1 ounce to 1 fluid ounce; Tinctura Aconiti, 54-1/2 grains to 1 fluid ounce.

Char. Usually from one to three inches long, not thicker than the finger at the crown, tapering, blackish-brown, internally whitish. A minute portion, cautiously chewed, causes prolonged tingling and numbness.

=ACONITI FOLIA.= See ACONITE LEAVES.

=ACONITI RADIX.= See ACONITE ROOT.

=ACONITIA.= C_{30}H_{47}O_{7}N. (B. P.) Syn. ACONITIA, L. An alkaloid obtained from aconite.

Take of Aconite root, in coarse powder, 14 pounds. Rectified spirit } Distilled water } of each Solution or ammonia } a sufficiency. Pure ether } Diluted sulphuric acid}

Pour upon the aconite root three gallons of the spirit, mix them well, and heat until ebullition commences; then cool and macerate for four days. Transfer the whole to a displacement apparatus, and percolate, adding more spirit, when requisite, until the root is exhausted. Distil off the greater part of the spirit from the tincture, and evaporate the remainder over a water bath until the whole of the alcohol has been dissipated. Mix the residual extract thoroughly with twice its weight of boiling distilled water, and when it has cooled to the temperature of the atmosphere, filter through paper. To the filtered liquid add solution of ammonia in slight excess, and heat them gently over a water bath. Separate the precipitate on a filter, and dry it. Reduce this to coarse powder, and macerate it in successive portions of the pure ether with frequent agitation. Decant the several products, mix and distil off the ether until the extract is dry. Dissolve the dry extract in warm distilled water acidulated with the sulphuric acid; and, when the solution is cold, precipitate it by the cautious addition of solution of ammonia diluted with four times its bulk of distilled water. Wash the precipitate on a filter with a small quantity of cold distilled water, and dry it by slight pressure between folds of filtering paper.

Characters and Tests. A white, usually amorphous, solid, soluble in 150 parts of cold, and 50 of hot water, and much more soluble in alcohol and in ether; strongly alkaline to reddened litmus, neutralising acids, and precipitated from them by the caustic alkalies, but not by carbonate of ammonia or the bicarbonates of soda or potash. It melts with heat, and burns with a smoky flame, leaving no residue when burned with free access of air. When rubbed on the skin it causes a tingling sensation, followed by prolonged numbness. It is a very active poison.

=ACONITIA, CRYSTALLISED.= C_{27}H_{40}NO_{10}. Exhaust the root of wild aconite, carefully picked and powdered, with very strong alcohol, to which 1 per cent. of tartaric acid has been added. Distil at a gentle heat, and sheltered from the air, to recover the alcohol. Treat the extract with water to separate all the fatty and resinous matters. The solution which contains the aconite in the state of acid tartrate is first shaken with ether to remove colouring matters, and then the alkaloid is set free by the addition of alkaline bicarbonate, until the cessation of effervescence. A fresh treatment with ether of this alkaline solution removes the alkaloid, which crystallizes upon the concentration of the ethereal liquid, with an addition of petroleum spirit. The crystals are colourless tables, rhombic or hexagonal, according to the modifications produced principally in the acute angles. Crystallized aconitia is soluble in alcohol, ether, benzine, and chloroform; insoluble in petroleum oils and glycerine.

ACONITIA NITRATE, CRYSTALLISED. Crystallised aconitine q. s.; nitric acid, sp. gr. 1·442, q. s. Saturate the nitric acid with the aconitine and evaporate. Voluminous crystals are easily obtained (from ‘Formulæ for New Medicaments adopted by the Paris Pharmaceutical Society’).——‘Pharm. Journal.’ Owing to the decomposition which this alkaloid undergoes in the animal organism, as well as to its liability to decompose during the process of evaporation, and exposure to the air, it often becomes extremely difficult, if not impossible, to obtain it in a separate state in conducting a post-mortem examination. The physiological effects seem to furnish the most prominent and characteristic evidence of its presence in such cases, or at any rate these may serve as a valuable guide to the toxicologist.

Uncrystallised aconitia is sometimes contaminated with delphinia, as well as with aconella, another constituent of aconite root. For the dissection of these see ALKALOIDS. One fiftieth of a grain of aconitia is stated to have killed a dog.

Antidotes. See ACONITE.

=ACONITIC ACID.= (Identical with Pyrocitric Acid.) An acid extracted by Peschier from aconitum napellus, and by Bracconnot from equisetum fluviatile. It exists in these plants chiefly in the form of aconitate of calcium.

Properties. A white, colourless, semi-crystalline mass.

=ACONITINA.= See ACONITIA.

=ACONITINE.= See ACONITIA.

=ACONI′TUM.= [L.] Aconite. The pharmacopœial name of aconitum napellus(see below).

=Aconitum Ferox.= (Ind. P.) Habitat. Temperate and sub-Alpine Himalaya, at 10,000 to 14,000 feet elevation, from Gurhwal to Sikkim.

Officinal part. The dried root (Aconiti ferocis Radix), in common with those of other Himalayan species, viz., aconitum napellus, a. palmatum, and a. luridum, constitutes the drug well known in the bazaars of Upper India under the Hindostani name of Bish or Bikh.

It occurs in the form of tuberous roots of a more or less conical form, from two to three inches in length, and from half an inch to one inch in thickness at their upper end. They have usually a shrunken appearance, and are covered with a dark shrivelled bark; fracture shining and resinous; sometimes waxy, varying in colour from pale to deep brown. Some specimens are white and spongy; and these, it is asserted, are superior in activity to the more compact kinds. Inodorous; taste at first slightly bitter, leaving a peculiar sense of numbness on the tongue and fauces. Active principle, aconitia.

Medical Properties and Uses. Similar to those of aconitum napellus of Europe. Preparations. This root may be advantageously used for the manufacture of aconitia, the proportion of this alkaloid being much larger than in the European drug; and also for the preparation of Linimentum Aconiti. From its greater activity, however, it is unsuited for the preparation of this tincture, which is intended for external use.

=Aconitum Hetorophyllum.= (Ind. P.) Habitat. Western temperate Himalaya, at 8000 to 13,000 feet elevation; from Indus to Kumaon. Officinal part. The dried root (Aconiti heterophylli Radix). Ovoid tuberous roots, tapering downwards to a point, from one to one and a half inches or more in length, and from three eighths to half an inch in thickness. The surface, which is covered with a thin greyish epidermis, is slightly wrinkled longitudinally, and marked here and there with root scars. It is inodorous, and of a bitter taste, devoid of acridity. Does not contain aconitia. It may be readily distinguished from other roots sold in the bazaars under the same vernacular name (Atis) by its characteristic bitterness. Properties. Tonic and antiperiodic. It may be administered internally with safety, as it contains no poisonous principle. Therapeutic uses. In convalescence after debilitating diseases, and in intermittent and other paroxysmal fevers, it has been found an efficient remedy. Doses. Tonic, 5 to 10 grains thrice daily; antiperiodic, 20 to 30 grains of the powdered root every three or four hours, irrespective of the presence of pyrexia.

=Aconitum Napell′us.= [Linn.] Syn. ACONI′TUM, Ph. L., E., & D.; ACONITNAPÈL, CHAPERON DE MOINE, Fr.; EISENHUT, BLAUERSTURMHUT, Ger. Early blue wolfsbane, or deadly aconite. Hab. Various parts of Europe; grows wild in England, flowering in June and July. The fresh and dried leaves (ACONITI FO′′LIUM), Ph. L. & E. The root (ACONITI RA′DIX), Ph. L. & D. This is the species of aconite ordered in the pharmacopœias, and commonly used in medicine. When chewed it imparts a sensation of acrimony, followed by a pungent heat of the lips, gums, palate, and fauces, which is succeeded by a general tremor and chilliness. The juice applied to a wound or the unsound skin affects the whole nervous system. Even by remaining long in the hand, or on the bosom, it produces unpleasant symptoms. Fatal cases of poisoning, by eating the root in mistake for horseradish, have been common of late years. The two roots may be, however, easily distinguished from one another; when scraped aconite emits an earthy, and horseradish its well-known pungent odour. Moreover, the shape of the roots is very different. In the accompanying figure a represents aconite root, and b horseradish root.

The leaves should be gathered as soon as the flowers appear. The root should be taken up in autumn. When the whole plant is employed, it should be gathered as soon as the flowers begin to open. The strength (richness in aconitia) varies considerably with the time of the year. 1 oz. of the fresh root contains 1/4 to 3/4 gr. of aconitia; 1 lb. of the dried English root contains from 12 to 36 gr. (Herapath). The leaves possess the greatest activity just before flowering; the root, after it. The root is at all times fully six times as strong as the leaves or herb. The wild plant contains much more aconitia than that which is cultivated. The herb, and all its preparations, lose their efficacy if long kept. The powder, more particularly, cannot be relied on. Mr Holmes says it is difficult to find in a commercial sample of aconite root one root in a dozen, which upon fracture appears sound and in good condition.

Properties, Antidotes, &c. See ACONITE.

Tests, &c. See ACONITE.

Uses, &c. In small doses aconite is narcotic, powerfully diaphoretic, and sometimes diuretic; in larger ones, the symptoms are similar to those produced by aconitia. It acts as a powerful sedative on the heart’s action, and destroys sensibility without disturbing the mental faculties. It has been given in chronic rheumatism, gout, paralysis, scirrhus, scrofula, cancers, venereal nodes, epilepsy, amaurosis, intermittents, &c.; but its exhibition requires the greatest possible caution. As a topical benumber it has been used with great advantage in painful affections depending on increased sensibility of the nerves. Externally it “is most valuable for the cure of neuralgic and rheumatic pains. In neuralgia, no remedy, I believe, will be found equal to it. One application of the tincture produces some amelioration; and after a few times’ use, it frequently happens that the patient is cured. In some cases, the benefit appears almost magical. In others, however, it entirely fails to give permanent relief.” “I do not think that in any (case) it proves injurious.” “When it succeeds, it gives more or less relief at the first application. When the disease depends on inflammation, aconite will be found, I think, an unavailing remedy.” “In rheumatic pains, unaccompanied with local swelling or redness, aconite is frequently of very great service.” (Pereira, iii, 691.) Dose, of the powder, 1 to 2 gr., gradually increased to 6 or 8. Dr Stocrk was the first who gave wolfsbane internally, about the year 1762. It has since been successfully employed in Germany in cases of chronic rheumatism, gout, &c., some of which were of long standing and had resisted every other remedy. In England it has been less extensively used.

=Aconitum Panicula′tum.= Panicled wolfsbane; a species formerly ordered in the Ph. L.; and, with a. napellus, also in the Ph. U. S. It is less active than the officinal species.

=A′CORN.= Syn. GLANS. QUER′CUS, L. The seed or fruit of the oak. In the early ages of the world, acorns probably formed one of the principal articles of the food of man. (Ovid, Met., i, 106; Virgil, Georg., i, 8; &c.) In modern times, during periods of scarcity, they have been consumed as food on the Continent. Besides starch, they contain a peculiar species of sugar, which crystallises in prisms, and is unfermentable; they also contain tannic and gallic acids. Mannite and dulcose are the substances which it most nearly resembles. (M. Dessaignes.) During the autumn, acorns are said to be sometimes poisonous to cattle and sheep. Supposed cases of so-called acorn poisoning are best treated by withdrawing the supply of acorns, or removing the animals from the pastures on which the acorns fall, and by the administration of aperients, alkalies, and stimulants.

=AC′ORUS CAL′AMUS.= See SWEET FLAG.

=ACOTYLE′DONS= (-ko-te-lē′-). Syn. ACOTYLE′DONES (dŏn-ēz; L., prim. Gr.), Jussieu; ACOTYLÉDONS, Fr.; OHNE SAMENLAPPEN, Ger. In botany, plants whose seeds are not furnished with distinct cotyledons or seed-lobes. Acotyledonous plants form one of the two great divisions of the vegetable kingdom, according to the natural system. They are remarkable by increasing chiefly in length, by additions to their end; and not by addition to the outside, as in Exogens; nor to the inside, as in Endogens. They are also termed ASEX′UAL and FLOWERLESS PLANTS, and answer to the CRYPTOGAMIA of the Linnean system. See ACROGENS, CELLULARES, THALLOGENS, &c.

=ACOUS′TICS= (-kow′-). The science of audition and sound; that branch of physics which treats of their cause, nature, and phenomena. The doctrine of the production and transmission of sound is termed DIACOUS′TICS; that of reflected sound CATACOUS′TICS.

=Acoustics.= In medicine, remedies employed to relieve deafness. See DEAFNESS and DROPS, ACOUSTIC.

=ACQUETTA.= [IT., Little Water.] Syn. AQUA TOFFANA; A. TOFFANIA; ACQUETTA DI NAPOLI DELLA TOFFANA, IT. A celebrated poison, prepared by an Italian woman named Toffano, or Tophana, and in great request in Rome about the middle of the 17th century. The composition of this poison has been a matter of frequent controversy. Pope Alexander VII, in his proclamation, described it as “aquafortis distilled into arsenic.” This would produce a concentrated solution of arsenic acid. The Emperor Charles VI, who was governor of Naples during Toffano’s trial, declared to his physician, Garelli, that it was arsenic (arsenious acid) dissolved in aqua cymbalariá. According to Gerarde this cymbalarià was an aquatic species of pennywort, highly poisonous. The only objection to the latter statement is the smallness of the dose, regard being had to the comparative insolubility of arsenious acid; but if the woman Toffano prepared two poisons, as is probable from history——one, a single dose of which was fatal, and another, of which the dose required repetition, and which was more gradual in its activity——the discrepancy will be at once removed.

=AC′RID.= Syn. AC′ER, AC′RIS, L.; ACRE (âcre), Fr.; BEISSEND, SCHARF, Ger. In chemistry and medicine, sharp, pungent, acrimonious. Acrid substances are such as excite a sensation of pungency and heat when tasted, and which irritate and inflame the skin; as mustard, turpentine, cantharides, &c.

=ACRIDITY.= Syn. ACRETÉ, Fr.; ACRITUDO, L. The quality of being acrid.

=AC′RIMONY.= Syn. ACRIMO′NIA, L.; ACRIMONIÉ, ACRETÉ, Fr.; SCHARFE, Ger. In medicine and chemistry, the quality or property of inflaming, irritating, corroding, dissolving, or destroying other bodies.

=ACROGENS.= Syn. ACROGENÆ, L.; ACROGÈNES, Fr. In botany, acotyledonous or cryptogamic plants, in which stems and leaves, or an organisation approaching leaves, are distinguishable; which have stomates or breathing spores on their surface, are propagated by spores, and increase by the growth of the stem at the point only. Ferns and club-mosses are examples of this class of plants.

=ACROLEIN.= Syn. ACRYLIC ALCOHOL. This substance occurs amongst the products of decomposition when glycerine or any of its compounds is subjected to ordinary distillation. It derives its name from its violently irritant effect upon the mucous membranes of the eyes and respiratory organs. It is best prepared by the process of Redtenbacher (see ‘Leibig’s Ann.,’ xlvii, 114), by distilling in a capacious retort, a mixture of glycerine with phosphoric anhydride, or with hydric-potassic sulphate (the acid sulphate or bisulphate of potash); the vapours must be condensed in a properly cooled receiver, which is luted on to the retort and provided with a tube opening into a chimney having a good draught. The distilled liquid separates into two layers, the upper one consisting of acrolein, and the lower one of an aqueous solution of the same substance mixed with a quantity of acrylic acid. This distillate, after digestion with finely powdered litharge, with the object of neutralising the acid, must be rectified by the heat of a water bath: the acrolein so obtained must be submitted to a second rectification from calcic chloride. All these operations must be conducted in vessels filled with carbonic anhydride (carbonic acid) because acrolein becomes rapidly oxidized when exposed to the air.

Acrolein is a clear colourless liquid, lighter than water, boiling at about 125° F. It has great refracting power and a burning taste; when pure it is neutral to test paper.

=AC′ROSPIRE= (-spire). Syn. ACROSPI′RA, L.; PLUMULE, Fr.; BLATTKEIM, Ger. The shoot or sprout of a seed, when it begins to grow; the part of a germinating seed termed the plume, or plumula.

When the growth of a seed begins to be developed, the germ, from which the stem originates, shoots forth under the form of a delicate curved fibre, which, gradually bursting its covering, makes its appearance at the end of the seed. The fibrils of the radicle first sprout forth from the tip of the grain; a white elevation appears, that soon divides into three or more radicles, which rapidly grow larger, and are succeeded by the plumula, which peeps forth at the same point, in the form of a pale green leaflet, which, twisting thence beneath the husk to the other end of the seed, ultimately bursts its prison-house, and becomes a perfect leaf. See GERMINATION and MALTING.

=ACTINIC RAYS.= See ACTINISM.

=ACTINISM.= Syn. ACTINIC RAYS; CHEMICAL RAYS. A term given to a supposed principle accompanying the heat and light of the sunbeam. Actinic rays chiefly exist beyond the violet extremity of the solar spectrum, and are characterised by the power of exciting chemical change, e.g., the decomposition of certain silver salts (in photography); the combination of a mixture of chlorine and hydrogen, &c. The so-called vital functions of animals and plants are also greatly influenced by the actinic or chemical rays.

=ACTINOGRAPH.= An instrument for registering the intensity of the chemical influence (actinism) of the sun’s rays.

=ACT, TOWNS IMPROVEMENT CLAUSES, 1847= (10 & 11 Vict., c. 34), The following provisions of this Act are incorporated in the Public Health Act, 1875, and refer exclusively to urban districts:——

1. With respect to naming the streets and numbering the houses.

2. With respect to improving the line of the streets and removing the obstructions.

3. With respect to ruinous or dangerous buildings.

4. With respect to precautions during the construction and repair of sewers, streets, and houses.

5. With respect to the regulation of slaughter houses.

Notices for alterations under the 69th, 70th, and 71st sections, directions under the 73rd section, and orders under the 74th section of the said Towns Improvement Clauses Act, may, at the option of the urban authority, be served on owners instead of occupiers, or on owners as well as occupiers, and the cost of works done under any of these sections may, when notices have been so served on owners, be recovered from owners instead of occupiers; and when such cost is recovered from occupiers, so much thereof may be deducted from the rent of the premises where the work is done as is allowed in the case of private rates under the Act.

=AC′TUAL.= Real, effectual, absolute; as opposed to that which is merely virtual or potential. In surgery, a red-hot iron, or any other heated body, used as a cautery, is termed the ACTUAL CAUTERY; whilst a caustic or escharotic so employed is called the POTENTIAL CAUTERY.

=ACTUAL CAUTERY.= See ACTUAL.

=ACUTE′.= Syn. ACUT′US, L.; AIGU, Fr.; HEFTIG, HITZIG, SPITZIG, Ger. Sharp, pointed, sensitive. Applied to the senses, as acute hearing, eyesight, &c. In pathology, diseases exhibiting violent symptoms, and whose course is short, are said to be acute diseases.

=ADAPTER.= In chemistry, a tube placed between two vessels (commonly a retort and receiver) for the purpose of uniting them or increasing the distance between them, so as to facilitate the condensation of vapour in distillation. (See figure.)

=ADDER’S TONGUE.= Syn. COMMON ADDER’S TONGUE; OPHIOGLOS′SUM VULGA′TUM, Linn. A perennial plant, of the natural order Filices (DC.), growing wild in England. It is found in our woods and pastures, and flowers in May and June. It was once used to form a celebrated traumatic or vulnerary ointment and is still highly esteemed among rustic herbalists.

=ADEPS.= Syn. LARD. See ADEPS PRÆPARATUS, FAT, and LARD.

=ADEPS BENZOATUS.= Syn. BENZOATED LARD.

=ADEPS PRÆPARATUS.= Syn. AXUNGE; PREPARED LARD.

=ADHE′SION= (-hē-zhün). Syn. ADHÆ′SIO, L.; ADHESION, Fr.; ANHÄNGUNG, ARXLEBUNG, Ger. The act or state of sticking or being united.

=Adhesion.= In physics, the force with which bodies remain attached to each other when brought into contact; e.g., ink adheres to paper, paint adheres to wood, &c. It differs from ‘cohesion’ in representing the force with which different bodies cling together; whereas cohesion is the force which unites the particles of a homogeneous body with each other, e.g., particles of iron cohere and form a mass of iron; particles of water cohere and form a mass of water, &c.

=Adhesion.= In pathology, the morbid union, from inflammation, of parts normally contiguous but not adherent.

=Adhesion.= In surgery, the reunion of divided parts, by the adhesive inflammation; as when incised wounds heal by what is termed the ‘first intention.’

=ADHE′SIVE.= Syn. ADHÆSI′VUS, L.; ADHÉSIF, Fr.; ADHÄSIVE, VERWACHSEND, Ger. In pharmacy, &c., having the quality or property of sticking or adhering. Hence adhe′siveness.

=AD′IPOCERE= (-sēre). Syn. GRAVE-WAX‡; ADIPOCE′′RA, L.; ADIPOCIRE, Fr.; FETEWACHS, Ger. A substance resembling a mixture of fat and wax, resulting from the decomposition of the flesh of animals in moist situations, or under water. It is chiefly margarate of ammonium. Lavoisier proposed to produce this substance artificially, for the purposes of the arts. Attempts have since been made to convert the dead bodies of cattle (carrion) into adipocere, for the purposes of the candle-maker and the soap-boiler, but without success. Besides, dead animal matter can be worked up more profitably than in making artificial adipocere.

Hatchettine or rock-fat is sometimes called ‘adipocere’; and bog-butter is a substance nearly similar to it.

=AD′JECTIVE.= Syn. ADJECTI′VUS, L.; ADJECTIF, Fr. In dyeing, depending on another, or on something else; applied to those colours which require a base or mordant to render them permanent. See DYEING.

=AD′JUVANT.= [Eng., Fr.] Syn. AD′JUVANS, L.; AIDANT, &c., Fr. Assistant; helping. (As a substantive——) In prescriptions, see PRESCRIBING (Art of).

=ADULTERATION.= Strictly speaking, this term ought only to be applied to the practice of adding substances to articles of commerce, food or drink, for the purposes of deception or gain, but a wider interpretation is frequently placed on the word than the definition given by magistrates and analysts, these latter often regarding accidental impurity, or even, in some instances, actual substitution as acts of adulteration.

The following definition of an adulterated substance has been adopted by the Society of Public Analysts——

A substance shall be deemed to be adulterated——

A. In the ease of food or drink:

1. If it contain any ingredient which may render such article injurious to the health of a consumer.

2. If it contain any substance that sensibly increases its weight, bulk, or strength, or gives it a fictitious value, unless the amount of such substance present be due to circumstances necessarily appertaining to its collection or manufacture, or be necessary for its preservation, or unless the presence thereof be acknowledged at the time of sale.

3. If any important constituent has been wholly or in part abstracted or omitted, unless acknowledgment of such abstraction or omission be made at the time of sale.

4. If it be an imitation of or sold under the name of another article.

B. In the case of drugs:

1. If when retailed for medical purposes under a name recognised in the ‘British Pharmacopœia’ it be not equal in strength and purity to the standard laid down in that work.

2. If when sold under a name not recognised in the ‘British Pharmacopœia’ it differs materially from the standard laid down in approved works on materia medica, or the professed standard under which it is sold.

Limits. The following shall be deemed limits for the respective articles referred to:

Milk shall contain not less than 9·0 per cent., by weight, of milk solids, not fat, and not less than 2·5 per cent. of butter fat.

Skim Milk shall contain not less than 9·0 per cent. by weight, of milk solids not butter fat.

Butter shall contain not less than 80 per cent. of butter fat.

Tea shall not contain more than 8·0 per cent. of mineral matter, calculated on the tea dried at 100° C., of which at least 3·0 per cent. shall be soluble in water, and the tea as sold shall yield at least 30 per cent. of extract.

Cocoa shall contain at least 20 per cent. of cocoa fat.

Vinegar shall contain not less than 3 per cent. of acetic acid.

The practice of fraudulent adulteration has been indulged in for centuries. In every civilised state there have been enactments against it. The Romans had their inspectors of meat and corn. In England an Act to prohibit adulteration was passed as early as 1267, and penalties against it were in force in 1581, 1604, 1836, 1851. In 1822, Accum published a work having the sensational title of ‘Death in the Pot,’ and in 1855 appeared Dr Hassall’s book, ‘Food and its Adulterations.’ The information conveyed in these works, added to the revelations of the ‘Lancet’ Sanitary Commission, and the contributions to scientific literature on the subject of food by Letheby, Pavy, Parkes, Blyth, and others, together with the published evidence given before the House of Commons Commission appointed to carry out an inquiry into the subject, roused public attention to such a degree as to lead to the passing by the legislature of the Adulteration Acts.

The sophistications may be divided into several distinct classes:

1. To give weight or volume, such as water added to butter, plaster of paris to flour, &c.; red earths to annatto, sand to tea-leaves, &c.; water to milk, &c.; all these, therefore, are substitutions of worthless or very cheap articles which take the place of the real.

2. To give a colour which either makes the article more pleasing to the eye, or else disguises an inferior one, e.g., Prussian blue, black lead, &c., to green teas; annatto to cheese, &c.; arsenite of copper to sweetmeats, &c.

3. Substitutions of a cheaper form of the article, or the same substance from which the strength has been extracted put in the place of the real, e.g., tea mixed with spent leaves, &c.

4. A very small class where the adulteration is really added with no fraudulent intent, but to enhance the quality of the goods sold——alum to bread in small quantities.

The following, according to Blyth (‘Dic. of Hygiène’), is a list of articles most commonly adulterated, with the names of the substances used in their sophistication:——

ACONITIA with other alkaloids, e.g., delphinia, aconella, &c. ALE, common salt, Cocculus indicus, grains of paradise, quassia, and other bitters, sulphate of iron, alum, &c. ALLSPICE, mustard husks. ANCHOVIES, other fish, and colouring matters, e.g., Armenian bole, Venetian red, &c. ANNATTO, all sorts of starch, soap, red ferruginous earths, carbonate and sulphate of lime, salts, &c. ARROWROOT, various other fecula, such as sago, tapioca, potato, and others. BALSAM OF COPAIBA, turpentine and fixed oils. BEEF (POTTED), Armenian bole. BISMUTH, carbonate of lead, sometimes arsenic (this latter is an impurity not intentional). BLOATERS (POTTED), Armenian bole. BRANDY, water, burnt sugar, &c. BREAD, potatoes (mashed), alum, inferior flour, &c., &c. BUTTER, water, salt, colouring matter, lard, tallow, and other fats. CAJUPUT OIL, copper, camphor dissolved in oil of rosemary, and coloured with copper as a substitute. CALAMINE, coloured sulphate of baryta. CALOMEL, sulphate of baryta, chalk, white precipitate, white lead, pipe-clay, &c., &c. CALUMBA, tinged bryony root, root of Frasera Walteri, and others. CAMBOGE, starch, &c. CAMPHOR, a substitution of Borneo camphor has been made. CANTHARIDES, golden beetle, artificially coloured glass, &c. CARBONATE OF LEAD, sulphate of baryta, sulphate of lead, chalk, &c., &c. CARMINE (COCHINEAL), sulphate of baryta, bone black, &c. CASSIA (SENNA), leaves of Solenostemma argel, and other foreign leaves. CASTOR OIL, other oils, often small quantities of croton oil. CAYENNE, ground rice, vermilion, Venetian red, turmeric. CHAMPAGNE, gooseberry and other wines as substitutes, different colouring matters, &c. CHEESE, annatto, bole (Armenian), and other colouring matters. CHICORY, colouring matters, such as ferruginous earths, and burnt sugar, Venetian red, &c., and different flours, such as wheat, rye, beans, &c., and sometimes sawdust. CIDER, lead (as an impurity, not intentional). CIGARS, substitutions of hay and other rubbish, inferior tobacco, leaves sometimes darkened by some brown vegetable dye. CINNAMON, cassia, clove stalks, and different flowers. CLARET, brandy, and substitution of inferior wines. CLOVES, clove stalks. COCOA AND CHOCOLATE, cheaper kinds of arrow-root, such as _Tous les mois_ and East Indian, animal matter, corn, sago, tapioca, &c. COFFEE, chicory, roasted wheat, rye flowers, and colouring matters, such as burnt sugar, &c. COD-LIVER OIL, other oils mixed with it. COLOCYNTH (COMPOUND EXTRACT OF), the extract is not unfrequently made with the pulp and seeds. CONFECTIONERY, injurious colouring matters, such as arsenite of copper, chromate of lead, &c. CONFECTION, AROMATIC (AROMATIC CHALK POWDER), expensive ingredients omitted, turmeric substituted for saffron, &c., &c. COPAL, gum dammar, resin, &c. CURRY-POWDER, red lead, ground rice, salt. CUSPARIA BARK, the bark of Strychnos Nux Vomica is said to have been substituted. CUSTARD AND EGG POWDER, turmeric, chrome yellow, and different flours. ELATERIUM, starch, flour, chalk, &c. EPSOM SALTS, chloride magnesium, chalk, &c. ETHER, alcohol. FLOUR, other and inferior flours, as the flour from rice, bean, Indian corn, potato, &c., sulphate of lime, alum. GELATINE, salt and sugar. GIN, water, sugar, capsicum, flavouring matters of different kinds, turpentine, alum, tartar. GINGER, turmeric, and husks of mustard, flour from wheat, sago, &c. GUAIACUM RESIN, other resins. HONEY, flour, cane sugar, &c. HOPS, Cocculus indicus, grains of paradise, &c., &c. IODIDE OF POTASSIUM, water, carbonate of potash, chlorides of soda and potash, iodate of potash, iodine, &c. IODINE, water, plumbago, charcoal, black oxide of manganese, &c. IPECAQUANHA, other roots, extraneous woody fibre; when in powder, chalk, flour, &c., have been added. ISINGLASS, gelatine. JALAP, raspings of guaiacum, false jalap root, &c. LARD, carbonate of soda, salt, potato, flour, and lime. LEMON JUICE, a mixture of sugar and water, acidulated with sulphuric acid, has been substituted. LIQUORICE, rice, chalk, gelatine, and different flours. MAGNESIA, MAGNESIA SULPHATE, lime, carbonate of magnesia. MAGNESIA, CARBONATE, lime, sulphate, &c., &c. MARMALADE, apple, or turnip pulp. MERCURY, lead, tin, zinc, bismuth, &c. MERCURY GREEN IODIDE OF, red iodide of MERCURY RED OXIDE OF, brick-dust, red lead, &c. MERCURY AMMONIATED (WHITE PRECIPITATE), chalk, carbonate of lead, plaster of Paris, &c., &c. MILK, water. MUSTARD, turmeric, wheat flour. MYRRH, gum bdellium, and other gum resins. OATMEAL, barley flour, rubble. OPIUM, stones, sand, clay, vegetable extracts, sugar, treacle, water, &c. PAREIRA ROOT, different roots substituted. PEPPER, linseed meal, different flours, mustard husks, &c. PICKLES, salts of copper, acetate of copper. PORTER AND STOUT, sugar, treacle, water and salt. POTASH, carbonate, sulphate, and chloride of potash, lime, iron, and alumina. POTASH, ACETATE OF, sulphates, and chlorides of potash. POTASH, CARBONATE OF, sulphates, and chlorides of potash. POTASH, BICARBONATE OF, carbonate of potash. POTASH, CITRATE OF, sulphates of potash. POTASH, CHLORATE OF, chloride of potassium. POTASH, TARTRATE OF, tartrate of lime. POTASH, NITRATE OF, sulphate or chloride of potassium. PRESERVES, salts of copper. QUININE, sulphate of lime, chalk, magnesia, cane-sugar, sulphate of cinchonine, &c. RHUBARB, turmeric, and inferior varieties substituted for Turkey. RUM, water, cayenne, burnt sugar. SAGO, potato flour. SAUCE, treacle, salt, cochineal, Armenian bole, and other colouring matters. SCAMMONY, chalk, starch, guaiacum, jalap, dextrin, &c. SENEGA, guiseng, gillenia. SENNA, leaves of cynanchum argel. SHERRY, sulphates of potash, soda, brandy, burnt sugar, &c. SNUFF, carbonate of ammonia, glass, sand, colouring matter, &c. SODA, BICARBONATE, carbonate and sulphate of soda. SODA, CARBONATE, sulphate of soda. SODA, PHOSPHATE OF, phosphate of lime. SPICES, colouring materials, substitutions, and different flours. SQUILLS (POWDERED), wheat flour. SUGAR (MOIST), sand, flour, &c. SULPHUR, sulphurous acid (as an impurity). SULPHURIC ACID, lead, water, arsenic, hydrochloric acid, &c. TAPIOCA, mixing inferior starches with the pure tapioca. TEA, sand, iron filings, exhausted tea leaves, foreign leaves; and in green teas, black lead, Prussian blue, China clay. TOBACCO, inferior tobacco, water. TURMERIC, yellow ochre, carbonate of soda, or potash. UVA URSI (BEARBERRY LEAVES), leaves of red whortleberry, and others. VINEGAR, sulphuric acid, and metallic impurities. WINES, water, jerupiga, bitartrate of potash, substitution of inferior wines, brandy, spirits, and various other matters. ZINC, OXIDE OF, chalk, carbonate of magnesia.

“The Sale of Food and Drugs Act” has now supplemented several Acts which were passed during the present century for the prevention of adulteration. An Act prohibiting the mixture of injurious ingredients with intoxicating liquors remains unrepealed, as do also one or two statutes relating to trade frauds as for example the Adulteration of Seeds Act, 1809. These latter have not been incorporated in “the Sale of Food and Drugs” Act.

=Æ= (ē). [L.] For words sometimes written with this initial diphthong, and not found below, look under =E=.

=ÆGI′RINON= (-jī′-). [Gr.] See OINTMENT.

=ÆGYPTI′ACUM=† (-jĭp-tī′-). [Lat.] Syn. UNGUEN′TUM ÆGYPTIACUM, L. Oxymel or liniment of verdigris. The name originated with Hippocrates, who is said to have learned its composition in Egypt.

=ÆOL′IPILE= (-pĭle). A hollow ball of metal, having a slender neck with a very small orifice, contrived to exhibit the conversion of water into steam by the action of heat, and to account for the natural production of winds. It was known to the ancients, is mentioned by Vitruvius, and was studied by Descartes and others. It has been used in surgery to produce eschars, in the same cases as moxas; the effect of the steam being limited by means of a piece of perforated pasteboard. When filled with alcohol, and the jet of vapour inflamed, it is sometimes employed as a blowpipe. M. Soyer used an apparatus of this kind to supply the heat in his portable furnace. The liquid, however, which he employed was camphine.

=A′ER=, (ā′-ĕr). [L. prim. Gr.] Air.

=A′ERATED= (ā′-ĕr-rāte-ĕd). In chemistry, &c., impregnated with carbonic acid. See ALKALI, LEMONADE, WATERS, MINERAL.

=AE′′RIAL= (ā-ēre′-e-ăl). Belonging to the air or atmosphere; produced by, consisting of, depending on, or partaking of the nature of the air.

AERIFICA′TION (ā-ĕr-e-). Syn. AËRIFICA′TIO, L.; AÉRIFICATION, GAZÉIFICATION, Fr. In chemistry, the conversion of a body into gas.

=A′ERIFORM= (ā′-ĕr-). Syn. AËRIFORM′IS, L.; AÉRIFORME, GAZÉIFORME, Fr. LUFTFORMIG, &c., Ger. In chemistry, air-like, gaseous.

=AEROL′OGY.= Syn. AËROLO′GIA, L.; AÉROLOGIE, Fr., Ger. In physics, a discourse or treatise of the air. In physiology and hygiène, the doctrine of the air, more especially with regard to its salubrity and action on organised beings.

=AEROM′ETER.= Syn. AËROME′TRUM, L.; AÉROMÈTRE, Fr. An instrument used in aërometry.

=AEROM′ETRY=. Syn. AËROME′TRIA, L.; AÉROMÉTRIE, Fr.; LUFTMESSKUNST, &c., Ger. In chemistry and physics, the art of measuring gases, and of determining their densities.

=AERONAUT′ICS.= Syn. AÉRONAUTIQUE, Fr. The art of sailing in, or of navigating the air. See BALLOONS.

=AEROPHO′BIA.= [L.] Syn. AÉROPHOBIE, Fr. In pathology, a dread of air (wind); a common symptom in hydrophobia, and occasionally present in hysteria and phrenitis.

=AEROSTAT′ICS.= Syn. AÉROSTAT′ICA, L.; AÉROSTATIQUE, Fr. That branch of pneumatics which treats of air, and other elastic fluids, in a state of rest.

=AEROSTA′TION.= [Eng., Fr.] Syn. AËROSTA′TIO, L. The art of weighing the air; aërial suspension and navigation. See BALLOONS.

=ÆRU′GO= (ē-). [L.] The rust of brass, bronze, or copper; verdigris.

=ÆSCULIN.= C_{21}H_{24}O_{13}. A crystalline fluorescent substance existing in the bark of the horse-chestnut (æsculus hippocastanum) and of other trees of the genera Æsculus and Paria. In the above-named sources Æsculin is associated with another fluorescent body called Pariin.

=Æ′′THER.= See ETHER.

=ÆITHE′′REA= (-thēré-). [L. pl.] Ethers.

=ÆSTHET′ICS= (ēz-). Syn. ÆSTHET′ICA, L. Medicines or agents which affect sensation. See ANÆSTHETICS and HYPERÆSTHETICS.

=ÆTHIOPS.= See ETHIOPS.

=AFFEC′TION.= [Eng., Fr.] Syn. AFFEC′TIO, L. In pathology, a term nearly synonymous with disease.

=AFFINITY.= Syn. CHEMICAL AFFINITY; AFFINITAS, L.; AFFINITÉ, Fr.; VERWANDTSCHAFT, Ger. If oil and water be shaken together they produce no change upon one another, as is proved by their separating into two layers with their properties unaltered, when the mixture is allowed to remain at rest for a short time. Such bodies are said, in chemical language, to have no affinity for one another. If iodine and metallic mercury be rubbed together in a mortar they will unite in definite proportions by weight, and form a combination possessing properties totally distinct from those of its constituents. Thus, iodine is a greyish, metallic-looking solid, convertible into a violet vapour by heat, perceptibly soluble in water, and capable of producing a blue compound with starch. Mercury is a metallic, silvery-looking liquid. The product of their union (biniodide of mercury) is a scarlet powder, destitute of metallic lustre, convertible into vapour by heat, without the production of violet fumes, insoluble in water, and incapable of developing a blue colour with starch. Again, the greenish-yellow and intensely poisonous gas, chlorine, unites in definite proportions by weight with the soft, wax-like, and highly poisonous metal sodium to produce the white crystalline solid chloride of sodium (common salt), a compound which, except in very large quantities, is not only not poisonous, but actually beneficial to health.

Such combinations are called chemical compounds, and the force which binds their constituents together is distinguished from all other attractive forces by the term affinity or chemical affinity. Bodies united by affinity are also said to have united chemically.

Affinity is in most cases exerted between different substances, in which respect it resembles adhesion; but bodies united by adhesion, e.g. ink to paper, paint to wood, &c., unlike those united by affinity, suffer no change of properties.

Affinity is exerted at immeasurable distances, therefore substances to be submitted to its influence must be brought into (apparently) actual contact. This condition is frequently fulfilled by the vaporisation, fusion, or solution of one or more of the bodies to be submitted to its action.

In many instances substances which have no affinity for one another at ordinary temperatures manifest this power when heated.

Whenever chemical union takes place, heat is invariably evolved; conversely, the decomposition of a chemical compound is always accompanied by an apparent loss of heat or reduction of temperature.

Finally, the most striking phenomena characteristic of, and accompanying, chemical affinity are, development of heat, change of properties, and union in definite or constant proportions by weight.

=AFFUSION.= In chemistry, the washing of a precipitate, &c., for the purpose of removing soluble matters. In medicine, affusion is of three kinds:——

1. Lotions, which consist in washing a part of the body with a sponge or rag soaked in a liquid.

2. Aspersions, which consist in throwing a liquid drop by drop, like rain, upon the body.

3. Shower baths, which consist in allowing a number of small streams of water to fall from a height upon the surface of the body. If the water fall from a considerable height, affusion is then termed douche by the French.

=AFT′ER-DAMP.= Syn. CHOKE-DAMP. Carbonic acid gas resulting from explosion of air and fire-damp (light carbonetted hydrogen) in coal mines.

=AFT′ER-PAINS.= Those following childbirth. The only remedy is patience; they may, however, be frequently alleviated by small doses of morphia or liquor opii sedativus. Heated cloths and warm fomentations are sometimes useful, particularly if assisted by moderate but sufficient pressure on the abdomen, by means of a broad bandage. They seldom follow with severity the first birth.

Treatment for Animals. Remove clots from parts, raise the hind-quarters. Give clysters of linseed tea, lukewarm, and laudanum or belladonna extract. Syringe out parts with Condy’s fluid considerably diluted. Give internally belladonna, opium, or chloroform. Draw away milk.

=AFT′ER-WASH= (wŏsh). In the art of the distiller, the liquor in the still after the spirit has been drawn over.

=AG′ARIC.= [Eng., Fr.] Syn. AGAR′ICUM, AGAR′ICUS, L.; BLÄTTERSCHWAMM, PILZ, SCHWAMM, Ger. In botany, a genus of fungi, of numerous species, embracing the mushrooms and champignons. Of these plants, some are edible; others poisonous. The term is also commonly applied to the boletus found on oaks (TOUCHWOOD), and on larches (MALE AGARIC). See MUSHROOMS.

=Fly-agaric.= Syn. FLY MUSH′ROOM; AGAR′ICUS MUSCA′′RIA, Linn.; AMANI′TA M. One of the most narcotic and poisonous of our fungi, producing, in small doses, intoxication and a pleasing species of delirium; for which purpose it is commonly employed in Kamschatka. (Hooker.) It possesses the singular property of imparting an intoxicating quality to the urine, which continues for a long time after taking it. This secretion is, therefore, commonly saved by the natives during a scarcity of the fungus. “Thus, with a few amanitæ, a party of drunkards may keep up their debauch for a week;” and the intoxication so produced is capable of “being propagated through five or six individuals.” (Langsdorff.) Water in which it has been boiled is poisonous; but the boiled fungus itself is inert. The liquid from it is used as a fly-poison; whence the name mushroom is derived. It may be known by its rich orange-red colour in autumn.

=AG′ATE= (-āte, -ĕt‡). [Eng., Fr.] Syn. ACHA′TES (-kā′-tēz), L. A semi-pellucid uncrystallised species of quartz, remarkable for its hardness, variety of colour, and susceptibility of receiving a high polish. It is an aggregate of various siliceous minerals, of which chalcedony appears generally to be the base. Carnelian, jasper, amethyst, and other similar minerals, often enter into its composition. The colours are often delicately arranged in stripes, bands, or clouds. Those which take an angular form, as the Scotch pebble, are called FORTIFICATION AGATES. It is the least valuable of the precious stones, and is chiefly made into rings, seals, beads, burnishers, &c., on account of its hardness. Its powder is used for cleansing and polishing iron, brass, &c., and to sharpen edge-tools.

=AGEING LIQUOR.= Dissolve 3 lbs. of chlorate of potash in 4 galls. of boiling water. Add 20 lbs. of powdered white arsenic to 20 lbs. of solution of caustic soda at 60° Tw., and boil until the arsenic is completely dissolved. Add the latter solution to the former, with stirring, until the mixture stands at 28° Tw.

=AG′NAIL.= See WHITLOW.

=AGRYPNOT′ICS= (-grĭp-). Syn. ANTHYPNOT′ICS (-hĭp-); AGRYPNOT′ICA, ANTHYPNOT′ICA, L. In medicine and pharmacology, agents or substances which prevent sleep; as tea, coffee, digitalis, vinegar, &c.

=A′GUE= (-gŭ). Ague may be defined as febrile phenomena occurring in paroxysms, and observing a certain regular succession, characterised by chill, abnormal heat, and unnatural cutaneous discharge, which prove to be a temporary crisis and usher in a remission. These phenomena are developed in an uninterrupted series or succession more or less regular, which pass into each other by insensible stages. Ague is paludal fever, and has always been observed to prevail in marshy moist districts, and in low, swampy humid countries, in which seasons of considerable heat occur.

The neighbourhood of marshes, or of a district which has been at some recent time under water; the banks of extensive lakes, and the shores of rivers and seas where the water flows sluggishly, and in some places stagnates; shallow rivers; extensive level tracts of forest land, where moisture is always present; and the surface of the land constantly covered with excavation from the ground,——these are the terrestrial physical conditions, in which marsh and littoral fevers are almost universally to be found, although it must be admitted that there are some marshy districts in which the disease does not show itself.

In these latter localities the effects of the miasmatic poison, show themselves in cholera or typhus. No precise knowledge of the nature and source of this subtle poison which, in default of a better name we call malaria, has yet been acquired; indeed it has yet to be proved that malaria has a distinct existence. Science has as yet been unable to discover the presence of any poisonous principle in the air of ague on other regions.

Ague may exist without any alteration of structure being set up; but in the milder forms of this fever a greater number of organs and tissues are morbidly altered than perhaps in any other form of disease. The parts so affected are the liver, spleen, lungs, heart, brain, and the serous and mucous membranes of the body generally. Within certain limits, the specific action of the malarial poison may be said to be in the inverse ratio of the intensity of the fever which attends its action. The affections of the liver and spleen also vary greatly according to the locality in which the patient is attacked; for instance, whilst in some parts of India the spleen is the organ principally involved, in other districts of the same continent it is the liver. In England, under proper medical treatment, the patient usually recovers without any manifest derangement either of structure or impairment of function of any organ or tissue. The liver may, however, become affected if the patient suffering from the disease has been neglected for any length of time.

Notwithstanding the opinions of Finke and Professor Colin, there appears to be considerable ground for the supposition that ague may be caused by drinking marsh and surface water. In an interesting paper on the ‘Indian Annals’ for 1856, Mr Bettington, of the Madras Civil Service, says:——“It is notorious that the water produces fever and affections of the spleen.” In confirmation of this assertion, he brings forward what seems to be some remarkably strong evidence. He cites cases of villages placed under the same conditions as to marsh-air in some of which fevers were prevalent, whilst in others they were absent; and he found on inquiry that whilst the latter villages were supplied with pure water, the inhabitants of the former had to drink marsh or mullah water, full of vegetable débris. In one village there were two sources of supply——a spring and a tank, the first fed by surface, and the other by marsh water. Those only who partook of the tank water were attacked by fever. Again, in Tulliwaree the fever was so universal that scarcely any inhabitant escaped it. In this village Mr Bettington caused a well to be dug, and the result was that the fever disappeared. Similar cases have occurred in this country. Twenty years ago Mr Blower, of Bedford, directed the attention of medical men to a case that occurred in a village, in which ague had nearly disappeared when a well was dug; and to another instance which occurred in the village of Houghton. In this parish almost the only family which escaped ague was that of a farmer; the members of this family partook of well water; whilst those who did not escape the disease drank ditch water.

In the ‘Indian Annals’ for 1867 is a paper by Dr Moore, confirming the opinion that ague may be produced by the causes already stated, and M. Commaille (‘Rec. de Mêm. de Med. Mil.,’ Nov., 1868) states that in Marseilles, paroxysmal fevers, formerly unknown, have made their appearance, since the water supply to that city has been drawn from the Marseilles Canal.

In his report for 1870 Dr Townsend, the Sanitary Commissioner for the central provinces of India, states that the natives of India hold an opinion that the use of river and tank water during rainy seasons (when the water always contains an increased quantity of vegetable matter) will almost always cause ague. Boudin (‘Traité de Géographie et de Statistiques Médicale,’ 1857, t. i, p. 142), records an extraordinary case. Eight hundred soldiers, in good health, embarked in three vessels to pass from Bona, in Algiers, to Marseilles, in the year 1834. They all arrived at Marseilles the same day. In two vessels there were 680 men, without a single sick one amongst them. In the third vessel, the Argo, there had been 120 soldiers; 13 died during the short passage, and of the 107 survivors no less than 98 were disembarked suffering from all forms of paludal fevers. We may presume that the diagnosis was correct, since Boudin himself examined the men. When the vessels started the crew of the Argo had not a single sick man aboard. The crew and soldiers of all the boats were exposed to the same atmospheric conditions. The influence of air must, therefore, be excluded. There is no mention of food, but it has never been suggested that food has ever been concerned in the production of malarious fever. It was a very different matter, however, with the water supply. In two of the vessels the water was good, whilst the Argo had been supplied with marsh water, which was offensive to the smell, as well as unpalatable. This latter was supplied to the soldiers, whilst the crew drank uncontaminated water. Amongst those who deny that marsh water is the cause of ague must be quoted Professor Colin. The professor, who is regarded as an authority on intermittent fever, in his work De l’Ingestion des Eaux Marécageuse comme cause de la Dysenterie et des Fièvres intermittentes,’ instances numerous cases in Algiers and Italy in which impure marsh water gives rise to indigestion, diarrhœa, and dysentery, but in no case to intermittent fever; and he states that in all his observations he has never met with an instance of ague having such an origin. Without contesting the case of the Argo, he views it with considerable suspicion, and doubts whether Boudin is correct in his details. Finke also states that, in Hungary and Holland, marsh-water is daily drank without causing any ill-effects. The inhalation of the fumes of oxide of zinc appears to produce in workers of this metal a variety of ague termed by Shackrah “brass ague,” and by Dr Greenhow, “brass-founder’s ague.” The symptoms of the malady are tightness and oppression of the chest; with indefinite nervous sensations, followed by shivering, an indistinct hot stage, and profuse perspiration. These attacks, however, are not periodical.

It is open to doubt whether the malarious poison exists in the form of a gas, for the observations of microscopists go to show the extreme minuteness of the germs of disease, which are probably not more than 1/70000th of an inch in size, and it is regarded as probable that the real cause of ague is the entry into the circulation of some low forms of spores of fungi, or of some minute animalcules. Ague is always to be met with in places where fungi grow, and is always associated with what Pettenkofer calls “the ground air”——that is, the air contained in the interstices of the soil, no inconsiderable volume of which is drawn into every house which has a fire on the floor which rests on the earth. That animalcules (?) may exist in the blood is evidenced by the discovery of Dr Lewis, who found hair-like worms in the circulation; and whilst considering this point, we must bear in mind that the remedial agents employed to check ague, quinine, arsenic, &c., are drugs capable of destroying animal life, and it is not impossible that they may exercise a beneficial effect in destroying the spores or animalcules to which the disease may be due.

The best means to be employed to combat malarial fevers in any district are thorough and efficient drainage (and it must be remembered that drainage purifies both the ground-air and the ground water) and a supply of wholesome water free from decomposing vegetable matter.

That the adoption of the above means cannot fail to succeed is incontestably proved by the fact, that during the last 200 years, ague in England has diminished to a wonderful extent, in short, as good drainage and a pure water supply have prevailed, there has been a proportionate diminution of paludal poisoning.

During the protectorate of Cromwell great mortality prevailed in London, from the ravages of ague; at that time London was as swampy as the fens of Lincolnshire. See FEVER (Intermittent).

=Ague-cake.= The popular name of a tumour felt under the false ribs on the left side, formed by enlargement and induration of the spleen, following protracted ague; also, sometimes, of indurations of the liver following ague.

=Ague-drop.= See DROPS.

=Ague-salt= (sŏlt). Disulphate of quinine.

=Ague-tree.= Sassafras.

=Ague-weed.= The herb thorough-wort (‘Eupato′′rium perfolia′tum,’ Linn.).

=AIG′REMORE= (ĕg′r-mor). [Fr.] Pulverised charcoal in the state it is used to make gunpowder.

=AIGUILLETTE= (ATTELETTE). [Fr.] In cookery, a term applied to several small dishes, from the articles of which they consist being mounted on silver needles, or skewers, with ornamental handles or tops. (See engr.) They form one of the varieties of the ‘hors-d’œuvres’ of Soyer; and are commonly served on a napkin. The skewers should be about four inches long, and of the thickness of an ordinary packing needle. The person eating what is served on them takes the head of the skewer between the thumb and fingers of the left hand, and picks it off with his fork. Those noticed by Soyer are——

=Aiguillettes à l’Éperlan= (smelts);

=Aiguillettes aux Huitres= (oysters);

=Aiguillettes de Filets de Sole= (soles);

=Aiguillettes de Homard= (lobsters);

=Aiguillettes de Langue de Bœuf= (ox-tongue);

=Aiguillettes de Ris de Veau= (sweetbread of veal);

=Aiguillettes de Volaille à la Jolie Fille= (fowl);——

all of which are prepared in a nearly similar manner, merely varying the sauces, &c., to suit the article and palate. See ATTELETTES, HORS-D’ŒUVRES, &c.

=AHORNZUCKER= (genuine American maple sugar). For coughs, hoarseness, and all affections of the throat and chest caused by cold. The raw maple sugar as imported. (Hager.)

=AILANTHUS.= The inner bark of the ailanthus glandulosa, a common tree growing in northern China, said by Dr Dudgeon to have proved very successful in dysentery.

The ailanthus glandulosa is also well known throughout the United States. Professor Hétet, of Toulon, tried the effect of the powdered bark, leaves, and various preparations of the bark or drugs, with the result of their administration being attended with purgative effect——and the discharge of worms.

The powdered bark has been given in small cases of tape-worm in the human subject, with marked success. The dose of the powder found sufficient for the expulsion of the tapeworm was from seven or eight to thirty grains.

=AIL′MENT.= Pain, indisposition; disease. Its use is generally restricted to the non-acute, and milder forms of disease.

=AIR.= [Eng., Fr.] Syn. Aer, L. (from αηρ Gr.); LUFT, Ger.; ATMOSPHERIC AIR; THE ATMOSPHERE. This name was formerly given to any aëriform body; thus, by the old chemists ammoniacal gas was called alkaline air; oxygen,——dephlogisticated, vital, or empyreal air; carbonic anhydride (carbonic acid), fixed air; hydrogen, inflammable air; heavy carbonetted hydrogen, olefiant gas, heavy inflammable air; nitrogen,——mephitic, phlogisticated, or nitrous air. At the present time the term air is usually restricted to the gaseous envelope surrounding the solid and liquid parts of our globe.

=Air, Atmospheric= (or simply, The Air). The air chiefly consists of a mechanical mixture of four volumes of nitrogen and one volume of oxygen, or more accurately——

By volume. By weight. Nitrogen 79·1 76·8 Oxygen 20·9 23·2 ————— ————— 100 100[12]

[Footnote 12: At a meeting of the Paris Academy of Sciences, held on the 31st of December, 1877, it was announced that M. Cailletet had succeeded in liquefying atmospheric air.]

We may premise our description of the functions of the constituents of the atmosphere by the following quotation from Mr Blyth’s ‘Dictionary of Hygiène and Public Health’:——“One of the most important properties of air is its power of penetration and its universality. Air is, indeed, present everywhere; there is scarcely a solid, however compact it may appear to be, which does not contain pores, and these pores filled with air. The soil contains no small quantity; indeed, if it were not so the numberless insects, worms, &c., which burrow in its interstices would cease to exist. The most compact mortar and walls are penetrated with it, and water of natural origin contains a large quantity of air in solution. The atmosphere is supposed to extend to a very great height, from 200 to 300 miles; it used to be considered only five (forty-five) miles high, but observations on shooting stars, &c., show that this opinion is erroneous. Owing to the force of gravity, the air is much denser near the earth, and gets more attenuated layer by layer as you ascend. If, then, the atmosphere were possessed of colour, it would be very dark just round the globe, and the tint would gradually fade into space. The air is by no means wholly gaseous; it contains, indeed, an immense amount of life, and small particles derived from the whole creation. In the air may be found animalcules, spores, seeds, pollen cells of all kind, vibriones, elements of contagion, eggs of insects, &c., and a few fungi, besides formless dust, sandy, and other particles of local origin; for example, no one can ride in a railway carriage without being accompanied with dust, a great portion of which is attracted by a magnet, and is, indeed, minute particles of iron derived from the rails. The purest air has some dust in it. There probably never fell a beam of light from the sun since the world was made which did not show, were there eyes to see it, myriads of motes; these, however, generally speaking, are quite innocuous to man——some, indeed, may possibly be beneficial. Another most important property of air is its mobility; on the calmest day and in the quietest room there are constant currents of air which rapidly dilute any noxious odours of gases.”

The chief functions of the oxygen are to maintain respiration and support combustion, while the office of the nitrogen is to dilute the oxygen and control its energy.

Besides nitrogen and oxygen, aqueous vapour, carbonic anhydride, ammonia, and nitric acid are met with in the atmosphere, the last especially during and shortly after thunder storms.

Although, doubtless owing to local conditions, trifling variations may occur in the proportion of oxygen present in the atmosphere, this variation is so trifling that the difference of the amount in air from places separated by very long distances will be found in the second decimal place only; thus, whilst a portion of air taken during a balloon ascent by Mr Green gave on analysis 20·88 per cent. by vol., Dr Frankland found in air collected by himself on the summit of Mont Blanc 20·96 per cent. by vol. A still nearer approximation in uniformity in the amount of oxygen present in atmospheric air is exhibited in the following table, which gives the results of 95 analyses by Regnault on air obtained from nine different localities:——

100 from Paris gave in 100 parts, by vol. of oxygen 20·913 to 20·999 9 from Lyons and around gave in 100 parts, by vol. of oxygen 20·918 to 20·966 30 from Berlin gave in 100 parts, by vol. of oxygen 20·908 to 20·998 10 from Madrid gave in 100 parts, by vol. of oxygen 20·916 to 20·982 23 from Geneva and Switzerland gave in 100 parts, by vol. of oxygen 20·909 to 20·993 15 from Toulon and Mediterranean gave in 100 parts, by vol. of oxygen 20·912 to 20·982 5 from Atlantic Ocean gave in 100 parts, by vol. of oxygen 20·918 to 20·965 1 from Ecuador gave in 100 parts, by vol. of oxygen 20·960 2 from Pichincha gave in 100 parts, by vol. of oxygen 20·949 to 20·981 ------ ------ Mean of all foregoing 20·949 20·988 ” of the Paris specimens 20·96

Vapour of water is essential to the respiration of animals and plants, in order that the organs concerned in this operation may be kept in a soft and moist condition.

Carbonic anhydride is evolved during combustion, putrefaction, and fermentation; it is also a product of the respiration of animals, and highly poisonous to them, even when diluted with large proportions of air. This gas is, however, greedily absorbed by plants, which decompose it; they assimilate the carbon and return the oxygen to the atmosphere, ready to be again consumed in supporting the life of the animal world.

Dr Angus Smith has defined a very pure air to be one that contains with 20·99 per cent. of oxygen 0·30 of carbonic acid (anhydride).

This latter varies in amount in the atmosphere of cities, as will be seen upon inspection of the subjoined table, extracted from Dr Smith’s work ‘Air and Rain’:——

Per cent. Air of Madrid, outside the walls, mean of 12 analyses, by Luna ·045 Mean of 12 analyses, within the walls of Madrid, by Luna ·051 Mean of 14 analyses, by Angus Smith, in Manchester suburbs ·369 In Manchester streets ·403 Usual weather ·0403 During fogs ·0679

De Saussure’s analyses show that there is more carbonic acid on the mountains than in the plains, as might be inferred from the comparative absence of vegetation in elevated positions. Dr Pietra Santa states that the air of hills or mountains, at the height of 2300 feet, is lighter than common air, contains a smaller proportion of oxygen, and is impregnated with a largely increased amount of aqueous vapour. It also contains a large quantity of ozone. He considers such a climate peculiarly soothing to persons suffering from chest diseases.

Dr Angus Smith’s analysis of the air from the mountainous districts of Scotland confirms the above statement of Dr Pietra Santa’s. The heaths and mountains of that country are remarkably healthy localities, and the air from them gave on analysis 20·94 per cent. by vol. of oxygen, and only ·033 of carbonic acid.

Ammonia is derived from the putrefaction of animal and vegetable substances. It is from atmospheric ammoniacal compounds that plants obtain much of the nitrogen which is essential to the formation of many parts of their structure.

Nitric acid, like ammonia, is absorbed, and its nitrogen assimilated, by plants.

In addition to the gases and vapours already enumerated, as well as others which exist in minute quantity, or which are of only occasional occurrence, Pasteur and other investigators have discovered in the air living germs which are capable of exciting putrefaction and fermentation, and which are competent, in some instances, to engender disease when they are injected into the blood of animals. In fact, the spread of infectious diseases, e.g., smallpox, typhus fever, cattle plague, &c., is attributed to the presence in the atmosphere of the germs of such maladies. These germs are believed to be living beings, which develope and multiply at the expense of the tissues of the larger animals into whose systems they have found entrance.

=Air, Vitiated.= As has been stated in the previous article, the air consists chiefly of two gases, oxygen and nitrogen. In all open places it has a similar composition, as might be concluded from the constant mingling which takes place by the agency of currents continually in movement, although sometimes to an inconsiderable extent only. Dr Angus Smith regards air as very pure when it contains not less than 20·99 per cent. by volume of oxygen, and 0·030 of carbonic anhydride (acid). According as the proportion of the former gas diminishes and that of the latter increases beyond certain limits in the air by which we are surrounded, it becomes more or less deteriorated and unfit to be breathed, particularly as the increased amount of carbonic acid is, in crowded dwellings, assembly rooms, theatres, and confined inhabited spaces, associated with deleterious and putrescent exhalations from the person.

The following tables exhibit the amount of carbonic acid in close places in London.

Per-centage =I.= by volume. Chancery Court, closed doors, 7 feet from the ground, March 3 ·193 Same, 3 feet from ground ·203 Chancery Court, doors wide open, 4 feet from ground, 11·40, March 5 ·0507 Same, 12·40 p.m., 5 feet from ground ·045 Strand Theatre, gallery, 10 p.m. ·101 Surrey Theatre, boxes, March 7, 10·30 p.m. ·218 Olympic, 11·30 p.m. ·0817 Same, 11·55 p.m. ·1014 Victoria Theatre, boxes, March 24, 10 p.m. ·126 Haymarket Theatre, dress circle, March 18, 11·30 p.m. ·0757 Queen’s Ward, St. Thomas’s Hospital, 3·25 p.m. ·052 Edward’s Ward, St. Thomas’s Hospital, 3·30 p.m. ·052 Victoria Theatre, boxes, April 4. ·076 Effingham, 10·30 p.m., April 9, Whitechapel ·126 Pavilion, 10·11 p.m., April 9, Whitechapel ·152 City of London Theatre, pit, 11·15 p.m., April 16 ·252 Standard Theatre, pit, 11 p.m., April 16 ·320

Dr Angus Smith states that out of 339 specimens of air obtained from various mines he found 35 normal or nearly so, 81 decidedly impure, and 212 exceedingly bad; he also adds that owing to the frequent firing of charges of gunpowder within the mines, and from other causes, the atmosphere is further contaminated with sulphuretted hydrogen, sulphate, carbonate, sulphide, sulphocyanide of potassium, and nitrate of potassium, carbon, sulphur, carbonate of ammonia, organic matter, sand, and sulphurous and arsenious acids.

The air of large cities, which are the seats of manufacturing industry, is always more or less charged with the exhalations given off by chemical and other works. The sulphuric-acid works contribute sulphuric, sulphurous, nitrous, and arsenious acids; copper works, in which pyrites is employed, give off large quantities of sulphurous acid, mixed with arsenic and a little copper; manure works, in many cases, send out compounds of fluorine, besides sulphuric acid; glass works, sulphuric and hydrochloric acids; and alkali works, hydrochloric acid (although in small quantities), which very frequently contains arsenic. Of ammonia, Angus Smith remarks: “It is one measure of the ‘sewage’ of the air; it is the result of decomposition. It is not, in these small quantities, hurtful, so far as we know. The ammonia is in no case free, but combined probably with hydrosulphuric, hydrochloric, and sulphuric acid in towns. In country places it is, at all events partly, united to carbonic acid.

II. _London Air.——Carbonic Acid, Metropolitan Railway, November, 1869._

+--------+----------------------------+------------+---------+---------+ | | | |Carbonic | Oxygen, | | Date. | Place. |Time of Day.| Acid, |per cent.| | | | |per cent.| | +--------+----------------------------+------------+---------+---------+ | 1869. |Tunnel between Gower Street | | | | |Nov. 12.|and King’s Cross Stations; | 10 a.m. | ·150 | 20·60 | | |specimen taken at the open | | | | | |window, first-class | | | | | |carriage. | | | | | | | | | | | ” 12.|Tunnel between Gower Street | | | | | |and King’s Cross Stations; | 7·30 p.m. | ·078 | 20·79 | | |specimen taken at the open | | | | | |window, first-class | | | | | |carriage. | | | | | | | | | | | ” 12.|Tunnel Praed Street; | | | | | |specimen taken at the open | 10·30 a.m. | ... | 20·71 | | |window, first-class | | | | | |carriage. | | | | | | | | | | | ” 15.|Specimen taken during | | | | | |journey between Gower Street| 10·15 a.m. | ·338 | 20·66 | | |and King’s Cross, | | | | | |first-class carriage, window| | | | | |open. | | | | | | | | | | | ” 15.|Same | 3 p.m. | ·155 | 20·70 | | | | | | | | ” 15.|Same | 11 p.m. | ·150 | 20·74 | | | | | | | +--------+----------------------------+------------+---------+---------+ | |Average | | ·1452 | 20·70 | +--------+----------------------------+------------+---------+---------+ ANGUS SMITH.

The Air of Mines (Metalliferous).

+-------------+---------------------+-------+-------+-------+--------+ |Name of Mine,|Description of place,|Thermo-|Number |Oxygen,|Carbonic| |and depth |where taken and time |meter, |of Men | per | Acid, | |from surface,|when taken. |Fahr. |working| cent. | per | |in fathoms. | | |in it. | | cent. | +-------------+---------------------+-------+-------+-------+--------+ | | | | | | | | Hurst |End, 300 ft. beyond | ... | 2 | ... | 1·99 | | |a rise, 9 ft. high, | | | | | | |7 ft. wide. | | | | | | | | | | | | | Old Gang |End of level | ... | 2 | 20·58 | ·48 | | | | | | | | | ” |End of level | ... | 2 | ... | ·28 | | | | | | | | | ” |(a) Rise 7 ft. | ... | 2 | 20·25 | ·39 | | |high, 132 ft. from | | | | | | |current. | | | | | | | | | | | | | Grassington |(b) End of cross | ... | 2 | 20·94 | ·06 | | |cut, 480 ft. from | | | | | | |rise. | | | | | | | | | | | | | ” |End, 480 ft. from | ... | 2 | 19·53 | 1·59 | | |rise. | | | | | | | | | | | | | ” |Rise 60 ft. high in | ... | 2 | 19·52 | 1·72 | | |shale. | | | | | | | | | | | | | ” |End, 60 ft. from | ... | 2 | 20·47 | 1·06 | | |rise. | | | | | | | | | | | | | ” |(c)End, 840 ft. | ... | 2 | 20·08 | ·94 | | |from rise. | | | | | +-------------+---------------------+-------+-------+-------+--------+ (a) Air machine. (b) Unusual amount of dust. (c) Crystals were chiefly hexagons. ANGUS SMITH.

The following table, showing the amount of ammonia present in rain collected at the different places named, is from Dr Smith’s work, ‘Air and Rain.’

COMPARATIVE. AMMONIA.

That of Valentia (Ireland) taken as 1 or 100.

Ireland, Valentia ·1 Scotland, sea-coast, country places, west 2·69 Scotland, inland, country places, west 2·96 Scotland, sea-coast, country places, average 4·10 Scotland, sea-coast, country places, east 5·51 England, inland, country places, east 5·94 England, sea-coast, country places, west 10·55 German specimens 10·61 London, 1869 19·17 Scotland, towns (Glasgow not included) 21·22 St. Helen’s 25·33 Runcorn 25·72 England, towns 28·67 Liverpool 29·89 Manchester, 1869 35·33 Manchester, 1869 and 1870, average 35·94 Manchester, 1870 36·54 Glasgow 50·55

The effects resulting from breathing an impure atmosphere are necessarily dependent upon the extent of the pollution and other conditions. When the contamination is moderate the first effect is headache, accompanied with lassitude, and a general paleness of the face and skin, owing to a diminution of the red corpuscles of the blood or to their imperfect aëration; the pulse becomes lowered, and at the same time the breathing is accelerated. When in addition to breathing such air from day to day is superadded the misfortune of an insufficiency of food, scrofula and consumption very often follow. Dr Guy has demonstrated the great mortality that is caused by consumption in those trades in which workmen pursue their calling in hot, close, gas-lit rooms, in comparison with those who pass most of their time in the open air. The amount of air required by each person in a room is no less than 2100 feet per hour; when the ventilation does not supply this amount of fresh air, the apartment smells stuffy, the furniture becomes coated with a film of organic matter, unless constantly cleaned, and the carbonic acid becomes increased beyond its normal quantity.

Dr Parkes has shown that bronchitis and consumption are more frequently than not contracted by those who live in an atmosphere of foul air. In the years 1834 to 1847 the proportion of deaths in the ill-ventilated prison of Leopoldstadt in Vienna was 86 per 1000, out of which number 51·4 per 1000 was due to phthisis or consumption; while in the well-ventilated House of Correction in the same city the deaths were 14 per 1000, of which 7·9 were from phthisis; hence 43·5 cases per 1000 of the deaths were clearly traceable to foul air and nothing else.

Mr Noel Hartley, in his valuable little manual, ‘Water, Air, and Disinfectants,’ says: “During the outbreak of cattle plague in 1866, in sheds containing twenty to thirty cows——which the owners kept closed to such an extent that all chinks in the doors and windows were stuffed with straw and matting, under an ignorant belief that thus the plague could be kept out——very frequently the entire stock died in two or three days after the first appearance of disease; while in other cases where animals were housed in a well-cleaned and tidily-kept shed, with a plentiful supply of fresh air, not only did some of them escape the disease altogether, but the deaths were reduced to one third of the number of beasts attacked.”

The large supply of fresh air necessary in hospitals for contagious diseases is fully recognised by medical men, and more especially so in America. Wounds carefully protected from contact with impure air do not suppurate, and organic fluids do not putrefy. On the other hand, in a bad atmosphere sores become unhealthy, and are difficult to heal, erysipelas and hospital gangrene frequently set in, while the best prevention and the best means of cure for such afflictions is the greatest possible exposure to fresh air.

Vitiated air, as a consequence of over-crowding, aids the spread of measles, scarlet fever, and the much to be dreaded smallpox; it brings on ophthalmia, a troublesome inflammation of the eyes, and is not unfrequently the cause of the ricketty and scrofulous condition of children. Although exposure to cold does cause such affections as bronchitis, pneumonia, cold in the head, sore throat, and other affections of the respiratory organs, it is more frequently the case that they are the result of a sudden change of temperature, such as experienced in coming out of a crowded assembly in a close, badly-ventilated building, than by actually cold weather. This is decidedly and strikingly shown by the fact which Dr de Chaumont has quoted, that the British Army when in the Crimea, when lodged in tents during extremely rigorous weather, experienced a wonderful condition of health, such a thing as a cold being an unknown complaint; but when some of the men were placed in huts which were much warmer, and into which there was a smaller circulation of fresh air, the sick rate increased, and coughs and colds began to put in an appearance. Persons who during summer and winter sleep with their windows more or less open cannot endure a night spent in the chamber with the chimney closed and the window shut. A less refreshing sleep occupies the night, and a somewhat feverish sensation is felt next morning.

If in cold weather the window be opened only one inch at the top, the difference in the air in the bedroom is something quite beyond comprehension to those who have not paid attention to these things. See VENTILATION.

=Air, Analysis of.= Priestley’s discovery of oxygen gas in 1774 prepared the way for the knowledge of the real composition of air, which was discovered about the same time by Scheele and Lavoisier. Scheele’s method of operating was by exposing some atmospheric air to a solution of sulphide of potassium. Lavoisier effected the same object by the combustion of iron wire and phosphorus, and subsequently by heating mercury on a flask filled with air for some time, just below its boiling point.

These, however, were but elementary methods, which, however creditable to the ingenuity of the great founders of modern chemistry, not only failed in accuracy, but took no account of the presence and amount of two most important constituents in the atmosphere, viz. carbonic anhydride (acid) and ammonia.

Determination of Aqueous Vapour. To effect this an aspirator must be used (see ASPIRATOR). This instrument is easily made, and is not expensive. The accompanying figure will illustrate the arrangement generally adopted: a is an aspirator made of galvanised iron or sheet zinc. It holds from 50 to 200 litres (from 11 to 44 gallons). By this means a known volume of air is drawn through the tubes marked b, c, d, e, which may be filled with pumice-stone moistened with strong sulphuric acid; but if the carbonic acid is to be estimated as well, b and c are filled with moist hydrate of lime (potash used to be employed, but hydrate of lime is to be preferred, as the potash absorbs oxygen), and d and e as above. Each of the tubes is accurately weighed previously to connecting them with the apparatus.

It is imperative to have each of the tubes connected by perfectly air-tight joints. The gain of weight in d and e gives the water in b and c the carbonic acid.

Determination of Carbonic Acid. A better and perhaps more exact means of determining the carbonic acid is that invented by PETTENKOFER. It may be briefly described as follows:——Baryta water of definite strength is prepared and accurately standardised by a standard solution of oxalic acid. A portion of this baryta water is then made to act upon a definite quantity of air. It will absorb the whole of the carbonic acid in that air.

The alkalinity of the liquid will in consequence be diminished; it will take less of the oxalic-acid solution than before, which shows so much less caustic baryta, and from which the carbonic acid absorbed may be easily calculated.

The actual Analysis. Two kinds of baryta water may be used, the one containing 7 grammes to the litre, the other three times that strength; 1 c. c. of the stronger = 3 m. grms. of carbonic acid; 1 c. c. of the weaker = 1 m. grm. The baryta water is best kept in the bottle represented below.

The bottle (a) contains the baryta water. It has an accurately-fitting double-perforated stoppered caoutchouc. The left-hand tube is connected with the tube (b) containing pumice-stone moistened with potash, while the right-hand one is a syphon. When required for use the stop-cock (f) is opened, and suction applied by a glass tube to F. The syphon is thus filled and the stop-cock closed. If a pipette is required to be filled its nozzle is inserted at F, the stop-cock compressed, and the fluid immediately rises into the pipette.

The air entering the bottle as the fluid decreases in a is, of course, thoroughly deprived of its carbonic acid by the tubes at b.

The first thing to be done is to standardise the baryta solution by a solution of oxalic acid, containing 2·8636 grammes of crystallised oxalic acid to the litre.

Thirty c. c. of baryta solution are run into a small flask, and the oxalic acid run in from a Mohr’s burette with float, the vanishing-point of the alkaline reaction being ascertained by delicate turmeric paper. As soon as a drop placed on turmeric paper does not give a brown ring the end is attained.

The actual analysis is performed by filling a bottle of known capacity, with the aid of a pair of bellows, with the air to be analysed, then distributing over its sides 45 c. c. of the baryta water it is left for half an hour. The turbid water is poured into a cylinder, closely secured, and allowed to deposit; then take out 30 c. c. by a pipette of the clear fluid, run in the solution of oxalic acid, multiply the volume used by 1·5, and deduct the produce from the c. c. of oxalic acid used for 45 c. c. of the fresh baryta water. A different method has been suggested by Dr Angus Smith, viz. to measure the carbonic anhydride by the turbidities of the baryta water; this is, in fact, a colorimetric test. For rough approximative results Dr Smith’s process will be found a very useful and convenient one. It depends upon the fact that the amount of carbonic acid in a given quantity of air will not produce a precipitate in a given quantity of lime or baryta water unless the carbonic acid is in excess. The following is one of his tables:——Columns 1 and 2 give the rates of carbonic acid in the quantity of air which will produce no precipitate in half an ounce of lime water. Column 3 is the same as column 2; but 14·16 c. c. (half an ounce) is added to give the corresponding size of the bottle, and column 4 gives the size of the bottle in ounces.

To be used when the point of observation is “no precipitate.” Half an ounce of baryta water contains about ·08 gramme of baryta.

Air at 0° C. and 760 millims. Bar.

Carbonic Acid Volume of Size of bottle Size of bottle in the Air, Air in cubic in cubic in ounces per cent. centimètres. centimètres. Avoirdupois.

·03 185 199 7·06 ·04 139 154 5·42 ·05 111 125 4·44 ·06 93 107 3·78 ·07 79 93 3·31 ·08 70 84 2·96 ·09 62 76 2·69 ·10 56 70 2·46 ·11 51 65 2·29 ·12 46 60 2·14 ·13 43 57 2·01 ·14 40 54 1·90 ·15 37 51 1·81 ·20 28 42 1·48 ·25 22 36 1·29 ·30 19 33 1·16 ·40 14 28 1·04 ·50 11 25 ·89 ·60 9 23 ·89 ·70 8 22 ·78 ·80 6 20 ·72 1·00 5·5 19·7 ·70

Mr Wanklyn’s process for the determination of carbonic acid in the atmosphere is as follows:——A solution of carbonate of soda is first made as follows: 4·47 grammes of gently-ignited carbonate of soda are dissolved in one litre of water, giving a solution of such a strength that 1 c. c. contains exactly 1 c. c. of carbonic acid (= 1·97 milligrammes of CO_{2}); a large quantity of baryta water (strength about 0·1 per cent.) is prepared.

If now 100 c. c. of clear baryta water be treated with 1 c. c. of carbonate of soda, just described, a certain degree of turbidity is produced.

If 2 c. c. of the solution be taken another degree of turbidity is produced, and so on. If, then, a bottle capable of holding 2000 c. c. of air, together with 100 c. c. of baryta water, be filled with the sample of air to be tested, there will be a certain depth of turbidity produced by shaking it up. Having got the air to expend itself on 100 c. c. of baryta water the degree is to be found by comparison with another 100 c. c. of baryta water, in which a like turbidity has been induced by means of the standard solution of carbonate.

Every c. c. of soda solution counts for a c. c. of carbonic acid in two litres of air. A consumption of 1 c. c. will correspond to ·05 volumes of carbonic acid per cent. Good air should accordingly not take more than 1 c. c. of soda solution, air which takes already 2 c. c. being already bad.

In order practically to carry out this method of estimating carbonic acid the following apparatus is required:——Several bottles capable of holding 2·210 c. c., and well stoppered (failing bottles of exactly the right capacity Winchester quart bottles will answer); a small pair of bellows; several colourless glass cylinders marked at 100 c. c. capacity——the Nesslerising cylinders will answer for this purpose——a graduated pipette or burette to deliver tenths of a c. c. of solution, the standard solution of carbonate of soda, and the baryta water, which may be of moderate strength.

The testing is managed thus: Winchester quart bottles having been made clean are rinsed with distilled water, and allowed to drain a little. They are then closed with their stoppers, and are ready for use. The operator having provided himself with two or three of these bottles and a small pair of bellows enters the room the air of which is to be tested. The stopper is then removed from one of the bottles, and some air of the room blown through with the bellows, and then the stopper is replaced, and the bottle carried away to be tested.

The testing is done by pouring into the bottle 100 c. c. of clear baryta water, shaking up for two or three minutes, and then pouring out into a cylinder of colourless glass, and observing the depth of the turbidity in various lights and against various backgrounds. The turbidity is to be exactly imitated by means of the standard solution of carbonate of soda. In order to imitate the turbidity produced by a Winchester quart full of good air only 1 c. c. of this solution of carbonate of soda is required.

If 2 c. c. or more than 2 are required, the air is bad and the ventilation is defective.

In place of the first c. c. of solution of carbonate of soda the carbonic acid naturally present in a Winchester quart of good average air may be used, and a little practice and intelligence will suggest the necessary precautions.

Estimation of the Oxygen.——To determine this Angus Smith has recourse to the endiometer. Five or six of Bunsen’s endiometers were used at once and the mixed gases were exploded by means of a powerful battery and a Ruhumkorff’s coil. In his ‘Inorganic Chemistry,’ Miller thus explains the principle upon which the action of the endiometer is based: “By means of the endiometer various gaseous mixtures may be analysed with great exactness. Many different forms of this instrument are in use. One of the most convenient is Hoffmann’s. It consists of a stout syphon tube. (See next figure.) Into the sides of the tube, near the sealed end, two platinum wires (a, b) are fixed for the purpose of transmitting an electric spark through the cavity of the tube. The sealed limb is accurately graduated to tenths of a c. c. or other suitable divisions. Suppose it be desired to ascertain the proportion of oxygen in atmospheric air. The instrument is first filled with mercury, after which a small quantity of air is introduced; the bulk of the air is accurately measured, taking care that the liquid metal stands at the same level in both tubes, which is easily effected by adding mercury, or by drawing off the mercury if needed, through the caoutchouc tube, which is fixed upon the small inlet tube just above the bend, and which is closed by means of a screw tap (c).

A quantity of pure hydrogen, about equal in bulk to the air, is next introduced, and the bulk of the mixture is then accurately measured. The open extremity of the tube is now closed with a cork, below which a column of atmospheric air is safely included. This portion of air acts as a spring, which gradually checks the explosive force, when the combination is effected by passing a spark across the tube by means of the platinum wires. The mixture is then exploded by the electric spark. The remaining gas now occupies a smaller volume, owing to the condensation of the steam which has been formed. Mercury is, therefore, again poured in the open limb until it stands at the same level in both tubes, and the volume of the gas is measured a third time. One third of the reduction of the bulk experienced by the gas will represent the entire volume of oxygen which the mixture contained. Liebig’s method is as follows. It is based upon the fact that an alkaline solution of pyrogallic acid absorbs oxygen:

1. A strong measuring tube holding 30 c. c., and divided into one fifth or one tenth c. c., is filled to two thirds with the air intended for analysis. The remaining part of the tube is filled with mercury, and the tube is inverted over that fluid in a tall cylinder widened at the top.

2. The volume of air confined is measured——a quantity of solution of potash of 1·4 sp. grf. (1 part of dry hydrate of potash to 2 parts of water), amounting from 1/40th to 1/50th of the volume of the air, is then introduced into the measuring tube by means of a pipette with the point bent upwards (see drawing), and spread over the entire inner surface of the tube by shaking the latter. When no further diminution of volume takes place the decrease is read off. The carbonic acid is thus removed.

3. A solution of pyrogallic acid containing 1 gramme of the acid in 5 or 6 c. c. of water is introduced into the same measuring tube by means of another pipette similar to the above. The mixed fluid (the pyrogallic acid and the solution of potash) is spread over the inner surface of the tube by shaking the latter, and when no further diminution of volume is observed the residuary nitrogen is measured.

4. The solution of pyrogallic acid mixing with the solution of potash of course dilutes it, causing thus an error from the diminution of its tension; but this error is so trifling that it has no appreciable influence upon the results. It may, moreover, be readily corrected by introducing into the tube, after the absorption of the oxygen, a small piece of hydrate of potash, corresponding to the amount of water in the solution of the pyrogallic acid.

There is another slight error on account of a portion of the fluid adhering to the inner surface of the tube, so that the volume of the gas is never read off with absolute accuracy.

In conducting these endiometric experiments the necessary corrections for temperature and barometric pressure must, of course, be made.

Estimation of the Nitrogen. The amount of this gas is usually determined by deducting the aqueous vapours, oxygen and carbonic acid, from the volume of air examined.

Determination of Ammonia and Organic Matter. These are best determined by drawing a known volume of air through absolutely pure water. To obtain this latter it is best to redistil distilled water, to reject the first portions, then to add an alkaline solution of permanganate of potash, and to discard any portions of the distillate which give the slightest reaction with the Nessler test. The water through which the air is drawn must be kept cool, and afterwards submitted to the proper tests, which will be found under AMMONIA and WATER ANALYSIS. Mr Blyth says, “Solid bodies such as vibrionic germs, dust, fungi, &c., may be obtained by using an aspirator, and drawing the air either through a drop of glycerine or water. Organic matter may also be obtained by suspending glass vessels filled with ice water, over or in the places to be investigated, and submitted to the microscope. High powers, such as immersion lenses, are requisite for the investigation of germs,” &c.

Of these germs Dr Angus Smith says:——“They may probably be divided into many kinds——the useful and the deleterious, those which promote health and those which bring disease. The idea of any of them bringing health is not founded on anything positive, but we can scarcely imagine these numberless forms to be all useless. The idea that they bring disease is, I think, one well confirmed.” See a paper by the same author “On the Air and Rain of Manchester.” ‘Memoirs of the Literary and Scientific Society of Manchester,’ vol. x. See AIR, VITIATED.

=AIR-GAS.= Air deprived of its carbonic acid and moisture, and then impregnated with the vapours of very volatile fluid hydrocarbons, such as benzine and benzoline, can be used as an illuminating agent. It is requisite, however, to use burners with wide openings, and to apply a low pressure, because if the current be too rapid the flame becomes too much cooled, and is readily extinguished. Apparatus for preparing air-gas have been devised and constructed by Marcus, Mille, Methei, and others.

=AIR-PUMP.= An instrument designed for the removal of air from closed vessels. The simplest form of air-pump is the exhausting syringe, which consists of a cylinder fitted with a stop-cock, and having a valve at the bottom opening inwards. Another valve opening outwards is attached to a piston working inside the cylinder, and by screwing the instrument on to a vessel, and alternately elevating and depressing the piston, all except a very small quantity of residual and comparatively inelastic air is pumped out of the vessel (Figs. a and b). The accompanying figures show relative positions of the valve during (a) the elevation, and (b) the depression of the piston. In the usual and more convenient form of air-pump, a brass tube passes from the bottom of the syringe and terminates in the centre of a disk of brass or glass ground accurately; the vessel from which the air is to be exhausted has its edge very accurately ground, and is mounted upon the plate as shown in the subjoined figure.

=Air-pump, Bunsen’s Water.= (See figure on page 53.)

This consists of a wide glass tube, a, into which another tube, b, b′, b′′, passes air-tight. c is an india-rubber tube connecting a with the water supply, d is a clamp to stop the flow of water through c. e is another clamp to regulate the flow, f is a reservoir to prevent any water which may accidentally come over from getting into j. g is a plug to let out any water from f. h is a screw for connecting a air-tight to a piece of tubing, which should pass 32 feet, if possible, below the level of a. i is a piece of strong india-rubber tubing to connect the pump with the vessel to be exhausted. The water rushes in at c and down h, carrying bubbles of air with it till the exhaustion is complete. The figure illustrates a common application of this pump to the rapid filtration of liquids which ordinarily pass through paper with difficulty. a is represented as being about half full of water. k is a funnel fixed air-tight in the india-rubber stopper of the bell-jar j. l is a small cone of platinum foil to prevent the paper filter which fits into it from being broken. m is a plate of ground glass, n is a beaker to receive the filtrate.

=Air-pump, Sprengel’s.= This apparatus depends on the principle of converting the space to be exhausted into a torricellian vacuum.

In the subjoined figure, c, d is a glass tube longer than a barometer, open at both ends, and connected by means of india-rubber tubing with a funnel, A, filled with mercury and supported by a stand. Mercury is allowed to fall in this tube at a rate regulated by a clamp at C; the lower end of the tube, c, d, fits in the flask B, which has a spout at the side a little higher than the lower end of c, d; the upper part has a branch at x to which a receiver R can be tightly fixed. When the clamp at C is opened, the first portions of mercury which run out close the tube and prevent air from entering below. As the mercury is allowed to run down the exhaustion begins, and the whole length of the tube from x to d is fitted with cylinders of air and mercury, having a downward motion. Air and mercury escape through the spout of the bulb B, which is above the basin H, where the mercury is collected. It is poured back from time to time into the funnel A, to be repassed through the tube until the exhaustion is complete.

=AIRY’S (Dr.) NATURE’S MEDICAL TREATMENT= is the title of a pamphlet which recommends four secret remedies against 166 diseases:

a. The Pain Expeller, a mixture of about 35 parts of tincture of capsicum, 20 parts of diluted spirit, and 20 parts of spirit of ammonia.

b. Sarsaparillian, a fluid extract of sarsaparilla and China root, containing 1 per cent. of iodide of potassium.

c. Pills composed of powdered iron, jalap resin, jalap powder, and marsh mallow powder, made into a mass with some bitter extract. Each pill weighs 0·1 gramme.

d. Calming Pastilles are thick, hard tablets, composed of sugar, with oil of anise, and coloured with liquorice juice. (Hager.)

=AKUSTICON= (an ear essence). A proved remedy for every kind of ear disease, by Pserhofer. This may be imitated by dissolving in common glycerine one fifth of its weight of fir tar, filtering, and adding a few drops of cajeput oil dissolved in spirit (Hager.)

=AL-.= [Ar.] An inseparable article equivalent to the English the. It is found in many chemical and other words derived from the Arabic; as alchemy, alcohol, alembic, almanac, &c.

=AL′ABASTER.= Syn. ALBÂTRE, Fr.; =Alabas′ter=, =Alabastri′tes=, =Alabas′trum=, L. A soft, white species of calcareous and of gypseous stone, used by sculptors. There are several varieties, all of which may be ranged under two heads:——

1. CALCA′′REOUS ALABASTER; ORIENT′AL, A.; CALC-SIN′TER. A sub-variety of carbonate of calcium, formed by the deposition of calcareous particles in the caverns of limestone rocks. It has a foliated, fibrous, or granular structure, and a pure, soft, rich, semi-translucent whiteness, generally agreeably variegated with undulating zones or stripes of various shades of yellow, red, or brown. This variety is that most esteemed by sculptors, and for the manufacture of alabaster ornaments. The ancients used it for ointment and perfume boxes. At the baths of San Filippo (Tuscany), the process of its formation may be examined by the observer. The natural spring of boiling water holds carbonate of lime in solution by means of sulphuretted hydrogen, which, escaping into the air, leaves the lime as a precipitate, which is gradually deposited in a concrete form. (M. Alex. Brogniart.)

2. GYP′SEOUS OR COMMON ALABASTER; GYPSUM. A natural hydrated sulphate of calcium, containing a little carbonate of calcium. That from the quarries of the Paris basin contains about 12% of the latter substance. When calcined or roasted, and powdered, it forms the substance known under the name of PLASTER OF PARIS. The more compact, fine-grained specimens of this variety are, like the preceding one, sculptured into almost numberless articles of ornament and utility, such as vases, clock-stands, statuettes, &c. The inferior kinds only are manufactured into the ‘plaster of Paris’ of the shops. The best specimens are obtained from the lower beds of the gypsum quarries, and are white, and granular, not unlike Carrara marble. It takes a high polish; but from its softness and liability to become discoloured, articles formed of it require more careful treatment than even those of ‘calcareous alabaster.’

Alabaster is wrought, turned, and fashioned, in a nearly similar manner to the softer varieties of marble. The tools resemble those employed for the like operations in ivory and brass. Machinery is now often applied to this purpose.

Alabaster is polished, first with pumice-stone, and then with a paste or pap made of whiting, soap, and milk or water; and lastly, with dry flannel. A better method, however, is to rub it first with dried shave-grass (equisetum), and afterwards with finely powdered and sifted slaked lime formed into a paste with water. The surface is then ‘finished off’ by friction with finely powdered talc or French chalk, until a satiny lustre is produced, or with putty powder, in a similar way to marble.

Alabaster is engraved with tools resembling those employed for other soft minerals. It is etched by covering every part of the surface, except that to be acted on, with a solution of white wax in oil of turpentine (1 to 4), thickened with a little finely powdered white lead, and subsequent immersion in water acidulated with acetic acid or hydrochloric acid, for the calcareous variety; and in spring water, for 20 to 50 hours (according to the effect desired), for the gypseous variety. The varnish is washed off with oil of turpentine, and the etched parts carefully brushed over with finely powdered gypsum.

Alabaster is joined and repaired by means of white of egg, or rice glue, thickened with finely powdered quicklime; or by a paste of newly baked and finely powdered gypsum, mixed up with the least possible quantity of water.

Calcareous alabaster is usually cleaned with a brush and warm soap-and-water, or with tepid water to which a few grains of carbonate of soda or of ammonia have been added; followed in either case by rinsing in clean water. If much discoloured, thoroughly cover the article with a paste of freshly slaked lime and water, and let it remain twenty-four hours; then wash off the paste with soap and water, rubbing hard the stains.

Delicate objects in gypseous alabaster can only be safely cleaned with benzol, or with pure oil of turpentine. If necessary, the surface must be repolished. Grease spots may be removed from either variety with a little benzol or oil of turpentine.

Alabaster is occasionally stained or coloured, and, for the calcareous variety, in a similar way to marble, except that heat is not employed; and for the gypseous variety, in the manner noticed under PLASTER OF PARIS. The gypseous variety is also bronzed and hardened in a similar way to that adopted for casts in the latter substance.

Obs. Gypseous alabaster is dissolved by water; and the beauty of both varieties is almost irrecoverably destroyed by grease, coloured oils, varnishes, smoke, &c. It is, therefore, unfitted for garden ornaments, or other objects exposed to the rain or weather, unless it be painted or bronzed; and is even then very perishable. Contact with acids, alkalies, and ammoniacal and sulphurous fumes, also injure, and, if prolonged, destroy it. Even an uncorked phial of smelling-salts placed on a mantel-piece beside an alabaster vase will soon destroy its beauty. Thus, all delicate objects in alabaster should be protected by a glass shade.

=Alabaster, Orient′al= (Factitious). Figures, basso relievos, &c., of considerable hardness and beauty, may be formed by imitating the process adopted at the baths of San Filippo, before referred to.

Proc., &c. Moulds of sulphur are placed either vertically or obliquely in an open tub or cistern, having a freely perforated bottom. Surmounting the whole are two or more pieces of wood in the form of a cross or star. The sulphurous calcareous water, falling on this cross, is scattered into spray or streamlets, and losing the gaseous portion which holds the lime in solution, deposits it in the form of oriental alabaster on the surface of the moulds. In from 1 to 4 months, according to the nature of the article, a sufficiently thick deposit is obtained. The object is then removed from the mould, and trimmed and polished. It is found that the more vertical the position of the mould, the finer is the grain of the resulting deposit. The water of the Spring of San Filippo may be exactly and easily imitated by the chemist; and the whole process offers a new and valuable ornamental art for the amusement and profit of the ingenious and enterprising.

=Alabaster, Shand’s Chinese.= Carbonate of lime. (Chandler.)

=Alabaster Tablets, John Swine’s Chinese.= Carbonate of lime. (Chandler.)

=ALAMODE′= (ăl-ăh-mōdé). [Fr., à la mode.] According to the prevailing mode or fashion. In cookery, applied to several dishes, but more particularly to one of beef (alamode beef), commonly shortened by the lower class of Londoners into “alamode.” See BEEF, STEWING, &c.

=ALAN′TINE.= [Eng., Fr., Ger.] Syn. ALANTI′NA, L. A substance identical with inulin, found in the roots of garden angelica (‘angelica archangelica,’ Linn.).

=ALBA′TA.= [L., Eng.] A name given to several alloys resembling silver. See ALLOYS, GERMAN SILVER, &c.

=ALBION= (Parisian). “Will preserve the skin white and free from wrinkles.” An aromatic water with chloride of lead and calomel suspended in it. (Landerer.)

=ALBOLITH.= A cement powder prepared by W. Riemann, Breslau. Made with calcined magnesia (obtained from magnesite) and chloride of magnesium. It is recommended for painting walls, stairs, and wooden articles. (Hager.)

=ALBU′MEN.= [Eng., L.] Syn. ALBUMIN; ALBUMINE, Fr.; EIWEISS, EIWEISTOFF, Ger. Literally, the white of egg; a peculiar nitrogenous substance which enters largely into the composition of animal bodies. It abounds in the blood, muscles, bones, coagulable lymph, vitreous and crystalline humour of the eye, fluid of dropsy, &c. The white of egg consists of nearly pure albumen dissolved in water.

A substance identical with albumen is found in many vegetables. It enters largely into the composition of all the emulsive seeds. According to Seguin, it exists in considerable quantity in all those vegetables and fruits that afford a vinous liquor without the addition of yeast.

Prep. The white of egg and the serum of blood, when strained through muslin, furnish albumen, in solution, in a sufficiently pure state for all the ordinary purposes of the arts. Pure solid albumen may be prepared as follows:——

1. Agitate strained white of egg with 10 or 12 times its bulk of alcohol, collect the precipitated flocculi on a muslin filter, and suffer it to dry at a temperature not exceeding 120° Fahr.

2. Add a little water to white of egg, mix, filter, exactly neutralise with acetic acid, and then largely dilute with pure cold water; the precipitate which falls may be collected on a filter and washed. Strained serum of blood may be used instead of white of egg, in both the above forms.

Comp., &c. The following is the composition of albumen according to Lieberkühn:——

Carbon 53·3 Hydrogen 7·1 Nitrogen 15·7 Oxygen 22·1 Sulphur 1·8 ---- 100·0

Chatin found iodine in the white of egg; it also contains chloride, sulphate, phosphate, and carbonate of sodium, phosphate of calcium, and traces of potassium in it; but, unlike the sulphur, none of these substances form a constituent part of pure albumen, though probably always present in white of egg.

Prop. Pure solid albumen (unaltered by heat) is nearly colourless, inodorous, and tasteless; scarcely soluble in water, but readily so in water, containing an exceedingly small quantity of caustic soda or potash, and in a strong solution of nitrate of potassium. When dried by a gentle heat it shrinks into a translucent horny mass; and when exposed to a sufficient temperature, yields the usual ammoniacal odour and products of animal matter. Its solution (as white of egg) is solidified or coagulated by a heat of from 145° to 165° Fahr., forming a white, opaque mass; when very dilute, on boiling (only) it separates in fine light flocks. When thus coagulated, it is insoluble in water at a less temperature than 302° Fahr. (Wöhler and Vögel), unless alkalised. Ordinary solutions of albumen give precipitates with sulphuric, hydrochloric, nitric, and metaphosphoric acids, with tannin and astringent solutions, and with most of the metallic salts; but are not affected by either acetic acid or tribasic (common) phosphoric acid. Alcohol, in quantity, also precipitates albumen. Strong oil of vitriol turns it black in the cold, but on applying a gentle heat, a gorgeous, red-coloured liquid is produced. Strong hydrochloric acid gives a deep violet-blue solution. White of egg or serum exposed in a thin stratum to the air, dries up into a pale, yellow, gum-like substance, and in this state may be kept for any length of time, retaining its property of redissolving when immersed in slightly warm water.

Tests.——1. Both heat and alcohol (or strong spirit) coagulate it:——2. A solution of perchloride of mercury dropped into a fluid containing albumen occasions a white precipitate:——3. Subacetate of lead acts in the same way. Either of the last two will render turbid a solution containing only the 1-2000th part of fresh white of egg, or the 1-10,000th part of dry albumen:——4. Tannin and tincture of galls give yellow, pitchy precipitates:——5. If dry caustic potash or soda be triturated with either liquid or solid albumen, ammoniacal fumes are evolved, and the mixture on calcination yields ferrocyanide of potassium:——6. Its coagulability by heat, and its incoagulability by acetic acid, distinguish it from casein.

Uses, &c., Independently of its value as an alimentary substance, albumen is largely employed in photography as a glaze or varnish, for fixing colours in calico printing, as a cement, &c., and more particularly as a clarifier for wines, syrups, vegetable solutions, and other liquids. Its efficacy for the last purpose depends on its entangling the impurities in its meshes during coagulation, and either rising to the surface with them as a ‘scum,’ or sinking with them as a precipitate. In France it is prepared on an extensive scale, at the abattoirs, by being spread in thin layers to dry; the source of supply being of course the stream of the blood of the slaughtered animals. When the liquid operated on does not spontaneously coagulate albumen, it is necessary to apply heat to it. In cases of poisoning by the mineral acids, corrosive sublimate, nitrate of silver, sulphate of copper, bichloride of tin, or sugar of lead, the white of egg (or indeed the yolk as well) is one of the best antidotes that can be administered.

=Albumen, Flake.= Syn. ALBUMEN IN POWDER, SOLID A., SOLUBLE A., PLANTER’S A. Prep. Expose strained white of egg or serum of bullock’s blood, in a thin stratum, to a current of dry air, until it concretes into a solid transparent substance, resembling horn. In this state it may be kept any length of time, or it may be further dried until brittle, and then reduced to coarse powder.

Use. It is extensively employed as a ‘clarifier’ in the sugar plantations of the West Indies, and elsewhere. It is prepared for use by soaking and stirring it with cold water until it is dissolved, when it is whisked to a froth in the usual way, and agitated with the liquid to be clarified.

=Albumen, Iodised.= 1. To the white of every egg employed add 7-1/2 grains of iodide of potassium dissolved in an equal weight of distilled water. Beat the mixture to a froth, let it stand until insoluble matters have settled, pour the clear portion into a wide-mouthed bottle, and keep in a cool place. 2. Dissolve 50 grains of iodide of potassium and 10 grains of bromide of ammonium in 2-1/2 oz. of distilled water, and add 120 minims of strong liquor ammoniæ. Add this solution to 10 oz. of albumen, let the mixture stand to settle, and filter. This preparation is said to keep good for a long time.

=Albumen, Solution of (B. P.).= Take of white of one egg; distilled water, four fluid ounces. Mix by trituration in a mortar, and filter through clean tow, first moistened with distilled water. This solution must be recently prepared.

=Albumen, Vegetable.= This substance, long considered to be a distinct proximate principle peculiar to the vegetable kingdom, has been shown, by recent researches, to be identical with animal albumen. It is particularly abundant in carrots, turnips, cabbages, green stems of peas, and oleaginous seeds.

=ALBU′MEN.= In botany, the solid, fleshy, or horny substance found in many seeds, between the integuments and the embryo. It is the part that furnishes the flour of the ‘cereals,’ the flesh of the ‘cocoa-nut,’ and the great mass of the seeds of coffee and other vegetables. However poisonous the plants which produce it may be, this substance is never deleterious.

=ALBUMENISED PAPER.= A French paper highly glazed, having a fine surface, and made by Rive; a German paper having a more uniform texture, and made by Saxe; also a paper by Towgood, are recommended for the preparation of albumenised paper. Positive paper may be albumenised as follows:——Add 15 grains of finely pulverised common salt to the white of every egg used, and whisk until the mixture is entirely converted into a white froth. Allow this froth to stand in a glazed earthenware pan which must be rather larger than the sheets of paper to be albumenised, for about twelve hours. At the end of this pour the clear portion of the liquid into a flat porcelain tray. Mark the inferior side of the paper, slightly damp it, lift it by its ends, and float it carefully on the prepared albumen, keeping its inferior and dry side uppermost. Then raise the paper at each end, and if any air bubbles are seen remove them with a card or brush and replace the paper in the bath. Remove the paper from the bath and suspend it at the corners by clips. Albumenised paper should be kept dry by enclosing it in tin or zinc cases.

=ALBUMENOIDS.= A term applied to albumen, fibrin, casein, and similar bodies.

=ALBU′MENOUS.= Syn. ALBUMINO′SUS, L.; ALBUMINÉ, ABUMINEUX, Fr.; EIWEISSTOFFHALTIG, Ger. Formed of, containing, or having the properties of albumen.

=Albuminous Plants=. In botany, all plants whose seeds contain albumen in a separate state; as in the cereals, palms, &c.

=Albuminous Principles or Substances.= Albumen, casein, fibrin, gluten, &c.

=ALBURN′UM.= [L.] Syn. ALBURN*; SAPWOOD. In botany, the white and softer parts of the wood of exogenous plants, lying between the inner bark and the heartwood. It consists of empty or nearly empty tubes or cells, which gradually acquire solidity by the deposition of resins, tannin, and other products of vegetation, and in time becomes wood. It is through the alburnum that the ascending sap chiefly flows.

=ALCARAZ′ZA.= [Sp.] A species of porous earthenware, or a vessel formed of it, made in Spain from a light, sandy marl, and but slightly fired. Their value as ‘coolers’ arises from the copious evaporation of the water, which gradually transudes. A similar ware and articles are made in France, under the name of HYGROCERA′MEN; and in England, under the names of POROUS WARE, WATER COOLERS, WINE COOLERS, BUTTER COOLERS, &c. The following are forms said to be used in our potteries:——

Prep. 1. Take of sandy marl, 2 parts; brine, q. s.; make a dough, and then knead in of common salt, in fine powder, 1 part. Bake the pieces slowly, and lightly.

2. Good clay, 2 parts; fine siliceous sand, 3 parts; brine, q. s.; common salt, 1 to 2 parts; as before.

3. Powdered clay, 2 parts; powdered charcoal, 3 parts (by weight); water q. s. to form a stiff dough. The kilning must be so arranged that the heat is applied gradually, and the vessels exposed to a current of hot air; and it must be continued until all the charcoal is burnt out, carefully avoiding over-firing.

=AL′CHEMY= (-kĭm-). Syn. AL′CHYMY (-kĭm-); HERMETIC ART*; ALCHEM′IA, ALCHYM′IA, L.; ALCHIMIE, Fr.; ALCHEMIE, Ger.; ALCHIMIA, It. The romantic forerunner of the modern science of chemistry. An imaginative art or science, having for its objects the discovery of a substance (PHILOSOPHER’S STONE) capable of transmuting the baser metals into gold——a panacea, or universal remedy (ELIXER VITÆ), by which disease and death were to be avoided by its possessor——an alkahest, or universal solvent——a universal ferment; and other like absurdities. A mixed metal formerly used for utensils was also called by this name.

=AL′COHOL.= C_{2}H_{6}O. [Eng., L.; B. P.] Syn. AL′KOHOL, Eng., L.; ALCOÖL, ALCOHOL, Fr.; ALKOHOL, HÖCHST RECTIFIEIRTER WEIN-GEIST., Ger.; ALCOÖLE, It. A term commonly applied to one kind of spirit——that obtained by the distillation of any fermented saccharine liquid, and forming the characteristic principle of wines, beers, spirits, and other intoxicating liquors.

Etym. Kohol, a Hebrew-Syriac word, is the name given to a preparation of powdered antimony used by Oriental ladies to paint their eyebrows. In course of time this term was applied to other fine powders, and ultimately to highly rectified spirits.

Hist., &c. Although the art of distillation was probably known at a comparatively early age of the world, the preparation of pure rectified spirit is a discovery of modern times. It was not until the 13th century that Raymond Lully first showed the way to concentrate spirit by means of carbonate of potash; after which date pure concentrated spirit gradually rose into note as an article of trade and commerce in Europe. In the 16th century its distillation was in common practice in these countries. (Burns.) By means of chloride of calcium, Dr Black obtained alcohol of sp. gr. 0·800 (about A.D. 1760); and Richter afterwards procured it of a sp. gr. so low as 0·796 at 60° Fahr. (Crell’s ‘Annals,’ 1796.) Lavoisier first demonstrated the composition of alcohol (about 1780). Its analysis was subsequently perfected by M. Saussure, jun., and confirmed by MM. Dumas and Boullay, and Gay-Lussac; and by many others since.

Nat. Hist. Alcohol is peculiar to the organic kingdom, being exclusively produced, in the natural way, by the process of fermentation.

Sources, &c. Dilute alcohol may be procured, by the ordinary process of distillation, from all fermented liquors. When drawn from wine (as in France), it constitutes BRANDY; when from the refuse juice of the sugar-cane, it is called RUM; when from malt, grain, or molasses (as in England), it is called MALT, RAW-GRAIN or MOLASSES SPIRIT; and when from rice or palm-wine, ARRACK. Brandy, rum, Hollands, and whisky, contain only about half their volume of alcohol; and gin much less. When distilled from any of these spirituous liquors, the alcohol contains, besides water, variable quantities of essential oils, ethers, and other flavouring matters, which, by one or more redistillations with charcoal or lime, it for the most part loses, and then becomes commercial spirit of wine. By a further rectification from chloride of calcium, lime, carbonate of potash, or any other substance having a strong affinity for water, the water is retained, and a strong spirit passes over containing not more than 10 per cent. of water. By repeating the process, and using the proper precautions, it may be obtained almost entirely free from water, and is then called absolute or anhydrous alcohol.

Preparation I. Of Absolute Alcohol:——

a. Alcohol (highly rectified spirit), of 85% (sp. gr. ·835 to ·822), is mixed, in a tubulated retort, with about half its weight of fresh-burnt quick-lime, in coarse powder; and the whole, after securely stopping the neck with a cork, and agitation, is allowed to repose for several days. The alcohol is then carefully distilled off, drop by drop, by the heat of a water bath, until the weight of the distillate nearly equals that of the ‘anhydrous alcohol’ in the spirit operated on. The sp. gr. of the product should be ·795 or ·796; but by carefully repeating the process with the distillate and a fresh quantity of lime, and prolonging the last digestion with the latter for several weeks, absolute alcohol of the sp. gr. ·79381 at 60° Fahr. may be easily obtained.

b. (Drinkwater; Fownes.) The strongest rectified spirit of wine is digested in a stoppered bottle for several days, with about half its weight of anhydrous carbonate of potash, in powder, frequent agitation being had recourse to; the alcohol, after repose, is then decanted, and treated with sufficient fresh-burnt quick-lime to absorb the whole of the spirit. After 48 hours’ digestion, the spirit, when distilled, will have the sp. gr. ·793 at 60° Fahr.

c. (Liebig; Ure.) Alcohol of about 90% is saturated with fused chloride of calcium, in powder, and after repose for a few hours in a stoppered bottle, is submitted to distillation as before. The product should nearly equal the quantity of dry alcohol in the sample. Ure recommends equal weights of the spirit and chloride to be taken; and the process to be stopped as soon as about half the volume of the spirit employed has passed over, or the distillate acquires a higher sp. gr. than ·791 at 68°, or ·796 at 60° Fahr.

d. (B. P. 1867.) Take of rectified spirit, 1 pint; carbonate of potash, 1-1/2 ounce; slaked lime, 10 ounces. Put the carbonate of potash and spirit into a stoppered bottle and allow them to remain in contact for two days, frequently shaking the bottle. Expose the slaked lime to a red heat in a covered crucible for half an hour, then remove it from the fire, and, when it has cooled, immediately put the lime into a flask or retort, and add to it the spirit from which the denser aqueous solution of carbonate of potash, which will have formed a distinct stratum at the bottom of the bottle, has been carefully and completely separated. Attach a condenser to the apparatus, and allow it to remain without any external application of heat for twenty-four hours; then applying a gentle heat, let the spirit distil until that which has passed over shall measure 1-1/2 fluid ounce; reject this, and continue the distillation into a fresh receiver until nothing more passes at a temperature of 200° Fahr.

e. (Poggendorff.) Saturate alcohol with caustic potash, then add half its volume of water, and distil at a low temperature.

II. Of Hydrated or Commercial Alcohol:——

a. (ALCOHOL, Ph. L. 1836.) Take of rectified spirit (sp. gr. 0·838), 1 gal.; chloride of calcium, 1 lb.; proceed as above, and distil 7 pints and 5 fl. oz. Sp. gr. of product 0·815. It contains about 7% of water, by weight, and 5% by volume.

b. (ALCOHOL, Ph. D. 1826.) Rectified spirit, 1 gal.; pearl-ashes (dried and still hot), 3-1/2 lbs.; mix, digest in a covered vessel, with frequent agitation, for seven days; then decant the clear portion, and add to it of chloride of calcium, 1 lb.; agitate to effect solution, and distil off the spirit until the mixture in the retort begins to thicken. Sp. gr. of product 0·810. It contains about 5% of water, by weight.

c. (Without distillation.) Rectified spirit is agitated, in a closed vessel, with anhydrous carbonate of potash (prepared by heating the salt to redness, and still slightly warm), until the powder sinks to the bottom undissolved; the carbonate is then added in considerable excess, and the agitation repeated at short intervals for some hours or even days; lastly, after sufficient repose, the clear upper portion is decanted.——Obs. If a clean spirit, and pure carbonate of potash (or at least one perfectly free from caustic potash or any other impurity soluble in strong spirit), be used, an alcohol sufficiently pure and free from water for many common purposes may be thus obtained; otherwise the product contains a little potassa, &c., which can only be removed by distillation. For some purposes, however, this would not be objectionable. Sp. gr. about ·812.

III. (Soëmmering.——VARNISH-MAKER’S ALCOHOL.) The bladder of an ox or calf, thoroughly cleansed from fat, and washed and dried, is nearly filled with rectified spirit, and then securely fastened and suspended in any dry situation, at a temperature of about 122° Fahr. In from six to twelve hours, when the heat is properly maintained, the spirit is generally sufficiently concentrated, and in a little time longer is rendered nearly free from water (anhydrous), or of the strength of 96 to 98%.——Obs. The same bladder will serve for more than one hundred operations. If not kept very nearly full, a portion of the spirit escapes through the empty part. To prevent this accident, a bottle with a double neck, of the shape represented in the engr., may be employed; by which means the bladder may be kept constantly full during the process. After the first or second time of using, the bladder gives alcohol sufficiently pure for all ordinary purposes. Before hanging the apparatus up, it is better to enclose it in a coarse potato-netting, to prevent any accident arising from the strain on the neck of the bladder. Soëmmering recommends both the inside and outside of the dry bladder to be smeared over 2 or 3 times with a strong solution of isinglass; but this is not necessary to the success of the process.

IV. Rectified Spirit. (B. P. 1867.) Spiritus Rectificatus. Alcohol with 16 per cent. of water; obtained by the distilling of fermented saccharine fluids. Sp. gr. 0·838.

V. Proof Spirit. (B. P. 1867.) Spiritus Tenuior. Take of rectified spirit, 5 pints; distilled water, 3 pints. Mix. Sp. gr. of product 0·920.

Prop. of Alcohol. Light, transparent, colourless; highly volatile and inflammable, burning with a pale blue and smokeless flame; very mobile; odour, agreeable; taste, strong and pungent; miscible in all proportions with water, with the evolution of heat, and temporary expansion, but ultimate condensation of the mixture, some hours elapsing before the union is complete, and the normal temperature restored. The mixture has a higher sp. gr. than the mean of its constituents; and this is greatest when 54 vols. of alcohol are mixed with 49·77 vols. of water, the resulting compound measuring only 100 volumes. It absorbs water from moist air; dissolves resins, essential oils, camphor, bitumen, soaps, sugar, carbonic and boracic acid, iodine and the iodides, lime, ammonia, soda, potash, the alkaloids, wax and spermaceti (when boiling), all the deliquescent salts (except carbonate of potassa), and various other substances. It curdles milk, coagulates albumen, and (in quantity) separates both starch and gum from their mucilages. It boils, in the air, at 173° Fahr., when in the anhydrous state. When diluted with water its boiling point rises in proportion to the amount of water added. It boils, in vacuo, at 56° Fahr. Every volume of boiling alcohol yields 488·3 vols. of vapour at 212° Fahr. Its sp. gr. is 0·793811 at 60° Fahr., that of its vapour being 1·6133. It has never been frozen; when cooled to -166° Fahr., it acquired the consistence of castor oil, but did not solidify. It contracts by cold; between -15° and +99° Fahr., this occurs with great regularity, at the rate of ·00047 part of its volume for every degree of the thermometer. Its evaporation, like that of ether, produces intense cold. The products of its combustion are carbonic anhydride and water. It acts as a powerful antiseptic on organic substances immersed in it, and is in consequence extensively employed in the preservation of anatomical preparations. With the acids it forms ethers.

Phys. eff. Alcohol is a narcotico-acrid poison. In small doses it occasions excitement and intoxication; in larger ones, delirium, somnolency, coma, apoplexy, and death. It acts as a violent nervous stimulant, and, by abstracting water from the soft tissues of the stomach and primæ viæ, destroys their organisation. It is alike poisonous to all animals;——2 drs. will kill a dog. All strong spirits act in the same way, the effect being proportionate to the state of concentration and the quantity taken. On plants it acts as a rapid and fatal poison.

Ant., &c. Copious internal use of tepid water, with cold affusions to the head and spine, and injection of cold water into the ears. In the absence of vomiting, a strong emetic should be given, or the stomach-pump used. Ammonia may be used as a stimulant, and, added to water just in sufficient quantity to flavour it, is one of the best antidotes. The head should be kept elevated, and bleeding had recourse to, if cerebral congestion threatens.

Tests in cases of death. 1. The odour of the contents of the stomach and ejected matters, and their ready inflammability. 2. The spirit may be separated by digestion with water, filtration, the addition of carbonate of potash, and distillation.

Comp., &c. Its per-centage composition is——

Dumas and Brande and Ure. sp. Boullay. Ure. gr. 0·812. Carbon 52·37 52·18 47·85 Hydrogen 13·01 13·04 12·24 Oxygen 34·61 34·78 39·91 ------- -------- -------- 99·99 100·00 100·00

This nearly represents 2 equivalents of carbon, 3 eq. of hydrogen, and 1 of oxygen. The atom of alcohol is now regarded as a multiple of these numbers, and formed by the breaking up of one atom of grape sugar (C_{13}H_{28}O_{11}) into 4 eq. of alcohol, 8 eq. of carbonic acid, and 4 eq. of water. It was formerly regarded as a compound of 1 eq. of olefiant gas, and 1 eq. of water; but it is now generally viewed as HYDRATE OF THE OXIDE OF ETHYLE (C_{2}H_{5}.HO), or a compound of ethylene and water (C_{2}H_{4}.H_{2}O). Grape sugar alone yields alcohol; cane sugar, before it undergoes the vinous fermentation, being first converted into this substance by contact with the ferment.

Purity. The presence of water is shown by the specific gravity (see ALCOHOLOMETRY); the absence of other foreign matter by the following tests:——

1. Its colour and transparency is not affected by the addition of a little colourless oil of vitriol (Liebig), or by a solution of nitrate of silver, and subsequent exposure for some time to solar light (Vögel), unless either essential oil or organic matter be present, when it assumes a reddish tinge. 2. It should be neutral to test-papers, colourless, leave no residue on evaporation, and be miscible, in all proportions, with water and with ether. 3. Its boiling point should never be less than 170° Fahr.; a lower temperature suggests the presence of wood spirits, or acetone, or one of the ethers. To detect wood spirit (wood naphtha) see Nessler’s Test. For the reverse of this adulteration——the evasion of the duty by the introduction of spirit, under the disguise of naphtha, turpentine, &c.——see those articles.

4. The presence of water in alcohol may be detected, not only by the sp. gr., but also by white anhydrous sulphate of copper burning blue when dropped into it. 5. Potassium placed on alcohol does not take fire, unless a considerable per-centage of water be present.

Tests, &c. 1. It may generally be recognised by its volatility, inflammability, odour, taste, miscibility with water, power of dissolving camphor and resins, and other qualities already described. 2. If a few fibres of asbestos be ‘moistened’ with a saturated solution of bichromate of potash in oil of vitriol, and exposed to the smallest possible portion of hot alcohol vapour, it is almost instantly turned green, owing to the formation of oxide of chromium. In practice, the asbestos may be inserted in the neck of a retort, or even of a bulbed glass-tube containing a few drops of the suspected solution, when the effect occurs as soon as distillation commences. Ether and pyroxylic spirit produce a nearly similar result; but the ‘first’ of these is distinguished from alcohol by its not being miscible with water in all proportions; and the ‘other’ by Nessler’s Test; whilst both may be readily distinguished by their peculiar and characteristic odour. 3. Dissolve 3 pts. crystallised carbonate of soda in 10 pts. water. To this solution add 1 pt. of liquid to be tested, and heat to about 160° Fahr. Lastly, add iodine in small pieces, till it has entirely dissolved, and the liquid has become colourless. If alcohol be present, iodoform will make its appearance on cooling, and sink to the bottom in the form of a yellow powder. As a similar result is obtained with wood spirit, this must be proved to be absent before applying this test.

The only reliable method of proving that a sample is ethylic alcohol is the production of ether, by acting on the suspected liquid with sulphuric acid. See ETHER.

Uses. In the arts, alcohol is used by the varnish-maker to dissolve resins; by the perfumer, to extract the odour of plants, and dissolve essential oils, soaps, and other similar substances; by the pharmaceutist, to prepare tinctures and other valuable medicinals; by the instrument-maker, to fill the bulbs of thermometers required to measure extreme degrees of cold; by the photographer, in the preparation of collodion; by the chemist, in analysis, and in the manufacture of numerous preparations; by the anatomist and naturalist, as an antiseptic; and by the physician, for various purposes and applications as a remedy. It is also frequently burnt in lamps, and in parts of the world where it is inexpensive, it is employed in the manufacture of vinegar. Its uses, when dilute, as in the ‘spirituous liquors’ of commerce, are well known. In medicine, it is employed both concentrated (‘alcohol,’ ‘rectified spirit’) and dilute (‘proof spirit,’ ‘brandy,’ ‘gin,’ &c.), as a caustic, irritant, stimulant, tonic, &c. It has also been used in a multitude of other cases, and has been applied to an almost infinite variety of other purposes.

Gen. commentary. The selection of any one of the processes given above for the preparation of alcohol must greatly depend on the convenience or position of the operator. Chloride of calcium, and quick-lime, from their powerful affinity for water, and easy application, are the hygrometric substances most generally employed; but the processes involving the use of the other substances and methods already noticed, have all of them advantages under particular circumstances. Gay-Lussac has recommended the use of caustic baryta instead of lime; and others have employed dry alumina, as an absorbent of the water prior to distillation. Common proof spirit may be concentrated until its sp. gr. falls to about 0·825, by simple distillation in a water bath; at which sp. gr. it contains only about 11% of water, by weight, and is then nearly as volatile as pure alcohol.

A convenient apparatus for the preparation of alcohol, on the small scale, is that figured in the engr., and which will be self-explanatory to every one competent to use it. The tank (i) should be supplied with ice-cold water; and the receiver (g) should be covered with cloths kept continually wet with water of the same temperature. The capsule or basin (c) is a water bath heated by the little gas furnace (d). On the large scale, for commercial alcohol, a copper still, fitted with a glass refrigeratory and receiver, is commonly employed.

By surrounding the capital of a still, or other like apparatus, by a water bath kept at the proper temperature, the alcoholic richness or content of the product may be regulated to the greatest nicety, for any desired strength.

The different statements of chemical authors as to the boiling point, specific gravity, &c., of alcohol, already noticed, may be referred to their having either experimented with samples which have not been absolutely anhydrous, or to their not having made the proper corrections for temperature, and for the different materials of which their vessels and instruments were composed——some probably having been made of glass, and others of brass or some other metal. In some instances the differences are more apparent than real, as in the Tables by Tralles and Lowitz; in the former of which water, at its lowest sp. gr., is taken as the standard. Until recently, the only known source of alcohol was the fermentation of saccharine solutions. Its production by synthesis, though often attempted, is, however, erroneously said to have always failed. It had long been employed as an occasional source of bicarburetted hydrogen (olefiant gas) at a high temperature; but M. Berthelot succeeded in reproducing it, from bicarburetted hydrogen, by agitating the latter, in a closed vessel, with sulphuric acid and metallic mercury (‘Journ. de Chimie Med.,’ 1855, p. 175); and Henry Flennel, nearly thirty years before M. Berthelot’s discovery, found that pure olefiant gas is absorbed by agitation with concentrated sulphuric acid, with the formation of sulphovinic acid, and that by subsequent dilution with water, and distillation, alcohol passes over into the receiver.

=ALCOHOLATE.= Syn. ALCOHATE; ALCOHOLAS, L. A salt in which alcohol appears to replace the water of crystallisation, as is the case with certain chlorides, nitrates, &c. Some of them may be formed by simple solution and crystallisation of the salt in alcohol. (Graham.) They are all very unstable, being readily decomposed by water.

=ALCOHOLIC.= Syn. ALCOHOLICUS, L.; ALCOHOLIQUE, &c., Fr.; ALKOHOLISCH, Ger. Pertaining to, containing, of the nature of, or made with, alcohol.

=ALCOHOLICA.= [L.] Syn. ALCOÖLIQUES, Fr.; WEINGEIST-VERBINDUNGEN, Ger. In pharmacy, liquids containing, or preparations made with, alcohol, as a characteristic ingredient.

=ALCOHOLISATION.= [Eng., Fr.] Syn. ALCOHOLISATIO, L.; ALCOÖLISATION, &c., Fr.; ALKOHOLISERUNG, Ger. In chem. and pharm., the development of the characteristic properties of alcohol in a liquid, or the use of it either as an addition or a menstruum; also the act or process of obtaining alcohol from spirit by rectification.

=ALCOHOLOM′ETER= (-lŏm′-). Syn. ALCOHOL′METER (hŏl′-; -hŏm′-‡); ALCOHOLOMÉTRUM, L.; ALCOÖLOMÈTRE, ALCOÖMÈTRE, ALCOHOLMÈTRE, &c., Fr. An instrument or apparatus used in alcoholometry. Alcoholometers are simply ‘hydrometers’ adapted to the densities of alcohol, either concentrated or dilute. Some of these, as BAUMÉ’S, CARTER’S, &c., merely indicate the number of degrees corresponding to the state of concentration of the liquid. Others, of a like construction, as those of RICHTER (a), TRALLES (b), and GAY-LUSSAC (c), have their stems so graduated as at once to indicate the proportion per cent. of alcohol present, either by weight, or by volume, at some standard temperature. (See engr.) A third class, as those of the Abbé BROSSARD-VIDAL, FIELD, &c. are essentially thermometers, with scales which indicate the boiling points of spirits of different strengths, instead of the common thermometric degrees; whilst to a fourth class belong the alcoholometer of M. SILBERMANN, which is based upon the known rate of expansion of alcoholic liquors by heat, expressed in alcoholometric degrees; and that of M. GEISSLER, which depends on the measurement of the tension of the vapour of the liquid, as indicated by the height to which it raises a small column of mercury. In SYKE’S HYDROMETER, used by officers of the Revenue, the scale of the instrument is enormously extended by the use of movable weights, with each of which it becomes, in fact, a separate instrument, adapted to a certain range of specific gravities.

A very convenient alcoholometer for ordinary purposes (d) has been lately produced by some of the instrument makers. It is of the usual form, but its stem on one side exhibits the per-centage richness of the sample in alcohol by volume; and on the other, the per-centage by weight. Thus, both results may be obtained at one trial. This instrument is sometimes called RICHTER’S ALCOHOLOMETER, in England. A further improvement, still more recently introduced, is a similar ‘double-scale’ instrument, showing the degrees of Sykes on one side, and carrying a small spirit-thermometer in the bulb, to which a scale is fixed ranging from 35° to 82° Fahr.

=ALCOHOLOM′ETRY.= Syn. ALCOHOL′METRY (-hŏl′-; -hŏm′-‡); SPIRIT TESTING‡; ALCOHOLME′TRIA, L.; ALCOÖLOMÉTRIE, ALCOÖMÉTRIE, &c., Fr. In chemistry, the art or process of ascertaining the richness of spirits in alcohol. In commerce, the determination of the quantity of spirit of a certain strength, taken as a standard, present in any given sample of spirituous or fermented liquors. In England, this standard is called “proof spirit.”

Hist., &c. The great importance of being able accurately to determine the strength of spirits in the United Kingdom, on account of the high duties levied on them, has induced the Government authorities, at various times, to investigate the subject. In 1790, the matter was referred to Sir C. Blagden, then Secretary to the Royal Society, who instituted an extensive series of experiments to determine the real specific gravities of different mixtures of alcohol and water. The results of his labours and researches were put forward, with ‘Gilpin’s Tables,’ in 1794, but no practical measures appear to have been taken in consequence. In 1832 a committee of the Royal Society, at the request of the Lords of the Treasury, examined into the accuracy of the Tables, and the construction and application of the instrument (SYKE’S HYDROMETER) now used by the Revenue officers, on which they reported favorably, and declared that they were sufficiently perfect for all practical and scientific purposes. The errors introduced into calculations of the strength of spirits by these tables were found to be quite unimportant in practice, and did not, in any one instance, amount to unity in the fourth place of decimals. This method adapts the specific gravity as the test of the strength of spirits, and is founded on the fact that alcohol is considerably lighter than water, and that (with proper corrections for condensation and temperature) the sp. gr. regularly increases, or decreases, according to the relative proportions in which the two are mixed.

Several other methods of alcoholometry have been proposed, founded upon——the variations in temperature of the vapour of alcohol of different strengths——the heat involved by its admixture with water——its dilatation by heat——the tension of its vapour——the insolubility of carbonate of potash in alcohol——its volatility, boiling point, &c. &c., the more important and useful of which are noticed further on. The method adopted by the Boards of Inland Revenue and Customs is, however, the one which is almost exclusively employed in trade and commerce in Great Britain, not only on account of its simplicity and correctness, but for the purpose of the results exactly coinciding with the results obtained by the Revenue officers.

METHODS OF ALCOHOLOMETRY.

1. Methods based on the specific gravity, or per-centage strength, by VOLUME:——

a. With SYKES’ HYDROMETER. Revenue system. The engraving below represents Sykes’ hydrometer, as made by Mr Bate, under the directions of the Commissioners of Inland Revenue and Customs. It consists of a spherical ball or float, with an upper and lower stem, and is made of brass, which (in the more expensive instruments) is usually coated with gold, to prevent corrosion from damp, and the acidity so generally present in spirituous liquors. The upper stem (A) is about four inches long, and is divided into ten parts, each of which contains five subdivisions. There are nine movable weights of the form b, of different sizes, numbered respectively 10, 20, 30, &c., to 90, each of which represents so many of the principal divisions of the stem, as its number indicates. In use, one of these weights is slipped on to the lower stems; and thus, by means of them, the instrument acquires a range of above 500 divisions, or degrees, extending from the Revenue ‘standard alcohol’ (sp. gr. ·825) to water. It is so formed as to give the sp. gr. with almost perfect accuracy, at 62° Fahr. When loaded with the weight 60 it sinks in proof spirit to the line marked (P) on the narrow edge of the stem at 51° Fahr.; and, by further placing the square weight or cap (also supplied with the instr.) on the top of the upper stem, it floats exactly at the same point in distilled water. This weight or cap is found to weigh 43·66 grs., which is practically 1-12th of the total observed weight of the instrument, and its poise 60, and hence shows the difference between the gravity of proof spirit and water, as explained hereafter. The whole is fitted up in a neat mahogany case, accompanied with a thermometer, and a book of tables containing corrections for temperature, &c.——Process. A glass tube of the form of fig. B is filled to about the mark (a) with the sample for examination; the thermometer is then placed in the liquor, and stirred about for two or three minutes (observing not to breathe upon the glass, nor hold it in the hand), and the temperature noted. The hydrometer is next immersed in a similar manner, and gently pressed down in the liquor to the 0 on the stem with the finger; it having been previously loaded with any one of the nine weights that will cause it to float with the surface of the spirit at some point on the graduated part of the scale. The indication at the point cut by the surface of the liquor, as seen from below, added to the number of the weight with which the float is loaded, gives a number which must be sought in the hook of Tables, which is always sold with the instrument. In this book, at the page headed “Temperature as observed by the Thermometer,” and against the part of the column appropriated to the given indication (weight), will be found the strength per cent., expressed in degrees over or under proof, by VOLUME, in whole numbers or decimal parts. In reading off the indication, to ensure accuracy, it is necessary to allow for the convexity of the liquor at the part where it immediately rests against the stem.

Obs. In an instrument requiring so much care and skill in its manufacture the purchaser should be careful to procure a perfect one. A very slight blow, friction from continual wiping with a rough cloth, and other apparently trivial causes, tend to injure so delicate an instrument. The shape of the weights occasionally vary; some being intended to be attached to the hydrometer at the bottom of the spindle, and others to rest on its top. The first plan is, perhaps, the best, as it tends to make the instrument float with greater steadiness in the liquor; but, at the same time, it renders its adjustment by the maker a matter of greater difficulty.

In employing this instrument, the Revenue officers are instructed to take the nearest degree above the surface of the mercury, when it stands between any two degrees of the thermometer; and the division on the scale of the hydrometer next below the surface of the liquid, when it cuts the stem between any two lines; thus giving the difference in favour of the trader in both cases.

By means of the Table at page 64 the hydrometer indication, or the degrees over or under proof, of the Revenue system, may be converted into ‘real specific gravities,’ by mere inspection; and the corresponding ‘per-centage richness’ in alcohol of any sample may be found, either by WEIGHT or VOLUME.

The specific gravities in this table are such as, on being referred to Gilpin’s Tables, will give the expressions of proof strength answering to the whole indications of the Revenue hydrometer. Intermediate values at fifths of indications may be had by taking proportional differences between the nearest tabular numbers. Thus, to find the specific gravity that should stand opposite to Indication 70·6, we first obtain the difference between the densities standing in a line with Indications 70 and 71 respectively, and then say, as 1 : 0·6 :: ·00192. 00·115, and ·94135 + ·00115 = ·94250, the specific gravity required.

b. With GLASS ALCOHOLOMETERS. That of Tralles, and most others of a like description (as made in England), gave the per-centage strength, by VOLUME, with tolerable accuracy, at the standard temperature of 60° Fahr. Gay-Lussac’s ALCOÖMETRE, which closely resembles that of Tralles, is adjusted for the temperature of 59° Fahr. (15° Cent.). All of these, to give at once accurate results, must, of course, be employed at the ‘normal temperature’ of the instrument. As, however, in practice, the experiment cannot be conveniently performed at any ‘fixed’ temperature but only at that of the atmosphere, it is obvious that certain corrections are constantly required in order to obtain results of any value. Perfect accuracy requires that table for every variation of the thermometer, founded on actual experiments, should accompany each instrument; as, without them, tedious and difficult calculations are necessary, which, in the hurry of the cellar and laboratory, or by persons inexpert at figures, are not easily performed. A series of such Tables were prepared by Gay-Lussac, and, with his instrument, are those which are almost exclusively used in France. For rough purposes, in the absence of Tables or nicer calculations, it may be useful to know that, for commercial spirits, at ordinary temperatures, a variation of——

By VOLUME, 5° Fahr. is equal } 1·00% of Alcohol; } 1·794% of Proof to (about) } or (about) } spirit. 1° ” ” 0·20% ” 0·359% ” 5° Cent. ” 1·80% ” 3·229% ” 1° ” ” 0·36% ” 0·646% ”

By WEIGHT, 5° Fahr. is equal } 0·80% of Alcohol; } 1·62% ” to (about) } or (about) } 1° ” ” ·16% ” ·32% ” 5° Cent. ” 1·43% ” 2·9% ” 1° ” ” ·28% ” ·58% ”

TABLE I.——Showing the Densities and Values of Spirits at 60° Fahr., corresponding to every Indication of Sykes’ Hydrometer.

+-----------+---------+----------+--------------------+ | | | | Per Cents. of | | Sykes’ | | | Absolute Alcohol. | |Hydrometer |Strength | Specific +----------+---------+ |Indication.|per cent.| Gravity. | By | By | | | | | Measure. | Weight. | +-----------+---------+----------+----------+---------+ | | O.P. | | | | | 0 | 67·0 | ·81520 | 95·28 | 92·78 | | 1 | 66·1 | ·81715 | 94·78 | 92·08 | | 2 | 65·3 | ·81889 | 94·31 | 91·42 | | 3 | 64·5 | ·82061 | 93·84 | 90·78 | | 4 | 63·6 | ·82251 | 93·33 | 90·07 | | 5 | 62·7 | ·82441 | 92·80 | 89·36 | | 6 | 61·8 | ·82622 | 92·29 | 88·67 | | 7 | 60·9 | ·82800 | 91·77 | 87·99 | | 8 | 60·0 | ·82978 | 91·25 | 87·30 | | 9 | 59·1 | ·83151 | 90·74 | 86·63 | | 10 | 58·2 | ·83323 | 90·23 | 85·96 | | 11 | 57·3 | ·83494 | 89·72 | 85·30 | | 12 | 56·4 | ·83661 | 89·21 | 84·65 | | 13 | 55·5 | ·83827 | 88·70 | 84·00 | | 14 | 54·6 | ·83993 | 88·17 | 83·33 | | 15 | 53·7 | ·84153 | 87·67 | 82·70 | | 16 | 52·7 | ·84331 | 87·10 | 81·99 | | 17 | 51·7 | ·84509 | 86·51 | 81·26 | | 18 | 50·7 | ·84680 | 85·95 | 80·58 | | 19 | 49·7 | ·84851 | 85·39 | 79·89 | | 20 | 48·7 | ·85022 | 84·81 | 79·19 | | 21 | 47·6 | ·85205 | 84·19 | 78·44 | | 22 | 46·6 | ·85372 | 83·61 | 77·74 | | 23 | 45·6 | ·85537 | 83·04 | 77·07 | | 24 | 44·6 | ·85700 | 82·47 | 76·39 | | 25 | 43·5 | ·85878 | 81·85 | 75·66 | | 26 | 42·4 | ·86055 | 81·21 | 74·92 | | 27 | 41·3 | ·86229 | 80·59 | 74·19 | | 28 | 40·2 | ·86402 | 79·97 | 73·47 | | 29 | 39·1 | ·86574 | 79·34 | 72·75 | | 30 | 38·0 | ·86745 | 78·71 | 72·03 | | 31 | 36·9 | ·86915 | 78·08 | 71·32 | | 32 | 35·7 | ·87099 | 77·40 | 70·54 | | 33 | 34·5 | ·87282 | 76·71 | 69·77 | | 34 | 33·4 | ·87450 | 76·08 | 69·06 | | 35 | 32·2 | ·87627 | 75·41 | 68·32 | | 36 | 31·0 | ·87809 | 74·72 | 67·55 | | 37 | 29·8 | ·87988 | 74·03 | 66·79 | | 38 | 28·5 | ·88179 | 73·29 | 65·98 | | 39 | 27·3 | ·88355 | 72·60 | 65·23 | | 40 | 26·0 | ·88544 | 71·86 | 64·43 | | 41 | 24·8 | ·88716 | 71·17 | 63·68 | | 42 | 23·5 | ·88901 | 70·43 | 62·89 | | 43 | 22·2 | ·89086 | 69·69 | 62·10 | | 44 | 20·9 | ·89268 | 68·95 | 61·32 | | 45 | 19·6 | ·89451 | 68·21 | 60·53 | | 46 | 18·3 | ·89629 | 67·47 | 59·76 | | 47 | 16·9 | ·89822 | 66·67 | 58·92 | | 48 | 15·6 | ·89997 | 65·93 | 58·15 | | 49 | 14·2 | ·90182 | 65·14 | 57·34 | | 50 | 12·8 | ·90367 | 64·34 | 56·52 | | 51 | 11·4 | ·90551 | 63·54 | 55·70 | | 52 | 10·0 | ·90732 | 62·74 | 54·89 | | 53 | 8·6 | ·90913 | 61·94 | 54·09 | | 54 | 7·1 | ·91107 | 61·09 | 53·23 | | 55 | 5·6 | ·91299 | 60·24 | 52·38 | | 56 | 4·2 | ·91479 | 59·43 | 51·57 | | 57 | 2·7 | ·91666 | 58·58 | 50·73 | | 58 | 1·3 | ·91839 | 57·78 | 49·94 | | | U.P. | | | | | 59 | 0·3 | ·92037 | 56·86 | 49·04 | | 60 | 1·9 | ·92228 | 55·96 | 48·17 | | 61 | 3·4 | ·92408 | 55·10 | 47·33 | | 62 | 5·0 | ·92597 | 54·19 | 46·46 | | 63 | 6·7 | ·92798 | 53·22 | 45·53 | | 64 | 8·3 | ·92984 | 52·30 | 44·65 | | 65 | 10·0 | ·93176 | 51·36 | 43·76 | | 66 | 11·7 | ·93367 | 50·39 | 42·84 | | 67 | 13·5 | ·93586 | 49·34 | 41·86 | | 68 | 15·3 | ·93758 | 48·31 | 40·90 | | 69 | 17·1 | ·93949 | 47·29 | 39·96 | | 70 | 18·9 | ·94135 | 46·29 | 39·04 | | 71 | 20·8 | ·94327 | 45·20 | 38·04 | | 72 | 22·7 | ·94518 | 44·09 | 37·03 | | 73 | 24·7 | ·94709 | 42·96 | 36·01 | | 74 | 26·7 | ·94899 | 41·82 | 34·98 | | 75 | 28·8 | ·95092 | 40·63 | 33·92 | | 76 | 31·0 | ·95288 | 39·40 | 32·82 | | 77 | 33·2 | ·95484 | 38·10 | 31·68 | | 78 | 35·6 | ·95677 | 36·76 | 30·50 | | 79 | 38·1 | ·95877 | 35·32 | 29·24 | | 80 | 40·6 | ·96068 | 33·90 | 28·01 | | 81 | 43·3 | ·96259 | 32·41 | 26·73 | | 82 | 46·1 | ·96457 | 30·77 | 25·32 | | 83 | 49·1 | ·96651 | 29·08 | 23·88 | | 84 | 52·2 | ·96846 | 27·31 | 22·38 | | 85 | 55·5 | ·97049 | 25·39 | 20·77 | | 86 | 59·0 | ·97254 | 23·41 | 19·11 | | 87 | 62·5 | ·97458 | 21·39 | 17·42 | | 88 | 66·0 | ·97660 | 19·41 | 15·78 | | 89 | 69·4 | ·97857 | 17·46 | 14·16 | | 90 | 72·8 | ·98057 | 15·51 | 12·56 | | 91 | 76·1 | ·98261 | 13·58 | 10·97 | | 92 | 79·2 | ·98452 | 11·85 | 9·56 | | 93 | 82·3 | ·98657 | 10·04 | 8·08 | | 94 | 85·2 | ·98866 | 8·28 | 6·65 | | 95 | 88·0 | ·99047 | 6·83 | 5·48 | | 96 | 90·7 | ·99251 | 5·25 | 4·20 | | 97 | 93·3 | ·99448 | 3·80 | 3·03 | | 98 | 95·9 | ·99658 | 2·31 | 1·84 | | 99 | 98·2 | ·99851 | ·997 | ·793 | | 100 | ... | 1·00000 | ... | ... | +-----------+---------+----------+----------+---------+

This Table {above} has been copied, by permission, from Loftus’s ‘Inland Revenue Officer’s Manual,’ and its correctness verified by W. H. Johnston, Esq., Surveying General Examiner.

TABLE II.——Table for finding the Specific Gravity of any Spirit at 60° Fahr., when the Specific Gravity at any other Temperature is given.

Water taken as 1000. +-----------------+----------+-----------------+----------+ | |Correction| |Correction| |Specific gravity.| for each |Specific gravity.| for each | | | degree. | | degree. | +-----------------+----------+-----------------+----------+ | 810 to 820 | ± ·475 | 910 to 920 | ± ·434 | +-----------------+----------+-----------------+----------+ | 820 ” 830 | ± ·473 | 920 ” 930 | ± ·424 | +-----------------+----------+-----------------+----------+ | 830 ” 840 | ± ·472 | 930 ” 940 | ± ·406 | +-----------------+----------+-----------------+----------+ | 840 ” 850 | ± ·471 | 940 ” 950 | ± ·381 | +-----------------+----------+-----------------+----------+ | 850 ” 860 | ± ·471 | 950 ” 960 | ± ·340 | +-----------------+----------+-----------------+----------+ | 860 ” 870 | ± ·466 | 960 ” 970 | ± ·269 | +-----------------+----------+-----------------+----------+ | 870 ” 880 | ± ·460 | 970 ” 980 | ± ·165 | +-----------------+----------+-----------------+----------+ | 880 ” 890 | ± ·456 | 980 ” 990 | ± ·090 | +-----------------+----------+-----------------+----------+ | 890 ” 900 | ± ·450 | 990 ” 1000 | ± ·084 | +-----------------+----------+-----------------+----------+ | 900 ” 910 | ± ·442 | | | +-----------------+----------+-----------------+----------+

Thus, by making the proper ADDITION to the apparent strength per cent., when the observed temperature is BELOW the normal temperature of the instrument, or a corresponding SUBTRACTION, when it is ABOVE it, the strength of the sample may be determined sufficiently near for all practical purposes.

The following Table, taken from Loftus’s ‘Inland Revenue Officer’s Manual,’ will be found of great value in making these corrections, and has the merit of being easily applied.

An example will show how this Table is to be used.

Example.——If a quantity of spirit is of the sp. gr. 894 at 73°, what will be its sp. gr. at 60°?

Here the sp. gr. being between 890 and 900, we must add ·450 for each degree of temperature between 73° and 60°. The sp. gr. at 60° would, therefore, be 894 + (·450 × 13) = 899·85. When the temperature is below 60°, the correction for each degree must be subtracted. When, however, very accurate results are desired, and the necessary Tables are not accessible, the sample for trial must be brought to the normal temperature of the instrument, in the manner explained under HYDROMETRY.

c. From the SPECIFIC GRAVITY. The temperature having been taken by a thermometer, and the specific gravity ascertained by any of the usual methods, but preferably by means of an accurate glass hydrometer, it merely becomes necessary to refer to Table I, where, against the number expressing the specific gravity, the alcoholic content per cent., by volume, of the sample examined, will be found for 60° Fahr., subject to the corrections just referred to, when the temperature is either above or below this point.

If the precise specific gravity sought cannot be found in the Table, the difference between it and the next greater specific gravity must be taken for the numerator of a fraction, having for its denominator the difference between the greater and the next less specific gravity in the table. This fraction, added to the per-centage of alcohol in the fourth column of the table, opposite the greater sp. gr., will give the true per-centage sought. Thus, the sp. gr. ·96051 is not in the table, and the next greater number is ·96068; the former must, therefore, be deducted from the latter, and the difference (17) put as the numerator of the fraction, having for its denominator 191, the difference between ·96068 and ·95877. The fraction (17/191) ·089, so found, added to the per-centage strength opposite ·96068 in the third column, gives 33·989 as the true per-centage of alcohol in the given sample.

The per-centage by volume may be converted into per-centage by weight, by multiplying the former by ·793811, the sp. gr. of absolute alcohol, and dividing the product by the sp. gr. of the sample. The quotient is the number of pounds of alcohol in 100 pounds of the given spirit. Thus:——Suppose 1000 grains by measure of alcohol to weigh 950·92 grains, and to contain (see Table I) 40·63 per cent. by volume of absolute alcohol, what per cent. by weight does the sample contain?

·793811 × 40·63 = 32·25254093, and this product divided by ·95092 = 33·917, the true per-centage by weight of absolute alcohol in the sample.

2. Method based on the specific gravity, or per-centage strength by WEIGHT:——

The specific gravity is ascertained and the Table used in precisely the same manner as in the “method by volume,” already described.

The per-centage by weight may be converted into per-centage by volume, by multiplying the former by the sp. gr. of the sample, and dividing the product by the sp. gr. of absolute alcohol. This is merely the reverse of the operation described above.

Obs. The preceding methods of alcoholometry, as well as all others depending on the sp. gr. refer to UNSWEETENED SPIRITS only; and are inapplicable to those holding sugar in solution, or any other organic matter capable of altering the sp. gr. For sweetened spirits, fermented worts, wine, beer, &c., one or other of the following processes must be adopted:——

3. Other methods, adapted to either SWEETENED or UNSWEETENED SPIRITS, Tinctures, Fermented Liquors, &c.——

a. By DISTILLATION as originally proposed by M. Gay-Lussac. 300 parts of the liquor under examination (measured in a graduated glass tube) are placed in a retort or small still, and a quantity exactly equal to one third (i.e., 100 parts), carefully drawn over; a graduated glass tube[13] being used as a receiver, and the operation stopped as soon as the distillate reaches the hundredth degree. The ‘alcoholic strength’ of the distilled liquor is then ascertained by any of the usual methods, and the result divided by three, when the per-centage of alcohol in the original liquor is at once obtained. If, from want of attention, more than 100 parts should be distilled over, the number which expresses the relation of the volume of the distilled product to the original bulk of the liquor tested, must be employed as the divisor. Thus, if 106 parts of liquor have distilled over (instead of 100), containing 33% of alcohol, the 300 must be divided by 106, which gives 2·83, and the 33% by this 2·83, which gives 11·66%, the true proportion of alcohol in the original liquor. The strength at ‘proof’ may be calculated from this in the usual way.

[Footnote 13: Mulder, in his ‘Chemistry of Wine’ recommends this receiver to be shaped like a bottle, with its neck, or tubular part, bent at right angles above the line of its scale; and that it should be set in the centre of a glass jar kept filled with very cold water.]

To ensure accurate results, the acidity (if any) of the liquor must be neutralised with carbonate of sodium, prior to distillation. It is also advisable to add 8% or 10% of common salt to the liquor in the retort or still; this, by raising the boiling point, causes the whole of the spirit to pass over into the receiver before the distillate has reached the required measure. This applies more particularly to weak liquors. With those of greater strength (as the stronger wines), it is better to distil over 150 parts, and divide the result by 2 instead of 3. To liquors stronger than 25% by volume of alcohol, or above 52% to 54% under proof, add about an equal volume of water to the liquor in the still, and draw over a quantity equal to that of the sample tested; when the alcoholic strength of the distillate gives, without calculation, the true strength sought. To liquors stronger than 48% to 50% (14 to 12 u. p.), add thrice their bulk of water, and do not stop the process until the volume of the distillate is double that of the sample tested, when the per-centage obtained must also be doubled. In each case a proportionate quantity of salt is employed.

REVENUE METHOD. The following is the method adopted in the Inland Revenue and Customs Laboratories for the estimation of the per-centage of alcohol in wines, liqueurs, &c. A measure flask is filled up to a mark on its neck, with the wine, which is then carefully transferred to a distilling flask or retort, the traces of wine remaining in the former vessel being rinsed out with small quantities of distilled water, and the rinsings added to the wine in the latter vessel. About two thirds of the contents of the retort are then distilled over into the clean measure flask, and made up to the original bulk with distilled water, at the same temperature as the sample was previous to distillation. The strength is then taken by Sykes’ hydrometer, and this (if u. p.) deducted from 100, gives the per-centage of proof spirit in the wine. Thus:——

Strength of distillate = 74·6 u. p. = 25·4 per cent. proof spirit.

b. From the TEMPERATURE of the VAPOUR, as originally proposed by Gröning. The bulb of a thermometer is thrust through a cork into the head of the still, or other vessel employed, and the temperature of the vapour in which it is immersed being noted, is sought in the following table:——

TABLE III.——Showing the Alcoholic Content, by VOLUME_, of Boiling Spirits, and of their Vapour, from the Temperature of the latter, as observed by a Thermometer._ By GRÖNING.

+---------------+-------------------+-------------------+----------------+-------------------+------------------+ |Temperature of | Alcoholic content | Alcoholic content | Temperature of | Alcoholic content | Alcoholic content| | the Vapour. | of the Distillate | of the Boiling | the Vapour. | of the Distillate | of the Boiling | | Fahr. | per cent. | Liquid per cent. | Fahr. | per cent. | Liquid per cent.| +---------------+-------------------+-------------------+----------------+-------------------+------------------+ | 170·0 | 93 | 92 | 189·8 | 71 | 20 | | 171·8 | 92 | 90 | 192·0 | 68 | 18 | | 172·0 | 91 | 85 | 194·0 | 66 | 15 | | 172·8 | 90-1/2 | 80 | 196·4 | 61 | 12 | | 174·0 | 90 | 75 | 198·6 | 55 | 10 | | 174·6 | 89 | 70 | 201·0 | 50 | 7 | | 176·0 | 87 | 65 | 203·0 | 42 | 5 | | 178·3 | 85 | 50 | 205·4 | 36 | 3 | | 180·8 | 82 | 40 | 207·7 | 28 | 2 | | 183·0 | 80 | 35 | 210·0 | 13 | 1 | | 185·0 | 78 | 30 | 212·0 | 0 | 0 | | 187·4 | 76 | 25 | | | | +---------------+-------------------+-------------------+----------------+-------------------+------------------+

This method is admirably adapted to the purposes of the distiller and rectifier, as it furnishes a ready means of approximately determining the strength of the spirit passing over, at every part of the process of distillation, as well as that of the wash left in the still.

c. From the BOILING POINT, as originally proposed by M. l’Abbé Brossard-Vidal. This method is founded on the fact, that the boiling points of mixtures of alcohol and water, unlike water alone, are scarcely disturbed by the addition of saline, saccharine, or extractive matter within certain limits. It hence offers a ready means of determining the proportion of alcohol present in spirits, wines, fermented liquors, &c., with sufficient accuracy for all ordinary purposes. In applying it, a thermometer, with a large bulb and a narrow bore, and a movable scale graduated from 180° to 212° Fahr., is usually employed. Before using it as an alcoholometer, it is set, with its bulb immersed, in a small metallic boiler (brass or copper) containing distilled water, which is then raised to the boiling-point, and the 212° of the scale accurately adjusted on a level with the surface of the mercury, should it vary from that point. This is necessary on account of variations of atmospheric pressure causing corresponding variations of the boiling-points of liquids. It is then ready for several hours’ operations, and, generally, for an entire business day, without further adjustment. The little boiler is next filled with the liquor to be examined, and the lamp again lighted. The temperature as shown by the scale of the instrument at the commencement of full ebullition being ascertained, may be sought in one of the following Tables, against which the alcoholic content of the liquor will be found (nearly).

TABLE IV.——Exhibiting the BOILING POINTS of Mixtures of Alcohol and Water of the given strengths. By GRÖNING.

---------------+------------+----------------+------------ | Alcohol | | Alcohol Boiling point. | per cent. | Boiling point. | per cent. Fahr. | by volume. | Fahr. | by volume. ---------------+------------+----------------+------------ 205·34 | 5 | 179·96 | 55 199·22 | 10 | 179·42 | 60 195·8 | 15 | 178·7 | 65 192·38 | 20 | 177·62 | 70 189·50 | 25 | 176·54 | 75 187·16 | 30 | 175·46 | 80 185· | 35 | 174·92 | 85 183·38 | 40 | 174·2 | 90 182·12 | 45 | 173·14 | 95 181·58 | 50 | 172· | 100 ---------------+------------+----------------+------------

TABLE V.——Showing the BOILING POINTS of ‘under proof’ spirit. By Dr URE.

----------------+-------------+--------------- Boiling points. | Per-centage | Corresponding Fahr. | strength. | Sp. Gr. ----------------+-------------+--------------- 178·5 | Proof. | ·9200 179·75 | 10· U.P. | ·9321 180·4 | 20· ” | ·9420 182·1 | 30· ” | ·9516 183·4 | 40· ” | ·9600 185·6 | 50· ” | ·9665 189· | 60· ” | ·9729 191·8 | 70· ” | ·9786 196·4 | 80· ” | ·9850 202· | 90· ” | ·9920 ----------------+-------------+---------------

Obs. This method does not answer well with spiritous liquor above ‘proof,’ owing to the variations of their boiling point being so slight as not to be easily observed with accuracy; but with liquors under ‘proof,’ and particularly with wines, beer, and other fermented liquors, due care being observed, it gives results closely approximating to those obtained by distillation, and sufficiently accurate for all ordinary purposes. In testing strong alcoholic solutions it is, therefore, proper to dilute them with twice their bulk of water; and commercial spirits, with an equal bulk of water; the results obtained being doubled or tripled as the case may be.

d. From the EXPANSION of the LIQUID when heated: Silbermann’s DILATATOMETER. The expansion of alcohol between 0° and 212° Fahr. is triple that of water; and between 77° and 122° Fahr. it is much greater. Between -14° and -98° Fahr. the rate of expansion is about the ·00047th part in volume for every degree of Fahrenheit’s scale. The measurement of this expansion has been proposed as a new and ready method of alcoholometry, adapted to nearly all spirituous and fermented liquors. Silbermann’s instrument, which is based on it (see engr.), simply consists of a flat brass or ivory plate (A), on which are fixed a mercurial thermometer (D) graduated from 22° to 50° Cent. (= 77° to 122° Fahr.); and the DILATATOMETER (B), which is a glass pipette open at both ends. A valve of cork, or vulcanised india rubber, closes the tapering end (c); this valve is attached to a movable rod (C) which is fastened to the supporting-plate, and connected with a spring (f) and a handle (g) bearing a four-threaded screw, by which the lower orifice of the pipette can be opened or closed at will. In use, the pipette is filled with the liquor under examination, to a little above the zero point (0) on the scale. This is effected by suction, by means of a little piston of leather (i), which fits tightly in the long and wider limb of the pipette; the valve (d) being previously opened by turning the knob (h). The proper quantity of liquor being introduced, and the lower end closed, the piston is moved up and down two or three times, for the purpose of drawing the air-bubbles and absorbed air out of the liquid, the presence of which would vitiate the results of the trial. To allow the piston to be withdrawn without any shock, or the danger of dividing the column abruptly, the rod attached to it is made hollow throughout. In using it the operator applies the ball of his forefinger to the top of the piston-rod (E), in order to create a vacuum as he raises it; and then withdraws it, to readmit the air when he thrusts it down or removes it from the tube. The excess of liquid (if any) in the pipette is then run off until its upper surface is exactly level with the zero (0) of the scale, at 25° C., to which it is raised by immersion in a water bath of that temperature, as observed by the thermometer; which is done by very cautiously turning the rod which depresses the valve. The whole apparatus is now again immersed in the water bath; and, held by the upper portion of the plate, kept in gentle motion with the hand, until the temperature rises to exactly 50° C., when the coefficient of expansion is obtained, and hence also the proportion of alcohol——the scale of the instrument being so graduated, from actual experiments previously made upon mixtures of known composition, as to give, at once, the per-centage of alcohol by VOLUME (nearly).[14]

[Footnote 14: ‘Comptes Rendus,’ xvii, 418.]

e. From the TENSION of the VAPOUR:——Geissler’s ALCOHOLOMETER. This method, for which we are indebted to M. Geissler, of Bonn, depends on the measurement of the tension or elastic force of the vapour of the liquid, as indicated by the height to which it raises a small column of mercury. The spirit, wine, or other liquor, of which it is desired to ascertain the strength, is put into the little flask (a), which, when completely filled, is screwed on to the curved glass-tube which contains the mercurial column (which is inverted for the purpose), and is closed by the stop-cock (b). The instrument (see engr.) is then placed erect, and the flask and lower part of the tube immersed in a water bath, as in the previous method. The number, on the graduated scale of the instrument corresponding to the height of the mercury, at the boiling point of the liquor under examination, gives the per-centage of alcohol by VOLUME (nearly).

This method furnishes approximative results with great facility and expedition; and, with proper care, these do not vary more than 1/3 to 1/2 of 1%, from those obtained by distillation. We find, that by having the diameter of the part of the tube at which the surface of the mercury is acted on by the vapour a little larger than that of the longer limb, and by previously abstracting the air from the sample, as in Silbermann’s method, or even by agitation and exposure in an open vessel, the two may be made to correspond almost exactly.

f. From the DIFFERENCE between the sp. gr. BEFORE and AFTER ebullitiom:——Taberié’s method and ŒNOMETER. The sp. gr. of the sample is first accurately determined by any of the usual methods. It is next carefully evaporated, in an open vessel, to one half its volume. The residuum, when cold, is made up with pure water to exactly its original measure at its original temperature, and the sp. gr. again ascertained. The difference between the two being due to the spirit originally present, furnishes the means of calculating a new sp. gr., from which the per-centage richness of the sample may be obtained by mere inspection of the Tables. The observed sp. gr. is the true one, whenever the liquor, after ebullition and restoration to its original volume, has the same sp. gr. as water (i. e., 1·000), at 60° Fahr. Taberié employs a peculiar instrument, which he calls an œnometer; but its use is not essential to his method of alcoholometry. The results are, of course, only approximative, though sufficient for all ordinary purposes. Prof. Mulder, however, says that he prefers it to any of the previous methods; and that the results, with care, are almost as accurate as those obtained by distillation.

g. By means of CARBONATE OF POTASH:——

g. a. (Brande’s Method.) The liquor for trial is poured into a long, narrow glass tube (graduated centesimally), until the vessel is half-filled, and, after the solution of about 12% or 15% of a strong solution of subacetate of lead, or a little finely powdered litharge, is agitated until the colour is entirely, or nearly removed. Anhydrous carbonate of potash, in powder, is next added, until it sinks undissolved, even after prolonged agitation of the liquid. The whole is now allowed to repose for a short time, when the alcohol is seen floating on the top of the aqueous portion of the liquid in a well-marked stratum. Its quantity, read off by means of the graduations of the tube, and doubled, gives the per-centage richness of the sample in alcohol, by volume.

This process answers well with cordials, wines, and the stronger ales; but with very weak liquors it is not to be relied on. The whole operation may be performed in two to five minutes, and (with these exceptions) furnishes very reliable approximative results. In most cases the decolouring part of the process may be omitted. The alcohol thus separated has a sp. gr. of from ·8061 to ·8118, and contains 3% or 4% of water; but for ordinary purposes it may be regarded as pure alcohol.

4. Alcoholometry of MINUTE QUANTITIES of liquid. When only a few drops, or a quantity too small for the application of the preceding methods, can be obtained, an organic analysis may be had recourse to, and the quantity of absolute alcohol calculated from that of the resulting carbonic anhydride and water; care being previously taken to free the sample from other volatile bodies, if it contains any of them.

Gen. commentary. The duties on spirits in England are charged on the number of proof gallons they contain, which is ascertained by gauging or weighing the spirit, and then trying its strength by Sykes’ hydrometer. The per-centage of proof spirit multiplied by the number of gallons gives the net amount of proof spirit to be charged.

‘PROOF STRENGTH’ is an arbitrary standard, adopted for the purpose of facilitating calculations, for which it is well suited; although pure alcohol would, for this purpose, be more simple. As defined by Act of Parliament, 58 Geo. III, c. 28, “proof spirit” is such “as shall, at the temperature of 51° of Fahrenheit’s thermometer, weigh exactly twelve thirteenth parts of an equal measure of distilled water.”

Taking, therefore, water at 51° Fahr. as unity, the sp. gr. of “proof spirit” at 51° Fahr. is 12/13 of 1·000 or ·92308. When such spirit is raised to the temperature of 60° Fahr., its density is ·91984.

Spirit at “proof” contains very nearly equal weights of absolute alcohol and water; the exact proportions according to recent experiments are:——

--------------------------------------------------------------------- | By VOLUME. | | By WEIGHT. |---------------------------------------| Sp. gr. at | | Bulk before | Bulk after admixture| 60° Fahr. | | admixture. | and condensation. | | ----------------+-----------------+----------------------------------| Alcohol. Water.| Alcohol. Water.| | 100·00 + 103·08 | 100·00 + 81·80 | 175·23 } ·91984 | 49·24 + 50·76 | 57·06 + 46·68 | 100·00 } | ---------------------------------------------------------------------

The standard alcohol of the Revenue authorities, and that on which Gilpin’s Tables are founded, is a spirit of the sp. gr. ·825 at 60° Fahr., which is said to contain, by weight, 89% of pure alcohol of ·796; and 92·6% of alcohol, by volume, which corresponds to about 62·5 o. p.

It is of great importance to the spirit dealer to be able to estimate correctly the number of ‘proof gallons’ in any quantity of his commodities, or in the whole or any portion of his stock, as disagreeable errors frequently result from ignorance on this point. Calculations of this kind are extremely simple. Thus, when we find, by the hydrometer, that a given sample of spirit is 10 per cent. over-proof, it means, that 100 gallons of such spirit contain as much alcohol as 110 gallons of proof spirit.

In over-proof spirit, the per-centage o. p. always represents the quantity of water which the given spirit requires to reduce it to proof. By adding this per-centage over-proof to 100, we obtain a number which, multiplied by any number of gallons, and divided by 100, gives the exact number of proof gallons which is contained in any quantity of the spirit referred to. Thus:——A puncheon of rum gauged at 91 galls., and shown by the hydrometer to be 21 o. p., contains——

21 o. p. of sample added to 100 121 No. of gallons of rum 91 —————— 11011

No. of gal. of proof-spirit = 11011 / 100 = 110·11

In like manner when a spirit is said to be 11 u. p., or under-proof, it means that 100 gal. of such spirit contains 11 gal. of water, and 89 gal. of ‘proof spirit.’ By deducting the per-centage under-proof from 100, we not only obtain the number of proof gal. contained in 100 gal. of such spirit, but, as in the last case, a factor which multiplied by any number of gal., and divided by 100, gives the exact number of ‘proof gallons’ contained in any quantity of the given strength. Thus:——An ullage brandy piece containing 45 gal. of spirit at 10 u. p., would have the proof value of——

Per cent. u. p. of sample 10, } subtracted from 100 } 90 No. of gall 45 ——— 4050

Quantity of proof spirit = 4050 / 100 = 40·50

Or exactly 40-1/2 gallons.

The strength of absolute alcohol (sp. gr. ·7938) is estimated at 75-1/4% over-proof. It therefore contains 175-1/4% of ‘proof spirit,’ whilst proof spirit (sp. gr. ·91984) contains 57·06% of ‘absolute alcohol,’ both being by measure or volume. Thus——

(meas. of alc. × 175-1/4) / 100 = equiv. meas. of pf. spt.

And——

(meas. of pf. spt. × 57·06) / 100 = equiv. meas. of abs. alc.

From which we derive the ‘constant multipliers’ 1·7525 (or roughly 1-3/4), and ·5706, applicable to any number of volumes or gallons. For——

meas. of alc. × 1·7525 = equiv. meas. of pf. spt.

and——

meas. of pt. spt. × ·5706 = equiv. meas. of alc.

To ascertain what quantity of a spirit at any given strength is equiv. to or contains 100 lbs. of absolute alcohol, we have only to divide the constant number 2207·7 by the proof value per cent. of such spirit.[15] Thus——for a spirit 12 u. p.——this would be

[Footnote 15: This number is obtained thus:——

100 /·79381 = 12·6 (nearly),

12·6 × 175·25 = 2207·7.

]

100 - 12 = 88% of proof spirit;

and——

2207·7 / 88 = 25·1 gal. (nearly).

That is, 25-1/10 gal. of such spirit would contain 100 lbs. of absolute alcohol.

By removing the decimal point one place to the right, we have the equiv. measure of 1000 lbs. By removing it one, two, or three places to the left, we have it respectively for 10 lbs., 1 lb., and 1/10 lb.; from which the equiv. for all other weights may be easily obtained.

By reversing the above operation, the measure of alcohol corresponding to any given weight of spirit, at any strength, may also be easily found.

The weight of 1 gal. of absolute alcohol being 7·938 lbs.; that of 1 gal. of proof spirit, 9·2 lbs,; and that of the ‘alcohol’ in 1 gal. of proof spirit, 4·53 lbs.; the weight of any number of gallons or volumes of either, and their equivalents, may be easily found. Thus:——

gallons of alc. × 7·938 = lbs. weight of alc. ” pf. sp. × 9·2 = lbs. w. of pf. spt.

and——

gallons of alc. × 16·121 = lbs. weight of pf. spt. ” pf. spt. × 4·53 = content in lbs. weight of alc.

In these cases a knowledge of the first four rules of decimal fractions is necessary, or, at least, advantageous; as the Excise officers carry their calculations to two figures of decimals, or 1/100ths. Their plan is to reject the third decimal figure when less than 5; but to carry 1 to the next figure on the left hand, when it exceeds 5. Thus, 5·432 is set down as only 5·43; but 5·437 is written 5·44. In the delicate chemical processes of the laboratory, even greater accuracy is observed.

Formerly, spirit was said to be 1 to 3, 1 to 4, &c., over-proof, by which it was meant that 1 gal. of water added to 3 or 4 gals. of such spirit would reduce it to ‘proof.’ On the other hand, 1 in 5, or 1 in 8, under-proof, meant that the 5 or 8 gals., as the case might be, contained 1 gal. of water, and the remainder represented the quantity of ‘proof spirit.’ This method of calculation has now long given way to the ‘centigrade system,’ which not only admits of greater accuracy, but is quite as simple. It should be adopted by every spirit-dealer in England, from being that which is employed by the Revenue officers, whose ‘surveys’ it is absolutely necessary that the trader should understand, in order that his own estimation of his stock and his business calculations should correspond with theirs.

Several other methods of alcoholometry, besides those already noticed, have been adopted at various times, but the majority of them possess so little accuracy as to be quite inapplicable to the purposes of trade, and of the laboratory. Thus, the strength was at one time estimated by what was called the ‘proof.’ A little of the spirit was poured upon a small quantity of gunpowder, contained in a spoon or saucer, so as just to moisten it, and was then inflamed. If at the end of the combustion the gunpowder took fire, the spirit was held to be ‘above proof,’ if it only languidly fizzed away, or slowly burnt, the spirit was said to be ‘proof,’ but if the gunpowder failed to ignite, the spirit was esteemed ‘below proof.’ Hence arose the terms ‘proof’ and ‘proof spirit,’ which have since been adopted by Act of Parliament. Another method was that of dropping oil into the spirit; if the oil floated, the spirit was considered to be ‘under proof,’ if it sunk, it was rated as ‘proof’ or ‘over-proof.’ The ‘gunpowder test’ is quite fallacious; for, if a certain quantity of a spirit is capable of firing the gunpowder, a little excess of a spirit 20% or 25% stronger will often fail to do so, so much water being formed as to prevent the ignition. The ‘PREUVE D’HOLLAND’ test, of the French, or the ‘BEAD,’ is still frequently employed by persons unacquainted with the use of the hydrometer. It consists in shaking the spirit in a phial, and observing the size, number, and duration of the bubbles or beads, as they are called. The larger and more numerous these are, and the more rapidly they break and disappear, the stronger the spirit is presumed to be. This method is unreliable, as the presence of sugar or acid, even in minute quantities, will sometimes give to a weak sample the appearance of one many degrees stronger. LOVI’S BEADS are also often employed to ascertain approximately the strength of spirit, when a hydrometer is not at hand.

The insufficiency of most of the methods of alcoholometry here referred to, throws us back on the Revenue System (Sykes’ hydrometer), or on the specific gravity for unsweetened spirits. For sweetened spirits, as cordials, wines, beers, &c., there are none of the tests which give such accurate results as the distillation test, previously described as the Revenue Method.

The spirituous liquors of commerce being sold by measure, and not by weight, the methods of alcoholometry which give the results, per cent., by volume, are those we have chiefly explained. In the laboratory, the method by weight is that most generally employed in delicate processes and in analyses. By weight, the per-centage of alcohol remains the same for all temperatures, for the same sample; whilst by volume, the per-centage varies with the temperature of the liquid. This variation explains the cause of many of the sudden apparent decreases and increases, which occur in large stocks of spirits. Persons purchasing spirits during very warm weather, and paying for them according to their apparent quantity and strength, lose considerably by selling the same spirit when the weather becomes colder, without being conscious of such loss from the hydrometer. The reason of this is obvious, for, whilst the relative proportions of the alcohol to the water continue the same, the sp. gr. and the volume alter with the temperature; the latter being increased by warmth, and decreased by cold, in exact opposition to the former. Accuracy requires, in all cases, that a spirituous liquor should be tested for its strength at the temperature at which it was measured; and measured at the same temperature at which its strength was determined.

A consideration of these facts has led some of the great houses to introduce the system of weighing their spirits, instead of measuring them, the weight of an imperial gallon at 60° Fahr. being taken as the standard gallon. This is the method adopted by the Inland Revenue, at all distilleries, for assessing the duty, and will be readily understood by the following example:——

Cwts. qrs. lbs.

Gross weight of full cask = 13 2 27 Tare = 2 2 5 ------------ Net weight of spirit = 11 0 22

or 1254 lbs. Let us suppose the hydrometer indication to be 43·0, the weight per imperial gallon would be 8·903 lbs. (see Table VI), and 1254 ÷ 8·903 = 140 gallons.

TABLE VI.——Table for determining the Weight per Gallon of Spirits by Sykes’ Hydrometer.

A = Indication on Sykes’ Hydrometer. B = Weight per Gallon.

A B A B A B A B A B 0 8·145 8 8·509 6 8·878 4 9·264 2 9·667 2 8·157 21 8·512 8 8·881 6 9·267 4 9·671 4 8·161 2 8·516 42 8·885 8 9·271 6 9·674 6 8·164 4 8·519 2 8·889 63 9·275 8 9·678 8 8·168 6 8·523 4 8·892 2 9·279 84 9·682 1 8·171 8 8·526 6 8·896 4 9·283 2 9·686 2 8·174 22 8·530 8 8·899 6 9·286 4 9·690 4 8·178 2 8·533 43 8·903 8 9·290 6 9·694 6 8·181 4 8·537 2 8·907 64 9·294 8 9·698 8 8·185 6 8·540 4 8·911 2 9·298 85 9·702 2 8·188 8 8·544 6 8·914 4 9·302 2 9·706 2 8·191 23 8·547 8 8·918 6 9·305 4 9·710 4 8·195 2 8·551 44 8·922 8 9·309 6 9·714 6 8·198 4 8·554 2 8·926 65 9·313 8 9·718 8 8·202 6 8·558 4 8·929 2 9·317 86 9·722 3 8·205 8 8·561 6 8·933 4 9·321 2 9·726 2 8·208 24 8·565 8 8·936 6 9·324 4 9·730 4 8·212 2 8·568 45 8·940 8 9·328 6 9·733 6 8·215 4 8·572 2 8·944 66 9·332 8 9·737 8 8·219 6 8·575 4 8·947 2 9·336 87 9·741 4 8·222 8 8·579 6 8·951 4 9·340 2 9·745 2 8·225 25 8·582 8 8·954 6 9·344 4 9·749 4 8·229 2 8·586 46 8·958 8 9·348 6 9·753 6 8·232 4 8·589 2 8·962 67 9·352 8 9·757 8 8·236 6 8·593 4 8·965 2 9·356 88 9·761 5 8·239 8 8·596 6 8·969 4 9·360 2 9·765 2 8·242 26 8·600 8 8·972 6 9·363 4 9·769 4 8·245 2 8·603 47 8·976 8 9·367 6 9·773 6 8·249 4 8·607 2 8·980 68 9·371 8 9·777 8 8·252 6 8·610 4 8·984 2 9·375 89 9·781 6 8·255 8 8·614 6 8·987 4 9·379 2 9·785 2 8·258 27 8·617 8 8·991 6 9·382 4 9·789 4 8·262 2 8·620 48 8·995 8 9·386 6 9·792 6 8·265 4 8·624 2 8·999 69 9·390 8 9·796 8 8·269 6 8·628 4 9·002 2 9·394 90 9·800 7 8·272 8 8·631 6 9·006 4 9·398 2 9·804 2 8·275 28 8·635 8 9·009 6 9·401 4 9·808 4 8·279 2 8·639 49 9·013 8 9·405 6 9·812 6 8·282 4 8·642 2 9·017 70 9·409 8 9·816 8 8·286 6 8·646 4 9·021 2 9·413 91 9·820 8 8·289 8 8·649 6 9·024 4 9·417 2 9·824 2 8·292 29 8·653 8 9·028 6 9·420 4 9·828 4 8·296 2 8·656 50 9·032 8 9·424 6 9·832 6 8·299 4 8·660 2 9·036 71 9·428 8 9·836 8 8·303 6 8·663 4 9·039 2 9·432 92 9·840 9 8·306 8 8·667 6 9·043 4 9·436 2 9·844 2 8·309 30 8·670 8 9·046 6 9·440 4 9·848 4 8·313 2 8·674 51 9·050 8 9·444 6 9·852 6 8·316 4 8·677 2 9·054 72 9·448 8 9·856 8 8·320 6 8·681 4 9·058 2 9·452 93 9·860 10 8·323 8 8·684 6 9·061 4 9·456 2 9·864 2 8·326 31 8·688 8 9·065 6 9·459 4 9·868 4 8·330 2 8·692 52 9·069 8 9·463 6 9·872 6 8·333 4 8·695 2 9·073 73 9·467 8 9·876 8 8·337 6 8·699 4 9·076 2 9·471 94 9·880 11 8·340 8 8·702 6 9·080 4 9·475 2 9·884 2 8·343 32 8·706 8 9·083 6 9·479 4 9·888 4 8·347 2 8·709 53 9·087 8 9·483 6 9·892 6 8·350 4 8·713 2 9·091 74 9·487 8 9·896 8 8·354 6 8·716 4 9·095 2 9·491 95 9·900 12 8·357 8 8·720 6 9·098 4 9·495 2 9·904 2 8·361 33 8·723 8 9·102 6 9·498 4 9·908 4 8·364 2 8·727 54 9·106 8 9·502 6 9·913 6 8·368 4 8·730 2 9·110 75 9·506 8 9·917 8 8·371 6 8·734 4 9·114 2 9·510 96 9·921 13 8·375 8 8·737 6 9·117 4 9·514 2 9·925 2 8·378 34 8·741 8 9·121 6 9·517 4 9·929 4 8·382 2 8·745 55 9·125 8 9·521 6 9·934 6 8·385 4 8·748 2 9·129 76 9·525 8 9·938 8 8·389 6 8·752 4 9·132 2 9·529 97 9·942 14 8·392 8 8·755 6 9·136 4 9·533 2 9·946 2 8·395 35 8·759 8 9·139 6 9·537 4 9·950 4 8·399 2 8·763 56 9·143 8 9·541 6 9·955 6 8·402 4 8·766 2 9·147 77 9·545 8 9·959 8 8·406 6 8·770 4 9·151 2 9·549 98 9·963 15 8·409 8 8·773 6 9·154 4 9·553 2 9·967 2 8·412 36 8·777 8 9·158 6 9·557 4 9·972 4 8·416 2 8·781 57 9·162 8 9·561 6 9·976 6 8·419 4 8·784 2 9·166 78 9·565 8 9·981 8 8·423 6 8·788 4 9·170 2 9·569 99 9·985 16 8·426 8 8·791 6 9·173 4 9·573 2 9·989 2 8·429 37 8·795 8 9·177 6 9·576 4 9·994 4 8·433 2 8·799 58 9·181 8 9·580 6 9·998 6 8·436 4 8·802 2 9·185 79 9·584 8 10·003 8 8·440 6 8·806 4 9·189 2 9·588 100 10·007 17 8·443 8 8·809 6 9·192 4 9·592 2 8·446 38 8·813 8 9·196 6 9·596 4 8·450 2 8·817 59 9·200 8 9·600 6 8·453 4 8·820 2 9·204 80 9·604 8 8·457 6 8·824 4 9·207 2 9·608 18 8·460 8 8·827 6 9·211 4 9·612 2 8·464 39 8·831 8 9·214 6 9·615 4 8·467 2 8·835 60 9·218 8 9·619 6 8·471 4 8·838 2 9·222 81 9·623 8 8·474 6 8·842 4 9·226 2 9·627 19 8·478 8 8·845 6 9·229 4 9·631 2 8·481 40 8·849 8 9·233 6 9·635 4 8·485 2 8·853 61 9·237 8 9·639 6 8·488 4 8·856 2 9·241 82 9·643 8 8·492 6 8·860 4 9·245 2 9·647 20 8·495 8 8·863 6 9·248 4 9·651 2 8·498 41 8·867 8 9·252 6 9·655 4 8·502 2 8·871 62 9·256 8 9·659 6 8·505 4 8·874 2 9·260 83 9·663

⁂ For further information in connection with Alchoholometry see ALCOHOL, BEER, BREWING, DISTILLATION, EBULLIOSCOPE, HYDROMETER, HYDROMETRY, LIQUEURS, MALT-LIQUORS, ORGANIC SUBSTANCES, SACCHARINE, SPECIFIC GRAVITY, SPIRIT, SUGAR, SYRUPS, TINCTURES, WINE, WORT, &c. &c.

=ALCOHOL; EFFECTS OF ALCOHOLISM.= Without entering into the controversy as to whether the moderate consumption of alcohol, or its total disuse, is the more conducive to personal health and comfort——whether, as Dr Anstie and others have asserted it acts, when prudently taken, as a food——or whether, as other medical authorities contend, even its moderate use is a disturbing factor in the human economy——there need be no qualification of the assertion, that when the drinking of spirituous liquids of any kind is indulged in to excess, the habit, if persisted in, must sooner or later terminate in impaired health, serious disease, and premature death.

A powerful array of facts could be brought in support of this statement. For instance, in NELSON’S statistics we find it mentioned that——

A temperate person’s | An intemperate person’s chance of living is—— | chance of living is—— | At 20 = 44·2 years. | At 20 = 15·6 years. ” 30 = 36·5 ” | ” 30 = 13·8 ” ” 40 = 28·8 ” | ” 40 = 11·6 ” ” 50 = 21·25 ” | ” 50 = 10·8 ” ” 60 = 14·285 ” | ” 60 = 8·9 ”

The average duration of life after the commencement of habits of intemperance is——

Among mechanics, working and labouring men 18 years. ” traders, dealers, and merchants 17 ” ” professional men and gentlemen 15 ” ” females 14 ”

Again, Dr Dickinson, writing “on the morbid effects of alcohol in persons who trade in liquor,” gave the results of an examination of 149 traders in liquor, as compared with 149 persons of various trades. The general results were diseases of the liver much more common in those who dealt in alcoholic drinks. In the lungs tubercle affected sixty-one persons of the alcoholic, forty-four of the non-alcoholic.

Tubercle in the brain, liver, kidneys, spleen, bowels, mesenteric glands, and peritoneum were twice as common in the alcoholic as in the non-alcoholic. The verdict, therefore, is unavoidable that alcohol (in excess) engenders tubercle in the brain, inflammations, atrophy, hæmorrhages; in the heart and vessels atheroma, hypertrophy, and other affections, were all more common in the alcoholic than in the non-alcoholic series. The evidence in kidney disease did not appear so conclusive, but some forms of kidney disease appear to be increased. The author sums up thus:——“Alcohol causes fatty infiltration and fibroid encroachment; it engenders tubercle, encourages suppuration, and retards healing; it produces untimely atheroma, invites hæmorrhage, and anticipates age. The most constant fatty change, replacement by oil of the material of epithelial cells and muscular fibres, though probably nearly universal, is most noticeable in the liver, the heart, and the kidney.”

Alcohol also seems to be the cause of special diseases, besides those more common and generally known ones, delirium tremens, alcoholism, &c. Of these we may mention one recorded by M. GALEZOWSKI, a peculiar affection of the eyes, which the doctor found very prevalent during the siege of Paris in 1870-1. In the five months of the siege fifty patients were affected by it, whilst during the twelve months preceding the siege only nineteen were to be found. Dr GALOWSKI ascribed the malady to the habit of taking alcoholic drinks in the morning fasting. A peculiar kind of palsy has also been referred to alcoholic poisoning.

The following table, compiled by Dr Joseph Williams, lends support to the fact that an indulgence in alcohol is either the cause of insanity, or that it tends to its increase:

Proportion Total caused by admission. intemperance.

Charenton 855 134 Bicêtre and Salpêtrière 2012 414 Bordeaux 156 20 Turin, 1830-31 158 17 ” 1831-36 390 76 Gard 209 4 United States 551 146 Palermo 189 9 Caen 60 16 Dundee 14 4 M. Parchappe 167 46 M. Batten 288 54 ———— ——— 5019 940

Commenting on these figures, Mr Walter Blyth remarks, “There may be another explanation of the fact that many mad people have been great drinkers. A large proportion of those subject to insanity are driven by their morbid minds to drink; so that it may be that insanity causes drink, and not drink causes insanity.”

Many medical writers who are no advocates for the total abandonment of alcohol limit its consumption, in healthy people, to one or two fluid ounces a day, in the form of wine, beer, or spirits and water; two fluid ounces is, we believe, the quantity apportioned daily to every able-bodied seaman in the Royal Navy. Any slight habitual departure from this standard——even when the evidences of excess are not perceptible to others——all authority, historical, pathological, and physiological (unless it be given as a medicine), shows to be injurious. The researches of Anstie, Parkes, and Count Wollowicz, appear to prove that any quantity of alcohol exceeding an ounce and a half taken by an adult showed itself in the urine, a circumstance which these writers look upon as tending to show that the system has taken more alcohol than can be used in the body itself. In slight doses the action of alcohol is to produce a sedative effect upon the nerves, to redden slightly the lining membrane of the stomach, and to stimulate the secretion of the gastric juice.

Thus, in small doses alcohol may, and doubtless does, promote appetite. In excess, however, all these effects are turned to evil, and then ensue an inflammatory condition of the stomach, compression of the gland ducts from thickening of the tissue around them, excessive mucous secretion, and great loss of appetite. When carried into the circulation it greatly increases the force of the heart’s action, and at the same time paralyses, as it were, the restraining nervous supply to the arteries and small vessels, so that they can no longer oppose themselves to the blood-current, but dilate. This action in a small degree, occurring in persons of a weak and languid circulation, is no doubt beneficial; on the other hand, when in excess, it is most dangerous, and is a cause of the greater part of the diseases of the heart and great vessels.

“There appears to be a slight fall of temperature with moderate doses of alcohol, a very decided fall with excessive doses; the muscular and nervous systems are transitorily stimulated, and may do more work when small doses are given in cases of fatigue, but in other cases there is a marked torpor of the nervous and a want of co-ordination of the muscular system.”——BLYTH.

Notwithstanding the researches of Percy, Strauch, Masing, Lallemand, Duroy, Parkes, Dupré, Anstie, Thudichum, and others, there is still a considerable divergence of opinion as to how alcohol is eliminated from the body. By some of the authorities just named it is affirmed to be eliminated as aldehyd, by others as carbonic acid; as to the latter, the experiments of Dr E. Smith show that the carbonic acid is decreased when brandy and gin are drunk, and increased by rum.

The only probable supposition, which facts support, tends to show that the alcohol is turned into acetic acid in the body, some of which unites with potash and other bases, and some is destroyed. All are pretty well agreed that in the form of spirits alcohol as a food is valueless, but that in the form of beer and wine it is possessed of a slight dietetic power, naturally varying with the amount and nature of the different substances held in solution in these beverages.

The imports of spirits into this country, in the seven years from 1850 to 1857, amounted to 70,740,980 gallons; whilst the imports in the seven years following, viz. from 1857 to 1864, were 78,016,071 gallons, showing an increase of 7,305,091 gallons. The population has, however, increased in the time, and a deduction on that account, as well as correction on one or two other heads, are required; still, that there is an increase is indisputable.

As respects France, a considerable increase in the consumption of spirits has taken place of late years, as the following table by M. Husson will illustrate:

The Mean Consumption of Spirits for each Inhabitant.

Litres. Litres.

From 1825 to 1830 8·96 yearly. ·024 daily. ” 1831 ” 1835 8·74 ” ·023 ” ” 1836 ” 1840 10·15 ” ·026 ” ” 1841 ” 1845 11·14 ” ·031 ” ” 1846 ” 1850 11·03 ” ·030 ” ” 1851 ” 1854 14·25 ” ·039 ”

In the United States, during the period from 1807 to 1828, the average was 27 litres for every inhabitant, which is even greater than the highest of the two sets of figures just quoted.

The demoralisation of the French army during the late Franco-Prussian war has been also unanimously ascribed to the excessive consumption of spirituous liquids.

The following results of an inquiry instituted in 1870 by the Massachusetts Board of Health into the comparative sobriety of different nations are gathered from an able paper which appeared in the ‘Medical Times and Gazette’ of April 15th, 1872, by Dr Druitt, in which he dissects and summarises the results in question. Dr Druitt writes:

“Highest in the scale of temperance come the Turks and Arabs; next the Iberians, Levantines, Greeks, and Latin races; lower down the Japanese, Scandinavians, Belgians, and the Irish Celt; lowest of all the so-called Anglo-Saxon of either continent.”

Professor Levi contributes to our knowledge on this subject by giving the following statistics:——In 1860 the committals for drunkenness in England and Wales were 88,000, and in 1870 134,000, an increase of 50 per cent.

In Manchester the increase from 1860 to 1870 was 375 per cent., or computed according to the increase of population 35·3 per cent. In London drunkenness is in the proportion of 5·43 per 1000, in Leeds 7·40, in Manchester 31·13, and in Liverpool 42·82. It must, however, be remembered that these figures are based on mere committals, which greatly depend on the activity of the police, and the noisy or quiet character of the drunkard.

We quote the following from Dr Blyth’s work on ‘Hygiene,’ without, however, attempting either to endorse or controvert what he says on the subject.

“Whether is Alcohol necessary or not. All experience, both at home and abroad, shows by facts that cannot be disputed that a person can do quite as hard work without alcohol as with it; and probably as the limits between moderation and excess are easily passed, and as the generality of mankind, even without intending it, err on the latter side, the result is that a comparison between total abstainers and even temperate men generally terminates in favour of the former. It would appear that total abstainers live longer, are better citizens, and can do more work than the rest of mankind. The figures of the “United Kingdom Temperance and General Provident Institution” go far to prove the above. This insurance society is divided into two sections. One section consists of abstainers, the other of persons selected as not known to be intemperate. The claims for five years anticipated in the temperance section were £100,446, but the actual claims were only £72,676. In the general section of the anticipated claims were £196,352; the actual claims no less than £330,297. In war the march of 2000 miles in his War of Independence by Cornwallis and his troops (1783), the Maroon war of Jamaica, the 400 miles’ march of an English army across the Desert from Komer, on the Red Sea, a march of 1000 miles in the Kaffir war, experiences at sieges, in action, in hot, temperate, and cold climates, where abstinence was either forced through circumstances or followed, shows to every unprejudiced mind that soldiers endure more fatigue, are healthier, and fight better, without stimulants than with them; and this fact is endorsed by every commander of the present day.

The excess and abuse of spirits, as before remarked, lost the French their military prestige in the Franco-German war. In very hot and very cold climates the Indian observers and the Arctic explorers all unite in condemning its (that is, the use of alcohol) use in the slightest excess, or even in moderate doses. It does not warm the body in cold climates, and the reaction that follows the exciting of the circulation is followed by a dangerous depression; whilst in hot it combines with the climate, and quickly produces disease.”

=ALCOHOLIC DRINKS, EFFECTS OF.= In addition to the serious injury to health caused by an excessive or imprudent indulgence in spirituous stimulants (see previous article), even a moderate and not injudicious use of them may often be attended with very disagreeable consequences——a more or less mild or modified form of poisoning, in fact——if the beverages themselves are, as very frequently happens, contaminated, either accidentally or intentionally, with certain objectionable ingredients. These ingredients are described under the articles BEER, WINES, and the various SPIRITS, such as GIN, BRANDY, ABSINTHE, &c. Of spirit drinking it may be observed, that this dangerous practice is intensified by what is to be feared is the too prevalent custom of taking them undiluted, or “neat,” as it is termed. There is no doubt that they constitute the very worst form of alcoholic drinks, and shorten the lives of those who indulge in them to excess more summarily than any other intoxicating potion. The greatest and most ineradicable drunkards are almost always found to be spirit drinkers.

Liebig remarked that less bread was consumed in families where beer was drunk, and there seems to be little doubt that the different species of beer, including porter and ale, when pure and free from adulteration, act, although in a small degree, as food. Probably there are some who will agree with, whilst others will dissent from, Benjamin Franklin, who said “there was more sustenance in a penny loaf than in a gallon of beer.” The starchy extractive matters of the beer no doubt perform the same function in the animal economy that sugar does. It is well known that those who drink freely of beer mostly become corpulent, as witness the portly forms of draymen. The hop contained in the beer has doubtless tonic and stomachic qualities. We can speak with less certainty about the free acids contained in malt fluids. It is very certain that some people cannot drink a glass of beer without experiencing rheumatic pains in the joints, which effect is generally ascribed to the acidity of the beer; but which is really supposed to be due to the decreased elimination of urea and pulmonary carbonic acid from the system caused by the alcohol of the beer.

The heavy low-priced beers occasion drunkenness of a peculiarly violent and savage kind, a fact which strongly favours the inference that this form of intoxication is due to some toxic agent, used as an adulterant. Of wines, the clarets and subacid wines are undoubtedly antiscorbutic in properties, and light wines as beverages are preferable to the stronger. Port, sherry, beer, stout, and ale are almost universally condemned in cases where there is a tendency to gout. The light clarets and Rhine wines are far more desirable beverages when this is the case, and the German wines are said to be valuable drinks in many lithic affections. It seems probable that the ethers and the vegetable salts, together with the sugar contained in wines, perform the most important part in the human economy.

It has been proposed to introduce the red subacid wines as drinks for our sailors, because of their antiscorbutic qualities. Some of the alcoholic drinks prepared in India frequently cause temporary madness.

=ALCOHOLISM.= ALCOHOL; EFFECTS OF ALCOHOLISM.

=AL′COHOLS.= In chemistry, a term applied to compounds possessing a composition, formulæ, and chemical properties similar to those of ordinary alcohol. They form a series presenting an unmistakable symmetry, and differ from one another by well-marked gradations, as shown below:——

Methyl-alcohol (wood spirit). CH_{4}O Ethyl-alcohol (ordinary alcohol) C_{2}H_{6}O Amyl-alcohol (füsel-oil) C_{5}H_{12}O Capryl-alcohol C_{8}H_{18}O Cetyl-alcohol C_{16}H_{34}O &c., &c.

=Alcohols.= In commerce, pure spirits of a greater strength than about 58 o. p. (sp. gr. 8335), or containing more than about 85% by WEIGHT, or 90% by VOLUME, of pure alcohol, are commonly so called.

=Alcohols.= In perfumery, rectified spirit of wine, or commercial alcohol, holding essential oils or other odorous matters in solution.

=Alcohols.= In Fr. pharmacy, alcoholic tinctures and essences.

=ALCOOLATIFS= (alcoölatifs). [F.] Syn. ALCOHOLATI′VA, L. In Fr. pharmacy, alcoholic solutions of liniments, embrocations, &c., whether made by distillation, maceration, or solution.

=ALCOOLATS= (alcoölats). [Fr.] In Fr. pharmacy, spirits; applied by Béral, Henry and Guibourt, and others, to medicated distilled spirits.

=ALCOOLATURES= (alcoölatures). [Fr.] Syn. ALCOHOLATU′′RA, L. In. Fr. pharmacy, alcoholic tinctures, elixirs, &c. M. Béral confines the term to vegetable juices preserved by alcohol.

=ALCOOLES= (alcooölés). [Fr.] Tinctures; the ‘teintures alcoholiques’ of the Fr. Codex.

=ALCOOLIQUES= (alcoöliques). [Fr.] Syn. ALCOHOL′ICA, L. In Fr. pharmacy, alcoholic or spirituous solutions. (Béral.)

=AL′CORNINE= (-nĭn). [Eng., Fr.] Syn. ALCOR′NOCINE (-sĭn); ALCOR′NEUM, ALCORNI′NA, L. A crystallisable substance, apparently intermediate between fat and wax, discovered by Biltz, in alcornoco bark.

=ALCORNO′CO.= Syn. A.-BARK; ALCORNOQUE, Fr.; ALKORNOC, A.-RIND, Ger. The bark of an unknown tree of South America. It is astringent and bitter, and has been highly extolled as a specific in phthisis; but appears to possess little medicinal virtue. The bark of the young branches of the cork tree (quercus suber), used in tanning, is also sometimes called alcornoco-bark; but possesses none of the characters of the former article.

=AL′DECAY.= The galls on the leaves of myrobalanus chebula (Gaertn.), a forest-tree of Bengal. Equal to the best oak-galls.

=AL′DEHYD= (-hīd). [al-(cohol)-dehyd (rogenatus).] C_{2}H_{4}O. Syn. HYDRATED OXIDE OF ACETYLE; HYDRATE OF OTHYLE*; HYDROXIDE OF O.* Literally, dehydrogenated alcohol. In chemistry, a peculiar ethereal liquid, first obtained in a pure form by Liebig, from alcohol. It is produced under various circumstances, particularly during the destructive distillation of certain organic matters, and in several processes of oxidation. The following are the most convenient methods of preparing it:——

Prep. 1. (Liebig.) Sulphuric acid, 3 parts; is diluted with water, 2 parts; and as soon as the mixture has cooled, alcohol of 80%, 2 parts, is added; and, subsequently, peroxide of manganese (in fine powder), 3 parts. The whole, after agitation, is then distilled at a very gentle heat, from a spacious retort into a receiver surrounded with ice, the connection between the two being perfectly air-tight. The process is continued until frothing commences, or the distillate becomes acid which generally occurs when about one third (3 parts) has passed over. The distillate is next agitated in a retort, with about its own weight of fused chloride of calcium, in powder; after which about one half only is drawn over at a very gentle heat (85° to 90° Fahr.), by means of a water bath. This rectification is repeated in a precisely similar way. The last distillate is ANHYDROUS ALDEHYD only slightly contaminated with foreign matters.

2. (Liebig.) Aldehyd-ammonia, 2 parts, is dissolved in an equal weight of distilled water; and, after being placed in a retort, sulphuric acid, 2 or 3 parts, previously diluted with rather more than its own weight of distilled water, and allowed to cool, is added. The whole is now distilled, by means of a water bath, into a receiver surrounded with ice, or (preferably) a freezing-mixture, the temperature of the bath at first being very low, and the operation being stopped as soon, or rather before the water begins to boil. The distillate is then placed in a retort connected with a well-cooled receiver, as before; and after all the joints are made perfectly tight, powdered fused chloride of calcium, in weight equal to that of the liquid in the retort, is added through the tubulature. The heat produced by the hydration of the chloride causes the distillation to commence, after which it is carried on, by means of a water bath, at a temperature ranging from 80° to 82° Fahr. This rectification being very carefully repeated, the last distillate is PURE ANHYDROUS ALDEHYD.

Prop., &c. Limpid, colourless, ethereal, neutral, inflammable; mixes in all proportions with alcohol, ether, and water; odour peculiar, penetrating, and, when strong, exceedingly suffocating, the vapour, in quantity, producing spasmodic contraction of the thorax; boils at 72° Fahr. (70°——Ure, 5th ed.); sp. gr. ·790 at 60°, and ·800 at 32° Fahr.; sp. gr. of vapour, 1·532; by exposure to air it is gradually converted into acetic acid, and speedily so under the influence of platinum-black; heated with caustic potash, a brown substance resembling resin (ALDEHYD-RESIN) is formed; gently heated with protoxide of silver, or its solutions, metallic silver is deposited on the inner surface of the vessel, in a uniform and brilliant film, whilst ALDEHYDATE OF SILVER remains in solution; heated with hydrocyanic acid it yields ALANINE. By age, even in close vessels, it passes into one or more isomeric compounds (ELALDEHYDE; METALDEHYDE), with change of properties. Aldehyde for experiments should, therefore, be always recently prepared; and it must be kept in a well-stopped bottle, in a very cold place, and preferably in ice.

Obs. Aldehyd is important for its assumed position in the acetyl-series, and the part which it plays in the process of acetification, &c. The word is now also commonly employed, by chemists, as a generic term for any organic substance which, by assimilating two atoms of hydrogen, yields, or would yield, a compound having the composition or properties of an alcohol; or which, by taking up one atom of oxygen, yields an acid. Many of the essential oils (as those of almonds, cinnamon, and cumin) are composed principally of bodies which may thus be called aldehyds. One of the most valuable properties of these substances, is their strong tendency to combine with the bisulphites of ammonium, potassium, and sodium; and by which they may be separated from complex mixtures.

=AL′DEHYD-AMMO′NIA= (-hĭd-). An ammonia-compound of aldehyd, discovered by Döbereiner and Liebig.

Prep. (Liebig.) Aldehyd (of process No. 1, above) is mixed with an equal volume of ether,[16] in a flask surrounded with ice, or (what is better) a freezing-mixture; and is then saturated with dry gaseous ammonia. The crystals which soon form, after being washed with ether, and dried by means of bibulous paper and a short exposure to the air, are pure aldehyd ammonia.

[Footnote 16: Some authorities recommend the use of twice this quantity of ether.]

Prop., &c. It smells like a mixture of turpentine and ammonia; melts at 165° to 170°; volatilises, unchanged, at 212° Fahr.; decomposed by exposure to the air; very soluble in water; soluble in alcohol, and more or less so in most other menstrua, except ether; acids decompose it. With sulphuretted hydrogen it forms thialdine.——Use. Chiefly to make pure aldehyd (which see).

=AL′DER= (awl′-). Syn. AL′DER-TREE; AL′NUS (ăl-), L.; A. GLUTINO′SA (Gaertn.); BETU′LA ALNUS, Linn.; AUNE, AULNE, Fr.; ERLE, Ger. A well-known English tree, chiefly growing in moist grounds near rivers. Its wood is used for hurdles, for various articles of turnery and furniture, and when converted into charcoal, for making gunpowder; it possesses considerable durability under water; but is otherwise of little value. Bark and leaves very astringent, and reputed vulnerary; decoction used as a gargle in sore throat, and, in double the dose of cinchona, as a febrifuge in agues; bark and sap used in dyeing and tanning. The following belong to different nat. orders and genera to the preceding:——

=Alder, Black.= Syn. WIN′TER-BERRY; PRI′NOS VERTICILLA′TUS, Linn. A tree growing in the United States of America. Bark febrifuge, tonic, and astringent; berries tonic and emetic. (Bigelow.) It has been much recommended in dropsies, diarrhœa, intermittents, &c. Dose (of the dried bark), 1/2 to 1 dr., 3 or 4 times a day.

=Alder-tree, Black.= Syn. BERRY-BEARING ALDER-TREE; RHAM′NUS FRAN′GULA, Linn. A large shrub found in the woods and thickets of England, &c. Wood, BLACK DOG′WOOD; bark, bitter, emetic, purgative; used to dye yellow; root-bark, a drastic purgative; berries, purgative, emetic; unripe berries yield SAP-GREEN; charcoal of the wood esteemed the best for gunpowder.

=ALE.= Syn. BARLEY WINE*; AILE, Fr.; WEISS-BIER, Ger.; AEL, EALE, Sax.; CEREVIS′IA ALBA, C. LUPULA′TA, A′LA*, AL′LA*, L. Pale-coloured beer, prepared from lightly dried malt, by the ordinary process of brewing. The ale of the modern brewer is manufactured in several varieties, which are determined by the wants of the consumer, and the particular market for which it is intended. Thus, the finer kinds of Burton, East India, Bavarian, and other like ales, having undergone a thorough fermentation, contain only a small quantity of undecomposed sugar and gum, varying from 1 to 5 per cent. Some of these are highly ‘hopped,’ or ‘bittered,’ the further to promote their preservation during transit and change of temperature. Mild or sweet ales, on the contrary, are less attenuated by lengthened fermentation, and abound in saccharine and gummy matter. They are, therefore, more nutritious, though less intoxicating, than those previously referred to.

In brewing the finer kinds of ale, pale malt and the best East Kent hops of the current season’s growth, are always employed; and when it is desired to produce a liquor possessing little colour, very great attention is paid to their selection. With the same object, the boiling is conducted with more than the usual precautions, and the fermentation is carried on at a somewhat lower temperature than that commonly allowed for other varieties of beer. For ordinary ale, intended for immediate use, the malt may be all pale; but, if the liquor be brewed for keeping, and in warm weather, when a slight colour is not objectionable, one fifth, or even one fourth of ‘amber malt’ may be advantageously employed. From 4-1/2 lbs. to 6 lbs. of hops is the quantity commonly used to the quarter of malt, for ‘ordinary ales,’ and 7 lbs. to 10 lbs. for ‘keeping ales.’ The proportions, however, must greatly depend on the intended quality and description of the brewing, and the period that will be allowed for its maturation.

The stronger varieties of ale usually contain from 6 to 8% of ‘absolute alcohol,’ ordinary strong ale, 4-1/2 to 6%; mild ale, 3 to 4%; and table ale, 1% to 1-1/2%; (each by volume); together with some undecomposed saccharine, gummy, and extractive matter, the bitter and narcotic principles of the hop, some acetic acid formed by the oxidation of the alcohol, and very small and variable quantities of mineral and saline matter. For the adulterants of ale, see PORTER. See BEER, BREWING, FERMENTATION, MALT-LIQUORS, &c.

=Ale, Dev′onshire White.= A liquor once generally drunk, and still in demand, in the neighbourhood of Kingsbridge and Modbury, Devon.

Prep. Ordinary ale-wort (preferably pale) sufficient to produce 1 barrel, is slowly boiled with about 3 handfuls of hops, and 12 to 14 lbs. of crushed groats, until the whole of the soluble matter of the latter is extracted. The resulting liquor, after being run through a coarse strainer, and become lukewarm, is fermented with 2 or 3 pints of yeast; and, as soon as the fermentation is at its height, is either closely bunged up for ‘draught,’ or is at once put into strong stoneware bottles, which are then well corked and wired.

Obs. White ale is said to be very feeding, though apt to prove laxative to those unaccustomed to its use. It is drunk in a state of effervescence or lively fermentation; the glass or cup containing it being kept in constant motion, when removed from the mouth, until the whole is consumed, in order that the thicker portion may not subside to the bottom.

=Ales, Med′icated.= Syn. BRYT′OLES; BRUTOLÉS, Fr.; CEREVIS′IÆ MEDICA′TÆ, L. In pharmacy, ale prepared by macerating medicinal substances in it, either at the ordinary temperature of the atmosphere, or when heated; infusions and decoctions, in which ale or beer is employed as the menstruum. The old dispensatories enumerate several medicated ales; such as CEREVISIA OXYDOR′CICA, for the eyes; C. ANTI-ARTHRIT′ICA, for the gout; C. CEPHAL′ICA, for the head; C. EPILEP′TICA, against epilepsy; &c. Preparations of this kind are now seldom ordered by the faculty, and their use is chiefly confined to the practice of empirics, and to domestic medicine. Bark, rue, savine, antiscorbutic plants, aromatic bitters, and stomachics, are the substances most commonly administered in this way. Ale in which wormwood, gentian, orange-peel, and the like, have been steeped, taken warm early in the morning, is much esteemed as a restorative tonic by drunkards and dyspeptics. See BEER, PURL, &c.

=ALE′BERRY.= A beverage made by boiling ale with spice, sugar, and bread-sops; the last commonly toasted. A domestic remedy for a cold.

=ALE′GILL= (g hard). Ale or beer flavoured or medicated by infusing the leaves of ground ivy in it; pectoral, stomachic, and nervine.

=ALE′WIFE.= The clupea serrata, an American species of herring. Its proper name is a′loof, although the established pronunciation and common orthography is ale-wife.

=ALEM′BIC.= Syn. MOORS′HEAD†; ALEM′BICUS, L.; ALAMBIC, Fr.; DESTILLIRKOLBEN, Ger. An old form of distillatory vessel usually made of glass or earthenware, but sometimes of metal. The body (a) which holds the liquid for distillation is called the CU′CURBIT; the upper part (b) the HEAD or CAP′ITOL; (c) is the RECEIVER. It is still employed in the laboratory, in the distillation of articles that are apt to spurt over into the neck of the common retort, and thus vitiate the product.

=ALEUROM′ETER.= Syn. ALEUROMÈTRE, Fr. An instrument for determining the quantity and quality of gluten in wheat-flour, invented by M. Boland. It essentially consists of a hollow copper cylinder, about 6 inches long, and 3/4 of an inch internal diameter. This tube has two principal parts; the one, about 2 inches long, is closed at the lower end, forming a kind of cup, into which the gluten is placed; it screws into the remainder of the cylinder. The cup being charged with a sample of gluten, and the upper part of the cylinder being screwed on, it is exposed in an oven, or (preferably) in an oil bath, to a temperature of 350 to 380° Fahr.[17] From the length of the tube the gluten occupies in swelling, as measured by a graduated scale, its quality is determined. The ‘crude gluten’ of good wheat-flour augments to four or five times its original volume, when thus treated; but that from bad flour does not swell, becomes viscid and semi-fluid, and generally gives off a disagreeable odour; whilst that of good flour merely suggests the smell of hot and highly baked bread.

[Footnote 17: Mr Mitchell recommends the heat to be 420°; whilst Dr Masprett gives 284° Fahr. as the proper temperature; but of these the first is too high, and the other too low. About 210 gr. are also ordered to be taken for examination; but the exact quantity is immaterial. (See Mitchell’s ‘Falsification of Food.’)]

=AL′GA.= (-gă). [L.] Sea-weed. A common name of grass-wrack (‘zostera marina’——Linn.), though not one of the algæ.

=AL′GÆ.= (ăl′-jē). [L. pl.] Syn. AL′GALS; ALGÆ (DC.), AL′GALES (Lindl.), L.; ALGUES, VARECH, Fr.; ALGE, MEERGRASS, SEEGRASS, Ger. Sea-weeds. In botany, an order of Thallogens living in water or very moist places, nourished throughout their whole surface by the medium in which they live, having no distinct axis of vegetation, and propagated by zoöspores, coloured spores, or tetraspores. Linnæus defines them——“plants, the roots, leaves, and stems of which are all in one.” The algæ consist either of simple vesicles lying in mucus, or of articulated filaments, or of lobed fronds formed of uniform cellular tissue. Those that vegetate in salt water are popularly called SEA-WEEDS (fu′ci, L.) and LA′VER (ulvæ, L.); those found in fresh water CONFER′VÆ. One of their divisions (the Zoöspermeæ) comprehends the lowest known forms of vegetable life, being merely adhering cells, emitting, at maturity, seeds or sporules having a distinct animal motion. In Oscillatorias, the whole plant twists and writhes spontaneously; and Zymenas actually copulate like animals. Some of the Algæ possess great beauty. In the lower grades the colour is green; in the higher, red or purple.

Prop., Uses, &c. None of the Algæ are poisonous. Several are nutritious, emollient, and demulcent, from containing mucilage (carrageenin), starch, sugar (mannite), and a little albumen; and are hence used as esculents. The ash from the dried weed varies in different varieties from 9% to fully 25%; and contains variable quantities of potassa, soda, lime, magnesia, iron, manganese, and silica, with sulphuric acid, phosphoric acid, chlorine, and a little iodine and bromine. (Schweitzer; Forchhammer; Gödechens.) Sea-weeds, their charcoal, and their ashes, have been long regarded as alterative and resolvent; and anti-phthisic virtues have been attributed to them by Laennec and others. They were formerly much given in scrofulous affections and glandular enlargements; but their use is now almost superseded by that of iodine and its preparations. Dr Stenhouse has proposed some of the algæ as furnishing an economical source of mannite. The sea algæ are used for manure; their ashes form KELP.

The following table, showing the results of several analyses of different kinds of algæ, and illustrating the very large amount of nitrogen contained in them, is from Mr Walter Blyth’s excellent dictionary of ‘Hygiene and Public Health.’

-----------------------------+--------+-----------+-----------+------------ | | | Per cent. | Protein Kinds of Algæ. | Water. |Dry matter.|Nitrogen in|contained in | | |dry matter.|dry matter. -----------------------------+--------+-----------+-----------+------------ Chondrus crispus, | 17·92 | 82·08 | 1·534 | 9·587 bleached, from Bewlay | | | | Evans. | | | | Chondrus crispus, | 21·47 | 78·53 | 2·142 | 13·387 unbleached, Ballycastle. | | | | Gigastina mamillosa, | 21·55 | 78·45 | 2·198 | 13·737 Ballycastle. | | | | Chondrus crispus, | 19·79 | 80·21 | 1·485 | 9·281 bleached, second | | | | experiment. | | | | Chondrus crispus, | 19·96 | 80·04 | 2·510 | 15·687 unbleached second | | | | experiment. | | | | Laminaria digitata, or | 21·38 | 78·62 | 1·588 | 9·925 dulse tangle. | | | | Rhodomenia palmata. | 16·56 | 83·44 | 3·465 | 21·656 Porphyra laciniata. | 17·41 | 82·59 | 4·650 | 29·062 Iridæa edulis. | 19·61 | 80·39 | 3·088 | 19·300 Alaria esculenta. | 17·91 | 80·09 | 2·424 | 15·150 -----------------------------+--------+-----------+-----------+------------

From the above, we learn the important fact that the sea-weeds found on our coasts are amongst the most nutritious of vegetable substances, and that they, when dry, are even richer in nitrogenous matter than either oatmeal or Indian corn in the same state. The following are the chief varieties of algæ which are used as food by the dwellers on our coasts as well as on the continent:——PORPHYRA LACINIATA and VULGARIS, called laver in England, stoke in Ireland, and slouk in Scotland. CHONDRUS CRISPUS, called carrageen or Irish moss, and also pearl-moss, and sea-moss. LAMINARIA DIGITATA, known as the sea-girdle in England, tangle in Scotland, and red-ware in the Orkneys; and LAMINARIA SACCHARINA, ALARIA ESCULENTA, or bladder-lock, called also henware, and honey-ware by the Scotch. ULVA LATISSIMA or GREEN LAVER——RHODOMENIA PALMATA or dulse of Scotland. Under the name of “marine sauce” the LAVER was esteemed a luxury in London, where it may now occasionally be met with in the shops of provision merchants. The employment of the CHONDRUS CRISPUS or Carrageen in the form of an aliment for consumptive and weakly persons, would seem from the analysis of it given above to be fully justified. In preparing the algæ for food, they must be soaked in water to remove the saline matter, and where they are possessed of a bitter flavour this may be removed by adding a little carbonate of soda to the water. They should then be stewed in water or milk till they are tender. The best flavourings are pepper and vinegar. See JELLY.

=ALGARO′BA.= Syn. CA′′ROB-TREE, ST. JOHN’S BREAD; CERATO′NIA SIL′IQUA, Linn. A leguminous tree of southern Europe, Palestine, and part of Africa. Pods (ALGAROBA BEANS), used for food, and to improve the voice; they contain a sweetish, nutritious powder, and are supposed to have been the ‘locusts’ on which St. John fed in the wilderness; their decoction has been used as a pectoral in asthma and coughs.

=Algaroba or Algarovil′la.= The astringent pods of prosopis pallida, p. siliquastrum, and Inga Marthæ (South American trees), bruised and more or less agglutinated by the extractive exudation of the seed and husks. They are used in tanning, for which purpose they have been strongly recommended; indeed that of Chili, and of Santa Martha (New Carthagena), is said to possess “four times the power of good oak bark” (Ure); and in dyeing are only inferior to oak-galls.

=ALGONTINE.= A mouth and tooth wash. An aqueous solution of nitrate of potassium, aromatised with oil of peppermint, tincture of myrrh, and tincture of cinnamon.

=ALGOPHON= (Bernhard, Salzburg). For pains in decayed teeth. A solution of ethereal oil of mustard (2 grms.) in spirit of cochlearia (30 grms.), coloured green by saffron and litmus. (Wittstein.)

=AL′IMENT.= [Eng., Fr.] Syn. ALIMEN′TUM, L.; NAHRUNG, SPEISE, Ger. Food; nutriment; anything which nourishes or supports life.

=ALIMENT′ARY= Syn. ALIMENTA′′RIUS, L.; ALIMENTAIRE, Fr.; ZUR NAHRUNG GEHÖRIG, Ger. Pertaining to food or aliment; nutrimental; nourishing.

=Alimentary Canal′.= Syn. ALIMENTARY DUCT; CANA′LIS ALIMENTA′′RIUS, L. In anatomy, the cavity in the bodies of animals into which the food is taken for the purpose of being digested; the whole passage or conduit extending from the mouth to the anus. In some of the lower animals this is a simple cavity, with only one opening; when the same aperture which admits the food also gives egress to the excrementitious matter. In others it is a true canal, with both a mouth and an outlet. Another step, and we find this canal is divided into a stomach and intestines. In the higher grades, a mouth, pharynx, and œsophagus precede the stomach. Birds have one or two sacculi or crops added to the œsophagus. The stomach of the ruminants consists of four sacs or parts, each of which may be regarded as a separate stomach; that of the bottle-nose whale contains no less than seven of such sacs. The part below the stomach, forming the intestines, is also variously subdivided, complicated, and connected. In man, these subdivisions are termed——DUODENUM, JEJU′NUM, IL′EUM, CÆ′CUM, CO′LON, and REC′TUM; the lower end or orifice of the last being called the A′NUS. The existence of an alimentary canal is said to be the only true characteristic of an animal. Plants have no common receptacle for their food, nor canal for carrying away effete matter; but every animal, however low in the scale of being, possesses an internal cavity which serves it as a stomach.

=Alimentary Sub′stances.= Syn. ALIMENTS; MATE′′RIA ALIMENTA′′RIA, L. Substances employed as food.

=ALIMENTA′TION.= [Eng., Fr.] Syn. ALIMENTA′TIO, L.; NAHRHAFTIGKEIT, Ger. The act, process, power, or state of nourishing, or being nourished.

=AL′IZARI.= [Tur., ali-zari.] The commercial name of madder in the Levant.

=ALIZARIN.= C_{10}H_{6}O_{3} . 2H_{2}O. Syn. LAZARIC ACID. A red colouring matter obtained from madder.

Prep. 1. Exhaust madder with boiling water, and precipitate the decoction by sulphuric acid. Wash the precipitate, and, while yet moist, boil it with a concentrated solution of hydrate of aluminum in hydrochloric acid, and mix the solution with hydrochloric acid; red flakes of impure alizarin deposit. Dissolve this precipitate in alcohol or in dilute ammonia, and treat the solution with hydrate of aluminum. Boil the aluminum compound thus formed with carbonate of sodium, and, after freeing it from resinous impurities by digestion with ether, decompose it with hot hydrochloric acid. Wash the alizarin thus separated, dry it by simple exposure to air, and purify it by repeated crystallisation out of alcohol.

2. Sublime on a paper an alcoholic extract of madder. This method yields the purest alizarin.

Props. Red prisms; sublimes at 419° F.; odourless, tasteless, and neutral to test-paper; sparingly soluble in water, even at the boiling temperature; soluble in alcohol and ether; not decomposed by hydrochloric acid; dissolved, without decomposition, by strong sulphuric acid; soluble in solutions of the alkalies and their carbonates; acids precipitate alizarin from its alkaline solutions in orange-coloured flakes; alumina decolorises an alcoholic solution of alizarin, forming a red lake.

=ALIZARIN, ARTIFICIAL.= C_{14}H_{8}O_{4}. This colour was first obtained by Graebe and Liebermann in 1869 from anthrachinon, an oxidation product of anthracen, this latter being a substance which is formed during the destructive distillation of coal-tar. These chemists converted anthracen into antichinon by means of nitric acid.

The crude anthracen is previously purified by treatment with benzoline (petroleum spirit), aided by heat, and by being subjected to the action of the centrifugal machine to fusion, and to sublimation.

According to the original method of preparing alizarin, the anthrachinon was first converted into a dibromide of anthrachinon by treatment with bromine, and this bromated compound, by further treatment either with caustic potash or soda at a temperature of 180° to 200° C., converted into alizarin-potassium (or alizarin-sodium if caustic soda has been used), from which the alizarin is set free by means of hydrochloric acid.

Alizarin is now procured from anthrachinon by treatment at a temperature of 260° C., with concentrated sulphuric acid of 1·84 sp. gr., the anthrachinon being converted into a sulpho-acid; this acid is next neutralised with carbonate of lime, the fluid decanted from the deposited sulphate of lime, and carbonate of potash added to it, with the object of throwing down all the lime. The clear liquid is then evaporated to dryness, the resulting saline mass is converted into alizarin-potassium by heating it with caustic potash. From the alizarin-potassium thus obtained the alizarin is set free by the aid of hydrochloric acid.

In another method the preparation of anthrachinon is avoided, and anthracen employed directly, by first converting it, by means of sulphuric acid and heat, into anthracen sulphonic-acid. After having been diluted with water, the solution of this acid is treated with oxidising agents (peroxides of manganese, lead, chromic acid, nitric acid), and the acid fluid is afterwards neutralised with carbonate of lime. When peroxide of manganese has been used, the manganese is also precipitated as oxide. The oxidised sulpho-acid having been previously converted into a potassium salt, the latter being heated with caustic potash, alizarin is obtained. The details of these two processes will be found set forth in the terms of the patent taken out by Messrs Caro, Graebe and Liebermann, further on.

The following method of preparing alizarin from anthracene paranaphthalene and their homologues is by Girard. The material used is that which distils between 290° and 360°; it is purified by distillation and pressure, the portion which passes over, between 300° and 305°, being collected separately. This mixture is treated with potassium chlorate and hydrochloric acid, whereby it is converted into tetra-chlorinated products. These are oxidised either by nitric acid in the water bath, or by a metallic oxide (red or brown oxide of lead), and sulphuric or acetic acid. In the first place a mixture of dichloranthraquinine and chloride of chloroxyanthranyl are obtained. These substances are treated in presence of a metallic oxide (oxide of zinc, oxide of copper, or litharge), with an alcoholic solution of sodium acetate. The metallic oxide removes the last atom of chlorine from the sodium chloroxyanthranilate, and converts it, like the dichloranthraquinine, into alizarin. The purification is effected by means of benzine, petroleum, &c., which dissolve out the foreign matters, and by successive precipitation from the alkaline solutions by mineral acids. The foreign matters may also be separated by means of a little alum, when it is necessary to work with neutral potash or soda salts.

Another method for the preparation of alizarin has been patented by Dale and Schorlemmer. It is as follows: 1 part of anthracen is boiled with 4 to 10 parts of strong sulphuric acid, then diluted with water, and the solution neutralised with carbonate of calcium, barium, potassium, or sodium. The resulting sulphates having been removed by nitration or crystallisation, the solution is heated to between 180° and 260° with caustic potash or soda, to which a quantity of potassium nitrate or chlorate has been added, about equal in weight to the anthracen, as long as a blue-violet colour is thereby produced. From this product the alizarin is separated in the usual way by precipitation with an acid. Several other patents have been taken out for the preparation of artificial alizarin.

The specification of Messrs Caro, Graebe, and Liebermann, and dated June 25th, 1869, was the first which was taken out in England. We quote it here because it enters more fully into detail than any of the others.

“Our invention is carried into effect by means of either of the two processes which we will proceed to describe.

“In the one process we proceed as follows——We take about one part by weight of anthraquinone and about three parts by weight of sulphuric acid of about specific gravity of 1·488, and introduce the same into a retort, which may be made of glass, or porcelain, or of any other material not easily acted upon by sulphuric acid, and the contents are then to be heated up to about 260° Centigrade, and the temperature is maintained until the mixture is found no longer to contain any appreciable quantity of unaltered anthraquinone. The completion of this operation may be ascertained or tested by withdrawing a small portion of the product from time to time, and continuing the operation at the high temperature until such product upon being diluted with water is found to form a substantially perfect solution, thereby indicating that the anthraquinone has become either entirely or in greater part converted into the desired product. The products thus obtained are then allowed to cool, and are diluted with water; carbonate of lime is then added in order to neutralise and remove the excess of sulphuric acid contained in the solution; the mixture is then filtered, and to the filtrate carbonate of potash, or carbonate of soda, by preference in solution, is to be added until carbonate of lime is no longer precipitated; the mixture is then filtered, and the clear solution is evaporated to dryness, by which means the potash or soda salts of the sulpho-acids of anthraquinone are obtained, and which are to be treated in the following manner:——We take about one part by weight of this product, and from two to three parts by weight of solid caustic, soda, or potash; water may be added or not, but by preference we add as much water as is necessary to dissolve the alkali after admixture; we heat the whole in a suitable vessel, and the heating operation is continued at a temperature of from about 180° to 260° Centigrade, for about one hour, or until a portion of the mixture is found upon withdrawing and testing it to give a solution in water, which being acidulated with an acid, for example, sulphuric acid, will give a copious precipitate of the colouring matters. The heating operation having been found to have been continued for a sufficient time, the resulting products are then dissolved in water, and we either filter or decant the solution of the same, from which we precipitate the colouring matters or artificial alizarin, by means of a mineral or organic acid, such, for example, as sulphuric or acetic acid. The precipitated colouring matters thus obtained are collected in a filter or otherwise, and after having been washed may be employed for the purpose of dyeing and printing, either in the same way as preparations of madder are now used or otherwise.

“In carrying out our other process we proceed as follows:——We take about one part by weight of anthracene and about four parts by weight of sulphuric acid of specific gravity of about 1·848, and the mixture being contained in a suitable vessel, is heated to a temperature of about 100° Centigrade, and which temperature is to be maintained for the space of about three hours; the temperature is then to be raised to about 150° Centigrade, which temperature is to be maintained for about one hour, or until a small portion of the product when submitted to the two subsequent processes hereinafter described is found to produce the desired colouring matters; we then allow the result obtained by this operation to cool, and dilute it with water, by preference in the proportion of about three times its weight. To the solution thus obtained we add for every part of anthracene by weight which had been employed in the previous operations, from about two to three parts by weight of peroxide of manganese, preferring to employ an excess, and we boil the whole strongly for some time, and in order fully to ensure the desired degree of oxidation the mixture may be subsequently concentrated, and by preference be evaporated to dryness, and the heat be continued until a small portion of the oxidised product, when submitted to the subsequent processes hereinafter described will produce the desired colouring matters. We then neutralise and remove the sulphuric acid contained in this mixture, and at the same time precipitate any oxides of manganese that may be held in solution, by adding an excess of caustic lime, which we use by preference in the form of milk of lime, and we add the same until the mixture has an alkaline reaction. We then filter, and add to the filtrate carbonate of potash or soda, until there is no further precipitation of carbonate of lime. The solution is then filtered and evaporated to dryness, and we thus obtain the potash or soda salts of what we call the sulpho-acids of anthraquinone.

“In effecting the conversion of the oxidised products thus obtained into colouring matters, or into what we call artificial alizarin, we proceed as follows:——We take one part by weight of this product, and from two to three parts by weight of solid caustic soda or potash, and water may be added or not, but by preference we add as much water as may be necessary to dissolve the alkali. After admixture we heat the whole in a suitable vessel, and continue the heating operation at a temperature of about 180° to about 260° Centigrade for about one hour, or until a portion of the mixture is found to give a solution in water, which upon acidulation with an acid, for example, sulphuric acid, is found to give a copious precipitate of the colouring matters. The heating operation having been found to have been continued for a sufficient time, we then dissolve the product in water, and either filter or decant the solution of the same, from which we precipitate the colouring matters or artificial alizarin by means of a mineral or organic acid, such, for example, as sulphuric or acetic acid. The precipitated colouring matters thus obtained are collected on a filter or otherwise, and after having been washed may be employed for the purpose of dyeing and printing, either in the same way as preparations of madder are now used or otherwise.

“Instead of acting upon anthracen by means of sulphuric acid of the density before mentioned, fuming sulphuric acid may be employed, but we prefer to use the ordinary kind before described.

“In order to effect the process of oxidation, before referred to, other oxidising agents may be used in the place of the oxide of manganese, before mentioned, such, for example, as perioxide of lead, or chromic, nitric, or other acids capable of effecting the desired oxidation may be employed.”

Mr W. H. Perkin’s patent is similar in principle to that of Messrs Caro, Graebe, and Liebermann, and is dated only one day later.

The following is an outline of a patent taken out in France in May, 1869, by MM. Brœnner and Gutzkon, for the manufacture of artificial alizarin. One part of anthracen is heated with two parts of nitric acid, sp. gr. 1·3 to 1·5. The anthraquinone thus produced is washed and dissolved at a moderate heat in sulphuric acid. Mercuric nitrate is now added, which converts the anthraquinone into alizarin, The mass thus formed is dissolved in an excess of alkali, which precipitates the oxide of mercury, and retains the colouring matters in solution. The alkaline liquor is decanted and neutralised with sulphuric acid, and the precipitate thus formed is washed and collected. If not quite pure the treatment with alkali must be repeated. (The complete specification of this patent is published in the ‘Moniteur Scientifique,’ vol. xi, p. 865.)

In England a large quantity of artificial alizarin is manufactured by the process of Mr Perkin, and is used as a substitute for madder and madder extract, in Turkey red dyeing and topical styles. The largest makers of artificial alizarin on the continent are Messrs Gessert Frères, of Ebelfort, Messrs Maister, Lucius and Co., of Hæchst, near Frankfort, and the Badische Anilin und Soda Fabric, Mannheim.

The following recipes for printing with artificial alizarin are extracted from Mr Crookes’ ‘Practical Handbook of Dyeing and Calico Printing’:

REDS.

5 lbs. alizarin paste (10 per cent.); 16 lbs. thickening; 1 lb. acetate of alumina, at 15° Tw.; 1/2 lb. acetate of lime, at 25° Tw.

PINKS.

The above diluted with 2 or 3 parts of thickening.

For double printing, when deep red is printed on first, the goods must be steamed one hour before the second printing takes place. After the second printing the goods are again steamed for one hour, and aged for twenty-four hours; they are then passed through one of the following baths, at from 120 to 140 F., remaining in the bath not longer than 1 to 1-1/2 minute:——

250 gals. water; 60 lbs. chalk; 3 lbs. tin crystals.

Or, 250 gals. water; 40 lbs. chalk; 10 lbs. arseniate of soda.

The goods are then washed, and cleaned as follows:——

Take, for 10 pieces of fifty yards each,——

1st. Soaping at 120° F., 3 lbs. soap; 1/4 lb. tin crystals. 2nd. Soaping at 160° F., 3 lbs. soap; 3rd. Soaping at 175° F., 3 lbs. soap. Wash between each soaping.

RED FOR MOSAICS.

8 lbs. alizarin paste (10 per cent.); 10 quarts thickening; 9-1/2 oz. nitrate of alumina, at 23° Tw.; 19 oz. acetate of alumina, at 15° Tw.; 13 oz. acetate of lime, at 25° Tw.

Or, 10 lbs. alizarin paste (10 per cent.); 10 quarts thickening; 13 oz. nitrate of alumina, at 23° Tw.; 19 oz. acetate of alumina, at 15° Tw.; 16 oz. acetate of lime, at 25° Tw.

ANOTHER RED WITHOUT OIL.

8-1/2 lbs. alizarin paste (10 per cent.); 9-1/2 lbs. acetic acid, at 12° Tw.; 3-1/2 lbs. wheat flour; 5 pints water.

Boil well and stir till cold; then add——

1 lb. acetate of lime, at 29° Tw.; 2 lbs. nitrate of alumina, at 23° Tw.; 3 lbs. hyposulphite of lime, at 13° Tw.

PURPLE.

3 lbs. alizarin paste (10 per cent.); 10 quarts purple thickening; 6 oz. pyrolignite of lime, at 18° Tw.; 12 oz. acetate of lime, at 25° Tw.

The printed goods are steamed for an hour or two, and then aged from twenty-four to thirty-six hours. They are then padded in the chalk and arseniate of soda bath; after which they are washed and soaped in a single soap-bath without tin crystals; and, if needful, cleaned in a weak solution of bleaching powder.

THICKENING FOR REDS.

12 lbs. wheat starch; 40 quarts water; 4 quarts acetic acid, 9^{9} Tw.; 1-1/4 lbs. gum tragacanth; 2 lbs. olive oil.

Boil well together, and stir till cold.

THICKENING FOR PURPLE.

10 lbs. starch; 27 quarts water; 3 quarts acetic acid; 1-1/8 lbs. gum tragacanth; 2 lbs. olive oil.

Boil well together, and stir till cold.

The mordants in the above recipes are prepared as fellows:

ACETATE OF ALUMINA.

Stir 30 lbs. of hydrate of alumina into six quarts of acetic acid, warm, filter, and reduce to the specific gravity required.

The hydrate of alumina is prepared by dissolving 72 lbs. of alum in 100 gals. of water, and 62 lbs. soda in 100 gals. of water. The two solutions are mixed, this precipitate is washed eight times by decantation, collected on a filter and pressed. It must be dissolved on the filter before it gets dry.

NITRATE OF ALUMINA. 2 lbs. nitrate of lead; 2 lbs. alum; 2 quarts water.

Dissolve and filter off the liquid from the precipitate, and dilute to proper standard.

The reds are turned more yellow by nitrate than by acetate of alumina, and when the former is used more acetate of lime is taken in addition.

ACETATE OF LIME.

A solution of acetate of lime at 25° Tw. contains 25 per cent. of acetate of lime; generally 1/10th of the weight of alizarin paste is required; but with a fresh quantity of alizarin it is safer to ascertain, on a small scale, the amount needed.

BROWN.

13-1/4 lbs. alizarin paste (15 per cent.); 9 quarts thickening; 2 lbs. nitrate of alumina, at 29° Tw.; 15 oz. acetate of alumina, at 19° Tw.; 15 oz. red prussiate potash, dissolved in water; 1 lb. 1 oz. acetate of lime, at 29° Tw.

To obtain a yellower shade, for every quart of mixed colour, 1 oz. bark liquor, at 30° Tw., may be added.

Old spoiled red colours may be advantageously used for browns by adding per quart, 3/4 oz. to 1 oz. red prussiate, dissolved in water.

=ALKALI.= Syn. ALKALI, Fr.; LANGENSALZ, Ger. This word has been used in various senses, but is now usually applied to four substances only, viz. the hydrates of potassium, sodium, lithium, and ammonium (the latter being supposed to exist in the aqueous solution of ammonia). In a more general sense it is applied to the hydrates of barium, strontium, and calcium, which, for the sake of distinction, are called the alkaline earths. The following properties are characteristic of the alkalies:——(1) They are soluble in water, the alkalies proper more so than the alkaline earths. (2) They change the hue of many vegetable colouring matters; thus, they turn reddened litmus blue, yellow turmeric brown, and syrup of violets and infusion of red cabbage green. (3) They neutralise the strongest acids. (4) They precipitate most of the heavy metals from solutions of their salts as hydrates or oxides. (5) They saponify the fixed oils and fats. (6) They exert a caustic or corrosive action on animal and vegetable substances.

=ALKALI ACTS.= The principal alkali Act is the 26 and 27 Vict., c. 24, amended by 37 and 38 Vict., c. 43, the amended Act having come into operation in 1875.

Every alkali work must be carried on so as to ensure the condensation of not less than 95% of muriatic acid evolved therein; and it must be so condensed that in each cubic foot of air, smoke, or chimney gases, escaping from the works into the atmosphere, there is not contained more than one fifth part of a grain of muriatic acid. Penalty for first conviction, £50; for second and other offences, £100, or less (26 and 27 Vict., c. 124, s. 4; 37 and 38 Vict., c. 43, s. 4).

The owner of every alkali work is also bound “to use the best practicable means of preventing the discharge into the atmosphere of all other noxious gases arising from such work; or of rendering such gases harmless when discharged.”

The noxious gases are defined to be sulphuric acid, sulphurous acid (except that arising from the combustion of coals), nitric acid, or other noxious oxides of nitrogen, sulphuretted hydrogen and chlorine (37 and 38 Vict., c. 43, ss. 5 and 8).

The owner is liable for any offence against the Alkali Acts, unless he prove that the offence was committed by some agent, servant, or workman, and without his knowledge, in which case the agent, &c., is liable (26 and 27 Vict., c. 124, s. 5).

Every alkali work must be registered; penalty for neglect £5 per day (ibid., s. 6).

Powers are given to owners to make special rules for the guidance of their workmen (ibid. s. 13).

=ALKALIM′ETRY.= Syn. ALKALIME′TRIA, L.; ALCALIMÉTRIE, Fr. In chemistry, the estimation of the strength of the commercial alkalies; the art or process of determining the quantity or proportion of pure caustic alkali, or of its carbonate, in any given sample or simple solution. It is the reverse of ‘acidimetry,’ and it should be understood that it does not apply to alkalies occurring under any other form or condition than those just mentioned. Alkalimetric assays are now also frequently and conveniently extended to the estimation of the alkaline earths and their carbonates, as hereafter noticed.

Alkalimetrical processes. These, like those of ‘acidimetry,’ are for the most part founded on——the capacity of the bases to saturate acids——the estimation of the quantity of dry carbonic acid liberated from a given weight of an alkaline carbonate under the influence of a stronger acid; and, in the case of the pure alkalies, the sp. gr. of their solutions. From any one of these results the exact amount of alkali, or of alkaline carbonate, present in a sample, is easily found or calculated. These processes are, indeed, precisely similar to those described under ACIDIMETRY; but here the unknown quantity sought is the alkali, instead of the acid.

Assay. The SAMPLE is drawn from as near the centre of the cask containing the alkali as possible, and at once placed in a wide-mouthed bottle, which is then closely corked up and numbered. Before proceeding to the assay, the contents of the bottle are thrown on a piece of dry paper, the lumps crushed small, and the whole reduced to coarse powder as rapidly as possible. The number of grains required for the trial are then at once weighed, placed in a phial or small glass tube, and agitated with about 1/2 oz. of hot water. After a short time allowed for repose, the clear liquid is poured off into a beaker-glass or other vessel in which the trial is to be made. This process is repeated with a second and a third quantity of water, or until nothing soluble remains, shown by the last washings not affecting the colour of turmeric paper. The greatest care must here be taken not to waste the smallest portion of the liquid, which would render the results inaccurate.

To the solution in the beaker-glass a little solution of litmus is added, unless the acid is tinted with it when it is unnecessary. The solution is now heated until near its boiling point, and a piece of white paper or porcelain put behind it, to better show up the changes of colour. The alkaline solution is now treated with the standard test-acid, which is poured carefully from an alkalimeter or Mohr’s burette, until the solution, after turning a purple red, suddenly assumes a pink colour. Neutralisation being thus effected, the operator allows the sides of the alkalimeter or burette to drain, and then either ‘reads off’ the number of divisions which have been consumed, or (if using the test-acid by weight) determines the quantity by again weighing the alkalimeter. The common practice is to allow two drops (= 1/5th of an alkalimetrical division by VOLUME, or 2 gr. by WEIGHT) for over-saturation, which is, therefore, deducted from the ‘observed quantity’ of the test-liquor employed.

In testing solutions of the PURE or CAUSTIC ALKALIES, the colour, on neutralisation, suddenly changes from blue to pink or red, without any intermediate vinous or purple colour being produced.

The quantity of test-acid used gives the absolute or per-centage composition of the sample examined, according to the constitution of the test-acid used.

Standard Acids. The various test-acids in use as described below, each being used by different operators as they think best.

The most convenient test-acid, or normal solution, both for commercial and chemical assays, is perhaps dilute sulphuric acid, which, when intended to be used VOLUMETRICALLY, has the sp. gr. 1·032 at 60° Fahr., and contains in 100 alkalimetrical divisions 1000 water-grains measure, or 1 litre, exactly 49 gr. (or grammes) of sulphuric acid; and when intended to be used GRAVIMETRICALLY, or by weight, has the sp. gr. 1·033, and contains in 1000 gr. (or grammes) weight exactly 49 gr. (grammes) of sulphuric acid; and, in both cases, consequently corresponds to 1 equiv. of every other base. These dilute acids are easily prepared by mixing 1 part of the concentrated acid with 11 or 12 parts of distilled water; the precise quantity depending on the strength of the acid employed, and must be so arranged that 1000 grains shall exactly neutralise 1000 grains of water containing 53 grains of pure anhydrous sodium carbonate.

This acid (as well as all those hereafter mentioned) may be kept faintly tinged with litmus, which is often more convenient than tinging the alkaline solution at the time of making the assay.

It will at once be seen that every alkalimeter division of the first of the above acids, and every 10 gr. of the second, represent the 1/100th part, or 1% of alkali whenever the equivalent weight[18] of the latter is taken for the assay. Every 1-10th part of an alkalimeter-division (or every drop), and every grain weight (when a Schüster’s alkalimeter is employed) then respectively represents the 1/10 of 1%; and the result sought is obtained without the necessity of any calculation.

[Footnote 18: See Table II, at the end of this article.]

This is obvious——for if the equivalent of a pure alkali or of its carbonate (i. e. one of 100%) requires an equiv. (100 alkalimeter-divisions, or 1000 gr.) of test-acid to saturate it, an alkali or alkaline carbonate of 75%, 50%, or 25%, will respectively require only 75, 50, or 25 divisions, or 750, 500, or 250 gr.; and so of other strengths in proportion. The only precaution necessary is always to take the standard weight for the assay answering to the equiv. of the denomination of the per-centage result sought. Thus, in testing a carbonate of potash, we may either wish to determine its per-centage richness in ‘dry carbonate,’ or in ‘pure potassa,’ the latter being usually the case. To obtain the first, we must take 69 gr. for the assay; and to obtain the second, 47 gr. With CAUSTIC ALKALIES, or mixtures containing them, the weight, in grains, taken for the assay, must always correspond to the equiv. of the pure base. See Table II, at the end of this article.

In commercial assays, when 100 gr. (or some aliquot part thereof) are taken for trial, the per-centage result is obtained from the number of alkalimeter-divisions, or the number of grains, of the test-acid consumed, by the common Rule of Proportion. Thus:——A crude sample of potash having taken 90 alkalimeter-divisions of test-acid to neutralise it, would contain——

100 : 47 :: 90 : 42·30%

or nearly 42-1/3 per cent. of pure potassa. If only 50, 25, or 20 gr. are tested, the result must, of course, be double, quadruple, &c., as the case may be. Or the third term of the proportion may be multiplied by the denominator of the fraction representing the aliquot part. This, in the case of 50 gr. (repeating the above example), would be——

10 : 47 :: 45 × 2 : 42·30%

as before; but even these easy calculations may be simplified, as is shown below.

One of the advantages, and not the least, attending the use of test-acids corresponding to equivalents, is, that by means of the simple Rule of Three, the per-centage quantity of alkali may be found whether 100 or any other number of grains have been submitted to trial. For——The weight of the sample tested (in grains) bears the same relation to the equivalent weight of the alkali under examination, that the number of alkalimeter-divisions or of the grains of test-acid consumed do to the per-centage of alkali sought. Thus, with a sample of 33 gr. of pearlash taking 35 alkalimeter-divisions or 350 grains (every 10 gr. being = 1%) of test-acid for neutralisation, this would be——

33 : 47 :: 35 : 49·85%

or nearly 50 per cent. of pure potassa. By substituting the equiv. of the dry carbonate of potash (69), for that of pure potassa used above, the quantity of that article corresponding to the same weight of the pure alkali may be at once found. Repeating the last example this will be——

33 : 69 :: 35 : 73·18%

or nearly 73-1/4 per cent. The same applies to all the alkaline bases and their carbonates.

For commercial purposes, there is used, amongst others, an empirical solution, as a test-acid for potassa, soda, and ammonia, to save the necessity of calculation.

This is dilute sulphuric acid having a sp. gr. of about 1·071; 100 alkalimeter-divisions (1000 water-grains measure) exactly saturate 100 gr. of pure potassa, or 113 gr. of anhydrous carbonate of soda. The number of measures consumed, read off by mere inspection from the scale of the alkalimeter, gives the exact per-centage of alkali in the sample examined, for POTASH; and by multiplying it by ·66, that for SODA also. By employing ·362 as the multiplier, it gives the like result for AMMONIA. In fact, occasionally, in order to save the necessity of any calculation, two ‘test-acids’ are frequently employed——the one for potash and the other for soda.

These are made by diluting sulphuric acid to a sp. gr. of near 1·071 and 1·086 respectively; 1000 grains, by measure, of the first neutralising exactly 100 grains of pure potassa, or 113 of pure anhydrous soda carbonate, and the latter neutralising exactly 100 grains of pure soda, or 171 gr. of pure anhydrous sodium carbonate.

There is another system of preparing standard acids by means of a Faraday’s alkalimeter. A strong acid is prepared by diluting sulphuric acid to a sp. gr. of 1·1268 at 60°, and 455·7 grains exactly neutralise 100 of anhydrous carbonate of soda.

The glass tube here referred to, and known as Faraday’s ALKALIMETER, is graduated centesimally, in the usual manner; but opposite the numbers 22·1, 48·62, 54·43, and 65, are cut the words ‘soda,’ ‘potassa,’ ‘carbonate of soda,’ and ‘carbonate of potassa,’ to indicate the quantity of the test-acid to be employed for each of these substances. (See engr.) It is used by pouring the test-liquor into it until it reaches the line marked against the alkali, or carbonate, under examination, the remaining divisions being filled up with pure water, and the whole well mixed by placing the thumb on the orifice of the tube and shaking it well. The measure of the resulting dilute acid must then be very carefully observed, and more water added, if required, to bring it up to the zero (0) or 1000 gr. on the scale; careful agitation being again employed as before. The test-acid thus prepared is then added, with the usual precautions, to the sample until exact neutralisation is effected. The quantity consumed for this purpose, read off from the graduated scale, expresses the exact per-centage of the pure ALKALI, or of its CARBONATE, as the case may be, contained in the sample examined, provided 100 gr. have been taken for the assay.

Another method sometimes used is that of M. Mohr, and practised as follows:——The alkaline solution, slightly coloured blue with litmus, is strongly super-saturated with a standard acid (sulphuric or oxalic) of known strength, supplied from an alkalimeter in the usual manner; the last traces of carbonic anhydride being removed by boiling, shaking, blowing into the flask, and, finally, sucking out the air. A standard solution of caustic soda (of a strength exactly corresponding to that of the test-acid already used) is now cautiously added, drop by drop, until the colour, rendered yellowish-red by the acid, just appears of a light blue. The difference between the quantity of the solution of the test-alkali and of the test-acid consumed, expresses the exact quantity of acid neutralised by the alkali, and hence also its strength.

Besides the above methods, the alkaline carbonates are analysed, by the loss of carbonic anhydride (carbonic acid) they suffer, by being decomposed by a strong acid. The best method in use is that of MM. Fresenius and Will, and depends on the same principle, and is performed in a similar manner and in a similar apparatus to that described under ACIDIMETRY; the only difference being that here the uses of the small tube (e) is dispensed with, and that the alkali is tested under the form of carbonate, instead of bicarbonate.

Oper. The smaller flask (B) is about half filled with concentrated sulphuric acid, and the sample of alkali, in solution (under the form of carbonate), being placed in the larger flask (A), water is added until it is about one third full. The tubes are then fitted into the apparatus quite air-tight; the end of the tube (b) is fastened with a piece of wax, and the whole is very carefully weighed. The apparatus is now removed from the scales, and a perforated cork, or a small piece of india-rubber tube, being temporarily applied to the end of the tube (h), a few bubbles of air are sucked out of the flask (B) by means of the lips; the consequence of which is, that on removing the mouth the acid in (B) ascends to a certain height in the tube (c). If in a short time this little column of liquid maintains its height in the tube, it is a proof that the apparatus is perfectly air-tight, and as it should be. Suction is now again cautiously applied to the tube (h) and a little of the acid in (B) made to flow over into the flask (A), the quantity being proportionate to the vacuum produced by suction, and capable of being regulated at will. No sooner does the acid come into contact with the carbonate in the flask (A) than the evolution of carbonic acid commences, and this, from the construction of the apparatus, having to pass through the concentrated sulphuric acid, is rendered quite dry before it can escape by the tube (d) into the atmosphere. Whenever the effervescence flags, a little more acid is sucked over, until the whole of the carbonate is decomposed; after which an additional quantity is made to pass into (A), so as to raise the temperature considerably, for the purpose of expelling all the gas absorbed by the fluid during the operation. As soon as this is effected, the wax is removed from the aperture (b), and suction applied to (h), until all the carbonic acid in the apparatus is replaced by atmospheric air. The whole is now allowed to cool, and (together with the piece of wax removed) is again accurately weighed. The loss of weight gives the exact amount of dry carbonic anhydride, or anhydrous carbonic acid, which was contained in the specimen, from which the weight of PURE ALKALI is readily estimated, as every 22 gr. of dry carbonic acid gas evolved represents exactly 31 gr. of pure SODA, 47 gr. of pure POTASSA, &c. &c.; these numbers being the equivalents of the respective substances from which the per-centage strength may be found by the rule of proportion, as before explained.

Thus, in the case of a 100-gr. sample of carbonate of soda which has lost 15-1/4 gr. of carbonic acid, by the assay, this would be——

22 : 31 :: 15-1/4 : 21·48%

or nearly 21-1/2 per cent. of pure soda. If 53, the equiv. of anhydrous carbonate of soda, be taken, instead of 31 (the eq. of pure soda), the answer would have been, in the terms of that substance, 36·748%, or nearly 36-3/4 per cent. When an aliquot part of 100 gr. has been taken for the assay, either the result, or the third term of the proportion, must, of course, he multiplied by the denominator and divided by the numerator of the fraction representing such aliquot part.

By multiplying the weight of carbonic anhydride lost, by the numbers opposite the names of the respective alkalies and their carbonates in the second column of the following Table the equivalent per-centage value of the carbonates examined may be obtained in terms corresponding to the various denominations named therein, when 100 gr., or any aliquot part of 100 gr., have been tested; the result, in the latter case, being, of course, multiplied as before.

By taking certain standard weights for the assay, the quantity of carbonic acid evolved may be made to furnish the per-centage strength or value of the specimen in the terms of either the pure or carbonated alkalies, whether in their anhydrous or hydrated state. The numbers in the second column of the following Table represent the quantity in grains and decimal parts of each of the substances named in the first column, equivalent to one grain of carbonic anhydride. These numbers, as already mentioned, may be employed as factors for converting any numbers representing grains of that acid into the equivalents of these substances, true to 4 places of decimals; and further, they furnish us with the data for determining the exact number of grains which must be tested, so that the loss of weight in carbonic anhydride shall at once give us the per-centage richness of the sample in the terms of the denomination for which it is taken. The numbers in the third column of the Table, formed by simply moving the decimal point of the numbers in the second column one figure further to the right, indicate the weights to be taken for the assay, so that the loss of weight, reckoned in tenths of a grain, exactly represents the per-centage strength in the terms sought. The weights corresponding to the numbers in the fifth column give the same results, provided the loss of weight is reckoned in quarter-grains; those in the sixth column effect the same when the loss of weight is reckoned in half-grains; whilst those in the last column require that the gas eliminated should be counted in grains, and are simply the numbers in the second column of the Table multiplied by 100, or reproduced by moving the decimal point two figures to the right.

TABLE I.——_Multipliers and Standard Weights for the Principal Alkalies and their Carbonates._ (COOLEY.)

KEY:

A - Factors or Multipliers for converting the weight of carbonic acid expelled into real strengths. B - Quantity (in grains) to be taken, so that the per-centage value of the sample tested shall be shown in the terms of any of the denominations given, by the weight of the evolved Carbonic Acid reckoned—— C - in tenths of a grain. D - Whole numbers and decimals. E - Nearest common numbers. F - in quarter-grains. G - in half-grains. H - in grains.

-----------------------+-------+-------------------------------------------+ | | B | | |--------------------^----------------------+ NAMES, &c | | C | | | | | |------^--------| | | | | A | D | E | F | G | H | -----------------------+-------+------+--------+---------+--------+--------+ AMMONIA | | | | | | | (pure, gaseous) | ·77273| 7·727| 7-3/4 | 19-1/3 | 38-5/8 | 77-3/0 | | | | | | | | Carbonate of ammonia | | | | | | | (neutral, anhydrous) |1·77273|17·727|17-3/4 | 44-5/16 | 88-5/8 |177-1/4 | | | | | | | | Carbonate of ammonia | | | | | | | (neutral, | | | | | | | crystallised) |1·9773 |19·773|19-3/4 | 49-7/16 | 98-7/8 |197-3/4 | | | | | | | | Sesquicarbonate of | | | | | | | ammonia (translucent) |2·6818 |26·818|26-13/16| 67-1/10 |134-1/10|268-1/5 | | | | | | | | Bicarbonate of ammonia | | | | | | | (crystallised) |3·5909 |35·909|35-9/10 | 89-13/16|179-5/8 |359-1/10| | | | | | | | POTASSA (anhydrous) |2·1364 |21·364|21-1/2 | 53-1/2 |107 |213-3/8 | | | | | | | | Hydrate of potassa |2·54546|25·455|25-5/11 | 63-5/8 |127-1/4 |254-1/2 | | | | | | | | Carbonate of potassa | | | | | | | (anhydrous) |3·1364 |31·364|31-3/8 | 78-1/2 |157 |313-1/2 | | | | | | | | Carbonate of potassa | | | | | | | (granulated) |3·7727 |37·727|37-1/2 | 94-3/10 |188-5/8 |377-1/4 | | | | | | | | Carbonate of potassa | | | | | | | (crystallised) |3·9545 |39·545|39-5/8 | 99 |198 |395-1/2 | | | | | | | | Bicarbonate of potassa | | | | | | | (crystallised) |4·5454 |45·454|45-1/2 |113-3/4 |227-1/2 |454-1/2 | | | | | | | | SODA (anhydrous) |1·4091 |14·09 |14-1/10 | 35-1/4 | 70-1/2 |141 | | | | | | | | Hydrate of soda |1·8182 |18·182|18-1/5 | 45-1/2 | 91 |182 | | | | | | | | Carbonate of soda | | | | | | | (anhydrous) |2·4091 |24·091|24-1/10 | 60-1/4 |120-1/2 |241 | | | | | | | | Carbonate of soda | | | | | | | (crystallised) |6·5 |65· |65 |162-1/2 |325 |650 | | | | | | | | Sesquicarbonate of soda| | | | | | | (dry; theoretical) |2·9091 |29·091|29-1/10 | 72-1/2 |145 |290 | | | | | | | | Sesquicarbonate of | | | | | | | soda (Ph. L., 1836) |3·7273 |37·273|37-1/4 | 93-1/4 |186-1/2 |373 | | | | | | | | Sesquicarbonate of | | | | | | | soda (average | | | | | | | commercial) |3·7954 |37·954|38 | 94-7/8 |189-3/4 |379-1/2 | | | | | | | | Bicarbonate of soda | | | | | | | (crystallised) |3·8182 |38·182|38-1/5 | 95-1/2 |191 |382 | | | | | | | | LITHIA (pure, | | | | | | | anhydrous) | ·6818 | 6·818| 6-13/16| 17-1/20 | 34-1/10| 68-1/5 | | | | | | | | BARYTA (pure, | | | | | | | caustic) |3·4773 |34·773|34-4/5 | 86-7/8 |173-7/8 |347-3/4 | | | | | | | | LIME (pure, caustic) |1·2727 |12·727|12-3/4 | 31-3/4 | 63-5/8 |127-1/4 | | | | | | | | MAGNESIA (pure, | | | | | | | anhydrous) | ·90909| 9·091| 9-1/11 | 22-3/4 | 45-1/2 | 91 | -----------------------+-------+------+--------+---------+--------+--------+

In this ingenious method of alkalimetry it is absolutely necessary that the whole of the alkali in the specimen tested should be in the state of neutral carbonate. If a sample of potash contains any caustic alkali (as the potashes and pearlash of commerce generally do), Fresenius and Will direct it, previously to being tested, to be triturated with its own weight of pure quartzose sand, and about one third of its weight of carbonate of ammonia; and the resulting mixture, placed in a small iron capsule, or a porcelain crucible, to be moistened with water, and exposed to a gentle heat until it becomes quite dry, and all the ammonia is expelled. If the sample contains any bicarbonate or sesquicarbonate, it must be heated to dull redness before being placed in the apparatus and tested. In the case of crude soda (particularly soda ash), the proportion of carbonate of ammonia should be equal to at least one half the quantity operated on. With both alkalies, if the sample contains sulphides, sulphites, or hyposulphites, the same method is to be followed, except that solution of ammonia, instead of water, is to be employed for moistening the powder. To remedy the error which would arise from the apparent amount of carbonic anhydride liberated during the assay, being swelled by the disengagement of ‘sulphuretted hydrogen’ or sulphurous acid from these substances, a small quantity of neutral (i. e. yellow) chromate of potash may be added to the alkaline solution in the flask (A); by which they will be converted into sulphates, sulphur, and water, which will remain in the apparatus, the carbonic acid only being evolved. “As most sorts of soda of commerce contain one or other of the substances (just) named, and as it is far more simple to add at once some chromate of potassa to the soda solution, than to test the latter for either of the three salts, it is always advisable to make it a rule, in the examination of SODA, to add some chromate of potassa.” (Fresenius.)

If the sodium or other carbonate under analysis contains much chloride, the addition of more sulphuric acid than necessary must be avoided, and the carbonic anhydride expelled by gently heating over a warm bath, and not by the addition of excess of acid.

To obviate the difficulties, and to give greater precision and delicacy to volumetrical assays, the instrument known as Mohr’s ALKALIMETER, or Mohr’s BURETTE, and which is figured in the margin, may be employed. By means of it the test-acid in the graduated tube (a) may be added to the alkaline solution in (f), in any quantity at a time, however minute, by merely pressing the handles of the clamp (d) with the thumb and finger. The terminal tube (e) has its lower orifice very small, and it is connected with the burette by means of a small piece of vulcanised india-rubber tube, on which the clamp (d) acts. (See engr.) The inner cylindrical part of the arm (b) is lined with cork, to prevent injury to the glass burette, and to hold it the more firmly.

Generally the alkali in the specimen examined may be in either the caustic or carbonated state, or it may consist of any mixture of caustic alkali, or carbonates; but it is absolutely necessary for accurate results, that it should be free from sulphides, sulphites, and hyposulphites, as sulphuric acid acts upon these substances as well as on carbonates. The presence of chlorides does not interfere with the accuracy of the assay, unless a higher degree of heat is employed than that necessary for the expulsion of the absorbed carbonic acid. The SODA-ASH of commerce generally contains all these substances besides common salt, sulphate of soda, and insoluble matter, which do not interfere. Rough samples of POT-ASHES and PEARL-ASH also generally contain some sulphides, though not a large quantity. Various plans have been proposed to avoid this source of error. The best is that of MM. Fresenius and Will, given above, in which the value of the carbonates is estimated by their yield of carbonic anhydride.

The difference between an assay of a sample of the unprepared alkali and of another which has been treated as above, indicates the quantity of impurities contained in them under the forms just referred to. The presence of these substances in the commercial alkalies may be detected by the following tests:——

Sulphides. The addition of sulphuric acid causes the evolution of an odour like that of rotten eggs. The sample in solution yields a black precipitate with acetate of lead. But the most delicate test is the splendid violet-blue colour with nitro-prusside of sodium.

Sulphites and Hyposulphites. A solution of the alkali, insufficient for saturation, being added to sulphuric acid tinged reddish yellow with bichromate of potash, occasions a greenish tinge (owing to the formation of oxide of chromium), when these are present. Hydrochloric acid added to a clear solution, after some time, causes a turbidity and odour of sulphurous anhydride.

Chlorides yield a copious curdy precipitate with nitrate of silver, soluble in ammonia, and reprecipitated by excess of nitric acid.

The amount of pure caustic alkali in a sample of alkali is best determined by Fresenius’s method, as follows:——The total amount of pure alkali, both caustic and carbonated, expressed in per-cents. of carbonate of soda or carbonate of potassa, is ascertained by any of the usual methods. The apparent quantity of alkali per cent. is then determined, without previous treatment of the sample with carbonate of ammonia, by the method of Will and Fresenius (p. 86). The difference between the results indicates the per-centage of dry caustic alkali present; or if the volumetric method be in use, it can be often fairly estimated by adding the first portions of the test-acid very gradually to the sample, carefully observing the effect. When the effervescence at length commences the weight or measure of the test-liquor expended shows the quantity of pure caustic alkali under treatment (nearly). The result depends upon the fact, that little or no carbonic-acid gas is expelled from the liquid on the addition of the test-acid, until the caustic portion is very nearly neutralised.

The quantity of WATER or MOISTURE, per cent., present in an alkaline carbonate, is indicated by the loss of weight which 100 gr. suffer on gentle ignition in a loosely-covered iron dish or platinum crucible. So also with samples containing caustic alkali, except that here the water of hydration (= 1 equiv. = 9) is not expelled from the ‘caustic’ portion, and must therefore be determined by calculation.

Other matters deserving the serious attention of the operator are——hitting the exact point of neutralisation, and——preparing the test-acids of the proper strength. The method of effecting the former correctly has been already referred to in this article, and is also fully noticed under ACETIMETRY and ACIDIMETRY.

Test-acids may be very simply prepared by gradually diluting concentrated sulphuric acid with water until it is reduced to the proper strength; the dilution being made in a glass vessel containing a ‘hydrostatic bead’ exactly corresponding to the desired specific gravity of the dilute acid. When the proper point is reached, and the mixture has again acquired the normal temperature of 60° Fahr., the bead rises from the bottom of the vessel, and floats about indifferently in the middle of the liquid. The sp. gr. may then he carefully ascertained by means of an hydrometer or a specific gravity bottle; after which the strength must be accurately determined by means of a standard solution of either pure anhydrous carbonate of soda or pure caustic soda. An acid of any given strength or saturating power may also be prepared in the following manner:——49 parts of commercial sulphuric acid (oil of vitriol), sp. gr. 1·825, contain nearly 40 parts or 1 equiv. of anhydrous sulphuric acid; if we, therefore, wish to prepare a dilute acid containing in every 1000 grains weight, or measure, exactly 1 equiv. of hydrated sulphuric acid, we have only to make 49 gr. of such acid up to 100 gr. weight or measure with pure water. After it has recovered the proper temperature, its sp. gr., or rather its saturating power, must be carefully tried, and, if necessary, readjusted. As, however, it very often happens that the oil of vitriol employed is not so strong as that above referred to, it is better first to test its strength with pure anhydrous carbonate of soda, and to calculate the quantity required by the Rule of Proportion. Every 53 gr. of the dry carbonate are equal to 40 gr. of ‘dry sulphuric acid.’ Suppose we find the oil of vitriol to contain only 72% of hydrated acid, then——

100 : 40 :: 72 : 55·55

or, instead of only 40 gr., fully 55-1/4 gr. will be required, which are to be made up with water to 1000 gr., as before. Finally, the diluted acid must be very carefully re-tested, and if found correct, at once put into a well-stoppered bottle, and labelled, for use. Too much care cannot be taken to ensure the test-liquid, whether for alkalies or acids, being of the proper strength, of which the specific gravity alone is an insufficient proof. In practice, so small a quantity only of test-acid as that referred to above is, of course, seldom made; but as any larger quantities are mere multiples of the smaller one, the necessary proportions to be employed are easily calculated. The common plan is to prepare one or more gallons or quantities of 10 lbs. each, and to preserve the liquid in stoppered green glass ‘Winchester-quart bottles,’ so that it may be always ready for use.

Although, as may be inferred from the text, sulphuric acid is generally used as the standard acid, yet oxalic acid in pure crystals is recommended by M. Mohr, and answers admirably, and is prepared and used exactly in the same manner.

TABLE II.——Alkalimetrical Equivalents.

Grains. { 17 AMMONIA (pure or gaseous). { 43-1/2 Carbonate of ammonia { (neutral, hydrated). { 59 Sesquicarbonate of ammonia { (Ph. L.; translucent, hydrated). { 79 Bicarbonate of ammonia { (crystallised). { 47 POTASSA (anhydrous). { 56 Hydrate of potassa (pure { caustic potassa). { 69 Carbonate of potassa { (anhydrous). { 83 ” ” (granulated, { commercial). { 87 ” ” { (crystallised). {100 Bicarbonate of potassa { (crystallised). Grains { 31 SODA (anhydrous). 22 Carbonic anhydride } { 40 Hydrate of soda (pure caustic (dry). } { soda). 63 Oxalic acid } { 53 Carbonate of soda (anhydrous). (crystallised). } {143 ” ” (crystallised). 49 Sulphuric acid } are { 84 Bicarbonate of soda (liquid, }equivalent{ (crystallised). monohydrated, } to { 83-1/2 Sesquicarbonate of soda sp. gr. 1·8485). } { (average commercial). 75 Tartaric acid } { 84 Bicarbonate of soda (crystals, (crystallised). } { or cryst. powder, 1000 Dilute sulphuric acid} { free from moisture). (sp. gr. 1·033). } { ============ } { Water——gr. measure. } { 15 LITHIA. 1000 Dilute sulphuric } { 24 Hydrate of lithia. acid (sp. gr. 1·032). } { 37 Carbonate of lithia. { ============ { 76-1/2 BARYTA (pure, caustic). { 85-1/2 Hydrate of baryta. { 98-1/2 Carbonate of baryta. { 28 LIME (pure, caustic; { i. e. quick-lime). { 37 Hydrate of lime (slaked lime). { 50 Carbonate of lime { (chalk; marble). { 20 MAGNESIA (pure, calcined). { 42 Carbonate of magnesia (dry, { neutral). { 48-1/2 ” ” (ordinary { commercial). { 52 STRONIA (pure, caustic). { 61 Hydrate of strontia. { 74 Carbonate of strontia.

=ALKALOID.= Syn. VEGETABLE ALKALI, ORGANIC BASE; ALKALOÏDES (pl., -IDES, or -IDÆ), L.; ALCALOÏDE, ALCALI ORGANIQUE, Fr. In chemistry, a name commonly given to any proximate principle of vegetable origin possessing alkaline or basic properties, however feeble. In its most extended sense the term embraces all organic bases, whether obtained from the animal or vegetable kingdom, or produced artificially. The alkaloids form a numerous and important class of bodies. They exist in nature nearly always in the form of salts, the acid being often, like themselves, peculiar to the plant, or class of plants, in which they are found; whilst the medicinal activity of the latter, in most cases, almost entirely depends on their presence.

Prep. The following general methods of procuring the alkaloids will be found applicable to such as full directions are not given for under their respective heads:——

1. (When the base is insoluble in water, non-volatile, and existing in the plant in an insoluble form.) The bruised plant is boiled or macerated in water acidulated with hydrochloric or acetic acid, and the liquor, after filtration, is neutralised with an alkali (ammonia, potassa, lime, or magnesia); the resulting precipitate is purified by re-solution in dilute acid, digestion with a little animal charcoal, and subsequent crystallisation, or re-precipitation with an alkali; or the first precipitate is purified by dissolving it once, or, if necessary, several times, in boiling alcohol, which yields the pure alkaloid either on cooling or by evaporation.

2. (When the base is insoluble in water, and non-volatile, but existing in the plant as a soluble salt.) The bruised or sliced plant is boiled or macerated in water, and the filtered liquor precipitated and otherwise treated as before.

3. (When the base is soluble in water, and non-volatile.) An infusion made with very dilute acid, hydrochloric or acetic, is concentrated by a gentle heat; and the residual liquor treated with potassa (or concentrated solution of ammonia) and ether conjointly; after repose, the ethereal solution is decanted and evaporated. For those alkaloids which are insoluble in ether (as morphia and cinchonia), the previous process may be adopted.

4. (When the base is both soluble in water and volatile.) The vegetable, in a bruised or divided state, or its extract, is alkalised with potassa and distilled; the distillate is neutralised with dilute oxalic or sulphuric acid, and carefully evaporated to dryness; the residuum is next digested in alcohol, and the resulting tincture agitated with potassa and ether, the former being in quantity just sufficient to seize on all the acid; lastly, the ethereal solution thus formed, on careful evaporation, leaves the alkaloid nearly pure. It may be further purified by cautious distillation.

As some of the alkaloids are soluble in excess of the alkaline precipitant, over-saturation should be carefully avoided; or the precipitant may be used under the form of carbonate or bicarbonate. When lime and magnesia are employed, they are boiled for a few minutes with the solution.

Props. Alcoholic or aqueous solutions of the alkaloids generally exhibit an alkaline reaction with vegetable colours. Like the alkalies, also, they combine with acids to form salts which, when dissolved in water, are capable of producing the ordinary phenomena of saline double decomposition. Their taste is usually intensely bitter.

The majority of the natural alkaloids contain carbon, hydrogen, nitrogen, and oxygen, and are, at ordinary temperatures, solid, and not volatile without decomposition. Some natural alkaloids contain carbon, hydrogen, and nitrogen only; these are, for the most part, liquid at ordinary temperatures, and can be distilled without decomposition. The greater number of the artificial alkalies are composed of carbon, hydrogen, and nitrogen; some, however, contain oxygen in addition. Alkaloids have also been obtained artificially, in which nitrogen is replaced by phosphorus, arsenic, antimony, or bismuth. Most of the alkaloids, as they are obtained in the free state, correspond in function to ammonia, NH_{3}, rather than to the fixed alkalies; that is to say, they form salts by direct union with acids, without elimination of water or any other substance. In order to make them strictly comparable to the fixed alkalies, they require, like ammonia, the addition of water (H_{2}O) to their formulæ; they may then be considered as hydrates of compound radicles analogous to ammonium.

Physiological action. The alkaloids generally possess great medicinal power; some of them act with terrific energy, and are the most violent poisons with which we are acquainted. Perfectly pure aconitia is about 200 times more poisonous than arsenic, and at least 50 times more poisonous than ordinary medicinal prussic acid. The greater number act on animals in the same way as the plants which produce them, provided they are given in proportionately small doses. Many of them, when judiciously administered, are most valuable medicines.

Pois., Ant., &c. Some of the alkaloids act as narcotic or stupefying poisons; others are classed with the narcotico-acrid poisons, or those which produce both narcotism and irritation of the parts they touch. The general symptoms produced by opium and its preparations may be taken as an example of the former; those from aconite and strychnia, of the latter. In large doses of the greater number, narcotism predominates; in smaller ones, irritation; they are rarely coexistent.——Treatm. No common antidote to the effects of this class of substances has yet been discovered. The only safe treatment, of at all general application, is to immediately clear the stomach by means of a strong and quick-acting emetic (as sulphate of zinc), or the stomach-pump, and to administer copious and continued draughts of astringent vegetable solutions (as of tannin, nut-galls, oak-bark, or what is always at hand——very strong tea or coffee). These may be followed by or combined with a smart purge of castor oil, as soon as the stomach is thoroughly cleared of the poison. M. Bouchardat strongly recommends a solution of iodine, 3 gr., and iodide of potassium, 6 gr., in pure water, 16 fl. oz., in cases of poisoning by OPIUM, ACONITE, COLCHICUM, DEADLY NIGHTSHADE, HEMLOCK, NUX VOMICA, &c., or by the alkaloids obtained from them——ACONITINE, ATROPIA, COLCHICINA, CONIA, MORPHIA, STRYCHNIA, &c., or their salts; but not where foxglove or digitalin has been taken. The stomach having been well emptied by an emetic, the solution is to be given by wine-glassfuls for some time; the vomiting being still encouraged during the early part of the administration of the antidote. In the case of narcotics (as opium, morphia, &c.), this is to be followed by the free use of a strong infusion of coffee. According to Dr Garrod, purified animal charcoal is an ‘excellent antidote’ to many of the alkaloids, including those above enumerated, when taken in poisonous doses; as it not merely absorbs them, but, for the most part, renders them inert. To be serviceable it should be recently prepared and fresh-burnt; and should be given in doses of about an ounce at a time, diffused in warm or tepid water, and frequently repeated. The vomiting which follows its use, owing to the warm water, proves advantageous; but after a sufficient time may be lessened by employing less water, or cooler or even cold water. Drowsiness, if present, may be combated by the subsequent use of strong coffee or tea, as before. We have seen this plan succeed in several cases.——Lesions. These, like the symptoms, vary. In some cases there are redness and inflammation of the stomach and intestines, and turgescence of the vessels of the lungs and brain; in others, these appearances are either slight or wholly wanting. Wherever there has been much cerebral disturbance, traces of congestion are usually discernible.

Detec., Tests, &c. The identification of the pure alkaloids is extremely simple; but their detection, when combined with organic and colouring matters, is a task of considerable difficulty. One or other of the following plans may be adopted for this purpose:——

1. (Merck.) The matter under examination is digested, for several hours, with concentrated acetic acid, added in sufficient quantity to produce a strongly acid reaction; the fluid portion is then strained from the insoluble matter, and the latter being washed with water acidulated with acetic acid, the mixed liquors are gently evaporated to dryness in a water bath; the residuum of the evaporation is boiled first with rectified spirit, and next with rectified spirit acidulated with acetic acid; the mixed liquors are again evaporated, the residuum redissolved or diluted with distilled water, and carbonate of soda or potassa added to feebly alkaline reaction, and the whole, after evaporation to the consistence of a syrup, set aside to repose for 24 hours; it is now again diluted with water, filtered, and the insoluble portion washed with cold distilled water, and digested with concentrated acetic acid; this last solution is diluted with distilled water, and decoloured with pure blood-charcoal (if it be necessary); the fluid, either at once, or after cautious evaporation, may then be tested for the alkaloids, in the usual manner. The charcoal previously used should also be tested in the way described below. This method answers admirably with all the NON-VOLATILE ALKALOIDS, and may be applied to the stomach and viscera, and their contents, and to food, &c., in cases of poisoning.

2. (Stas.) The suspected matter, in a finely divided state, is digested, at 160° to 165° Fahr., with twice or thrice its weight of strong alcohol acidulated (according to the quantity) with 1/2 dr. to 2 or 3 dr., or more, of pure oxalic or tartaric acid. After a sufficient time, and when the whole has become quite cold, it is thrown on a filter, and the undissolved portion, after being squeezed dry, is washed with strong alcohol. The mixed and filtered alcoholic liquids are then evaporated at a temperature not exceeding 95° Fahr., and, if no insoluble matter separates, the evaporation is continued nearly to dryness;[19] but if fatty or other insoluble matter separates during the process of concentration, the concentrated fluid is passed through a moistened filter, and the filtrate evaporated nearly to dryness, as before. The residuum is next digested with absolute alcohol, in the cold, the insoluble portion, after filtration, washed with alcohol, and the mixed filtrates again evaporated in the air, or in vacuo. The acid residue is now dissolved in a little distilled water, and bicarbonate of soda added as long as effervescence ensues. To this mixture 4 or 5 times its volume of ether is added, and after lengthened agitation (the bottle or tube being held in a cold wet cloth), the whole is allowed to repose for a short time. A little of the supernatant ether is now removed to a small glass capsule or watch-glass, and allowed to evaporate spontaneously.[19] When this leaves oily streaks upon the glass, which gradually collect into a small drop, which emits, when gently heated, a disagreeable, pungent, and stifling odour, the presence of a LIQUID VOLATILE BASE or ALKALOID is inferred; whilst a solid residue or a turbid fluid with small solid particles floating in it, indicates a NON-VOLATILE SOLID BASE.[20] In either case the blue colour of reddened litmus is permanently restored by the residuum. If no residuum is left on the capsule, some solution of pure soda or potassa is added to the liquid, the whole well agitated for several minutes, and the ether (after repose) decanted; an operation which is repeated with fresh ether a second, third, and even a fourth time. The base, or bases (if any are present), will now be found in the mixed ethereal solution, which is, therefore, tested as before. The presence of an alkaloid being detected, the mixed ethereal solutions are allowed to evaporate spontaneously, care being taken, if a volatile alkaloid be present, to neutralise the liquid with an acid before the final evaporation. The last residuum is then tested for the particular alkaloid present, as before.[21]

[Footnote 19: The evaporation, according to Stas, should be conducted under a bell-glass over sulphuric acid, with or without rarefaction of the air; or in a tubular retort through which a current of air is made to pass.]

[Footnote 20: A merely disagreeable animal odour, without pungency, is here disregarded.]

[Footnote 21: ‘Bulletin de l’Académie de Méd. Belgique,’ ix, 304; ‘Jahrb. f. prakt. Pharm,’ xxiv, 313; &c.]

This method, according to Stas, answers well for all the ALKALOIDS which are soluble in ether; including——ACONITIA, ANILINE, ATROPIA, BRUCIA, CODEIA, COLCHICINA, CONIA, DELPHIA, EMETINA, HYOSCYAMINE, MORPHIA (?), NICOTIA, PETININE, PICOLINE, SOLANINE, STRYCHNIA, VERATRIA, &c. By means of it Stas found nicotia in the heart-blood of a poisoned dog. With such alkaloids as are, however, only very sparingly soluble in ether (as morphia for instance), the result must, necessarily, be doubtful. To detect these, as well as all the alkaloids which are insoluble in ether, it is, therefore, necessary, as directed by Otto, to add to the alkaline fluid left by the decantation of the ether, sufficient solution of soda to dissolve the morphia, &c. (if any has separated), and after the expulsion of the last traces of the ether by a gentle heat, to add a concentrated solution of hydrochlorate of ammonia, and to allow the mixture to repose for some time in the open air. When MORPHIA is present, it separates under the form of small crystals.[22] Or the alkaline liquor may be diluted with distilled water, and treated with charcoal, and this with alcohol, in the manner noticed under method 4 (below).

[Footnote 22: Otto’s ‘How to Detect Poisons.’]

4. (Graham and Hoffmann——slightly modified.) 2 or 3 oz. of purified animal charcoal are digested in about 1/2 gal. of the (neutral or only slightly acid) aqueous fluid under examination, with frequent agitation, for 10 to 12 hours, or longer. The liquid is then filtered, and the charcoal left on the filter is washed twice with cold distilled water. The charcoal is then boiled for 1/2 an hour with about 1/2 a pint of rectified spirit of 80 or 90%; the ebullition being conducted in a flask having a very long tube, open at both ends, fitted air-tight through the cork, to prevent loss of the alcohol by evaporation. The spirit, which now contains the alkaloid (if any was present in the original liquor), is next filtered whilst hot, and the filtrate is submitted to distillation until the whole of the alcohol is removed. A small quantity (commonly a few drops) of solutions of potassa is then added to the residual aqueous liquor, followed by 1 to 2 fl. oz. of pure ether, after which the whole is well agitated for several minutes, and allowed to repose for a short time. Lastly, the supernatant ether is decanted, and allowed to evaporate spontaneously, when the residuum (if any) left in the capsule may be tested by reagents, as before.

This method was devised for the detection of STRYCHNIA and NUX VOMICA in malt-liquors; but it is equally applicable to the detection of ANY ALKALOID which is soluble in ether. The CHARCOAL TEST may also be employed to detect alkaloids which are insoluble in ether; but then the base must be sought in the aqueous residuum obtained by the evaporation of the alcohol.[23]

[Footnote 23: ‘Journ. of the Chem. Soc.,’ v, 173.]

The presence of the alkaloids and their salts, in clear solutions, may be thus determined:——

I. (Fresenius).——1. The solution is rendered very slightly alkaline with dilute solution of potassa or soda, added drop by drop:——

a. No precipitate is formed; total absence of the alkaloids. (See 4, below.)

b. A precipitate is formed:——solution of potassa or soda is added, drop by drop, until the liquid exhibits a strong alkaline reaction:——

α. The precipitate redissolves; absence of Brucia, Cinchonia, Narcotina, Quina, Strychnia, and Veratria; probable presence of MORPHIA.

β. Precipitate does not redissolve, or not completely; probable presence of one or more of the first six of the above-named alkaloids:——the fluid is filtered from the precipitate, mixed with either bicarbonate of soda or of potassa, gently boiled nearly to dryness, and treated with water. If it dissolves completely; absence of morphia; an insoluble residue indicates MORPHIA.

2. The precipitate 1. b. β. is washed with cold distilled water, dissolved in a slight excess of dilute sulphuric acid, neutralised with a saturated solution of bicarbonate of soda, and allowed to repose a few hours:[24]——

[Footnote 24: Before setting the glass aside the liquor should be well mixed, and the glass stirrer vigorously rubbed against the sides of the vessel.]

a. No precipitate; absence of Cinchonia, Narcotina, and Quina:——the solution is gently evaporated nearly to dryness, and treated with cold water:——if it dissolves completely, pass on to 4; if there is an insoluble residue, it may contain Brucia, Strychnia, or Veratria. (See 3.)

b. A precipitate:——the filtered fluid is treated as directed at 2 a.; the precipitate is washed with cold distilled water, dissolved in a little hydrochloric acid, ammonia is added in excess, and subsequently a sufficient quantity of ether, agitation being had recourse to:——

α. The precipitate formed by the ammonia redissolves completely in the ether, and the clear fluid separates into two layers; absence of Cinchonia; probable presence of QUINA or NARCOTINA.

β. The precipitate produced by the ammonia does not redissolve in the ether, or not completely; probable presence of CINCHONIA, and perhaps also of Quina or Narcotina. The filtered liquid may be tested for these alkaloids as at a.

3. The insoluble residuum after the evaporation of the solution 2. a., or of the filtrate 2. b., is now dried in a water bath, and digested with absolute alcohol:——

a. It dissolves completely; absence of strychnia; probable presence of BRUCIA, QUINA (?), or VERATRIA:——the alcoholic solution is evaporated to dryness, and, if quina has been already detected, the residue is divided into two portions, one of which is tested for Brucia, the other for Veratria.

b. It does not dissolve, or not completely; probable presence of STRYCHNIA, and perhaps also of Brucia and Veratria:——the filtered fluid is divided into two portions, and tested separately as at a.

4. The original liquid 1. a. may contain Salicine, a proximate vegetable principle closely allied to the alkaloids:——a portion is boiled with hydrochloric acid for some time; the formation of a precipitate shows the presence of SALICIN. (See 2, below.)[25]

[Footnote 25: For further information on this subject, see the admirable ‘System of Qual. Chem. Anal.,’ by Dr C. R. Fresenius. Churchill.]

II. (Larocque and Thibierge.) Terchloride of gold is recommended, by these writers, as a more decisive test for the alkaloids than the ‘double chloride of gold and sodium’ commonly employed for this purpose. The following are the colours of the precipitates which it produces with the aqueous solution of their salts:——BRUCIA, milk-brown, passing into coffee-brown, and lastly chocolate-brown:——CINCHONIA, sulphur yellow:——MORPHIA, yellow, then bluish, and lastly violet; in this last state the gold is reduced, and the precipitate is insoluble in water, alcohol, the caustic alkalies, and sulphuric, nitric, and hydrochloric acid; it forms with aqua regia a solution which is precipitated by protosulphate of iron:——QUINA, buff-coloured:——STRYCHNIA, canary-yellow:——VERATRIA, pale greenish-yellow. All these precipitates, with the exception mentioned, are very soluble in alcohol, insoluble in ether, and only slightly soluble in water. Those with morphia and brucia are sufficiently marked to prevent these alkalies from being mistaken for each other; and those with brucia and strychnia are, in like manner, easily distinguishable.

III.——Mr Wanklyn discriminates the different alkaloids from the estimation of the ammonia they evolve. His process is as follows:——A small flask with a lateral tube, and connected with a Liebig’s condenser, is charged with about 25 c. c. of an alkaline solution of permanganate potash made by dissolving 200 grammes of caustic potash and 8 grammes of crystallised permanganate of potash in 1 litre of water. A minute quantity of the alkaloid carefully and accurately weighed is now introduced, and the mixture slowly distilled. The most satisfactory results are obtained by treating from 1 to 5 milligrammes of the alkaloid in this way, but quantities so small as 1/10th of a milligram will in skilled hands give accurate results. The ammonia is formed in the distillate by Nesslerising it, as described under WATER ANALYSIS. For all practical purposes the poisonous alkaloids may be divided into four classes:

(a) Those which yield from 5 to 2 per cent. of ammonia.

(b) Those which yield from 2 to 3 per cent. of ammonia.

(c) Those which yield from 3 to 5 per cent. of ammonia.

(d) Those which yield a larger quantity than 5 per cent., e.g.

I.

NH_{3} per cent.

SOLANINE yields half its nitrogen as Ammonia 0·98

II.

MORPHIA yields half its nitrogen as Ammonia 2·98

CODEINE, ditto, ditto 2·87

PAPAVERINE, ditto, ditto 2·50

VERATRIA, ditto, ditto 2·87

III.

ATROPIA yields all its nitrogen as Ammonia 5·73

NARCOTINE, ditto, ditto 4·11

STRYCHNIA yields half its nitrogen as Ammonia 5·09

BRUCINE, ditto, ditto 4·32

ACONITE, ditto, ditto 3·50

CONEINE, ditto, ditto 4·60

IV.

NICOTINE yields half its nitrogen as Ammonia 10·49

IV. Dr Guy, as well as others, have made researches, having for their object the determination of the exact temperature at which the poisonous alkaloids melt and sublime. A very minute speck of the substance is placed on a porcelain plate or copper disc, and a square or oval of microscope-covering glass is placed over it, supported by a thin ring of glass or any other convenient substance.

Heat is then applied to the plate or copper, and the temperature, as indicated by a thermometer at which the substance fuses or volatilises, is carefully noted.

CANTHARIDINE sublimes as a white Fahr. Cent. vapour without change of form or colour. 212° 100°

Sublime. Melt. /----------\ /----------\ Sublime, melt and Fahr. Cent. Fahr. Cent. MORPHINE } yield carbonaceous { 330° 165° 340° 171° STRYCHNINE} residue. { 345° 174° 430° 224°

Melt. Sublime. /----------\ /----------\ Fahr. Cent. Fahr. Cent. ACONITINE } { 140° 60° 400° 204° ATROPINE } Melt, change { 150° 66° 280° 138° VERATRINE } colour, sublime, { 200° 93° 360° 182° BRUCINE } and { 240° 116° 400° 204° DIGITALIN } deposit carbon. { 310° 154° 310° 154° PICROTOXIN} { 320° 160° 320° 160° SOLANINE } { 420° 215° 420° 216°

Selmi’s method of extracting poisonous alkaloids in forensic investigations. The alcoholic extract of the viscera, acidified and filtered, is evaporated at 65° C., the residue taken up with water, filtered to separate fatty matters, and decoloured by means of basic acetate of lead, leaving the solution in contact with the air for 24 hours. It is then filtered, the lead precipitated by means of sulphuretted hydrogen, and the solution after concentration repeatedly extracted with ether. The ethereal solution is then saturated with dry carbonic anhydride, which generally causes a precipitate of minute drops adhering to the sides of the vessel, and containing some of the alkaloids. The ethereal solution is then poured into a clean vessel, mixed with about half its volume of water, and a current of carbonic anhydride passed for about twenty minutes, which may cause the precipitation of other alkaloids not precipitated by dry carbonic anhydride. Usually the whole of the alkaloids present in the ether are thrown down by these means, but if not, the solution is dehydrated by agitation with Barium oxide, and then a solution of tartaric acid in ether added to the clear liquid, taking great care not to employ excess of acid. This throws down any alkaloid that may remain. In order to extract any alkaloids that may still remain in the viscera, they are mixed with Barium hydrate and a little water, and then agitated with purified amylic alcohol; the alkaloids may subsequently be extracted from the alcohol by agitation with very dilute sulphuric acid.

A knowledge of the different solubilities of the alkaloids will be found an important auxiliary in their analysis. The following is a summary of the relative solubility of the most important of them. The figures denote the number of parts of the liquid required for their solution:——

Absolute alcohol.——Strychnine insoluble; brucine soluble.

Amylic alcohol.——Solanine (1061); digitalin sparingly soluble; morphine (133); strychnine (122); veratrine, brucine, atropine, aconitine, and picrotoxin, freely soluble.

Benzol.——All the poisonous alkaloids, except solanine, are soluble in benzol.

Chloroform.——Solanine (50,000); morphine (6550); strychnine (8); the rest freely soluble.

Ether.——Solanine (9000); morphine (7725); strychnine (1400); aconitine (777); brucine (440); veratrine (108); atropine, picrotoxin,[26] and digitalin, very soluble.

[Footnote 26: Digitalin and picrotoxin, although not alkaloids, are inserted in the above list, because they have a general similarity in chemical properties to them; and for the convenience of the toxicologist.]

Water (cold).——Strychnine (8333); veratrine (7860); morphine (4166); aconitine (1783); solanine (1750); brucine (900); atropine (414); picrotoxin (150); digitalin very soluble.

The principal Alkaloids and their Salts, in the state of powder, or with ‘conia’ and ‘nicotia,’ in the state of an oily looking liquid, may be thus distinguished:——

1. a. The powder is treated with nitric acid:——It is coloured red; probable presence of Brucia, Delphia, Morphia, or commercial Strychnia. If the reddened acid becomes violet on the addition of ‘protochloride of tin,’ it is BRUCIA; if it becomes black and carbonaceous, it is DELPHIA. If the powder is fusible without decomposition, and strongly decomposes iodic acid, it is MORPHIA; if it is not fusible without decomposition, and does not decompose iodic acid, it is STRYCHNIA.

b. If instead of a red, the powder strikes a green colour with nitric acid, it is SOLANIA; if it is insoluble in ‘ether,’ and not reddened by ‘nitric acid,’ it is EMETIA; if soluble in ether, not reddened by ‘nitric acid,’ but melts and volatilises when heated, it is ATROPIA; if it is thus affected by ether or nitric acid, but does not volatilise, it is VERATRIA. (See 2, below.)

2. a. The powder, or (with ‘conia and nicotia’) concentrated liquor, is treated with a drop or two of concentrated sulphuric acid:——A red colour is produced; probable presence of Brucia, Nicotina, Salicine, or Veratria. If the reddened mixture has at first a roseate hue, turning deep red on the addition of nitric acid, it is BRUCIA; if the original substance moistened with solution of potassa evolves the odour of tobacco, it contains NICOTINE; if the red colour produced by the acid is permanent and of an intense blood-hue, and the powder agglutinates into lumps like resin, it is SALICINE; if the colour is at first yellowish, changing to blood-red, and ultimately to crimson and violet, it is VERATRIA.

b. If instead of the substance being ‘reddened’ by strong sulphuric acid, no particular action ensues in the cold, it contains either Conia or Strychnia; if a small fragment of bichromate of potassa being now dropped in, produces a rich violet colour, it is STRYCHNIA; if the original matter on being heated, or treated with solution of potassa, evolves a penetrating, disagreeable odour, somewhat analogous to that from ‘hemlock,’ or to a mixture of those from tobacco and mice, it is CONIA.

“Reactions with ceroso-ceric oxide. This oxide exhibits characteristic colours with several alkaloids, especially with STRYCHNINE. When strong sulphuric acid is poured upon strychnine, and then a small quantity of ceroso-ceric oxide added, a fine blue colour is produced, similar to that which strychnine exhibits with potassium bichromate, but much more permanent. The blue colour gradually changes to cherry-red, and then remains unaltered for several days. This reaction is capable of detecting one part of strychnine in a million parts of liquid. BRUCINE similarly treated acquires an orange-colour, gradually changing to yellow; MORPHINE, olive-brown, finally brown; NARCOTINE, brown cherry red, finally wine-red; CODEINE, olive-green, finally brown; QUININE, pale-yellow; CINCHONINE and THEINE remain colourless; VERATRINE becomes reddish-brown; ATROPINE, dingy yellowish-brown; SOLANINE, yellow at first, finally brownish; EMETINE, brown; COLCHICINE, first green, then dirty brown; ANILINE, after a long time, acquires a blue colour extending from the edges inwards; CONINE becomes light-yellow. PIPERINE colours the sulphuric acid blood-red, and is turned dark-brown, almost black by the cerium oxide” (Sonnenschein).

“Reactions with picric acid. This acid is a very good precipitant for alkaloids, affording a very delicate test for many of them, and may perhaps also serve for separating them one from another. The precipitation takes place even in solutions containing a large excess of sulphuric acid, and is sometimes complete. Precipitated are, BRUCINE, STRYCHNINE, VERATRINE, QUINIDINE, CINCHONINE, and most of the opium alkaloids; not precipitated, MORPHINE, ATROPINE (English), PSEUDO-MORPHINE, CAFFEINE, and all glucosides” (Hager).

The presence of one or more of the alkaloids being shown by any of the preceding methods, a portion of the original clear solution or powder, or of the precipitates or filtrates above referred to, must be treated with their characteristic tests, as given under the individual notices of these articles, so as to set at rest all doubt as to their identity. No single test must ever be relied on as a positive proof. The presence of Brucia, Morphia and Strychnia may be determined in substances which after being mixed with the salts of these alkaloids have undergone the acetous, vinous, or putrefactive fermentation, as shown by Orfila, MM. Larocque and Thibierge, and many other eminent chemists and toxicologists, and confirmed, in numerous cases, by our own experiments. Opium and morphia may thus be readily detected in beer, wine, soup, and milk. A paper by Professor DRAGENDORF in the ‘American Chemist’ for April, 1876, may be consulted with advantage.

Concluding Remarks. It is a singular fact that none of the organic bases found in plants have yet been formed artificially, although several analogous substances have been thus produced. Closely allied to the alkaloids there also exists an extensive series of neutral proximate principles, which differ from those substances chiefly in the absence of basic properties, and in most of them being destitute of nitrogen. They are usually bitter, and, like the alkaloids, generally represent the active properties of the plants in which they are found; whilst some of them possess considerable medicinal energy. Of this kind are asparagin, elaterin, gentianin, picrotoxin, salicin, &c. These two classes of bodies, though actually distinct, are frequently confounded. See ALKALI, ORGANIC BASES, POISONS, PROXIMATE PRINCIPLES, VEGETABLES, NOMENCLATURE, &c.; also the individual alkaloids under their respective heads.

=ALKALOIDS OF ACONITE=. The nature of the active principle of aconite root does not appear to have been satisfactorily determined. Messrs Groves, Wright, and Williams contend that the Aconitum napellus yields an active crystalline alkaloid, which they distinguish as Aconitine, and to which they assign the formula C_{33}H_{43}NO_{12}; they add that additionally the root contains more or less of another active alkaloid, which they term Pseudaconitine, and which is represented by the formula C_{36}H_{49}NO_{11}; they also assert that the extract of the roots contains varying quantities of certain decomposition products resulting from the saponification of the above bases by the acids, which are produced by the breaking up of part of the aconitine. The name of these decomposition products is Aconine and Pseudaconine. Of Aconitum ferox they report that it yields a comparatively large quantity of Pseudaconitine and a small quantity of Aconitine. They further affirm that the so-called aconitine of commerce is a mixture of true aconitine and pseudaconitine with variable quantities of their alteration products, aconine and pseudaconine, and of certain amorphous unnamed alkaloids.

Messrs Paul and Kingzett contest the accuracy of these deductions, and dispute the correctness of the formula given to aconitine. Dr Paul doubts whether the alkaloid to which the active properties of the root are ascribed has ever yet been obtained in an isolated condition. He thinks it probable that the substance obtained from aconite root was to a great extent a salt of an acid, like aconitic acid. For further information the reader is referred to the ‘Pharmaceutical Year Book’ for 1873, 1874, 1875, 1876, and 1877.

=AL′KANET.= Syn. ANCHU′SA, L.; ORCANETTE, Fr.; ORKANET, Ger.; OR′CHANET*, DYER’S AL′KANET, D. BU′GLOSS*. The anchu′sa tincto′′ria (Willd.; lithosper′mum tincto′′rium——Linn.), a deciduous herbaceous plant, with a perennial, dark blood-red root. Hab. Asia Minor, Greece, Hungary, &c. It is also largely cultivated in the neighbourhood of Montpellier. The dried root (ALKANET ROOT; RADIX ANCHUSÆ, R. A. TINCTORIÆ) is chiefly imported from the Levant. It contains a beautiful blood-red colour, which it freely gives out to oils, fats, wax, spirits, essences, and similar substances, by simply infusing it in them, and is consequently much employed to colour these articles. Wax tinged with it, and applied on warm marble, stains it of a rich flesh-colour, which sinks deep into the stone, and possesses considerable durability. Its spirituous tincture also imparts a deep red to marble.

Prop., &c. The colouring matter of alkanet was regarded by Pelletier as a fatty acid (ANCHUSIC ACID); but it has since been shown to be a species of resin (ANCHUSINE, PSEUDO-ALKANNINE, P.-ALKANIUM). According to Dr John, good alkanet root contains 5-1/2 per cent. of this substance. Anchusine melts at 140° Fahr.; is scarcely soluble in water, to which it only imparts a dirty red colour, but is very soluble in alcohol, oils, and acetic acid. Alkalies turn it blue. It is found wholly in the root-bark. In selecting this article, the smaller roots should therefore be chosen, as they possess more bark than the larger ones, in proportion to their weight. Exposure to ammoniacal fumes, or even handling it much with the fingers, changes its red to a crimson or purplish hue.

Uses, &c. It is much employed by druggists and perfumers to colour oils, lip-salves, plasters, pomatums, &c.; by varnish-makers, to tinge their varnishes and lacquers; by statuaries to stain marble; by dairy-farmers, to colour cheese; by wine-merchants and bottlers (in the form of tincture), to stain beforehand the corks of their port-wine bottles, in order to imitate the effects of age, and as colouring and flavouring for factitious port wine; and by dyers, and others. A species of crimson rouge was formerly prepared from it (hence its name).

=ALLANTO′IC ACID.= See ALLANTOIN.

=ALLAN′TOIN.= C_{8}H_{6}O_{6}N_{4}. Syn. ALLANTO′IC ACID*, AMNIOT′IC A.† AM′NIC A.†; ALLANTOÏ′NA, L. A substance discovered by Vauquelin and Buniva in what they imagined to be the liquor amnii of the cow, and hence named by them amniotic acid. It was afterwards shown by Dzondi and Lassaigne to exist in the fluid of the allantoïs, and not of the amnios. It has since been produced artificially by Wöhler and Liebig.

Prep. 1. The allantoïc fluid of the fœtal calf is evaporated to 1-4th or 1-5th of its volume, and then set aside for some time. The crystals thus obtained are purified by re-solution, digestion with animal charcoal, and re-crystallisation.

2. (Wöhler and Liebig.) Uric acid, 1 part; is dissolved in water, 20 parts; and freshly precipitated and well-washed binoxide of lead is added to the solution until the colour ceases to change; the liquid is next filtered while hot, evaporated until a pellicle forms on the surface, and then set aside to crystallise; the crystals being purified as before.

Prop., &c. Small, but very brilliant prismatic, transparent, colourless crystals; tasteless; neutral; soluble in 160 parts of cold water, and in much less at 212°; nitric acid converts it into ALLANTURIC ACID; oil of vitriol resolves it into ammonia, carbonic acid, and carbonic oxide; hot concentrated solutions of the caustic alkalies change it into ammonia and oxalic acid.

=ALLANTOX′ICUM.= [L.] Syn. ALLANTOX′ICUM, L. (prim., Gr.). The poison developed, during putrefaction, in sausages made of blood, liver, &c. “It often proves speedily fatal.” (Kraus.)

=ALLGEMEINE FLUSSTINCTUR= (Sulzberger, Salzungen). For the relief of a number of diseases, among which are cholera and sea-sickness. Aloes, 1 part; spirit of wine, 2 parts. (Spau.)

=ALLIA′CEOUS= (-sh′us). Syn. ALLIA′CEUS, L.; ALLIACÉ, AILIACÉ, Fr.; KNOBLAUCHARTIG, &c., Ger. Garlick-like; an epithet applied to substances having the odour or properties of garlic or onions.

=Alliaceous Plants.= Chives, garlic, leeks, onions, rocambole, shallots, &c.

=ALLIGA′TION.= Syn. ALLIGA′TIO, L. In commercial arithmetic, a rule for ascertaining the price or value of mixtures, and for determining the proportions of the ingredients that must be taken to produce mixtures of any given price, value, or strength. The first is called ALLIGATION ME′DIAL; the second, ALLIGATION ALTERN′ATE. Its principles and applications are explained under MIXTURES (Arithmetic of).

=ALLOP′ATHY.= Syn. ALLOPA′THIA, L. (from ἁλλος, other, different, and παθος, affection or disease, Gr.); ALLOPATHIE, Fr. In medicine, the method of curing disease by the use of remedies which tend to produce a condition of the system, either differing from, opposed to, or incompatible with the condition believed to be essential to the disease it is sought to cure. It is commonly employed to distinguish the ordinary system of medical practice from homœopathy (which see). Hence (an) ALLOP′ATHIST, and the corresponding adjective ALLOPATH′IC (allopath′icus, L.).

=ALLOT′ROPY.= Syn. ALLOT′ROPISM; ALLOTRO′PIA, ALLOTROPIS′MUS, L. Literally, a difference in character; another form of the same substance. In chemistry, a term invented, by Berzelius, to express the state or condition, or the change of character, assumed by certain substances at different temperatures, or under different treatment, whilst their nature and composition continue the same. It more particularly relates to colour, hardness, solubility, texture, &c. Boron, carbon, silicon, iron, sulphur, and phosphorus, afford striking examples of the changes here referred to.

=ALLOX′ANTIN.= C_{8}H_{4}N_{4}O_{7}.3H_{2}O. A crystallisable substance, first obtained by Dr Prout from uric acid.

Prep. 1. Uric acid, 1 part; is boiled in water, 32 parts; dilute nitric acid being added until solution is complete; the resulting liquid is evaporated to 2/3rds its volume, and then set aside for 10 or 12 hours; the crystals, which are deposited, are purified by re-solution and crystallisation.

2. Sulphuretted hydrogen gas is passed, in a full stream, through a moderately strong aqueous solution of alloxan, in the cold. The alloxantin, which is deposited as a crystalline mass, is purified by draining, cautious washing with cold water, re-solution in boiling water, and re-crystallisation. The impure mother-liquor from which crystals of alloxan have separated, if diluted with water, may be used for this purpose.

Prop., &c. Crystals, small colourless, transparent, four-sided, oblique rhombic prisms; scarcely soluble in cold water; solution reddens litmus; with baryta water it gives a characteristic violet-coloured precipitate, which disappears on heating; and with nitrate of silver a black precipitate of that metal; the crystals are reddened by ammoniacal vapours.

=ALLOY′.= Syn. ALLIAGE, Fr.; LEGIRUNG, VERMISCHUNG DURCH SCHMELZEN, Ger. In coinage, a compound of the precious metals with another, or others, of less value; also the least valuable metal, or metals, in such compounds. In chemistry and metallurgy, combinations of the metals with each other usually obtained by fusion. When mercury is one of the component metals, the compound is termed an AMALGAM.

Prep., &c. No General rules can be given for this purpose. Alloys of metals differing greatly in fusibility, are commonly made by adding the more fusible one, either in the melted state, or in small portions at a time, to the other melted, or heated to the lowest possible temperature at which a perfect union will take place between them. The mixture is usually affected under a flux, or some material that will promote liquefaction, and prevent volatilisation and unnecessary exposure to the air. Thus, in melting lead and tin together, for solder, resin, or tallow is thrown upon the surface; in tinning copper, the surface is rubbed with sal ammoniac; and in combining some metals, powdered charcoal is used for the same purpose. Quicksilver combines with many metals in the cold, forming AMALGAMS.

Comp. The following Table exhibits the composition of the more important compounds of this class:——

Table of the principal Alloys.[27]

NAMES. COMBINING METALS.

ALBATA See German Silver. AMALGAMS Mercury and other metals. BATH-METAL Copper and zinc. BELL-METAL Copper and tin. BRASS Copper and zinc. BRITANNIA METAL Tin with antimony, copper, and bismuth. BRONZE Tin and copper. BRONZE ALUMINIUM Copper and aluminium. CANNON-METAL Tin and copper. DUTCH GOLD Copper and zinc. FUSIBLE METAL Bismuth, lead, and tin. GERMAN SILVER Copper, nickel, and zinc, with, sometimes, a little iron and tin. GOLD (standard) Gold with copper. GOLD (old standard) Gold with copper and silver. GUN-METAL See Cannon-metal. MOSAIC GOLD Copper and zinc. OR-MOLU Copper and zinc. PEWTER (common) Tin and lead. PEWTER (best) Tin with antimony, bismuth and copper. POT-METAL, COCK-METAL Copper and lead, with, sometimes, a little zinc. QUEEN’S METAL Tin with antimony, bismuth, and copper. SHOT-METAL Lead with a little arsenic. SILVER (standard) Silver and copper. SOLDER Tin and lead. SPECULUM-METAL Tin and copper, and arsenic. STEREOTYPE-METAL Lead, antimony, and bismuth. TOMBAC, RED TOMBAC Copper and zinc. TUTANIA See Britannia metal. TYPE-METAL Lead and antimony. WHITE COPPER (Packfong; Copper and arsenic. Whitetombac)

[Footnote 27: For the proportions of the component metals, refer to the alloys under their respective heads.]

Prop., &c. Alloys generally possess characteristics unshared by their component metals. Thus, copper and zinc form brass, which has a different density, hardness, and colour to either of its constituents. Whether the metals tend to unite in atomic proportions, or in any definite ratio, is still undetermined. The evidence afforded by the natural alloys of gold and silver, and by the phenomena accompanying the cooling of several alloys from the state of fusion, goes far to prove that such is the case. (Rudberg.) The subject is, however, one of considerable difficulty, as metals and metallic compounds are generally soluble in each other, and unite by a simple fusion and contact. That they do not combine indifferently with each other, but exercise a species of elective affinity not dissimilar to other bodies, is clearly shown by the homogeneity and superior quality of many alloys in which the constituent metals are in atomic proportions. The variation of the specific gravity and melting-points of alloys from the mean of those of their component metals, also affords strong evidence of a chemical change having taken place. Thus, alloys generally melt at lower temperatures than those required for their separate metals. They also usually possess more tenacity and hardness than the mean of their constituents.

Matthiessen found that when weights are suspend to spirals of hard-drawn wire made of copper, silver, gold, or platinum, they become nearly straightened when stretched by a moderate weight; but wires of equal dimensions composed of copper-tin (12% of tin), silver-platinum (36% of platinum), and gold-copper (84% of copper), scarcely undergo any permanent change in form when subjected to tension by the same weight.

The same chemist gives the following approximative results upon the tenacity of certain metals and wires hard drawn through the same gauge (No. 23):

Breaking strain for:

lbs. Copper 25-30 Tin under 7 Lead ” 7 Tin-lead (20% lead) about 7 Tin-copper (12% copper) ” 7 Copper-tin (12% tin) ” 80-90 Gold 20-25 Gold-copper (8·4% copper) 70-75 Silver 45-50 Platinum 45-50 Silver-platinum (30% platinum) 75-80

On the other hand, their malleability, ductility, and power of resisting oxygen is generally diminished. The alloy formed of two brittle metals is always brittle; that of a brittle and a ductile metal, generally so; and even two ductile metals sometimes unite to form a brittle compound. The alloys formed of metals having different fusing-points are usually malleable whilst cold, and brittle whilst hot. The action of the air on alloys is generally less than on their simple metals, unless the former are heated. A mixture of 1 part of tin and 3 parts of lead is scarcely acted on at common temperatures; but at a red heat it readily takes fire, and continues to burn for some time like a piece of bad turf. In like manner, a mixture of tin and zinc, when strongly heated, decomposes both moist air and steam with almost fearful rapidity.

The specific gravity of alloys is never the arithmetical mean of that of their constituents, as commonly taught; and in many cases considerable condensation or expansion occurs. When there is a strong affinity between two metals, the density of their alloy is generally greater than the calculated mean; and vice versâ, as may be seen in the following Table:——

Alloys having a density——

Greater than the mean of Less than the mean their constituents:—— of their constituents:——

Copper and bismuth, Gold and copper, ” palladium, ” iridium, ” tin, ” iron, ” zinc, ” lead, Gold and antimony, ” nickel, ” bismuth, ” silver, ” cobalt, Iron and antimony, ” tin, ” bismuth, ” zinc, ” lead, Lead and antimony, Nickel and arsenic, Palladium and bismuth, Silver and copper, Platinum and molybdenum, Tin and antimony, Silver and antimony, ” lead, ” bismuth, ” palladium, ” lead, Zinc and antimony. ” tin, ” zinc.

“Every alloy,” says Dr Ure, “is, in reference to the arts and manufactures, a new metal, on account of its chemical and physical properties. A vast field here remains to be explored. Not above sixty alloys have been studied by chemists, out of many hundreds which may be made, and of these very few have yet been practically employed. Very slight modifications often constitute very valuable improvements upon metallic bodies.” See ANALYSIS, ASSAYING, BRASS, BRONZE, ELECTROTYPE, GERMAN SILVER, GOLD, METALS, SPECIFIC GRAVITY, &c.

=ALL′SPICE.= See PIMENTO.

=ALLU′′VIAL.= (-l’ōōv′-yăl). Syn. ALLU′′VIOUS*; ALLU′′VIUS, L.; D′ALLUVION, Fr. In geology, applied to partial deposits of mud, sand, gravel, &c., left by rivers and floods upon land not permanently submerged beneath water; in agriculture, applied to soils so formed or deposited.

=ALLU′′VIUM.= [L., Eng.] Syn. ALLUVION, Fr.; ANFLÖSSUNG, ANSCHWEMMUNG, Ger. In geol. and agr., alluvial deposit or soil. See SOILS, &c.

=AL′LYL= (-lĭl). C_{3}H_{5}. In chemistry, the radical of the essential oils containing sulphur, as those of assafœtida, garlic, horseradish, mustard, onions, &c., which are either sulphides or sulphocyanides of allyl. Its probable existence was first shown by Captain Reynolds, who succeeded in producing several of its derivatives. It has since been obtained, in a separate state, by the action of sodium upon iodide of allyl. It is an oily substance with a high boiling point.

=Allyl, Sulphide of=, (C_{3}H_{5})_{2}S; obtained (artificially) by acting on sulphocyanide of allyl with sulphide of potassium. See OIL OF GARLICK.

=Allyl, Sulphocy′anide of=, C_{3}H_{5}CNS; obtained by submitting iodide of allyl to the action of sulphocyanide of potassium; or by gently heating a mixed alcoholic solution of sulphide of allyl and bichloride of mercury, with sulphocyanide of potassium. See OIL OF MUSTARD (VOLATILE).

=AL′MOND= (ah′-mŭnd). Syn. AMYG′DALA (also -US, -UM*), L.; AMANDE, Fr.; MANDEL, Ger., Dut., Dan., Swed. The ‘almond-tree’ (amyg′dalus commu′nis——Linn.; Ph. L., E., and D.; Amandier——Fr.), a tree of the nat. ord. Rosaceæ, indigenous to Persia, Syria, and the north of Africa; but also extensively cultivated in southern Europe. The almond-tree is about the size of the peach-tree, which it much resembles in appearance. It is incapable of ripening its fruit in this country, and is, therefore, only grown here for the sake of its beautiful vernal flowers. There are several varieties, of which the most important are the sweet and the bitter, so named from the flavour of the seed or kernel. These, for the most part, resemble each other in appearance. De Candolle (‘Prodromus,’ ii, 530) gives five varieties of this species:——A. AMA′′RA (bitter-almond); A. DUL′CIS (sweet-a.); A. FRAGILIS (tender-shelled a.); A. MACROCAR′PA (large-fruited a., pista′chio a., sultana a.); A. PERSICO′ÏDES (peach a.).

=Almond, Per′sian.= The peach.

=AL′MONDS=. Syn. AMYG′DALÆ, L.; AMANDES, Fr.; MANDELN, Ger. The seed or kernels of the almond-tree. They are met with in commerce both in the shell (AMYG′DALÆ CUM PUTAM′INE, -ĭn-e, L.), and shelled (AMYGDALÆ, L.). In the retail shops, most commonly in the latter form. Those rancid, broken, or worm-eaten should be rejected.

=Almonds, Bitt′er.= Syn. AMYG′DALÆ AMA′′RÆ, L.; AMYGDALA AMARA, Ph. E.; AMANDES AMÈRES, Fr.; BITTERE MANDELN, Ger. A variety imported from Mogadore, chiefly characterised by possessing the bitter flavour, and when rubbed with water, the odour of peach-kernels. They are also smaller and thicker than the sweet almond.

Uses, &c. Bitter almonds are used to relieve the flavour of sweet almonds, to clear muddy water, and to flavour confectionery, liqueurs, &c. By pressure, they yield their bland oil (OIL OF ALMONDS; O′LEUM AMYG′DALÆ, L.); the resulting cake (BITTER-A. CAKE; PLACEN′TA A. AMARÆ, L.) is distilled for the volatile oil (ESSENTIAL OIL OF A.; O. A. A., L.), and is afterwards again pressed into cakes (A.-CAKE), and used to fatten pigs, and for other purposes. Bitter almonds are now seldom employed in medicines, although it is said that they have cured ‘intermittents’ when bark had failed (Bergius), and that their emulsion has been found useful in pulmonary and dyspeptic affections, hooping-cough, and asthma; and externally as a lotion in acne. (Thomson.) In large quantities they are poisonous, and even in the smallest quantities have been known to produce nettle-rash (urticaria) and other unpleasant symptoms. They have long been in repute as an antidote to intoxication. The ancient bacchanals chewed them at their orgies, to lessen the effects of wine, and to enable them to take it in larger quantities with impunity.

=Almonds, Blanched′= (blăncht′-). Syn. AMYG′DALÆ DECORTICA′TÆ, L. Almonds from which the husk or seed-coat has been removed. This is effected by soaking them for a short time in warm water, until the skin can be easily removed by pressure between the thumb and forefinger. They are then peeled, rinsed in cold water, drained, and dried. When intended for the table, the last is effected by wiping them with a soft towel; but when they are intended to be powdered, or kept, they are dried by a very gentle heat in a stove, or in the sun.

=Almonds, Burnt′.= Syn. ROASTED ALMONDS; ALMOND COFFEE. Used to colour and flavour liqueurs and confectionery; and formerly, as a substitute for coffee.

=Almonds, Guia′na.= (g_h_e-ā_h_′-nă; g hard). Brazil-nuts.

=Al′monds, In′dian.= The fruit of terminalia catappa (Linn.). They are oleaginous, and nutritious; and are used as a substitute for almonds.

=Almonds, Ja′va= (jā_h_′-). The nuts or kernels of canarium commune (Linn.). They are eaten, made into bread, and pressed for their oil.

=Almonds, Sweet′.= Syn. ALMONDS; AMYG′DALÆ, L.; A. DULCES, Ph. D.; AMYGDALA, A. JORDAN′ICA, Ph. L.; A. DULCIS, Ph. E., & Ph. L. 1836; AMANDES, AMANDES DOUCES, Fr.; SÜSSE MANDELN, Ger. These are the well-known dessert or table fruit of the name, and are the kind always referred to when ‘almonds’ (simply) are spoken of or ordered.

Comm. var.——1. JOR′DAN ALMONDS, which are the finest, and are imported from Malaga. Of these there are two kinds; the one, above an inch in length, flat, and with a clear brown cuticle, sweet, mucilaginous, and rather tough; the other, more plump, and pointed at one end, brittle, but equally sweet with the former.——2. VALEN′TIA A. (which come next in quality) are about 3/8ths of an inch broad, not quite an inch long, round at one end, and obtusely pointed at the other, flat, of a dingy brown colour, with a dusty cuticle.——3. BAR′BARY and ITAL′IAN A., which resemble the latter, but are generally smaller and less flattened.——4. A variety, of medium quality, imported in baskets from Spain.

Uses, &c. Sweet almonds are nutritive, emollient, and demulcent; but frequently disagree with weak stomachs. The husk is apt to occasion indigestion and nausea. Owing to a peculiar idiosyncrasy of some habits, dyspepsia, diarrhœa, œdematous swelling of the face, and urticaria (nettle-rash), sometimes, though seldom, follow the use of unblanched almonds. Blanched almonds do not produce these inconveniences, and, therefore, should be preferred for the table. In medicine, almonds are employed chiefly under the form of emulsion, confection, &c., and to suspend oily substances in water. Their uses for dietetical purposes are well known. Preparations of them are also employed as cosmetics. The cake left after expressing the oil (ALMOND-CAKE) is used for washing the skin, which it is said to render beautifully soft and clear. See ALMOND PASTE, &c.

=AL′NIGHT=† (awl′-). A cake of wax with a wick in the midst. The forerunner of, and a rude form of the modern dumpy night-lights called MORTARS.

=AL′OE= (ăl′-o). Syn. AL′OË (-o-ē), L., Fr. (or ALOÈS), Ger., Ital., Sp., Belg., Dan., Dut., Swed. The aloe-tree. In botany, a genus of plants of the nat. ord. Liliaceæ (DC). The species, of which there are several, are succulent plants or small trees with endogenous stems, and stiff, fleshy, hard, pointed leaves, abounding in a purgative principle (ALOES), which is obtained from them by either evaporating the expressed juice or the decoction. They are all natives of warm climates, and most of them are indigenous to southern Africa.

Hist. [Hebrew: a-ènx], aehleem (aloe-trees), were known to the sacred historians; and both the plant and the inspissated juice are described by Dioscorides[28] and Pliny.[29]

[Footnote 28: Lib. iii, c. xxv.]

[Footnote 29: ‘Hist. Nat.,’ lib. xxvii, c. v.]

Uses, &c. In Africa, the leaves of the Guinea aloe are made into ropes, fishing-lines, bow-strings, stockings, hammocks, &c. The leaves of another species are used to catch and hold rain-water. The expressed juice and decoction are also used by the natives as a distaff. (Vide infrà.) Comparative trials, made in Paris, of the strength of cordage and cables formed of hemp, and of the aloe from Algiers, are said to have shown the great superiority of the latter. Fabroni obtained a fine violet colour from the recent juice of the aloe, which has been proposed as a dye for silk.[30]

[Footnote 30: ‘Annales de Chimie,’ xxv, 305.]

=American Aloe.= The agave Americana (Linn.) is a plant unconnected with the preceding, and belonging to the nat. ord. Bromeliaceæ. It is found in all parts of tropical America, and is largely cultivated on the shores of the Mediterranean; and less frequently, as an exotic plant in this country. It grows to the height of about 20 feet, and takes many years to produce its gigantic and magnificent pyramid of flowers; shortly after which it perishes, exhausted, as it were, by its efforts in bestowing its rare beauty on the floral world. The vulgar belief is that it blossoms only once in a century; but, as stated by the late Mr Loudon, it flowers sooner or later according to the culture bestowed on it. Its sap yields a kind of honey (AGAVE HONEY), and by fermentation an intoxicating liquor (PULQUE); desiccated juice, mixed with wood ashes, is used as soap, and lathers either with sea or fresh water; leaf-fibre, used as hemp to make thread and twine.

=AL′OE-RESIN.= Syn. RESI′NA AL′OËS, L. The resinous matter deposited by a decoction of aloes as it cools.

Prep. (Ph. L. 1746.) Boil aloes, 1 part, in water, 8 parts, and allow the decoction, strained whilst hot, to repose until the next day; then wash the deposited RESIN, and dry it by a gentle heat. It is probably a mixture of aloine and oxidised extractive.

=AL′OES= (-ōze). Syn. BITT′ER ALOES‡; AL′OË (-o-ē), L.; ALOÈS, SUC D’ALOÈS, Fr.; ALOE, GLAUSINDE ALOE, Ger.[31] The inspissated juice or extract of several species of aloe.

[Footnote 31: Also see ALOE, (above).]

Comp., Prep., &c. Aloes is a complex resinous substance containing a body called aloin, which is its active or purgative principle. It is completely soluble in boiling water, and in alcohol or rectified spirit. The decoction deposits an impure resin or resinoid on cooling.

Phys. eff., Uses, &c. Aloes is a warm stimulating purgative, in doses of 3 to 10 gr.; whilst even 1 or 2 gr. seldom fail to produce one motion without pain or inconvenience. It is considered highly serviceable in hypochondriacal, hysterical, and dyspeptic affections, particularly in phlegmatic habits, and in cases arising from deficiency of bile. As an emmenagogue, and a vermifuge, few medicines are more valuable. It acts on the large intestines, and principally on the rectum; and, therefore, should be administered with caution, or only in small doses, where there is a tendency to prolapsus or piles, and in cases where uterine stimulants (as in pregnancy, &c.) would be improper. “It is remarkable with regard to it, that it operates almost to as good a purpose in a small as in a large dose; and one or two grains will produce one considerable dejection, and twenty grains will do no more, except it be that in the last dose (case) the operation will be attended with griping, &c. It is one of the best cures for habitual costiveness.” (Cullen.) Many of the effects complained of arise from its slow solubility in the primæ viæ, and may be obviated by administering it in a liquid form, or in a solid form combined with soap, which renders it freely soluble in the juices of the stomach.

Aloes is more frequently taken than, perhaps, any known purgative. It enters into the composition of a majority of the aperient medicines prescribed by the faculty, and forms the principal ingredient of nearly all the advertised purgative, antibilious, and universal pills of the nostrum-mongers. The fact of aloetic pills not acting until about 8 to 10 hours after being swallowed——so that if taken on retiring to rest at night they do not generally disturb the patient before the usual time of rising in the morning——has contributed more than anything else to make such remedies popular with parties whose habits or business avocations would be otherwise interfered with.

Aloes is also extensively used in veterinary practice. It is the most valuable and reliable purgative for the horse of the whole materia medica; but is less to be depended on for cattle, sheep, and hogs. Barbadoes aloes is the best for this purpose. Cape aloes are, however, often employed, when 1-4th more must be given.——Dose (of the former), for a HORSE, 4 to 8 dr.;[32]——CATTLE, 3 to 6 dr. (followed by a purging drench);——HOGS, 5 to 15 gr.;——SHEEP, 15 to 30 gr.;[33]——DOGS (small ones), 10 to 30 gr., (middle-sized) 20 to 44, or even 60 gr., (large) 3/4 to 1 dr., or even 2 dr.

[Footnote 32: Aloes takes from 18 to 30, or even 36 hours, to operate on a horse.]

[Footnote 33: Aloes, however large the dose, often fails to purge sheep. In very large quantities it is poisonous to them.]

Aloes is also used in dyeing; and as a colouring matter in stains, lacquers, and varnishes. Aloes, and several of its preparations, are likewise extensively employed to adulterate porter.

Var. These, arranged in the order of their reputed medicinal value, are——Socotrine, Hepatic, Barbadoes, Cape, &c.; and alphabetically, as given below:——

=Aloes, Barba′does.= Syn. ALOES IN GOURDS; AL′OË BARBADEN′SIS, L., Ph. L. & E. Imported from Barbadoes and Jamaica, usually in gourds; sometimes in boxes. The best is the inspissated juice of the cut leaf of aloë vulga′′ris; an inferior quality is prepared from the decoction.——Char., &c. Opaque, lustreless, of a liver colour, a little tending to black, with a bitter nauseous taste, and a very disagreeable odour, especially when breathed on; powder a dull olive-yellow. It is the ‘hepatic’ aloes of most continental writers, and said to be the Αλοη of Dioscorides. It is more active than the other varieties of aloes; but is also more apt to occasion hæmorrhoids, and to gripe, than any of them.

=Aloes, Cab′alline= (-līne.) Syn. FŒT′ID ALOES, HORSE A.; ALOË CABALLI′NA, A. GUINIEN′SIS, L.; ALOÈS CABALLIN, Fr. From aloë In′dica (O’Shaughnessy); or from aloë spica′ta by long and careful boiling. (Lindley.) Used only by farriers. Scarcely known in English commerce.

=Aloes, Cape.= Syn. ALOË CAPEN′SIS, A. LU′CIDA (Geiger), L. Imported from the Cape of Good Hope, and obtained from aloë spica′ta, and other Cape species. Odour stronger and even more disagreeable than that of Barbadoes aloes; colour deep greenish-brown; appearance shining and resinous; fracture generally glassy; powder a lively greenish-yellow; almost completely soluble in boiling water, decoction paler than that of other kinds. It is weaker than Barbadoes or even hepatic aloes, and is more apt to gripe, &c., than the latter. A finer kind, known as ‘Bethelsdorp aloes,’ imported from Algoa Bay, is more of a liver colour, and softer than the preceding, and hence often called CAPE HEPATIC-ALOES.

=Aloes, Hepat′ic.= Syn. BOMBAY’ ALOES*, EAST-INDIA A.*, LIVER-COLOURED SOCOTRINE A.*; ALOË HEPAT′ICA, Ph. L. & D.; A. IN′DICA, Ph. E. Imported from Bombay and Madras. It is usually said to be obtained from “uncertain species of aloes;” but it is almost certain that it is “the juice of the Socotrine aloes plant which has been solidified without the aid of artificial heat.”[34]——Char., &c. “Opaque, of a liver colour, bitter taste, and an unpleasant odour.” (Ph. L.) It is less odorous, darker coloured, and more opaque than Socotrine aloes; its powder has also a duller colour, and weak spirit leaves much undissolved matter. Its decoction on cooling frequently deposits a yellow powder. The finer and brighter varieties of hepatic aloes are commonly sold for ‘Socotrines,’ and their medicinal virtues are nearly similar. (See below.)

[Footnote 34: Pereira, ‘Elem. Mat. Med. and Therap.,’ vol. ii, 188, 4th Ed.; ‘Pharm. Journ.,’ vol. xi.]

=Aloes, In′dian= (various);——1. Deep brown or black, very opaque, and less soluble than ordinary aloes. Scarcely known in commerce.——2. Several varieties ranging in character from ‘Cape aloes’ to ‘hepatics,’ and occasionally to ‘Barbadoes,’ obtained from several species.

=Aloes, Mo′cha= (-kăh). Syn. ALOË DE MOCHÂ, L. Imported from Muscat. An inferior kind of Indian aloes. (Christison.) It is obtained from the same plant as produces genuine hepatic aloes. (Lindley.) It holds an intermediate position between ‘Cape’ and ‘hepatics,’ but contains much impurity; the latter often amounting to upwards of 25%. Some specimens are, however, of excellent quality. When melted and ‘doctored,’ it is sold for Barbadoes, hepatic, and even Socotrine aloes.

=Aloes, Soc′otrine= (-trĭn; sŭk′-‡). Syn. SOC′OTORINE ALOES, SMYR′NA A., TUR′KEY A.; ALOË SOCOTRI′NA, Ph. L.; ALOË, Ph. L. 1836; A. SOCOTRI′NA, Ph. E. “The juice of the cut leaf of uncertain species hardened by the air.” (Ph. L.) Genuine Socotrine aloes is generally supposed to be obtained from aloë spica′ta; but is referred by De Candolle to a distinct species, A. SOCOTRI′NA; and by Martius, also to a. purpuras′cens. Formerly this variety was brought from the Island of Socotra or Zocotora (hence the name), by way of Smyrna and Malta; but it is now chiefly obtained from Bombay and Madras.——Char., &c. Colour garnet red to golden red; smell peculiar and aromatic, not unlike a decaying russet apple, especially when fresh-broken, or breathed on, or warmed; taste permanently and intensely bitter; fracture conchoidal; softens in the hand, and becomes adhesive, yet retains considerable brittleness; powder bright golden-yellow colour; central portions of the lumps often soft, especially when first imported. “It is brittle, bitter, of a reddish-brown colour, and an aromatic odour. Light permeates thin recently broken laminæ.” (Ph. L.) “In thin pieces, translucent and garnet red; almost entirely soluble in spirit of the strength of sherry. Very rare.” (Ph. E.)

Socotrine aloes are always preferred for medicinal purposes, and are the only variety used in perfumery, varnishes, and other nice purposes in the arts.

=Aloes, Strained.= Syn. MELTED ALOES; ALOË COLA′TA, L. Proc. 1. The aloes are melted in a copper pan, by the heat of steam or a water bath, and are then pressed through a strong hair or wire sieve, and allowed to cool.

2. As above, but with the addition of about twice its weight of water; the decoction being strained and evaporated.

Obs. Mocha, Indian, and other common aloes, treated in this way and coloured, are frequently sold for melted or strained ‘Socotrines’ and ‘hepatics.’ The colouring matter usually employed is the precipitated carbonate of iron (sesquioxide), or Venetian red, in very fine powder, with, sometimes, a little annatto. This fraud is not readily detected by mere inspection, by those unaccustomed to these matters; and hence the impunity with which it is perpetrated.

The object in melting aloes is to deprive it of the foreign matters, as sand, leaves, pieces of wood, &c., which the commoner kinds generally contain in large quantities. The action of the heat drives off much of their nauseous smell, at the same time that it deepens their colour, and renders their appearance more translucent and resinous, to the disguise of their original nature. The operation, on the large scale, is usually carried on at night, in consequence of the horribly nauseous fumes evolved, which may be smelt at a great distance, and contaminate the clothes of those engaged in it for a long time afterwards.

=AL′OES HEMP.= A plant growing in Peru, the East and West Indies, and Mexico (A. Americana, A. vivapara, A. fœtida, &c.), where the leaf is cultivated for its fibre, which is generally of a yellowish-white colour, and used for rope-making.

=AL′OES WOOD.= Syn. AL′OE-WOOD; EAGLEWOOD; AGAL′LOCHUM (-kŭm), LIG′NUM AL′OËS, L. AGAL′LOCHI, L. A. VE′′RI, L. AQ′UILÆ, L. ASPAL′ATHI, L.; AGALLOCHE, BOIS D’ALOÈS, Fr.; ALOEHOLZ, Ger.; CALAM′BAC, CALAM′BOUC, Ind.; XYLO-AL′OËS†. A name applied to the wood of alöex′ylon agal′lochum (Lam.), a leguminous tree of Cochin China; and, though apparently less correctly, to that of aquila′′ria agallochum and a. ova′ta (Lour.), trees of tropical Asia, belonging to a different nat. order. Both are highly fragrant and aromatic; used in fumigations and pastilles, and occasionally by cabinet makers and inlayers. The essential oil of the wood, dissolved in spirit, was regarded by Hoffmann as one of the best cordials and invigorants known. The same has also been said of a tincture of its resin.

The same name and synonyms are popularly applied to the resin of the above woods (ALOES-WOOD RESIN), of which there are two varieties:——the one, light and porous, and filled with a highly fragrant resinous substance; the other, denser and less resinous. It is an oily concretion in the centre of the tree, the result of disease, which gradually hardens, and, in time, kills it. It is highly fragrant, and is said to be nervine, cephalic, cardiac, and stimulant. The powder is regarded as tonic and astringent. Of all perfumes this is said to be the one most esteemed by oriental nations.

=ALOE′TIC.= Syn. ALOËT′ICUS, L.; ALOÉTIQUE, Fr. Of or belonging to aloes. In medicine, pharmacy, &c., applied to any preparation containing aloes as a characteristic ingredient; made or obtained from aloes. Substantively, an aloetic medicine.

=AL′OIN= (-o-ĭn). C_{17}H_{18}O_{7}. [Eng., Fr.] Syn. AL′ÖIN; ALOÏ′NA, L. The Messrs T. & H. Smith, of Edinburgh, have applied this name to a crystalline substance, which they assert to be the pure cathartic principle of aloes. Their process is to evaporate to the consistence of a syrup, in vacuo, a solution obtained by exhausting a mixture of aloes and sand, with cold water, and then to set it aside for a few days. The resulting dark crystalline mass is purified by pressure between folds of bibulous paper, and repeated crystallisation from hot water. Barbadoes aloes are commonly used for the purpose; but soft or semi-liquid Socotrine aloes, or the unevaporated Socotrine-aloes juice, is probably its best source. Tilden gives the following process for the preparation of aloin:——The aloes crushed small is to be dissolved in nine or ten times its weight of boiling water acidified with sulphuric acid. After cooling and standing for a few hours, the clear liquid is decanted from the resin, and evaporated. The concentrated solution deposits a mass of yellow crystals, which can be purified by washing, pressure, and recrystallisation from hot spirit. After several recrystallisations the aloin is obtained in the form of beautiful yellow needles, which are pretty soluble in water and in alcohol, but soluble with difficulty in ether.——Dose, 1 to 2 gr.

=ALOPE′CIA= (-sh′ă). [L.] Syn. AL′OPECY, FOX′-EVIL; ALOPÉCIE, Fr.; FUCHSRAUDE, Ger. In pathology, baldness from disease, often extending to the beard and eyebrows; as distinguished from ‘calvities,’ or ordinary baldness arising from attenuation of the scalp or defective nutrition. See BALDNESS.

=ALPAC′A.= A species of Llama, popularly known as the PERUVIAN SHEEP, an animal intermediate between the camel and sheep, having long silky hair, nearly as fine as that of the Cashmere goat. It was introduced to the British manufacturers in 1834, when only 5700 lbs. of it was imported; but it soon became an important article of commerce, the quantity imported having gradually risen to above 2-1/4 millions of lbs. in 1853; whilst the price has risen from about 9d. to 2s. 7d. the lb., in the same time. The name is also given to fabrics woven from the wool of this animal; and to others in fine wool, made in imitation of them. The gigantic factory, &c., erected at Saltaire, Yorkshire, in 1852, for this manufacture, covers about 12 acres of land. See LLAMA.

=ALPENKRAUTER-BRUST-TEIG= (Grablowitz, Gras). Pectoral cakes of Alpine herbs. Gum arabic, 100 parts; sugar, 200 parts; extract liquorice, 1 part; saffron, 1/8th part. Each box contains 48 lozenge-shaped yellowish cakes. Made into a mass with decoction of marsh mallow. (Hager.)

=ALPENKRAUTER GESUNDHEIT’S LIQUEUR= (Rudolph Bohl). Medicinal liqueur of Alpine herbs. A bottle containing 350 grammes of a liqueur which is an extract of star anise, cassia, frangula bark, centaury, chicory, gentian, and a little aloes. (Hager.)

=ALPENKRAUTER-MAGENBITTER= (Hauber). Stomachic bitters of Alpine herbs. A brown liqueur of bitter, spirituous, and slightly aromatic flavour, containing in 100 parts: oil of anise, 0·5; oil of cloves, 0·5; aloes, 1·5; alcohol, 40; water, 50. 157 grammes in each bottle. (Wittstein.)

=ALPHA-ORSELL′IC ACID.= See ORSELLIC ACID.

=ALPINE ROSE SOAP, SWISS.= A preservative against syphilitic infection (G. A. Sarpe, Zurich). A glass cylinder corked and sealed, about 2 inches long, and containing a hard brownish-grey mass weighing 12 grammes, prepared thus:——Ammonia, 1 part; sublimate, 3 parts; tannin, 2 parts; chloride of lime, 24 parts; Castile soap, 190 parts; oil of cloves, 1 part; spirit of wine, q. s. (Hager.)

=AL′QUIFOU= (-ke-fōō). Syn. BLACK LEAD-ORE, POTTER’S ORE. A native sulphide of lead used by potters to give a green glaze to coarse wares.

=ALSTONIA SCHOLARIS.= (Ind. Ph.) Habitat. Common in forests throughout India.——Officinal part. The bark (Alstoniæ cortex). It occurs in thick, irregular, more or less contorted pieces, easily broken. It consists of a rough greyish epidermis, investing a buff or pale cinnamon-coloured bark; internally, still lighter in colour, and of a spongy texture, having a very bitter taste, but devoid of odour.——Properties. Astringent, tonic, anthelmintic, antiperiodic——Therapeutic uses. In chronic diarrhœa and the advanced stages of dysentery; also as a tonic in debility after fevers, and other exhausting diseases.——Dose. 3 to 5 grains, either alone or combined, in bowel affections, with small doses of ipecacuanha and extract of gentian.——Preparations. TINCTURE OF ALSTONIA (Tinctura Alstoniæ). Take of alstonia bark, bruised, 2-1/2 ounces; proof spirit, 1 pint. Macerate for seven days in a closed vessel, with occasional agitation; filter, and add sufficient proof spirit to make 1 pint. Or prepare by percolation, as Tincture of Calumba.——Dose, 1 to 2 fluid drachms.

=Alstonia, Infusion of.= (Infusum Alstoniæ.) Take of alstonia bark, bruised, 1/2 an ounce; boiling water, 10 fluid ounces. Infuse in a covered vessel for an hour and strain.——Dose. From 1 to 2 fluid ounces twice or thrice daily. A good serviceable tonic.

=AL′TERATIVE= (awl′-tĕr-ă-tĭv). Syn. AL′TERANT*; AL′TERANS (ăl′-), L.; ALTÉRANT, ALTÉRATIF, Fr. In medicine, having power to alter; applied to substances and agents which occasion a change in the habit or constitution, and thus re-establish the healthy functions of the body, or any part of it, without producing any sensible evacuation or other obvious effect.

=ALTERATIVE EXTRACT=, or =GOLDEN MEDICAL DISCOVERY= (Dr Pierce, Buffalo), for the cure of all severe, acute, chronic, or long-standing coughs, inflammations, hoarseness, scrofulous, and syphilitic diseases. A clear light-brown fluid, 220 grms., composed of 15 grms. purified honey, 1 grm. extract of lettuce, 2 grms. laudanum, 100 grms. of proof spirit tasting of fusel oil and wood spirit, and 105 grms. water. (Hager.)

=AL′TERATIVES= (-tĭvz). Syn. ALTERAN′TIA, L.; ALTÉRATIFS, &c., Fr. Alterative medicines or agents. The preparations of mercury and iodine, when properly administered, are the most useful members of this class; and are those which are now the most generally employed.

=ALTHE′IN= (ăl-thē′-ĭn). Syn. ALTHÆ′INA, L. The name given by Braconnot to a substance identical with asparagin, which he discovered in the ‘marsh-mallow’ (althæ′a officina′lis, Linn.).

=ALTHOFF WATER= (aqua mirabilis), for torpid ulcers. Wine vinegar, 750 parts; sulphate of copper, 100 parts; potash, 25 parts; ammonia, 30 parts; salt of sorrel, 8 parts; French brandy, 375 parts. Digest for a few days in a glass vessel and distil to dryness from a glass retort. (Wittstein.)

=AL′UDEL= (-ū-). In chemistry, a pear-shaped glass or earthen pot open at both ends, formerly much used for connecting other vessels in the process of sublimation. A number of them joined together are still employed for the distillation of quicksilver, in Spain.

=AL′UM= K_{2}SO_{4}.Al_{2}(SO_{4})_{3}.24Aq. Syn. POT′ASH-ALUM, SUL′PHATE OF ALUMINUM AND POTASSIUM, COMMON ALUM; ALU′MEN, A. POTAS′SICUM, L.; ALUN, SULFATE D’ALUMINE ET DE POTASSE, Fr.; ALAUN, Ger.; ALUME, Ital.

The principal alum-works in England, until recently, were those of Lord Glasgow, at Hurlett and Campsie, near Glasgow, and those of Lords Dundas and Mulgrave, at Whitby, Yorkshire (est. 1600); but those of Mr Spence, at Manchester, and at Goole (Yorkshire), and of Mr Pochin, at Manchester, are now among the largest, if they be not actually the largest in the world. There are also extensive alum-works at and near Newcastle-on-Tyne; but none of importance, that we know of, in any other part of these realms.

Nat. hist. Alum is found native in some places (NATIVE ALUM), either effloresced on the surface of bituminous alum-schist (Göttwigg, Austria); or united with the soil in the neighbourhood of volcanoes (Solfatara, Naples); when it may be obtained by simple lixiviation and evaporation, a little potash being commonly added to convert the excess of sulphate of alumina present into alum. It is also found in certain mineral waters (East Indies).

Sources. The alum of commerce is usually obtained from schistose pyritic clays, commonly termed alum-ores, aluminous shale, a.-schist, &c.; and from alum-rock, a.-stone, or alunite. At La Tolfa, Civita Vecchia, where the best Roman-alum is produced, the source is stratified alum-stone. On the Continent, and in Great Britain, it is generally pyritaceous clays, volcanic aluminous ores, aluminous shale, or alum-slate. These minerals contain sulphide of iron, alumina, bitumen or carbon, and frequently a salt of potassium. Of late years large quantities of alum have been prepared on the banks of the Tyne from aluminous clay.

Prep. The manufacture of alum is technically said to be conducted according to the natural process when prepared from alum-schist or alum-ore; and according to the artificial process when made by acting on clay with sulphuric acid, and adding a potassium salt to the resulting lixivium. The manufacture of alum and of sulphate of alumina from such materials as contain only alumina, to which consequently sulphuric acid and alkaline salts have to be added, has come largely into practice in England. The materials employed are, in addition to clay, cryolite or Greenland spar, a fluoride of aluminum and soda; bauxite, a hydrate of alumina, of more or less purity; and slag. The following are the details of these processes:——

a. From ALUM-ORE, ALUMINOUS SCHIST, or SHALE, &c.:——

1. The mineral (alum-ore, a.-schist, &c.) is placed in heaps, and moistened from time to time with water, when it becomes gradually hot, and falls into a pulverulent state. This decomposition commonly occurs either wholly, or partially, on the floor of the mine. If the ore does not possess this property on mere exposure to air and moisture, it is broken into pieces and laid upon a bed of brushwood and small coal, to the depth of about four feet, when the pile is fired and fresh lumps of the alum-mineral thrown on, until the mass becomes of considerable height and size. The combustion, as soon as established, is conducted with a smothered fire, until the calcination is complete; care being taken to prevent fusion, or the disengagement of either sulphurous or sulphuric acid, from contact between the ignited stones and the carbonaceous fuel.[35] To promote these ends the pile, at the proper time, is ‘mantled’ (as the workmen call it) or covered with a layer of already calcined and exhausted ore, in order to protect it from high winds and heavy rains; as also to moderate the heat, and let it proceed gradually, so that the sulphur present may not be lost or wasted by volatilisation. The roasting is finally checked by a thicker ‘mantling,’ and the whole allowed to cool. By this time the pile has usually lost about one half its bulk, and become open and porous in the interior, so that the air can circulate freely through the mass; the latter, in dry weather, as the heap cools, being usually promoted by sprinkling a little water on it, which, by carrying down some of the saline matter, renders the interior still more open to the atmosphere. The whole, when cold, or nearly cold, is, if necessary, still further exposed to the action of air and moisture. The time required to calcine the heap properly, including that taken by the burned ore to cool, varies, according to its size and the state of the weather, from three to nine, or even twelve months. The residuum of the calcination is next placed in large stone or brick cisterns, and edulcorated with water, until all the soluble portion is dissolved out; the solution is then concentrated in another stone cistern, so made that the flame and heated air of its reverberatory furnace sweep the whole surface of the liquor. (See engr.) The evaporation is continued until it just barely reaches the point at which crystals are deposited on cooling; when it is run off into coolers. After the sulphate of iron, always present, has been deposited in crystals, the mother-liquor, containing the sulphate of aluminum, is run into other cisterns, and a saturated solution of chloride of potassium, or of sulphate of potassium, or (sometimes) impure sulphate or carbonate of ammonium, or a mixture of them,[36] is added until a cloud or milkiness ceases to be produced on addition of more.[37] It is next allowed to settle and get thoroughly cold, and the supernatant ‘mother-liquor’ being drawn off with a pump or syphon, the precipitate, which is alum in the form of minute crystals (technically termed ‘flour’), is well drained, and subsequently washed by stirring it up with a little very cold water, which is then drained off, and the operation repeated a second time with fresh water. A saturated solution of the pulverulent alum (‘flour’) is next formed in a leaden boiler, and the clear portion is run or pumped off, while boiling hot, into crystallising vessels, called roaching casks (see engr.), the staves of which are lined with lead, and nicely adjusted to each other. After the lapse of a week or ten days, the hoops and staves of these ‘casks’ are removed, when a thick crust of crystallised alum is found, which exactly corresponds in form and size to the interior of the cask. A few holes are then made in the sides of this mass, near the bottom, to allow the contained mother-liquor to drain off, after which the whole is broken up and packed in casks for sale. Sometimes the alum thus obtained, or the lower portion of it, is washed with a little very cold water, and, if discoloured, or small or slimy, is purified by a second crystallisation.

[Footnote 35: The generality of alum-minerals require roasting; and their own bituminous matter is, in many cases, sufficient to produce the heat required, which need not necessarily exceed 600 to 650° Fahr., provided it be continued for a sufficient period. It is only when they are less bituminous or carbonaceous that slack or saw-dust, &c., is employed.]

[Footnote 36: For pure POTASH-ALUM a salt of potash only must be employed. When ammonia (usually in the form of gas-liquor or gas-sulphate) is used as the precipitant, the product is AMMONIA-ALUM. The ordinary alums of commerce are now generally mixtures of the two.]

[Footnote 37: The respective quantities required to produce 100 parts of alum from the sulphate of alumina liquor are——

Chloride of potassium 15·7 Sulphate of ” 18·4 ” ammonium 13·9

In practice, the exact quantity required may be found by a previous trial of a little of the aluminous liquor; but the indications mentioned in the text will always show the operator when a sufficient dose is added.]

2. As ammonia-alum (Spence’s process; see below), but using a potash-salt as the precipitant, either wholly or in part, instead of ammonia; and, in the latter case, supplementing the deficiency of potash with ammonia, as there explained.

b. From ALUMINOUS CLAY and OIL OF VITRIOL:——

1. Clay, free or nearly free from carbonate of lime and oxide of iron, is chosen for this purpose. It is moderately calcined (in lumps) in a reverberatory furnace, until it becomes friable; great care being taken that the heat be not sufficient to indurate it, which would destroy its subsequent solubility. It is next reduced to powder, sifted, and mixed with about 45% of its weight of sulphuric acid (sp. gr. 1·45), the operation being conducted in a large stone or brick basin arched over with brickwork. Heat is then applied, the flame and hot air of a reverberatory furnace being made to sweep over the surface of the liquor. The heat and agitation are continued for 2 or 3 days, when the mass is raked out and set aside in a warm place for a few weeks (6 to 8), to allow the acid the more perfectly to combine with the clay. At the end of this time the newly-formed sulphate of alumina is washed out, the solution evaporated until of a sp. gr. of about 1·38 (1·24 for ‘ammonia-alum’), and the salt of potash added. The remaining operations resemble those above described. Good alum may be produced by this process at about two thirds the cost of rock or mine alum.

2. (Process of Mr Pochin.) Fine China clay is heated in a furnace, and mixed with a suitable proportion of sulphuric acid; the latter being considerably diluted with water, in order to moderate its action, which would otherwise be far too violent. The mixture is then passed into cisterns furnished with movable sides, where, in a few minutes, it heats violently and boils. The thick liquid gradually becomes thicker, until it is converted into a solid porous mass; the pores being produced by the bubbles of steam which are driven through it, owing to the heat resulting from the reaction of the ingredients on each other. This porous mass (ALUM-CAKE; CONCENTRATED ALUM) appears perfectly dry, although retaining a large amount of combined water. It also contains all the silica of the original clay, but in such a state of fine division, that the whole appears homogeneous; whilst it imparts a dryness to the touch which can scarcely be given to pure sulphate of alumina. From this substance a solution of pure sulphate of alumina is easily obtainable by lixiviation, and allowing the resulting solution to deposit its silica before using it, but for many purposes the presence of the finely divided silica is not objectionable. The sulphate of alumina solution so obtained is adapted to all the purposes in dyeing for which alum is now employed; the sulphate of potash or of ammonia in the latter being an unnecessary constituent, and one merely added to facilitate the purification and subsequent crystallisation of the salt. To obtain ALUM from the porous alum-cake, the proper proportion of acid having been used in its preparation, or subsequently added, it is only necessary to precipitate its concentrated solution with a strong solution of a salt of potash, or of ammonia, or a mixture of them, and to otherwise proceed as before.

Ratio. In the above process the sulphide of iron of the shale or schist is converted by atmospheric oxygen into sulphate of iron and sulphuric acid; the sulphuric acid decomposes the clay, setting silica free, and producing sulphate of aluminum. The sulphate of iron is mostly got rid of by concentrating the solution of the mixed sulphates, and the mother-liquors are converted into alum by the addition of the salt of potassium. When chloride of potassium is used, it yields chloride of iron and sulphate of potassium, the latter combining with the sulphate of aluminum, and the former remaining behind in the mother-liquor. See ALUMS (in Chemistry).

Comp. Potassium alum has the formula K_{2}SO_{4}.Al_{2}(SO_{4})_{3}.24Aq.

c. From CRYOLITE.

1. (Thomson’s method.) Decomposition of cryolite by ignition with carbonate of lime. From the ignited mass the aluminate of soda is obtained by lixiviation with water, and into the solution carbonic acid gas is passed, when there result precipitated hydrated gelatinous alumina and carbonate of soda, which remains in solution. If it be desired to obtain the alumina as an earthy compact precipitate, bicarbonate of soda is used instead of carbonic acid. While the clear liquor is boiled down for the purpose of obtaining carbonate of soda, the precipitated alumina is dissolved in dilute sulphuric acid; this solution is evaporated for the purpose of obtaining sulphate of alumina (the so-called concentrated alum), or the solution after having been treated with a potassa or an ammonia salt is converted into alum.

2. (Sauerwein’s method.) Decomposition of cryolite by caustic lime by the wet way. Very finely ground cryolite is boiled with water and lime, the purer the better, and as free from iron as possible, in a leaden pan. The result is the formation of a solution of aluminate of soda, and insoluble fluoride of calcium (lime). When the fluoride of calcium has deposited, the clear liquid is decanted, and the sediment washed, the first wash-water being added to the decanted liquor, and the second and third wash-waters being used instead of pure water at a subsequent operation. In order to separate the alumina from the solution of aluminate of soda, there is added to the liquid while being continuously stirred very finely pulverised cryolite in excess, the result of the decomposition being alumina and fluoride of sodium, (soda). When no more caustic soda can be detected in the liquid, it is left to stand for the purpose of becoming clear. The clarified solution of fluoride of sodium is then drawn off, and the alumina treated as above described. The solution of fluoride of sodium having been boiled with caustic lime yields a caustic soda solution, which having been decanted from the sediment of fluoride of calcium is evaporated to dryness. Recently the fluoride of calcium occurring as a by-product has been used in glass-making.

3. The decomposition of cryolite by sulphuric acid yields sulphate of soda convertible into carbonate by Leblanc’s process, and sulphate of alumina free from iron. This method of decomposing cryolite is, however, by no means to be recommended, as owing to the liberation of hydrofluoric acid, peculiarly constructed apparatus are required, whilst the sulphate of soda has to be converted into carbonate.

d. From Bauxite. This mineral, occurring in some parts of Southern France, in Calabria, near Belfast, and in other parts of Europe, consists essentially (viz. 60 per cent.) of hydrate of alumina, more or less pure. In order to prepare alums and sulphate of alumina from it, the mineral is first disintegrated by being ignited with carbonate of soda, or with a mixture of sulphate of soda and charcoal; in each case the lixiviation of the ignited mass yields aluminate of soda, from which, by the processes already described under “Cryolite,” alum, or sulphate of alumina, and soda are prepared.

e. From blast-furnace slag. Lürmann recommends the slag to be decomposed by means of hydrochloric (muriatic) acid. From the resulting solution of chloride of aluminum the alumina is precipitated by carbonate of lime, any dissolved silica being precipitated at the same time. The alumina is dissolved in sulphuric acid, leaving the silica.

Prop. Alum crystallises in regular octahedrons, often with truncated edges and angles; (see engr.); and sometimes in cubes, but only when there is a deficiency of acid in its composition, with the alkali in slight excess of the proper quantity. (Löwel.)[38] It is slightly efflorescent in dry air: soluble in 18 parts of cold water, and in rather less than its own weight of boiling water; tastes sweet, acidulous, and very astringent; is styptic; and reddens litmus. When heated it melts, loses its water of crystallisation, and becomes white and spongy (DRIED ALUM); a strong heat, short of whiteness, decomposes it, with the evolution of oxygen and a mixture of sulphuric and sulphurous anhydride; calcined with carbonaceous matter it suffers decomposition, and furnishes a pyrophoric residuum (HOMBERG’S PYRO′PHORUS). Ignited with alkaline chlorides, hydrochloric acid is liberated; which also occurs when their concentrated solutions are boiled together. Ammonia precipitates pure hydrate of aluminum from potassium alum; but only a subsulphate from the simple sulphate of alumina. Sp. gr. 1·724; but, when containing ammonia, often so low as 1·710.

[Footnote 38: The ordinary alum, of commerce, consisting of large crystalline masses, which do not present any regular geometrical form; but by immersion in water for a few days, octahedral and rectangular forms are developed on its surface. (Daniell.)]

Tests, &c. It is easily recognised by its crystalline form, its taste, and by its complete solubility in water. Its aqueous solution gives a white gelatinous precipitate soluble in excess; a platinum wire moistened with the solution imparts a violet colour to the blowpipe flame; and chloride of barium gives a white precipitate insoluble in nitric acid.

Pur. When pure, its solution is not darkened by tincture of galls, sulphuretted hydrogen or ferrocyanide of potassium; neither does it give any precipitate with solution of nitrate of silver. Heated with caustic potassa, or quick-lime, it does not evolve fumes of ammonia.

Adult., &c. The principal impurity, and one which renders alum unfit for the use of the dyer, is iron. This may be readily detected by the blue precipitate it gives with ferrocyanide of potassium, or the black precipitate with sulphide of ammonium, which are very delicate tests.[39] Lime, another very injurious contamination, may be detected by precipitating the alumina and iron (if any) with ammonia, and then adding oxalate of ammonia to the boiled and filtered liquid. The liquid filtered from the last precipitate (oxalate of lime) may still contain magnesia, which may be detected by the white precipitate caused on the addition of an alkaline phosphate. Common alum frequently contains ammonia, from urine, or the crude sulphate of the gas-works, having been employed in its manufacture. Powdered alum is frequently adulterated with common salt, in which case it gives a white curdy precipitate with nitrate of silver, turning black by exposure to the light.

[Footnote 39: Good English alum contains less than 0·1% of iron. The best Roman or Italian alums seldom contain more than ·005% of iron-alum, notwithstanding their exterior colour.]

Phys. eff. &c. In small quantities alum acts as an astringent; in larger doses as an irritant. It acts chemically on the animal tissues and fluids, is absorbed, and has been discovered in the liver, spleen, and urine (Orfila), the last often becoming acid (Kraus). Externally, it is astringent. The almost general use of alum by the English bakers is one of the most fertile sources of dyspepsia and liver and bowel complaints in adults; and of debility and rickets in children. Bad teeth and their early decay is another consequence of the daily use of alum in our food. The bone matter (phosphate of lime) of bread, instead of being assimilated by the system, is either wholly, or in part, converted into a salt of alumina, which is useless and incapable of appropriation. When alum has been taken in poisonous doses an emetic should be given, followed by warm diluents and demulcents, containing a little carbonate of soda; and subsequently by a purgative.

Uses, &c. The applications of alum in the arts and manufactures are numerous and important. It is used to harden tallow and fats; to render wood and paper incombustible; to remove greasiness from printers’ blocks and rollers; to prepare a paper for whitening silver and silvering brass in the cold; to help the separation of the butter from milk; to purify turbid water; to dress skins; to fix and brighten the colours in dyeing; to make lake and pyrophorus, &c., &c. It is also extensively used for clarifying liquors, and for many other purposes connected with the arts and everyday life. In medicine, alum is used as a tonic and astringent, in doses of 5 to 20 gr.; as a gargle (1 dr. to 1/2 pint of water); and as a collyrium and injection (10 to 15 gr. to 6 oz. of water). In lead colic, 1/2 to 1 dr. of alum (dissolved in gum-water), every 3 or 4 hours, is said to be infallible. Powdered alum is frequently applied with the tips of the fingers, in cases of sore throat and ulcerations of the mouth, &c. A teaspoonful of it is said to be one of the very best emetics in croup. (Dr Meigs.) Alkalies, alkaline carbonates, lime, magnesia, acetate of lead, astringent vegetables, &c., are incompatible with it.

Gen. commentary. In addition to the particulars of its manufacture given above, we may add, that the plan of getting rid of the ferric salts there referred to has to some considerable extent been successfully replaced by that of precipitating the alum, instead of the sulphate of iron, by adding alkaline matter to the lixivium. The crystalline precipitate is purified by draining, re-solution, and re-crystallisation; whilst the sulphate of iron and Epsom-salts contained in the mother liquor are obtained by subsequent evaporation and crystallisation; after which a fresh crop of alum may be got from it, by the use of an alkaline precipitant, as before.

In estimating the strength of his solution the alum-maker takes as a standard a measure or sp. gr. bottle capable of holding exactly 80 pennyweights of distilled water. The excess of the weight of liquor, in pennyweights, over 80, or that of water, is called so many ‘pennyweights strong.’ Thus one of 90 pennyweights (90 dwt.) is said to be ‘10 dwt. strong,’ or simply, ‘one of 90 dwt.’ These numbers correspond to 2-1/2 degrees of Twaddle’s hydrometer, and may easily be found by dividing Twaddle’s degrees by 2·5 or 2-1/2; or by multiplying them by 4, and pointing off the right-hand figure of the product for a decimal. The result is in alum-makers’ pennyweights.

By a patent now expired (Weisman’s, 1839) the ferric salts are precipitated by the addition of a solution of ferrocyanide of potassium (prussiate of potash); after which the supernatant clear liquor, which is now a solution of nearly pure sulphate of alumina, is decanted, and evaporated for future operations, until it either forms, on cooling, a concrete mass, which is moulded into bricks or lumps, for the convenience of ‘packing,’ or until it is sufficiently concentrated to be converted into ALUM by the addition of a salt of potash or of ammonia in the usual manner. The product, in each case, is perfectly free from iron. By a like addition of the ferrocyanide to a solution of ordinary sulphate of aluminia or alum, the dyer may himself easily render them free from iron, or iron-alum; when, as mordants for even the most delicate colours, they are equal to the very best Roman alum.

Another process has been patented (Barlow & Gore, 1851) for the manufacture of alum from the ash or residue of the combustion of Boghead-coal, which, though hitherto regarded as almost valueless, actually contains about 30% of alumina. It has not, however, been found a convenient material for the purpose.

By the latest and most approved processes the least possible quantity of boiling water or liquor is employed for making the solutions, so that they may crystallise without evaporation, and thus economise fuel; and the mother-liquors of previous operations are constantly employed for this purpose, when possible. Nor is anything which is convertible to use, from the drainage of the heaps, to the liquor and slime of the roaching casks, allowed to be wasted.

By whatever process, or from whatever materials alum is obtained, it is absolutely necessary for the successful and economical conduct of its manufacture, that the precise composition of the mineral or minerals employed should be exactly known. This can only be determined by actual analysis, which should be extended to several parts of the same bed, and particularly to the upper and lower strata, which frequently differ in composition from each other, and thus require different treatment, or may be most advantageously employed in combinations with each other. The necessity of this will be seen by reference to the composition of the following minerals, of which the top contains a larger proportion of iron-pyrites than the bottom, and the two require to be mixed, to equally diffuse the sulphuric acid generated by the calcination, &c., to which they are subjected.

The following is the per-centage composition of certain alum shales:——

+------------------+-------------------+ | | Whitby, Yorkshire.| | | (Richardson.) | | +--------+----------+ | | Top | Bottom | | | rock. | rock. | +------------------+--------+----------+ |Sulphide of iron | 4·20 | 8·50 | | (pyrites) | | | |Silica | 52·25 | 15·16 | |Protoxide of iron | 8·49 | 6·11 | |Alumina | 18·75 | 18·30 | |Lime | 1·25 | 2·15 | |Magnesia | ·91 | ·90 | |Oxide of manganese| traces | traces | |Sulphuric acid | 1·37 | 2·50 | | (SO_{3}) | | | |Potassa | ·13 | traces | |Soda | ·20 | traces | |Chlorine | traces | traces | |Coal | 4·97 | 8·29 | |Water | 2·88 | ·00 | |Loss | 4·60 | (?) | | | | | +------------------+--------+----------+ | | 100· | 100· | +------------------+--------+----------+

+---------------------+------------------------------+ | | Campsie, near Glasgow. | | | (Ronalds.) | +---------------------+---------+----------+---------+ | | Top | Top | Bottom | | | rock. | rock. | rock. | |---------------------+---------+----------+---------+ |Sulphide of iron | 40·52 | 38·48 | 9·63(?)| | (pyrites) | | | | |Silica | 15·40 | 15·41 | 20·47(?)| |Protoxide of iron | ... | ... | 2·18 | |Alumina | 11·35 | 11·64 | 18·91(?)| |Lime | 1·40 | 2·22 | ·40 | |Magnesia | ·50 | ·32 | 2·17 | |Oxide of manganese | ·15 | ... | ·55 | |Sulphuric acid | ... | ... | ·05 | |Potassa | ·90 | ... | 1·26 | |Soda | ... | ... | ·21 | |Carbon or | 27·65(?)| 28·80 | (?) | | bituminous matter | | | | |Coal | ... | ... | 8·51 | |Water | ... | ... | 8·54 | |Loss | 2·13(?)| 3·13 | 1·59(?)| +---------------------+---------+----------+---------+ | | 100· | 100· | 100· | +---------------------+---------+----------+---------+

Alum-rock, or alum-stone, is a species of impure alunite, and is not of very common occurrence. That of Tolfa, near Civita Vecchia, according to Klaproth, consists of——

Silica 56·5 Alumina 19· Sulphuric acid (SO_{3}) 16·5 Potassa 4· Water 3· Loss 1· —————— 100·

which exhibits an excess of about 3% of sulphuric acid, and about 14% of alumina, more than are requisite to form alum with the 4% of potassa; proportions which, therefore, require to be supplemented with a potassium salt during the process of manufacture. The alum-stone of Mont d’Or contains, according to Cordier, 1·4% of oxide of iron.

The presence of lime in alum-ore is most prejudicial, owing to its affinity for sulphuric acid being greater than that of either alumina or iron. Ores containing it in any quantity are, therefore, unfitted for the manufacture of alum. Magnesia is also prejudicial; but in this case the sulphate of magnesia left in the mother-liquors is not wholly valueless, as it may be crystallised and sold as ‘Epsom-salt,’——a thing which is actually done in some English alum-works.

The potash-salt employed by the alum-makers is either the sulphate or the chloride——chiefly the latter; its sources being the waste liquor of soap-works, saltpetre refineries, and glass-houses. Wood-ashes, although rich in potash, do not answer well unless freed by lixiviation from the large amount of carbonate of lime which is always present in them.

The ammonia-salt used in making alum is generally the crude sulphate prepared from the ammoniacal liquor of gas-works, or that from the manufacture of sal-ammoniac by the destructive distillation of animal matter. Both these liquors may be used without previous conversion into sulphate of ammonia whenever there is an excess of sulphuric acid in the aluminous solution.

Soda-salts are seldom, if ever, used as precipitants in the manufacture of alum, on account of the easy solubility of the resulting SODA-ALUM——a property which unfits them for this purpose. See ALUMS, AMMONIA, DYEING, MORDANTS, POTASH, SULPHURIC ACID, &c. (also below).

=Alum, Ammonia.= (NH_{4}){2}SO{4} . Al_{2}(SO_{4})_{3} . 24 Aq. Syn. (ALUMEN; ALUM; B. P.), ALU′MEN AMMONIA′TUM, L.; ALUN D’AMMONIAQUE, A. AMMONIACAL, Fr. This is an alum in which the sulphate of potassium is replaced by an equivalent of sulphate of ammonium. It is prepared by adding crude sulphate of ammonium to solution of sulphate of aluminum; or gas-liquor, putrid urine, &c., to the acid-sulphate.

Much of the common alum, especially that prepared on the Continent, contains both potassium and ammonium; and recently enormous works for its manufacture have been established in England. As an astringent, and as a source of alumina in dyeing, it resembles potash-alum (i. e. ordinary alum). It may, however, be readily distinguished from the latter by the fumes of ammonia which are evolved when it is moistened and triturated, or heated, with caustic potassa or quick-lime; and by the residuum of its exposure to a white heat being pure alumina. See ALUM (antè).

=Alum, Basic.= A variety of alum found native at Tolfa. On calcination and subsequent lixiviation it yields ordinary alum. A like substance falls as a white powder, when newly precipitated alumina is boiled in a solution of alum.

=Alum, Baumé’s.= Alum-white. See WHITE PIGMENTS.

=Alum, Dried; Alum, Burnt.= Syn. ALU′MEN US′TUM, A. EXSICCA′TUM (B. P.); ALUN SEC, Fr.; GEBRANNTER ALAUN, Ger.; ALUME CALCINATO, Ital. Alum deprived of its water of crystallisation by heat.

Prep. Take of alum, 4 oz. Heat the alum in a porcelain dish or other suitable vessel, till it liquefies, then raise and continue the heat, not allowing it to exceed 400°, till aqueous vapour ceases to be disengaged, and the salt has lost 47 per cent. of its weight. Reduce the residue to powder, and preserve it in a well-stopped bottle.

Prop., &c. Similar to those of common alum, but it is rather more astringent, and is less soluble. When moistened, or placed in contact with water, it resumes its water of crystallisation with evolution of heat.——Dose, 10 to 20 gr.; in colic (especially painters’ colic), hæmoptysis, &c. It is chiefly used as an escharotic, to destroy ‘proud flesh,’ &c. It must be kept in a stoppered bottle.

=Alum, Chrome.= See ALUMS (in Chemistry).

=Alum, I′ron= (-ŭrn). Syn. ALU′MEN FER′RICUM, SUL′PHAS FER′RI ET POTAS′SÆ, FER′RI PEROX′IDI POTASSIO-SUL′PHAS, &c., L.

Comp. K_{2}SO_{4} . Fe_{2}(SO_{4})_{3}.24Aq.

Prep. Take of peroxide of iron, 9 lbs.; sulphuric acid 14 lbs.; dissolve, dilute the mixture with water, q. s., and add of potassium sulphate, 10 lbs.; evaporate, and crystallise.

Prop., &c. Crystals, beautiful octahedrons of a pinkish or pale violet colour. It is strongly recommended, by Dr Tyler Smith, as a chalybeate tonic, and has been used by him, at St. Mary’s Hospital with marked success. It has also been used as a mordant, in dyeing black.——Dose, 1/2 gr. to 5 gr.

Spotted a typo or a problem in this chapter? Tell us