An epitome of chemistry, in three parts

Part I

INTENDED TO FACILITATE, TO THE STUDENT, THE ACQUISITION OF CHEMICAL KNOWLEDGE BY MI- NUTE INSTRUCTIONS FOR THE PERFORMANCE OF EXPERIMENTS.

Part II

DIRECTIONS FOR THE ANALYSIS OF MINERAL WA- TERS, OF EARTHS AND STONES, OF ORES OF ME- TALS, AND OF MINERAL BODIES IN GENERAL. AND

Part III

INSTRUCTIONS FOR APPLYING CHEMICAL TESTS AND REAGENTS TO VARIOUS USEFUL PURPOSES.

By WILLIAM HENRY.

THE THIRD EDITION, CORRECTED.

LONDON:

PRINTED FOR J. JOHNSON, NO. 72, ST PAUL’S CHURCH-YARD.

The small volume, which I now offer to the public, is one of humble pretensions; yet its plan and objects appear to me sufficiently distinct, from those of every other compendium of chemistry, to authorise the addition of one more to the ^tensive list of elementary works. The “ Chemical Pocket-Book” of Mr Parkinson, and the “ Description of a portable Chest of Chemistry,” translated from tire German of Gottling, and published a 2

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in the year 1791, might perhaps, from the similarities of title and size, be supposed to have precluded the necessity of this publication. A very cursory comparison, however, of Mr Parkinson’s work with this manual will evince, that the plan and objects ot the two books are totally different. To the work of Mr Gottling, the present bears, indeed, a nearer resemblance, but the coincidence is not such as to supersede the utility of this Epitome. The enumeration of tests for mineral waters, the instructions for applying Ihese reagents, and the rules for detecting adulterations, are subjects common to both. But the progress of chemical knowledge, during the last ten years, has been so rapid, as to enable me to make numerous additions to the information of Mr Gottling, and to induce me materially to vary the arrangement under which it was offered. It may be added, that the antient nomenclature of chemistry, employed throughout Mr Gottling’s work, must render it nearly unintelligible to students of the reformed system.

The arranged series of experiments was suggested to me as proper for publication, by a written catalogue, which I drew up, more than two years ago, of the experiments performed during my course of chemical lectures. This I deem it necessary to state, because something similar is to be found in an excellent manual, lately published by Bouillon la Grange.

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Another object, which I propose to be fulfilled by this Epitome, is, that it may serve as a companion to the collections of chemical substances, which I have been induced, by the repeated applications of students of this science, to fit up for public sale *. The utility of these collections has, hitherto, been limited, by the want of a concise but comprehensive code of instructions for their use. With the concurrent aid of the first part of this work, and of a corresponding chest of chemical reagents, the labours of the student cannot fail to be much facilitated 5 for one of the principal difficulties in studying the science of chemistry, experimentally, is the acquisition of a great variety of substances, nua-

* See the advertisement at the end ot the work.

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ny of which are not easy of attainment.

The directions for analyzing waters, and mineral bodies in general, I shall enable any one to apply practically, by corresponding collections of chemical tests, of so small a bulk, as to add, in the least possible degree, to the incumbrances of the traveller.

In a work, professedly compiled from others, new and original information is not to be expected, and it cannot be necessary to quote all the authorities for facts. If there be any one author, to whom I owe most, it is certainly to Mr Kirwan, whose interesting and masterly works comprehend almost every subject of chemical inquiry. The directions for

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analyzing minerals aye translated, with considerable additions and alterations, from Vauquelin’s paper, in the 30th volume of the Annales de Chimie.

The introductory part of the work formed, originally, the first of a series of lectures delivered in Manchester, and was afterwards published under the title of cc A general View of the Nature and Objects of Chemistry and of its Application to Arts and Manufactures.” As the readers of an elementary book may be presumed to require a similar plan of instruction with the hearers of a popular course of lectures, I have thought it unnecessary to alter the form under which the essay first appeared, though a few

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passages are applicable chiefly to the persons originally addressed in it. Another motive for prefixing it to this edition is, that the impression is sold, and that I have no intention of reprinting it in a separate form.

To this edition I have added the recent discoveries that have been announced since the former ones. Errors and omissions, however, I fear will still be discovered ; and to the candid suggestions of others, both through the channels of public and private communication, to which I am already much indebted, I trust for their future correction.

Manchester,

November 6, 1802 .

PART I. Page

Introduction : . . . .

Sect. I. Advice to Persons who are entering on

the Study of Chemistry 1

Sect. II. An arranged Series of Experiments to be

performed by the Student of Chemistry 3

Art. I. Chemical Affinity, Solution, &c 4<

Art. II. Properties and Effects of Caloric .... 8

Combinations of Caloric, — the Cause of

Fluidity 12

Caloric the Cause of Vapour J5

Art. III. Gases in General 16

Art. IV. Oxygenous Gas 21

Art. V. Azotic or Nitrogen Gas 21

Art. VI. Atmospheric Air . 25

Art. VII. Hydrogenous Gas 27

Art. VIII. Composition and Decomposition of

Water 31

Synthetic Experiments 32

Analytic Experiments 34-

Art. IX. Properties and Effects of Water .... 39

Art. X. Alcalis, — General qualities

Pure Potash and Pure Soda

Pure Ammonia 44.

Art. XI. Acids in General

Art. XII. Carbon, Carbonic Acid, Carbonates, and their Compounds xii

Page

Combination of Carbon with Oxygen . . 48

Carbonic Acid ib.

Carbonates, Carbonate of Potash .... 53

Carbonate of Soda 57

Carbonate of Ammonia 58

Gaseous Oxyd of Carbon 59

Carbonated Hydrogenous Gas 60

Art. XIII. Sulphur, Sulphuric Acid, Sulphates,

Binary Compounds of Sulphur .... 62

Sulphur ib.

Sulphuric Acid 63

Sulphureous Acid Gas 66

Sulphate of Potash, Sulphate of Soda . . 67

Sulphate of Ammonia 68

Binary Compounds of Sulphur 69

Sulphuretted Hydrogen Gas 70

Art. XIV. Combination of Azote w r ith Oxygen, constituting NitricAcid, Nitrous Gas, Nitrous Oxyd, and Compounds of

Nitric Acid with Alcalis 71

Nitrous Gas 73

Gaseous Oxyd of Azote, Nitrous Oxyd

of Davy • • 77

Nitrate of Potash 80

Nitrate of Ammonia 82

Muriatic Acid and its Compounds ... .83 Muriate of Potash, Muriate of Soda, Muriate of Ammonia 84

Oxygenized Muriatic Acid 85

Hyper-oxygenized Muriate of Potash . . 87

Nitro-muriatic Acid 92

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Page

Art, XV. Phosphorus, Phosphoric Acid, Phosphates 92

Phosphoric Acid 95

Phosphuretted Hydrogenous Gas ... 96

Art. XVI. Boracic Acid and its Combinations . 98

Art. XVII. Earths, — Lime 99

Alumine, or Argili 103

silex 110

Barytes 112

Strontites

Art. XVIII. Metals in general 115

Art. XIX. Gold H7

Art, XX. Platina

Art. XXI. Silver ib.

Art. XXII. Mercury -...121

Art. XXIII. Iron 124

Art. XXIV. Copper 132

Art. XXV. Lead 133

Art. XXVI. Tin * ! * 134

Art. XXVII. Zinc

Art. XXVIII. Bismuth ^

Art. XXIX. Arsenic 136

Art. XXX. Antimony 137

Art. XXXI. Manganese 13g

Art. XXXII. Cobalt . ..

Art. XXXIII. Nickel : 141

Art. XXXIV. Vegetable Substances 142

Art. XXXV. Animal Substances . . 15S

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Part II

Directions for examining Mineral Waters and Mineral Bodies in general.

Page

$F.CT. I. Examination of Mineral Waters .... 163

Tests enumerated 164

Infusion of Litmus, Syrup of Violets, &c. 166

Tincture of Galls . 167

Sulphuric Acid 168

Nitric and Nitrous Acids ib.

Oxalic Acid and Oxalates 169

Pure Alcalis and carbonated Alealis . . 170

Lime Water 171

Solution of Pure Barytes ib.

Metals 02

Sulphate of Iron . , ib.

Sulphate, Nitrate, and Acetite, of Silver 17 3

Nitrate and Acetite of Lead 174

Nitrate of Mercury 175

Muriate, Nitrate, and Acetite, of Barytes ib. Prussiates of Potash and of Lime ... 176

Solution of Soap in Alcohol 177

Alcohol ib.

Hydro-Sulphuret of Ammonia ib.

Substances that -may be expected in Mineral Waters, and the Means of

detecting them 178

Analysis of Water by Evaporation . . 180

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Page

Skg v. II. Examination of Minerals . 134

Method of examining a Mineral, the Composition of which is unknown .,187

Examination of Salts 189

— ■ Earths and Stones . . . 192

Substances which may be expected in

Earths and Stones, and the Means of separating them from each other . . . 208 Analysis of inflammable Fossils .... 210

Coals ib.

Analysis of Metallic Ores 211

Ores in the dry Way ... 219

Part III

Application of chemical Tests and Reagents to various useful Purposes.

Sect. I. Method of detecting Poisons 222

■ discovering Arsenic .... 223

Discovery of corrosive sublimate . . . 225 Method of detecting Copper or Lead . 227 Sect. II. Rules tor ascertaining the Purity of chemical Preparations employed for the Purposes of Medicine and for other

Uses

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Paw

Sect. III. Use of Chemical Reagents to certain

Artists and Manufacturers 250

Sect. IV. Application of chemical Tests to the Uses of the Farmer and Country

Gentleman 255

Analysis of Lime and i,ime-stones . . 2 56

Soils .261

Sect. V. Miscellaneous Uses of chemical Reagents ...... 26S

INTRODUCTION,

The custom of prefacing a course of lectures with the history of the science which is their subject has been so long established, that it may be necessary to state, briefly, the reasons that have induced me to depart from this unvaried usage.

The history of chemistry may either be a mere history of the science, that is, of the gradual developement of the facts and doctrines of which the science is composed, or it may comprehend, also, the biography of chemists. The detail of the progress of discovery, however, concerning particular objects of chemical research, would certainly be premature at so early a period of the course. Respecting chemists themselves little can be said, at present, that can I contribute to information or amusement; for, their lives, devoted to the abstract pursuits of science, b 3

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have seldom been productive of events that are suited to awaken or gratify general curiosity. Our interest, indeed, respecting philosophers is seldom excitedy unless by a knowledge of the additions they have made to the facts or theories of a science ; and with these a lecturer may fairly presume, however the fact may really be, that his hearers, at the commencement of a course, are wholly unacquainted. It may be added, that the history of chemistry admits of little illustration from experiment ; and I shall always be reluctant to bestow time on those subjects, which, requiring not the aid of an appeal to the senses, are equally well adapted for private study.

On these grounds, therefore, I hope to be excused for infringing the general plan of lectures on chemistry, and devoting to other purposes the time that would have been allotted to the history of the science. For this will be substituted a brief view of the nature and objects of chemistry, — of its connection with the arts and with other sciences, — and an outline of the plan on which the following lectures will be conducted.

Natural philosophy, in its most extensive sense, is a term comprehending every science, that has for its objects the properties and affections of matter. But it has attained, by the sanction of common language, a more limited signification •

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and chemistry, though strictly a branch of natural philosophy, is generally regarded as a distinct science. Between the two it may, perhaps, be difficult: to mark out precisely the line of separation : but, an obvious character of the facts of natural philosophy is, that they are always attended with sensible motion ; and the determination of the laws of motion is peculiarly the office of its cultivators. Chemical changes, on the other hand, of the most important kind, often take place without any apparent motion, either of the mass or of its minute parts, and where the eye is unable to perceive that any change has occurred. The laws of gravitation, of central forces, and all the other powers that fall under the cognizance of the natural philosopher, produce, at most, only a change of place in the bodies that are influenced by them. But, in chemical changes, we may always observe a if important difference in the outward properties of things. Two highly corrosive substances, by uniting chemically together, may become mild and harmless ; the combination of two colourless substances may present us with a compound of brilliant complection ; and the union of two fluids, with a compact and solid mass.

Chemistry, therefore, may be defined that scien ce, the object of which is to discover and explain the changesof composition, that occur among the integrant and constituent parts of bodies.

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From this definition, it may readily be conceived how wide is the range of chemical inquiry ; and, by applying it to the various events that daily occur in the order of nature, we shall be enabled to separate them with accuracy, and to allot to the sciences of natural philsophy and chemistry the proper objects of the cultivation of each. Whenever a change of place is a necessary part of any event, we shall call in the aid of the former. When this condition may be dispensed with, we shall resort to chemistry for the light of its principles. But it will be often found, that the concurrence of the two sciences is essential to the full explanation of phenomena. The water of the ocean, for example, is raised into the atmosphere by its chemical combination with the matter of heat ; but the clouds, that are thus formed, maintain their elevated situation by virtue of a specific gravity less than that of the lower regions of the air, a law, the discovery and application of which are due to the natural philosopher, strictly so called.

Chemistry may be considered in two views ; first, as a science, that is, as a collection of general principles, or general laws, under which are arranged individual facts ; and, secondly, as an art, instructing us in the practical use and application of these laws to the purposes of coxnmon life.

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The possession of its general principles enables ms to comprehend the relation to each other of a great variety of events that form a part of the established order of the universe, and of which we are only spectators, devoid of all power of directing or changing them. That knowledge, it may be objected, however, can be of little utility which does not enable us to alter, in the minutest circumstance, the fixed and immutable succession of things. But the indulgence of an enlightened and liberal curiosity is, surely, no mean reward of the attainment of knowledge ; and the mind is not only gratified but improved, in its moral views, by tracing the connection and dependencies of all the smaller parts that fill up the great plan of Providence.

The class of natural events, that call for the explanations of chemical science, is of very considerable magnitude ; and the natural philosopher (using this term in its common acceptation) is wholly incompetent to unfold their connection. He may explain, for example, on the principles of his own science, the annual and diurnal revolutions of the earth, and part of the train of consequences depending on these rotations : but here he must stop, and the chemist must trace the effects, on the earth’s surface, of the heat and light derived from the sun ; the absorption of heat by the various bodies on which it falls ; the consequent fluidity of some and vola-

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tihzation of ethers ; the production of clouds and their condensation in the form of rain ; and the effects of this rain, as well as of the surds heat, on the animal, vegetable, and mineral, kingdoms. In these minuter changes, we shall find, there is not less excellence of contrivance, than in the stupendous movements of the planetary system. And they even interest us more nearly ; because, though not more connected with our existence or comforts, yet they occur more within our sphere of observation, and our acquaintance with their laws admits of a more direct application to human affairs.

But the science of chemistry demands respect and attention, on grounds that are more likely to ensure them, even than the indulgence of an enlightened curiosity ; for, it is capable of ministering to our wants and our luxuries, and teaches us to convert, to the purposes of common life, many substances, which nature presents to us in a rude and useless form. The extraction of metals from their ores ; the conversion of the rudest materials into the beautiful fabrics of glass and porcelain ; the production of wine, ardent spirits, and vinegar ; and the dying of linen and woollen manufactures ; are only a few of the arts that are dependent on chemistry for their improvement, and even for their successful practice.

It cannot, however, be denied, that all the arts, which have been mentioned, were practised in

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times: when the rank of chemistry, as a science, was greatly degraded, and that they are daily the employment of unlettered and ignorant men. But to what does this confession amount, and how far does it prove the independence of the above arts on the science of chemistry ?

The skill of an artist is compounded of knowledge and of manual dexterity. The latter, it is obvious, no science can teach. But the acquirement of experience, in other words, a talent for accurate observation of facts, and the habit of arranging facts in the best manner, may be greatly facilitated by the possession of scientific principles. Indeed, it is hardly possible to frame rules for the practice of a chemical art, or to profit by the rules of others, without an acquaintance with the general doctrines of the science. For, in all rules it is implied, that the promised effect will only take place when circumstances are precisely the same as in the case under which the rule was formed. To insure an unerring uniformity of result, the substances employed in chemical processes must be of uniform composition and excellence ; or, when it is not possible to obtain them thus unvaried, the artist should be able to judge precisely of the defect or redundancy, that he may proportion his agents according to their qualities. Were chemical knowledge more generally possessed, we should hear less of failures and disappointments in chemical operations ; and the artist

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would commence his proceedings, not, as at present, with distrust and uncertainty, but with a well-grounded expectation of success.

No one will be presumptuous enough to contend, that any art has hitherto attained the extent of its possible perfection. In all there is yet a wide scope for improvement, and an extensive range for ingenuity and invention. But from what class of men are we to expect useful discoveries ? Are we to trust, as hitherto, to the favour of chance and accident, — to the fortuitous success of men not guided in their experiments by the light of any principles ? Or shall we not rather endeavour to inform the artist, and to induce him to substitute, for vague and random conjecture, the torch of induction and of rational analogy ? In the present imperfect state of his knowledge, the artist is eve® unable fully to avail himself of those fortunate accidents, by which improvements sometimes occur in his processes ; because, to the eye of common observation, he has acted agreeably to established rules, and has varied in circumstances, which he can neither perceive nor appreciate. The man of science, in these instances, sees more deeply, and, by availing himself of a minute and fortuitous difference, contributes at once to the promotion of his own. interest, and to the amendment ot his art.

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But it is the union of theory with practice that is now contended for. “ And, when theoretical knowledge and practical skill are happily combined in the same person, the intellectual power of man appears in its full perfection, and fits him equally to conduct, with a masterly hand, the details of ordinary business, and to contend successfully with the untiied difficulties of new and perplexing situations. In conducting the former, mere experience may frequently be a sufficient guide, but experience and speculation must be combined, to prepare us for new combinations of circumstances.”* “ Expert men,” says Lord Bacon, “ can execute and judge of particulars one by one ; but the general counsels, and the plots, and the marshalling of affairs, come best from those that are learned.”

This recommendation of the acquirement of scientific knowledge to artists is happily sanctioned by the illustrious success, in our days, of the application of theory to the practice of certain arts. Few persons are ignorant of the benefits that have resulted to the manufactures of this country from the inventions of Mr Watt and Mr Wedgwood ; both of whom have been not less benefactors of philosophy than eminent For practical skill. The former, by a clear insight into the doctrine of latent heat, resulting, in a great

* Stewart’s Elements of the Philosophy of the Human Miud-.

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measure, from his own acuteness and patience of investigation, and seconded by an unusual share of mechanical skill, has perhaps brought the steam-engine to its acme of perfection. Mr Wedgwood, aided by the possession of extensive chemical knowledge, made rapid advances in the improvement of the art of pottery ; and, besides raising himself to great opulence and distinction, has created for this country a source of most profitable and extensive industry. In an art, also, which is nearly connected with the manufactures of our own town, and the improvement of which must, therefore, “ come home to our business and bosoms,” we owe unspeakable obligations to two speculative chemists, — to Sc.heele, who first discovered the oxygenated muriatic acid ; and to Berthollet, who first instructed us in its application to the art of bleaching.

Examples, however, may be urged against indulgence in theory ; anu instances are not wanting, in which the love of speculative refinement has withdrawn men entirely from the straight path of useful industry, and led them on gradually to the ruin of their fortunes. But from such instances it would be unfair to deduce a general condemnation of theoretical knowledge. It would be the common error of arguing against things that are useful, from their occasional abuse. . — In truth, projects which have, for their foundation, a dependence on chemical principles, may

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be undertaken with a more rational confidence, than such as have in view the accomplishment of mechanical purposes ; because, in chemistry, we are better able, than in mechanics, to predict, from an experiment on a small scale, the probable issue of more extensive attempts. No one, from the successful trial of a small machine, can affirm, with unfailing certainty, that the same success will attend one on a greatly enlarged plan: for, the amount of the resistances that are opposed to motion, increases often in a ratio greater than, from theory, could ever have been foreseen. But the same law, by which the mineral alcali is extracted from a pound of common salt, must equal ly operate on a thousand times the quantity ; and, even when we augment our proportions in this great degree, the chemical affinities, by which so large a mass is decomposed, are exerted only between very small particles. The failures of the mechanic, therefore, arise from the nature of things ; they occur, because he has not in his power the means of foreseeing and calculating the causes that produce them. But, if the chemist fail in perfecting an economical scheme on a large scale, it is either because he has not sufficiently ascertained his facts on a small one, or has rashly embarked in extensive speculations, without having previously ensured the accuracy of his estimates.

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The benefits we are entitled to expect from the efforts of the artist and the man of science, united in the same character, and at the same time tempered and directed by prudential wisdom, affect not only individual but national prosperity. To the support of its distinction, as a comraermercial nation, this country is to look for the permanency of its riches, its power, and, perhaps, even of its liberties : and this pre-eminence is to be maintained, not only by local advantages, but on the surer ground of sriperiority in the productions of its arts. Impressed with a full conviction of this influence of the sciences, our neighbours and rivals, the French, offer the most public and respectful incitements to the application of theoryin the improvement of the chemical arts ; and, with the view of promoting this object, national institutions have been formed among them, which have been already, in several instances, attended with the most encouraging success. It may be sufficient, at present, to mention, as an example, that France has supplied, from her own native resources, her enormous, and, perhaps, unequalled, consumption of nitre.

The general uses of Chemistry have been thus fully enlarged upon, because it is a conviction of the utility of the science that can alone recommend it to attentive and persevering study. It may now be proper to point out, in detail, a few of its more striking applications.

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I. The art which is, of all others, most interesting, from its subserviency to wants that are interwoven with our nature, is agriculture, or the art of obtaining, from the earth, the largest crops of useful vegetables at the smallest expense.

The vegetable kingdom agrees with the animal one, in the possession of a living principle. Every individual of this kingdom is regularly organized, and requires for its support an unceasing supply of food, which is converted, as in the animal body, into substances of various forms and qualities. Each plant has its periods of growth, health, disease, decay, and death ; and is affected, in all these particulars, by the varying condition of external circumstances. A perfect state of agricultural knowledge would require, therefore, not only a minute acquaintance with the structure and economy of vegetables, but with the nature and effects of the great variety of external agents, that contribute to their nutriment or influence their state of health and vigour. The former attainment, it can hardly be expected, will ever be generally made by practical farmers ; and it is in bringing the agriculturist acquainted with the precise composition of soils and manures, that chemistry promises the most solid advantages. Indeed, any knowledge that can be acquired on this subject, without the aid of chemistry, must be vague and indistinct, and can neither enable its possessor to produce an intended effect with

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certainty, nor be communicated to others in language sufficiently intelligible. Thus we are told, by Mr Arthur Young, that in some parts of England any loose clay is called marl, in others marl is called chalk, and in others clay is called loam. From this confused application of terms, all general benefits of experience in agriculture must be greatly limited.

Chemistry may, to agriculturists, become a universal language, in which the facts, that are observed . in this art, may be so clothed as to be intelligible to all nations and ages. It would be desirable, for example, when a writer speaks of clay, loam, or marl, that he should explain his conception of these terms, by stating the chemical composition of each substance expressed by them. For, all the variety of soils and manures, and all the diversified productions of the vegetable kingdom, are capable of being resolved, by chemical analysis, into a small number of elementary ingredients. The formation of a welldefined language, expressing the proportion of these elements in the various soils and manures now so vaguely characterised, would give an accuracy and precision, hitherto unknown, to the experience of the tillers of the earth.

It has been said, by those who contend for pure empiricism in the art of agriculture, that it has remained stationary, notwithstanding all improvements in the sciences, for more than 2000

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years. “ To refute this assertion,’* says Mr Kirwan, “ we need only compare the writings of Cato, Collumella, or Pliny, with many modern tracts, or, still better, with the modern practice of our best farmers.” “ If the exact connection of effects with their causes,” he adds, has not been so fully and extensively traced in this as in other subjects, we must attribute it to the peculiar difficulty of the investigation. In other subjects, exposed to the joint operation of many causes, the effect of each, singly and exclusively taken, may be particularly examined, and the experimenter may work in his laboratory with the object always in his view. But the secret processes of vegetation take place in the dark, exposed to the various and indeterminable influences of the atmosphere, and require, at least, half a year for their completion. Hence the difficulty of determining on what peculiar circumstance success or failure depends ; for, the diversified experience of many years can alone afford a rational foundation for solid, specific, conclusions*.”