Cooley's Cyclopædia of Practical Receipts and Collateral Information in the Arts, Manufactures, Professions, and Trades..., Sixth Edition, Volume I (part 9 of 10)

Cooley's Cyclopædia of Practical Receipts and Collateral Information in the Arts, Manufactures, Professions, and Trades..., Sixth Edition, Volume I (part 9 of 10)

The late Mr Braidwood classes the causes of fires under the following heads:——1. Inattention in the use of fires and lights. 2. Improper construction of buildings, &c. 3. Furnaces or close fires, for heating buildings, or for mechanical purposes. 4. Spontaneous ignition. 5. Incendiarism.

Amongst many other causes of fire, too numerous to specify, may be noticed——incautiously approaching window- and bed-curtains with a candle or lamp, airing linen before the fire, allowing children to play with fire, women’s dresses taking fire, and taking off the burning coals from a fire and laying them on the hearth. Another very common cause of fire is covering up a fire-place when not in use with wood, or paper and canvas, &c. The soot falls either from the flue itself or an adjoining one into the grate; a neighbouring chimney takes fire, a spark from this falls down the blocked-up flue, ignites the soot in the grate, which smoulders until the covering is burnt through, and thus sets the building on fire.

Another cause of fire, and one which cannot be too strongly condemned, is the dangerous practice of reading in bed by candle-light. A very serious annual loss of property is also caused by want of proper care in hanging up or removing the goods in linendrapers’ shop windows when the gas is burning. Another frequent cause of fire is the employment of young children in lighting fires, from their propensity to play with flame.

The employment of close fires with brick flues is also a frequent source of danger. Frequently, from various causes, the furnace almost always cracks, thus giving egress to smoke and flame. When this occurs no time should be lost in thoroughly repairing the defect, or building a new furnace; merely plastering over the surface will be found an ineffective and dangerous remedy.

To guard against the dangers arising from the ignition of wearing apparel many methods have been suggested for rendering fabrics flame proof, all of them consisting in soaking the dress in a weak solution of a non-inflammable substance, such as chloride of zinc, alum, tungstate of sodium, sulphate of ammonia, &c. Of these alum has the advantage of greatly improving the appearance of the fabrics, especially if they be coloured.

Fire-guards, particularly where there are children, ought to be adopted much more generally than they appear to be.

Prev. This consists of the exercise of those ordinary precautions which the good sense of every careful and trustworthy man, be he taskmaster or servant, cannot fail to suggest. It would be useless to enumerate them.

Immediately on the fire being discovered, secure an alarm being given to the nearest of the fire escape stations, not delaying an instant; do not wait “to see if it is wanted.” Life is more valuable than property, and events have often proved how fatal even a moment’s hesitation is in sending for the fire-escape.[307]

[Footnote 307: ‘Handbook for Emergencies,’ Cassell.]

The late Mr Braidwood’s advice was, “that if the fire appears at all serious, and there are fire-engines within a reasonable distance, that it is best to wait until they arrive; many buildings have been destroyed from opening doors, and trying to extinguish fires with insufficient means. If no engines are within reach it is advisable to keep a hand-pump. If that is not to be had, the next best thing is to collect as many buckets outside the room on fire as can be obtained, keeping the door shut; then to creep into the room on hands and knees (if the heat and smoke are considerable), and throw the water as nearly in the direction of the fire as possible, keeping the door shut while more water is being collected.

“The police of the metropolis understand shutting up fires so well, that they have in many instances kept fires two or three miles distant from the engine-stations, shut up till the fireman arrived in time to extinguish them.”

Fires might often be readily extinguished when first discovered by the timely application of a few buckets of water. When an apartment is found to be on fire, the door, chimney, and windows should be immediately closed, if possible, and only opened for the purpose of projecting water on the flames. By this means the supply of air will be cut off, and rapid combustion prevented. The same applies to the lower doors and windows of a house (especially the shop window), which are often injudiciously kept open or removed, under the pretence of rendering assistance. The neglect of this precaution has often caused a mere smouldering fire, that might have been easily put out, to burst into an unextinguishable mass of flame.

It has been proposed at various times to make certain additions to the water used for the purpose of extinguishing fires, in order to render its action more certain and effective. It is found that sal ammoniac (5 oz. to the gall.) exerts this property in a remarkable degree. Several other articles, as common salt, pearlash, and kitchen soda, act in the same way, though less effectively. A few buckets of such water will speedily arrest the progress of a fire before it has much extended itself. Such a plan is easily applied, by adding the saline matter to the buckets of water, which are either used by hand, or to feed the engine for the first few minutes of its working. When, however, a fire has made much progress, the action of such substances becomes scarcely perceptible.

Chimneys on fire are readily extinguished in several ways, without having recourse to throwing water down them from the top, by which much damage is frequently done to the furniture in the rooms. One of the simplest methods is, to cautiously scatter a handful of flowers of sulphur over the dullest part of the burning coals; the sulphurous vapours, being incapable of supporting combustion, rapidly extinguish the flames. Another method is, to shut the doors and windows, and to stop up the bottom of the chimney with a piece of wet carpet or blanket, throwing a little water or flowers of sulphur, or even common salt, on the fire immediately before doing so. By this means the draught is stopped, and the burning soot extinguished for want of air. In many of the first-class houses recently erected, ‘fire-place shutters’ are provided, which, when partly drawn down, act as powerful bellows or ‘blowers’ and which, when wholly drawn down, so as to touch the hearth-stone, entirely close up the fireplace, and instantly extinguish the combustion of the fuel in the grate, or that of the soot in the chimney. This simple arrangement, the advantages of which were pointed out in an early edition of this work, renders fires in chimneys of little moment, as it is only necessary to draw down the shutter to put them out. If a chimney is stopped at top, instead of at the bottom, the whole of the smoke must, of necessity, be driven into the apartment.

In France, M. Marateuh has successfully applied the principle of Davy’s safety lamp for the prevention of fires in chimneys. He places fire-frames of iron work near the base of the chimney, one above the other, about one foot apart; no flame passes through them, whilst the draught in the chimney is not interfered with, the result being that no fire can happen in the chimney.

Escape from apartments on fire may be best effected by creeping on the hands and knees. In this way the window or door may be reached. It is found that the atmosphere of a room so full of smoke as to produce suffocation to a person standing upright, may generally be safely breathed on nearly a level with the floor. A damp cloth, or handkerchief, tied over the mouth and nostrils, or, still better, over the whole face and head, will enable a person to effect a passage through the densest smoke, and, in many cases, to escape from buildings on fire, when otherwise it would be impracticable. Should descent by the staircase be found impossible, then the window should be immediately sought, and a ladder or fire-escape waited for. In the absence of either, if the danger is imminent, a rope should be made by tying the sheets and blankets of the bed together, one end of which should be firmly secured to a chair or table, or preferably to one of the bed-posts, and with this apparatus descent should be cautiously attempted. Jumping out of the window should be avoided, as persons who have not been brought up as clowns, or harlequins, run just as much danger in performing such an exploit as they do by remaining in the burning building. When it is impossible to escape from a burning building by the stairs or windows, retreat may be sometimes secured by a trap door opening on to the roof, or by a skylight, when, unless it be an isolated house, the roof of one of the adjoining buildings may probably be gained with safety.

Fire-escapes of various kinds have been employed of late years in the metropolis, and have proved of the greatest value in rescuing persons from burning buildings.

It is said that there is no instance on record of a person being burnt to death in a dwelling-house in Edinburgh, where the houses are usually high; yet in London, where fire-engines and fire-escapes are provided in greater numbers, deaths are very frequent from this cause. The reason of this difference is, that in the former city the stairs are all made of stone, by which means a road of escape is secured.

The clothes of females and children, when on fire, may be most readily extinguished by rolling the sufferer in the carpet, hearth-rug, table-cover, a great-coat, cloak, or any other woollen article at hand. If this be expertly done, the flames may be rapidly put out, unless the skirts of the dress be distended by hoops or crinoline, when there is great difficulty in staying the progress of the flames. Should assistance not be at hand, the person whose clothes are on fire should throw herself on the ground, and roll the carpet round her, as before described; or if such a thing is not in the room, she should endeavour to extinguish the flames with her hands, and by rapidly rolling over and over on the floor. In this way the fire will be stifled, or at least the combustion will proceed so slowly that less personal injury will be experienced before assistance arrives. The advantage of assuming the horizontal position is manifest from the fact that nine times out of ten it is the lower parts of the dresses of females that first catch fire.[308]

[Footnote 308: For the mode of rendering muslin and other inflammable articles of ladies’ apparel fire-proof, see INCOMBUSTIBLE FABRICS.]

The extinction of fires on board ships by means of carbonic-acid gas was some years since suggested to the Admiralty by Mr J. R. Hancorn. He proposes that a simple and economical apparatus should be attached to every decked vessel capable of supplying this gas, which is a well-known non-supporter of combustion, and will extinguish fire at the very instant of coming in contact with the burning matter. Chalk with sulphuric acid diluted with water (vinegar with any other acid will do) yields 44% of the gas; hence, a ton of chalk, and a fourth part of that quantity of sulphuric acid, will be found sufficient to extinguish any fire on board a ship. Mr Hancorn also proposed this as a method of destroying vermin in ships, such as rats and cockroaches, for which purpose it is more easily applied and more effectual than that usually adopted. This plan was rejected by the Admiralty, from a fear that the destructive action of the gas might extend to the crew as well as the fire. But “it surely is possible by mechanical means to expel the gas before again entering the ship’s hold. At any rate, the grand point would be obtained of extinguishing the fire, though the crew might have only the deck to stand on.”

Precautions to be taken against a Fire amongst Farming Stock.——The following are the suggestions of Mr Beaumont, the secretary of the County Fire Office:——

“Forbid your men to use lucifer matches, to smoke or light pipes or cigars, destroy wasp nests, or fire off guns in or near the rickyard, or to throw hot cinders into or against any wooden out-building on the farm, on pain of instant dismissal.

“Place your ricks in a single line, and as far distant from each other as you conveniently can. Place hayricks and cornstacks alternately; the hayrick will check the progress of the fire. Keep the rickyard, and especially the spaces between the stacks and ricks, clear of all loose straw, and in all respects in a neat and clean state. The loose straw is more frequently the means of firing than the stack itself. Have a pond close to the rickyard, although there may be a bad supply of water. When a steam thrashing machine is to be used, place it on the lee-side of the stack or barn, so that the wind may blow the sparks away from the stacks. Let the engine be placed as far from the machine as the length of the strap will allow. Have the loose straw continually cleared away from the engine; see that two or three pails of water are kept close to the ashpan, and that the pan itself is kept constantly full of water.”

It is often difficult to get horses out of buildings on fire, but it is said that they will readily come out if, after being blindfolded, the saddle and bridle, or the harness, &c., to which they are accustomed, are thrown over them as usual.

We learn from the last report issued by Captain Shaw that the actual number of fires in the year 1877 in London was 1533. Of these fires 1374, or 90 per cent., were slight, no persons being endangered, and no considerable destruction of property taking place. The number of really serious conflagrations was 150; in 88 of these life was endangered, and in 24 cases there was loss of life. The actual number of persons whose lives were in danger was 165; but of these 136 were saved, and the lives eventually lost amounted only to 29. The smallness of the loss is due in great degree to the courage of the members of the Brigade, seven of whom have been commended for special efforts for saving life during the year. Even of the twenty-nine persons who perished fourteen were taken alive out of the burning buildings, and died in hospital of their wounds. It is very satisfactory in view of the vast height of buildings used in business, and the flimsy character of so many London houses, that the risk of death from fire should be so small. It is one of the very slightest risks to which we are exposed in modern London. The fire-escapes must of course be credited with much of this security. There are now 108 stations of these useful machines; and instances of their utility in rescuing the inmates of burning houses are constantly occurring.

The various tables which Captain Shaw appends to his report give some very curious details as to the character of London fires. The hours at which they most commonly break out are by no means those which are popularly supposed to be the most dangerous. No considerable proportion occur after people have gone to bed. From seven o’clock in the evening till eleven o’clock there are more alarms of fire than in an equal portion of the twenty-four hours. Not a third of the number which occur in these evening hours take place in the small hours of the morning, which are in fact less destructive than the same period in the afternoon. There are, moreover, in the detailed list of fires some curious statistics, illustrating the comparative security of private houses over places of business. A very large part of the half million houses in London must come under the description of private dwellings, yet the alarms of fire in this class of buildings were only 316 in the year, and only in five of those were there serious conflagrations. In the lists of business premises nearly every trade in the metropolis is mentioned; and next to houses let out in lodgings, public-houses seem to suffer most. The causes of fires tell the old story of carelessness. They were instances of the almost inconceivable folly of seeking for an escape of gas with a lighted candle. The throwing down of lights is responsible for a considerable number of fires. Ordinary cases of chimneys on fire are not included in Captain Shaw’s summary; but they give the brigade a good deal of work. The number of calls of this kind was 3744, of which 1256 proved to be false alarms. The number of these false alarms will probably be reduced when the stations at which men with hose are situated are more numerous.

=Fire Anni′hilator (Phillips’s).= This is essentially a gaseous fire engine, which at any moment can be made to discharge a stream of mixed gases and vapours having the power of checking combustion. When first introduced it was generally regarded as a most important invention, but it has not proved an effective substitute for the common water engine. For extinguishing fires on board ship and in close apartments it is undoubtedly well adapted, but as a street engine it is comparatively useless, owing to the unmanageable nature of its fire-annihilating vapours.

The composition with which the ‘Fire Annihilator’ is charged is a mixture of dried ferrocyanide of potassium, sugar, and chlorate of potassa. It is set in action by a blow on a glass vessel containing oil of vitriol, which, being fractured, permits the acid to flow over the ‘charge,’ when the anti-combustion gas is liberated, and rushes forth with great impetuosity.

=Fire-damp.= See HYDROGEN (Light Carburetted).

=Fire-engine.= The common fire-engine is a compound forcing-pump, consisting of two ‘forcing-pumps’ placed on opposite sides of an ‘air-vessel,’ with which both communicate. The ‘fulcrum’ of the ‘lever’ by which both pumps are worked is placed midway between them; consequently they act alternately in charging the air-vessel. In order to obtain a very forcible jet it is necessary to prevent the escape of any portion of the contents of the air-vessel until the confined air is considerably compressed. The lever is connected with handrails on each side of the engine, and these are alternately raised and depressed by the workers. Engines worked by steam power are now common in London and most of our large towns.

=Fire-Extinguishing Powder (Feuerloschpulver)=, Bucher Leipzig. Nitre, 59 parts; sulphur, 36 parts; coal, 4 parts; iron oxide, 1 part. (Wittstein.)

=Fire, how to light a.= In a close stove the first thing is to empty the fireplace. Take out the larger cinders and half-burnt coal with your fingers, and lay them on one side for lighting the fire; then rake out all the ashes (this can be done with the lids on, then it will not make so much dust). Next take off all the lids, and sweep all the soot carefully out; once or twice a week the flue pipe must be taken off and cleared out, also the flues under the oven. The soot should be carried away at once, as it blows about. Then blacklead the stove; put in a few cinders, lay on them a piece of paper and a few sticks crossing each other; on these lay very lightly some pieces of half-burnt coal and a few cinders, leaving space for the draught.

Do not fill the grate full; put the lids on, draw out the damper, light the fire, and shut the front door. An open fire is lighted in much the same way. There are no flues to clean out; but the chimney, as high as one can reach and behind the register door, should be cleared from soot daily.[309]

[Footnote 309: ‘Household Management, &c.,’ by W. T. Tegetmeier.]

=Fire-proofing.= See INCOMBUSTIBILITY, &c.

=Fireworks.= See PYROTECHNY, and below.

=FIRES.= (In pyrotechny.) Coloured fires may be termed, not inaptly, the chefs-d’œuvre of the pyrotechnist’s art, since on their excellence the attractions of most other varieties of fireworks depend. The following forms, under judicious management, yield fires of remarkable beauty.

=Blue Fire.= Prep. 1. From metallic antimony, 1 part; sulphur, 2 parts; nitre, 5 parts.

2. From realgar, 2 parts; charcoal, 3 parts; chlorate of potassa, 5 parts; sulphur, 13 parts; nitrate of baryta, 77 parts.

3. (Mr A. Bird.) Charcoal and orpiment, of each 1 part; black sulphuret of antimony, 16 parts; nitre, 48 parts; sulphur, 64 parts.

4. (Fownes.) Tersulphuret of antimony, a part; sulphur, 2 parts; dry nitre, 6 parts. This is the composition used for the Bengal or blue signal light employed at sea.

5. (Prof. Marchand.) Sulphur, sulphate of potassa, and ammonio-sulphate of copper, of each 15 parts; nitre, 27 parts; chlorate of potassa, 28 parts. For theatrical illuminations. This may be rendered either lighter or darker coloured by lessening or increasing the quantities of the sulphate of potassa and ammonio-sulphate of copper.

6. (LIGHT BLUE——Marchand.) Sulphur, 16 parts; calcined alum, 23 parts; chlorate of potassa, 61 parts.

7. (DARK BLUE——Marchand.) Calcined alum and carbonate of copper, of each 12 parts; sulphur, 16 parts; chlorate of potassa, 60 parts.

8. (Marsh.) Sulphate of copper, 7 parts; sulphur, 24 parts; chlorate of potassa, 69 parts.

9. (Ruggieri.) Nitre, 2 parts; sulphur and zinc, of each 3 parts; gunpowder, 4 parts.

10. From sulphur, 1 part; dried verdigris, 2 parts; chlorate of potassa, 9 parts.

=Fire, Crimson.= Prep. 1. (Marsh.) Chlorate of potassa, 4-1/4 parts; charcoal (alder or willow), 5-3/4 parts; sulphur, 22-1/2 parts; nitrate of strontia, 67-1/2 parts. For pots.

2. (Marsh.) Charcoal, 4-1/4 parts; sulphuret of antimony, 5-1/2 parts; chlorate of potassa, 17-1/4 parts; sulphur, 18 parts; nitrate of strontia, 55 parts. For boxes and stars.

3. (Marchand.) Sulphur, 16 parts; chalk (dry), 23 parts; chlorate of potassa, 61 parts. Turns on the purple. See RED FIRE (below).

=Fire, Green.= Prep. 1. Nitrate of baryta, 77 parts; chlorate of potassa, 8 parts; fine charcoal, 3 parts; sulphur, 13 parts.

2. From metallic arsenic, 2 parts; charcoal, 3 parts; chlorate of potassa, 5 parts; sulphur, 13 parts; nitrate of baryta, 77 parts. Very beautiful, particularly when burnt before a reflector.

3. (Mr A. Bird.) Charcoal and black sulphuret of antimony, of each 2 parts; chlorate of potassa, 5 parts; sulphur, 6 parts; nitrate of baryta, 80 parts.

4. (Fownes.) Lampblack, 1 part; chlorate of potassa, 4 parts; sulphur, 6 parts; dry nitrate of baryta, 18 parts.

5. (Marchand.) Boracic acid, 10 parts; sulphur, 17 parts; chlorate of potassa, 73 parts. Very beautiful.

6. (Marchand.) Chlorate of potassa, 18 parts; sulphur, 22 parts; nitrate of baryta, 60 parts. For theatrical illuminations.

7. (LIGHT GREEN——Marchand.) Sulphur, 16 parts; carbonate of baryta, 24 parts; chlorate of potassa, 60 parts. Extremely delicate.

8. (Marsh.) Charcoal and sulphuret of arsenic, of each 1-3/4 parts; sulphur, 10-1/2 parts; chlorate of potassa, 23-1/4 parts; nitrate of baryta, 62-1/2 parts. For pots or stars.

=Fire, Lilac.= Prep. 1. (Marsh.) Black oxide of copper, 6 parts; dry chalk, 20 parts; sulphur, 25 parts; chlorate of potassa, 49 parts. For pans.

2. (Marsh.) From black oxide of copper, 3 parts; dried chalk, 22 parts; sulphur, 25 parts; chlorate of potassa, 50 parts. For stars.

=Fire, Orange.= See RED FIRE, No. 8 (below).

=Fire, Pink.= Prep. (Marchand.) Charcoal, 1 part; chalk and sulphur, of each 20 parts; chlorate of potassa, 27 parts; nitre, 32 parts. For theatrical illuminations. See RED FIRE, No. 10 (below).

=Fire, Purple.= Prep. 1. From lampblack, realgar, and nitre, of each 1 part; sulphur, 2 parts; chlorate of potassa, 5 parts; fused nitrate of strontia, 16 parts.

2. (Marsh.) Sulphuret of antimony, 2-3/4 parts; black oxide of copper, 10 parts; sulphur and nitrate of potassa, of each 22-3/4 parts; chlorate of potassa, 42 parts. For pans.

3. (Marsh.) Sulphate of copper, 9-3/4 parts; sulphur, 13 parts; chlorate of potassa, 77-1/4 parts. For stars.

4. From sulphur, 12 parts; black oxide of copper, 12 parts; chlorate of potassa, 30 parts. See CRIMSON FIRE, No. 3 (above), and RED FIRE, No. 9 (below).

=Fire, Red.= Prep. 1. From sulphur, sulphuret of antimony, and nitre, of each 1 part; dried nitrate of strontia, 5 parts.

2. (Mr A. Bird.) Charcoal, 1 part; black sulphuret of antimony, 4 parts; chlorate of potassa, 5 parts; sulphur, 13 parts; dried nitrate of strontia, 40 parts.

3. (Fownes.) Lampblack, 2 parts; chlorate of potassa, 8 parts; sulphur, 9 parts; dried nitrate of strontia, 32 parts.

4. (Marchand.) Sulphur, 16 parts; carbonate of strontia, 23 parts; chlorate of potassa, 61 parts.

5. (Marchand.) Chlorate of potassa, 20 parts; sulphur, 24 parts; nitrate of strontia, 56 parts. For theatrical illuminations.

6. (Marsh.) Coaldust, 2 parts; gunpowder, 6 parts; sulphur, 20 parts; dried nitrate of strontia, 72 parts.

7. (Ruggieri.) Sulphuret of antimony, 4 parts; chlorate of potassa, 5 parts; sulphur, 13 parts; fused nitrate of strontia, 40 parts. A little charcoal or lampblack makes it burn quicker.

8. (ORANGE RED——Marchand.) Sulphur, 14 parts; chalk, 34 parts; chlorate of potassa, 52 parts.

9. (PURPLE RED——Marchand.) Sulphur, 16 parts; chalk, 23 parts; chloride of potassa, 61 parts.

10. (ROSE-RED——Marchand.) Sulphur, 16 parts; dried chloride of calcium, 23 parts; chlorate of potassa, 61 parts. See PINK FIRE.

11. From charcoal, 2 parts; chlorate of potassa, 6 parts; sulphur, 13 parts; dried nitrate of strontia, 40 parts.

=Fire, Violet.= Prep. 1. From charcoal, 8 parts; sulphur, 10 parts; metallic copper, 15 parts; chlorate of potassa, 30 parts.

2. (DARK VIOLET——Marchand.) Alum and carbonate of potassa, of each 12 parts; sulphur, 16 parts; chlorate of potassa, 60 parts.

3. (PALE VIOLET——Marchand.) Sulphur, 14 parts; alum and carbonate of potassa, 16 parts; chlorate of potassa, 54 parts.

=Fire, White.= Prep. 1. From nitre, 60 parts; sulphur, 20 parts; black antimony, 10 parts; meal powder, 6 parts; powdered camphor, 4 parts. For either pans or stars.

2. (Mr A. Bird.) White arsenic, 1 part; charcoal, 2 parts; black antimony, 16 parts; nitre, 48 parts; sulphur, 64 parts.

3. (Marchand.) Charcoal, 2 parts; sulphur, 22 parts; nitre, 76 parts. For theatrical illuminations.

4. (Marchand.) Gunpowder, 15 parts; sulphur, 21 parts; nitre, 64 parts. As the last.

5. (Marsh.) Gunpowder, 12-1/2 parts; zinc filings, 18 parts; sulphur, 23 parts; nitre, 46-1/2 parts. For pans.

6. (Marsh.) Zinc dust or filings, 15 parts; sulphur, 28 parts; nitre, 57 parts. For stars.

7. (Ruggieri.) Sulphur, 13-1/4 parts; sulphuret of antimony, 17-1/4 parts; nitre, 48 parts.

8. (Ruggieri.) From realgar, 2 parts; sulphur, 7 parts; nitre, 24 parts.

9. (Ruggieri.) Charcoal, 1 part; sulphur, 24 parts; nitre, 75 parts.

10. (Ruggieri.) Iron or zinc borings, 25 parts; gunpowder, 100 parts.

=Fire, Yellow.= Prep. 1. From sulphur, 16 parts; dried carbonate of soda, 23 parts; chlorate of potassa, 61 parts.

2. (Marchand.) Gunpowder, 14 parts; sulphur, 16 parts; dried soda, 20 parts; nitre, 50 parts.

3. (Marchand.) Charcoal, 1-1/2 parts; sulphur, 17-1/2 parts; dried soda, 20 parts; nitre, 61 parts.

Green-coloured Fires.[310]

------+----------------------+-----------------+-------------------- No. | Potassium Chlorate, | Barium Nitrate, | Sulphur, per cent. | per cent. | per cent. | ------+----------------------+-----------------+-------------------- 1 | 36 | 40 | 24 2 | 29 | 48 | 23 3 | 24 | 53 | 23 4 | 21 | 57 | 22 5 | 18 | 60 | 22 6 | 16 | 62 | 22 7 | 14 | 64 | 22 8 | 13 | 66 | 21 9 | 12 | 67 | 21 10 | 11 | 68 | 21 11 | 10 | 69 | 21 12 | 9·5 | 69·5 | 21 13 | 9 | 70 | 21 14 | 8·5 | 70·5 | 21 15 | 8 | 71 | 21 ------+----------------------+-----------------+--------------------

[Footnote 310: Kern (‘Chemical News,’ September 29th, 1876).]

Red-coloured Fires.

----+-------------------+------------------+---------+-------------- No.|Potassium Chlorate,|Strontium Nitrate,|Sulphur, |Carbon Powder, | per cent. | per cent. |per cent.| per cent. ----+-------------------+------------------+---------+-------------- 1 | 40 | 39 | 18 | 3 2 | 32 | 46 | 19 | 2 3 | 27 | 51 | 20 | 2 4 | 23 | 55 | 20 | 2 5 | 20 | 58 | 20·5 | 1·5 6 | 18 | 60 | 21 | 1 7 | 16 | 61·6 | 21·2 | 1·2 8 | 15 | 63 | 21 | 1 9 | 13 | 64 | 22 | 1 10 | 12 | 65 | 22 | 1 11 | 11 | 66 | 22 | 1 12 | 10 | 67 | 22 | 1 13 | 10 | 67·25 | 22 | 0·75 14 | 9·25 | 68 | 22 | 0·75 15 | 9 | 68·35 | 22 | 0·65 ----+-------------------+------------------+---------+--------------

Violet-coloured Fires.

----+-------------------+------------------+-------------------+--------- No.|Potassium Chlorate,|Calcium Carbonate,|Malachite powdered,|Sulphur, | per cent. | per cent. | per cent. |per cent. ----+-------------------+------------------+-------------------+--------- 1 | 52 | 29 | 4 | 15 2 | 52 | 28 | 5 | 15 3 | 52 | 26 | 7 | 15 4 | 52 | 24 | 9 | 15 5 | 52 | 23 | 10 | 15 6 | 52 | 21 | 13 | 15 7 | 51 | 20 | 14 | 15 8 | 51 | 18 | 16 | 15 9 | 51 | 16 | 18 | 15 10 | 51 | 15 | 19 | 15 11 | 51 | 13 | 21 | 15 12 | 51 | 11 | 23 | 15 13 | 51 | 10 | 24 | 15 14 | 51 | 8 | 26 | 15 15 | 51 | 6 | 28 | 15 ----+-------------------+------------------+-------------------+---------

4. (Marsh.) Charcoal, 6 parts; sulphur, 19-1/2 parts. For pans. Very beautiful.

In preparing coloured fires for fireworks according to the usual formulæ given in manuals of pyrotechny, it is often important to know the speed at which they burn; as in some cases, such as decorations and lances, they should burn slowly; whereas in others, such as wheels, stars for rockets, and Roman candles, they ought to burn quicker. The foregoing tables are so arranged that every formula with a higher number yields a slower burning mixture than one with a lower number. Thus No. 5 burns quicker than No. 6, and slower than No. 4.

Obs. The ingredients in the above compounds are to be separately reduced to powder and sifted through lawn, after which they should be kept in well-corked wide-mouthed bottles until the time of mixing them for use. The chlorate of potassa, more especially, must be separately treated and cautiously handled, in order to prevent the possibility of explosion from friction whilst it is in contact with combustible matter. The requisite quantity of each of the ingredients being weighed out and placed on a clean sheet of white paper, the whole is to be thoroughly but carefully mixed together with a light hand, by means of a bone or wooden knife. The compound is next lightly packed into small cups or pans for illuminations, or into small pill-boxes for stars and trains, a little priming and quick-match being lastly attached to each. To ensure success the several ingredients must be dry and commercially pure; and though reduced to the state of a uniform powder, care must be taken that they are not absolutely ‘dusty,’ or too finely pulverised. The nitrate of strontia, alum, saltpetre, carbonate of soda, &c., before being weighed, require to be gently heated in an iron pot or pan until they fall to powder, and lose their hygrometric moisture, or water of crystallisation. To ensure the perfect admixture of the ingredients, the whole, after they have been stirred together on paper, as before directed, may be passed through a hair or perforated zinc or brass sieve. Further, as coloured fires rapidly deteriorate by keeping, and even sometimes inflame spontaneously, to prevent disappointment and accidents they should not be prepared long before they will be required for use, and should be stored in some situation in which their spontaneous combustion would be productive of no disastrous consequences.

Of the above formulæ, those bearing the name of the late Mr Marsh, of Woolwich, more especially deserve the attention of the pyrotechnist. To guard against the danger sometimes arising from the spontaneous combustion of coloured fires containing sulphur and chlorate of potash, Mr Saunders recommends intimately mixing 120 grains of bicarbonate of potash with each pound of sulphur before using it in the manufacture of any composition into which chlorates enter. See FLAME, PYROTECHNY, &c.

=FISH.= Syn. PISCES, L. Fishes form the fourth class of vertebrate animals (VERTEBRATA) in the Cuvierian arrangement of the animal kingdom, and in the variety of their genera and species are second only to the INSECTA, whilst in prolificness and number they probably exceed all other animated beings that reach a size equal to that of even the smallest member of their prodigious race. Besides their value to man as food, they furnish him with oil, isinglass, and various other articles of utility and luxury, and provide, either directly or indirectly, an inexhaustible supply of manure for the fertilisation of his fields. As food fish are undoubtedly wholesome and nutritious, although less so than the flesh of animals or the grains of the cereals. Of all the various substances used as aliments by man, fish are, however, the most liable to run into a state of putrefaction, and should therefore be only eaten when perfectly fresh or, if not recently taken, then only when their perfect preservation has been ensured by any of the ordinary methods employed for the purpose. Those that are the whitest and most flaky when cooked, as cod, flounders, haddock, hake, soles, turbot, whiting, &c., are the most easily digested; and those abounding in oily matter, as eels, herrings, mackerel, salmon, &c., are most nutritious, though the most likely to offend the stomach. Salt-water fish have been said to be more wholesome than river fish, but without sufficient reason. Salted fish are hard of digestion, unless when carefully cooked and well masticated. Skin diseases are said to be more common among those who live continually on fish than among those who abstain from it; but this probably arises from their use being unaccompanied by a proper quantity of fresh vegetables or fruit, both of which are scarcer on the sea-coast than further inland. As one of the components of a mixed diet, the value of fish is indisputable. Acid sauces and pickles are the proper additions to fish, from their power of retarding the progress of putrefaction, and of correcting the relaxing tendency of large quantities of oil and butter.

Artificial Propagation. The fecundity of fish is positively marvellous. According to the recent observations of Mr Frank T. Buckland, salmon yield about 1000 ova or eggs to every lb. of their weight; a trout weighing 1 lb. produced upwards of 1000; a mackerel (1 lb.), 86,120; a herring (1/2 lb.), 19,840; a sole (1 lb.), 134,466; a turbot (8 lbs.), 385,200; and a cod (20 lbs.), 4,872,000. The ova here spoken of form what is commonly called the ‘hard roe’ of the female fish; the ‘soft roe’ is ‘the milt’ of the male fish. To protect the spawn, and the fry, when hatched, is the object of the art of fish culture, which has made great progress during late years. When the spawn is not artificially protected, the greater portion is always wasted, being swept away by the stream, and devoured by fish, birds, and insects. The natural enemies of the newly hatched fish are, again, so numerous, that it is really surprising that any should escape destruction. According to given data and accurate calculations of the returns of fisheries made by Messrs Ashworth and Buist, only one salmon egg out of every thousand deposited ever becomes a fish fit for human food. Other fish, both fresh and salt water, suffer in proportion. The hatching of fish by artificial means has been carried out on a large scale in France, and has been commenced in Scotland and Ireland, and on a small scale in England. The spawning fish, having been caught by a net, is made to deposit her eggs by gently pressing on the abdomen; these are impregnated by ‘milt’ expressed from the male fish in a similar manner, and mixed with them in a shallow tub or other vessel prepared for the purpose. The impregnated eggs are placed in long shallow boxes, bottomed with gravel and pebbles, and so arranged that a small stream of water from a reservoir may flow from one to another. The time of hatching depends entirely upon the temperature of the water; from 40° to 45° Fahr. seems to be the healthiest temperature. After about 50 days (in the case of salmon), when all goes well, the young fish makes its appearance as a misshapen creature about an inch long, with a bag containing the yolk of the egg attached to its abdomen. At 3 days old the fry is about 2 gr. in weight; at 16 months it has increased to 2 oz. To preserve the young fish in health, the boxes must be covered with shades of slate or zinc. The French fish-breeders generally feed the young fry with boiled frogs powdered fine. The Scotch give boiled liver. Mr Buckland prescribes a diet of roe of sole, or plaice, or whiting. As to the age at which it is advisable to turn the young fish out of the nursery, there is much difference of opinion. Some breeders recommend turning them out as soon as the ‘umbilical bag’ is absorbed; others think they should be taken care of till they are older and stronger, and better able to defend themselves or escape from attack. For full details respecting the artificial propagation of fish, the reader is referred to Mr Buckland’s recent work, entitled ‘Fish-Hatching.’

Nutritive Value of Fish.——The white varieties of fish, such as whiting, cod, haddock, sole, plaice, flounder, and turbot, according to Letheby, contain only about twenty-two per cent. of solid matter, of which eighteen is nitrogenous. To increase their nutritive value, therefore, these fish should be eaten with butter.

According to the same authority mackerel, eels, and salmon are richer in fat than the above kinds; mackerel containing about seven per cent., and salmon about six, whilst the oily matter of eels amount to nearly fourteen per cent. The same is the case with the sprat, the herring, and the pilchard, as well as with most of our fresh-water fish.

As regards shell-fish, all the different varieties of them afford about the same amount of nutrition. They contain about thirteen per cent. of solid matter, which in composition is similar to that of white fish. Shell-fish vary in digestibility; mussels, limpets, and whelks being rather difficult of digestion, whilst scallops, cockles, periwinkles, lobsters, and crabs are a trifle more easy of digestion, and oysters still more so. All shell-fish are unsuited for delicate stomachs; although they are largely eaten by the poorer dwellers on the coast.

On the Continent, vineyard snails, and in China, slugs, are eaten, and are said to possess a delicate flavour and nutritive properties.[311]

[Footnote 311: Letheby.]

Choice, &c. “The flesh of any fish is always in the highest perfection, or in season, as it is called, during the period of the ripening of the milt and roe. After the fish has deposited the spawn, the flesh becomes soft, and loses a great deal of its peculiar flavour. This is owing to the disappearance of the oil or fat from the flesh, it having been expended in the function of reproduction.” (Fleming’s ‘Phil. Zoology.’) Fish should be dressed as soon after being caught as possible, as much of their peculiar delicacy and flavour is lost by keeping, even for a few hours. Turbot and salmon are said by the fishmongers to be improved in flavour when 2 or 3 days old, but this is surely a mistake, as the former, when dressed immediately after being caught, possesses a fine creamy taste, which it afterwards loses; whilst the latter, by the loss of a single tide, loses a portion of the fine white curd which is previously found between the flakes, and by longer keeping, this curd, with the larger flakes, disappear altogether. In the eyes of some epicures the richness, is however, increased by this change. Mackerel, and some other fish suffer so much from keeping only a few hours, that they become quite unwholesome. Herrings offer a remarkable example of the advantage of dressing fish as fresh as possible. When cooked soon after being caught, they possess considerable delicacy and flavour, but after being kept for only a few hours, the oil separates from the flesh, and they become soft, greasy, and strong-flavoured.

In the choice of every kind of fish, stiffness, brightness of the eyes, and redness of the gills, may be regarded as invariable signs of freshness. A peculiar elasticity will also be perceived in fish recently caught, little or no permanent impression being made by the ordinary pressure of the fingers, from the flesh immediately rising when the pressure is withdrawn. Fresh fish also lie in a partly curled position, and never quite straight, as in the case when they have been kept for some time. Thickness and fleshiness are deemed marks of the good condition of all fish.

Cleaning, dressing, &c. On the proper cleaning of fish preparatory to dressing it, depends much of its delicacy and flavour. Ordinary cooks seldom do this well, from not slitting the fish sufficiently open to permit the inside to be thoroughly washed, and seldom using sufficient water. The superior flavour of fish cleaned by the fishmongers arises from their performing the operation more completely, and from the large quantity of water they employ about them. The flavour of all fish is improved by adding a little salt or vinegar to the last water in which they are washed. The sound, milt, and roe, should be carefully cleaned and preserved.

Fish is preferably ‘dressed’ by simple boiling, broiling, or frying; in fact, the finer kinds of fish are often injured by the excessive interference of the cook. When boiled, “all large fish, with the skin whole, must be placed on the fire in cold water; if crimped, or cut into slices or pieces, in boiling water; if whole, it must not be covered with more than two or three inches of water, or the skin will crack, and not only spoil the appearance of the fish, but will diminish the gelatine and gluten it contains, and instead of eating firm and full of flavour, it will be soft and woolly, especially if over-boiled.” (Soyer.) As soon as a scum rises from boiling, it should be removed by the skimmer. The addition of a little salt or vinegar to the water improves the flavour of most fish, and renders the flesh firmer. The proportions should be “two teaspoonfuls of salt to every quart of water.” “If the fish be whole, as soon as it begins to boil remove the cover on one side, and let it simmer gently until done. (Soyer.) A fish is known to be sufficiently dressed by the flesh in the thicker parts separating easily from the bone. “If a large fish I generally try it by gently pushing a wooden skewer through the thickest part; if it goes in easily it is done.” (Soyer.) When this is the case it should be removed from the kettle, as by soaking in the water fish loses its firmness, and becomes soddened. Sole, skate, and mackerel, are usually put into boiling water, whether whole or sliced. Fish for broiling should be well washed in strong vinegar, wiped dry with a towel, and floured before placing them on the gridiron; and the bars of the latter should be hot, and well buttered. (Rundell.) Fish for frying should be prepared as for broiling, and the butter, oil, or lard should be allowed to boil for a minute or two before putting them into the frying-pan. The latter should be perfectly smooth and bright, and the butter or oil in abundance, to prevent the fish sticking to it and burning. As the fish are cooked solely by the heat of the melted fat, to fry them in the highest perfection there should be enough of it to cover them. Butter or oil is the best for the purpose. To avoid loss, the contents of the frying-pan, after the fish is removed, should be poured into a clean jelly-jar or basin, and reserved for another occasion. The fish being removed from the pan, the superfluous fat should be drained from them preparatory to ‘serving’ them. When fish is divided into fillets or cutlets before being cooked, it is usual to take out the bones, and to dress it with force-meat, &c.

In serving fish of the finer kinds, no other additions are required than melted butter and the ordinary fish sauces and pickles. The dishes are commonly garnished with raw parsley, for the sake of appearance, but boiled parsley, chopped small, should accompany it. All kinds of fish should be served on a napkin.

Caution. It sometimes happens that a fishbone accidentally swallowed remains in the œsophagus, and occasions serious inconvenience; in fact, instances have been known where so much irritation has arisen that death has followed. In such cases it is advisable, as soon as possible, to take of tartar emetic, 4 gr., dissolved in warm water, 1/2 pint; and immediately afterwards the whites of six eggs. The coagulated mass will not remain in the stomach more than two or three minutes, and the remedy has been known to “remove no less than 24 pins at once.”

=FISH GLUE.= See GLUE and ISINGLASS.

=FISH POISONING.= See ACCIDENTS.

=FISH SKIN.= Syn. SHARK SKIN. The skin of the spotted dog-fish or rough hound (chien de mer, Fr.), stretched and dried. Used for polishing wood and ivory. Several other varieties of fish skin are employed in the arts. The dressed skin of the ‘rousette’ (peau de rousette, F.), is transparent, and very beautiful. Cemented on green paper, and rubbed down and polished, it is used as veneer for fancy boxes. The skins of several varieties of Squalus are also used for both the above purposes. See SHAGREEN.

=FIVE HERBS.= See SPECIES.

=FIX′ATURE= Syn. BANDOLINE, CLYSPHITIQUE, EAU COLLANTE, FIXATEUR, Fr. This consists of any of the simple vegetable mucilages, combined with a little spirit, to preserve it, and with a little perfume, to render it more agreeable.

Prep. 1. From carrageen, Irish, or pearl moss, soaked in cold water for an hour or two, and after being drained, and pressed dry in a clean napkin, dissolved by boiling in soft water, q. s. The decoction is strained through cambric, and when nearly cold is mixed with about 1/3rd or 1/4th of its volume of eau de Cologne or other scented spirit, with the further addition of a few drops (5 or 6) of oil of cloves. Sometimes a little brandy is added to the mucilage, and when it is intended for present use, as is common with home manufactures, the spirit is frequently omitted altogether. 1/4 oz. of the prepared moss is fully enough for 3/4 pint of strained decoction, if rightly managed.

2. From quince seed boiled in water, as the last. 1/4 oz. yields nearly 3/4 pint of strained decoction.

3. Pale gum arabic (picked), 1-1/2 oz.; rose water, 2 fl. oz.; pure water, 3 fl. oz.; dissolve.

4. Gum arabic, 3-1/4 oz.; water, 1/2 pint; dissolve, and drop in eau de Cologne, gradually, until the cloudiness at first occasioned ceases to be removed by agitation; the next day decant the clear portion. All of the above are very superior, and keep well.

5. (Redwood.) Gum tragacanth, 1-1/2 dr.; water, 7 oz.; proof spirit, 3 oz.; otto of roses, 10 drops; macerate 24 hours, and strain.

6. Malt, 7 oz.; hot water (that will barely permit the finger to be held in it without pain), 1/2 pint; infuse in a covered jug or basin, gently press out the liquid, and as soon as cold add of proof spirit (or brandy or Cologne water), 2-1/2 fl. oz. and strain.

Obs. Bandoline is used by ladies and by hairdressers for stiffening the hair, and to make it curl firmly and remain in place. It is applied either by moistening the fingers and passing the hair through them, or by means of a small sponge. See POMMADE.

=FIXED AIR.= See CARBONIC ACID.

=FIXED OILS.= See FAT and OILS.

=FLAKE WHITE.= See WHITE PIGMENTS.

=FLAME.= Gas or vapour in an incandescent state. The light emitted from pure flame is exceedingly feeble; illuminating power being almost entirely dependent upon the presence of solid matter. See ILLUMINATION, and below.

=Flame Colours.= The vapours of metallic compounds communicate colours to flames. The characteristic colours of some metals are very beautiful, and their exhibition forms a favorite experiment of chemical lecturers. The coloured flames are generally produced by the combustion of alcohol or rectified spirit upon certain salts in fine powder. In this way a GREEN colour is communicated by boracic acid or chloride of copper; a RED one by the nitrates of iron, lime, or strontia; a VIOLET, by potassa and its salts; and a YELLOW, by nitrate of soda. Messrs Church and Crookes have recently described a mode of exhibiting the characteristic flames of the metals which is admirably adapted for the lecture-table.[312] ‘Gun-paper,’ made in the same way as ‘gun-cotton,’ is to be soaked in solutions of the chlorates of the different metals, dried with care, and kept dry. A good ‘gun-paper’ for the purpose is prepared by soaking strips of Swedish filtering-paper for ten minutes in a mixture of 4 parts oil of vitriol with 5 parts strong nitric acid, both by measure. The strips, when taken out of the acid, should be washed first with cold, and then with hot rain or distilled water, till the washings are no longer sour to the taste. The solutions of the metallic salts need not be very strong; but if they are warm, the strips of ‘gun-paper’ will be more easily and completely saturated with them. Since some of the chlorates attract moisture from the air, it is better to dry the papers prepared with them before the fire previous to lighting them. They are shown to best advantage when a strip is loosely crumpled up into a pellet, lighted quickly at one corner, and thrown up into the air against a dark back ground. They leave after burning, if properly prepared, no ash whatever. Paper prepared with the salt of potassa gives a flash of VIOLET flame, that prepared with the soda salt the characteristic YELLOW flame, and that with chlorate of baryta a very beautiful GREEN light. The chlorates of strontium, lithium, and calcium, when thus ignited, give intense colours. The VIOLET-BLUE flame of copper is well seen, even with the chloride of that metal, while paper soaked in nitrate of potassa shows the potassium flame better than if the chlorate be used. ‘Gun-paper’ prepared with a very weak solution of chloride or chlorate of thallium shows the characteristic SPRIG-GREEN flame of that metal with great distinctness. Chlorate of barium, being an article of commerce, may be employed for the preparation of the other chlorates, it being merely necessary to add to this salt in solution an exactly equivalent quantity of the sulphate or carbonate of the metal whose chlorate is desired. For instance, in order to make ‘chlorate of copper,’ 15·1 gr. of chlorate of barium being dissolved in hot distilled water, a boiling solution containing 12·5 gr. of pure crystallised sulphate of copper is to be added to it. Insoluble white ‘sulphate of baryta’ falls, while the solution, filtered and evaporated, yields the new chlorate in crystals. See FIRES, PYROTECHNY, &c.

[Footnote 312: See ‘Intellectual Observer,’ April, 1863.]

=FLAN′NEL.= It has been shown by the experiments of Count Rumford that the conducting power of the different materials employed for clothing varies considerably. A thermometer surrounded with cotton wool, and heated by immersion in boiling water, took 1046 seconds to lose 135° Fahr., when plunged into a bath of melting ice; but, under the same circumstances, when sheep’s wool was employed, 1118 seconds elapsed before a like sinking of the thermometer took place (‘Phil. Trans.,’ 1792); thus showing the greater conducting power of the former, and consequently the superiority of the latter substance for the manufacture of warm clothing. But the chief advantage of wool, as an article of underclothing, depends less upon its actual power of conducting heat than its peculiar texture. Flannel acts as a gentle stimulus on the skin, and exercises the most beneficial action, by keeping the pores clean, and in a state most favorable to perspiration. This action is a species of friction similar in character, although inferior in degree, to that of the common flesh-brush or horse-hair glove, so long employed as a skin stimulant. Flannel has also the advantage of absorbing the perspiration as soon as emitted, and allowing its watery portion to pass off into the atmosphere almost as soon as formed, but this is not the case with cotton and linen fabrics. The different effects of flannel and linen are particularly susceptible during brisk exercise. When the body is covered with the former, though perspiration be necessarily increased, the perspired matter freely passes off through the flannel, and the skin remains dry and warm. If the same exercise be taken in linen shirts, perspiration, as in the former case, is indeed also increased, but the perspired matter, instead of being dispersed into the atmosphere, remains upon the linen, and not only clogs the pores of the skin, but gives a disagreeable sensation. From this property of flannel, persons who wear it next the skin seldom catch cold from changes of temperature, even though perspiring profusely; but in similar cases, when linen or calico shirts are worn, chilliness immediately comes on, followed by sniffling, sneezing, and cough, and all the other symptoms of severe catarrh.

The common objections raised against the use of flannel are founded on vulgar prejudices, ignorance, obstinacy, or bravado, and are undeserving of the notice of sensible people. In a fickle and moist climate like that of England, every person should wear a robe of flannel next the skin, or at all events a waistcoat of flannel reaching below the loins; and this should not be discarded as soon as the cold weather has passed, but its use should be continued all the year round; for in reality flannel is, if possible, even more required in summer than in winter, because persons perspire more freely in hot than in cold weather, and are consequently more susceptible of cold, while at that period of the year their clothing is less capable of protecting them from the effects of sudden changes of temperature and draughts of cold air, moisture, &c. Females, children, persons of delicate constitutions, and all others who from their habits of body or life perspire freely, or are much exposed, should wear flannel.

In washing flannels it is recommended that they should only be put into warm water, by which method their colour will be preserved, and they will be prevented from shrinking.

=FLASH.= Prep. From burnt-sugar colouring, 1 gall.; fluid extract of capsicum or essence of Cayenne, 3/4 pint, or enough to give a strong fiery taste. Used to colour spirits, and to give them a false strength. It is made by the brewers’ druggists, and labelled ‘ISINGLASS AND BURNT SUGAR,’

=FLASKS.= The late lamented and ingenious Mr Fownes suggested the employment of Florence oil-flasks as cheap substitutes for retorts, receivers, digesters, and some other vessels used for chemical purposes. His plan was to cut the neck smoothly round with a hot iron, and softening it in the flame of a good argand gas-lamp, to turn over the edge so as to form a lip, or border. The neck will then bear a tight-fitting cork without splitting.

=FLATULENCE.= Syn. FLATULENCY, WIND. In pathology, a morbid collection of gas in the stomach and bowels. Its most common cause is indigestion. When the natural fluids of the stomach are secreted in a healthy state, they exercise an antiseptic and digestive action on the food, by which it is speedily reduced to a magma that is little liable to spontaneous change whilst in the body; but when the reverse is the case, fermentation soon commences, and the stomach and associated viscera become distended with gas, and all the well-known symptoms of flatulency are developed in rapid succession. The quantity of gas thus accumulated in the ‘primæ viæ’ is often enormous. An ordinary apple during fermentation yields about 600 times its bulk of gas, and many vegetables yield much more. (Dr Hales.) It is, therefore, not at all surprising that so much inconvenience should be felt when the food, instead of being digested and assimilated, runs into the state of active fermentation.

The treatment of flatulency consists mainly in the selection of proper articles of food. Oleraceous vegetables, peas, beans, under-dressed potatoes, and indigestible fruits should be especially avoided, as well as the use of large quantities of weak or warm liquids. The diet should consist principally of animal food, carefully but not over-cooked, with a sufficient quantity of good mealy potatoes (mashed, not whole), and good wheaten meal-bread, moderately seasoned with common salt and spices. The most suitable beverages are toast-and-water, and a little good brandy largely diluted with water. The healthy tone of the stomach may be re-established by the proper use of tonics, bitters, and mild aperients.

To relieve the fit of flatulency, carminatives and aromatics, as black pepper, mustard, peppermint, ginger, cinnamon, lavender, and most spices, may be had recourse to. A glass of peppermint cordial, or of brandy strongly flavoured with peppermint or ginger, is a popular and efficient remedy. A few drops (15 to 30) of ether, with a little tincture of capsicum or spirit of sal volatile, seldom fail to give relief. See DYSPEPSIA.

=FLAVOURING SUBSTANCES.= See ESSENCE, OIL (Volatile), SPICE, WINE, &c.

=FLAX.= See LINEN, LINSEED, and OIL.

=FLEA.= This troublesome little animal is the Pulex irritans of Linnæus, and belongs to the Suctoria, or fourth order of the Insecta. Its favorite haunts are our warm underclothing, and its most productive breeding-places are in the ‘flue’ which careless servants allow to accumulate underneath our beds. Cold, light, perfumes, and ventilation, are inimical to its propagation.

=FLECHTENKAPSELN (Tetter Capsules, or Dr Berkeley’s Antiherpetic Capsules for Skin Diseases, Tetter, &c.)= Capsules filled with tar. (Hager.)

=FLECHTENMITTEL——Tetter Cure.= (Paris). 1. A Washing Fluid.——Common water, containing 1-1/2 per cent. sulphuric acid. 2. A Salve. A mixture of lard and spermaceti, with 1/24 of their weight of calomel. (X. Schmidt.)

=FLECHTENPULVER——Tetter Powder= (St Lube’s, France). Nitre, 100; antimony chloride, 10; antimony oxide, 200, 1·5 grammes for a dose. (Wittstein.)

=FLECHTENSALBE——Tetter Salve= (Fontaine, Paris). For all skin diseases. Olive oil and white wax, with 1/16 of white precipitate. (Wittstein.)

=Flechtensalbe= (Bruno Reichel, Apolda). A mixture of wax and lard coloured green. (Schädler.)

=Flechtensalbe= (F. Schwarzlose, Berlin, and S. G. Schwartz, Breslau). For salt-flux, tetters, and similar skin diseases. Peru balsam, 1; carbolic acid, 2; yellow wax, 10; lard, 30. (Schädler.)

=Flechtensalbe= (Surbi, Paris). For all kinds of skin diseases. A mixture of beef tallow, 30; olive oil, 10; zinc oxide, 2; steatite, 2. (Wittstein.)

=FLECHTENSEIFE, Tetter Soap= (Dr Berkeley). Ordinary tar soap. (Hager.)

=FLECHTENWASSER.= The wonderful wholesome mineral vegetable tetter-water (Dr A. von S.). Corrosive sublimate, ·25 grammes; water, 180 grammes; benzoin tincture, 6 grammes. (Weber.)

=FLECKENWASSER= (Bronner). Cleansing fluid (literally spot or stain water) for the removal of grease and dirt spots. Benzine only.

=Fleckenwasser, Englisches= (English cleansing fluid for removing acid, resin, wax, tar, and grease spots.) A mixture of 95 per cent. alcohol, 100 grammes; liq. ammon., sp. gr. ·875, 30 grammes; benzine, 4 grammes. (Artus.)

=FLEISCH-EXTRACT-LIQUEUR (Eau de Vie Alimenteuse——Extract of Meat Liqueur——Aqua Vitæ Incarnativa)= (A. Hensel, Berlin). A beautiful red spicy liquor, leaving, when distilled, 32 per cent. of solid matter. This residue contains in 100 parts (besides anilin-red), resin and extractive (partly from ginger and partly from cinnamon), 3-1/4; sugar, 27-1/2; extract of meat, 1-1/4. (Hager.)

=Fleisch-Extract-Syrup (Syrup of Extract of Meat)= (Meyer, Berk). Blood-serum made into a syrup with sugar. (Hager.)

=FLEISCHFASER-ZWIEBACK FÜR HUNDE——Fibrin Dog Biscuits= (New York). Said to be made of pure meal, fibrin, dates, and other ingredients, and recommended as an excellent food for dogs. According to the prospectus its use makes all other foods unnecessary, as it gives the animals peculiar endurance, strong muscles, and sound bones. The directions for use say that it is most advantageously given in its unprepared form, as dry, heavy, hard cakes, and only in case it is refused should it be softened for a short time in cold water. According to the analysis performed in the laboratory of the Poppelsdorf Agricultural Academy the proportion of nitrogenous to non-nitrogenous ingredients is 1 to 3·70. Microscopic analysis detects the presence of dried fibrin, and also a considerable admixture of structureless hyaline cartilaginous matter. From this it follows that the nitrogen revealed by analysis does not all represent protein or fibrin, and that the proportion which arises from indigestible gelatinous matter will be of smaller value. (Dr E. Kern.)

=FLESH.= Syn. CARO, L. The muscular substances of animals; the softer, solid portions of the body, as distinguished from the bones and fluids. See FIBRIN, FOOD, &c.

=Flesh-brush.= This simple instrument is used for exciting the cutaneous circulation. Those which have the bristles set on a leather back are esteemed the best. The flesh-glove or hair flesh-rubber is a useful modification of the common flesh-brush. Those manufactured by Messrs Savory and Moore, in imitation of the Indian kheesah or mitten, are superior to all others. In the absence of both flesh-brush and glove, a rough towel wound round the hand is no bad substitute. See FRICTION.

=FLIEGENPAPIER, GIFTFREIES——Non-Poisonous Fly Papers= (Bergmann & Co., Rochlitz). Contains abundance of arsenious acid. (Hager.)

=FLIEGENPULVER——Fly Powder= (Baumann, now Markel, Austria). 93 to 94 per cent. of dry sandy ferruginous clay (ordinary loam) saturated with a decoction of some bitter substance, as quassia or gentian. (Hager.)

=FLIES.= See FLY.

=FLIP.= See EGG FLIP.

=FLÖHEMITTEL——Flea Powder= (Leipsic). Powdered soap. (Fischer.)

=FLÖHEWASSER——Flea Water= (Koch, veterinary surgeon, Vienna). 7 brandy, 1 benzine, 1 black soap. (Hager.)

=FLORILINE——Vegetable Tooth Paste= made by John Yates (Albin Müller, Brünn). It is contained in a quadrangular china pot, and is a red, dry, rather hard mass made from prepared chalk, 20 grammes; starch powder, 10 grammes; glycerin, 8 grammes; pellitory tincture, 3 grammes; peppermint oil, 10 drops; and water q. s., coloured with Florentine lac. (Hager.)

=FLOUN′DER.= A flat fish, very like the plaice, but smaller, and of more obscure colour. It is very common about the British coast, and is found in the Northern, Baltic, and Mediterranean seas. Its flesh is very wholesome.

=FLOUR.= Syn. FARINA, L. The finely ground and ‘dressed’ meal of bread corn, and of the seeds of some of the leguminosæ. That known specifically as ‘flour’ in this country is obtained from spring varieties of Triticum vulgare (the common wheat).

Var., &c. Of varieties of flour there are several, depending chiefly on the amount of bran which they contain, and the relative fineness of the sieves through which they are passed:——

FINE WHEAT FLOUR, PASTRY FLOUR; FARINA, F. TRITICI, F. SEMINIS TRITICI. The finest flour, obtained from the meal produced in the first grinding of wheat between sharp stones, by means of a sieve of 64 wires to the inch. Used for pastry.

MIDDLINGS. The remainder of the flour of the first grinding, obtained by means of a slightly coarser sieve. Used for making household bread, but is mostly reground for the next variety.

SECONDS. The finest part of the flour, obtained by regrinding ‘middlings’ between blunt stones. Used by the bakers for their finest wheaten bread.

POLLARD. The coarse flour, from which the seconds has been sifted. Used for making sea biscuits and gingerbread, and to fatten poultry and hogs.

COUNTRY HOUSEHOLD FLOUR. This is usually ground only once, and sifted to 4/5ths of the weight of the wheat.

AMMUNITION FLOUR is ground and sifted to nearly 5/6ths the weight of the wheat.

According to Mr Accum, thirty-two pecks of wheat in the London mills yield, of flour 38-1/2 parts; pollard, 8 parts; and bran (furfur tritici), 12 parts; the bulk of the wheat being doubled by grinding.

According to Mr Hard, miller, of Dartford, quoted by Dr Pereira, the wheat having been ground in the usual way, is allowed to remain in the state of meal for some time before ‘dressing,’ which removes the heat caused by the process, and enables the miller to obtain more flour, and the baker a better quality, than if ‘dressed’ immediately it is ground.

“The process of dressing is by a wire cylinder containing a certain number of sheets of different texture or fineness, which cylinder contains eight hair brushes attached to a spindle passing through the centre of the cylinder, and laid out so as to gently touch the wire. This cylinder is fed by a ‘shoe’ with the meal; then the ‘flour’ and ‘offal,’ after passing through the wire in this way, are divided by wooden partitions fixed close to the outside of the cylinder.” “The produce of the wheat-meal dressed through the wire machine consists of——1, Flour;——2, White Stuff, or Boxings, or Sharps;——3, Fine Pollard;——4, Coarse Pollard, or Horse Pollard;——5, Bran. The 2nd product (i. e. the white stuff) is then submitted to another ‘dressing’ through a fine cloth machine, and produces——1, Fine Middlings, for biscuits;——2, Toppings, or Specks;——3, Dustings;——4, Best Pollard, Turkey Middlings, or Coarse Middlings.

TABLE of the Produce of One Quarter of Wheat (= 504 lbs.) By MR HARD.

Flour 392 lbs. Biscuit or fine middlings 10 ” Toppings or specks 8 ” Best pollard, Turkey p., or twenty-penny 15 ” Fine pollard 18 ” Bran and coarse pollard 50 ” Loss by evaporation and waste 11 ” ———— 504 ” ————

Analysis of Flour. ------------------------------------------------------------------------------- | | PELIGOT. | | | WANKLYN. | | |Mean of 14| LETHEBY. | PAYEN. |Fine Wheaten| | | Analyses.| | | Flour. | |--------------------------------+----------+----------+---------+------------| | |Per cent. | Per cent.|Per cent.| Per cent. | |Water | 14·0 | 15·0 | 14·22 | 16·5 | |Fat | 1·2 | 2·0 | 1·25 | 1·2 | |Nitrogenous matters, gluten, &c.| 12·8 | 10·8 | 14·45 | 12·0 | |Ditto, soluble in water | 1·8 | —— | —— | —— | |Non-nitrogenised substances, | | | | | | dextrin, sugar, &c. | 7·2 |} | | | |Starch | 59·7 |} 70·5 | 68·48 | 69·6 | |Cellulose | 1·7 |} | | | |Salts (ash) | 1·6 | 1·7 | 1·6 | 0·74 | -------------------------------------------------------------------------------

According to Vauquelin, French wheat flour contains about 10% of water, 11% of gluten, 71% of starch, 5% of sugar, and 3% of gum; and the water of the dough amounts to about 50%. The quantity of the bran in wheat ranges under 2%.

Pur. This article of food is very frequently adulterated both by the miller and the baker, as has been before alluded to in the article on bread. The principal physical characteristics of wheat flour of good quality are the following——it has a dull white colour, somewhat inclining to yellow;——it exhibits no trace of bran, even when pressed smooth with the hand, or with a polished surface;——its cohesiveness is so great that, on being squeezed in the hand, the lump is some time before it loses its shape;——it has a homogeneous appearance, and does not lose more than from 6% to 12% by being carefully dried in a stove. The smaller the loss in this way the finer is the quality, other matters being equal, and the more economical in use.[313] (See below.)

[Footnote 313: See also BREAD, Adult, and Exam.]

Tests. 1. Solution of ammonia turns pure wheat flour yellow; but if any other corn has been ground with it, pale brown; or if peas or beans have been ground with it, a still darker brown.

2. Solution of potassa, containing about 12% of caustic alkali, dissolves pure wheat-flour almost completely; but when it is adulterated with the flour of the leguminous seeds (beans, peas, &c.), the cellulosæ of these substances remains undissolved, and its hexagonal tissue is readily identified under the microscope. Mineral substances (chalk, plaster of Paris, bone dust, &c.) are also insoluble in this test, and appear as a heavy white sediment.

3. Boiling water poured on the sample causes the evolution of the peculiar odour of pea or bean flour when these substances are present. Bread made with such flour evolves a like odour on being toasted.

4. Pure hydrochloric acid poured on potato flour, or on wheat flour adulterated with it, develops a smell of rushes; it also dissolves starch, but changes the colour of pure wheat-flour to a deep violet.

5. Nitric acid turns wheat flour of an orange-yellow colour, but forms a stiff and tenacious jelly with potato fecula, the colour of which it does not alter.

6. A portion of the suspected sample submitted to dry distillation in a stoneware retort, and the distillate collected in a receiver containing a little water, the latter is found to remain perfectly neutral if the wheat flour is pure, but acquires a distinctly alkaline reaction when beans, pulse, or pea meal is present. (Rodrigues.)

7. Triturate 300 gr. of the sample with an equal weight of clean siliceous sand, and after five minutes form a homogeneous paste with water; afterwards further adding more water, until about 2 fl. oz. have been used. The filtered liquid, treated with an equal quantity of a strong and pure aqueous solution of iodine, develops a pink colour, which gradually disappears when the specimen examined consists of pure wheat flour; but assumes a deep-purple colour, which disappears much more slowly, if the flour is adulterated with even 10% of fecula or potato flour. This test succeeds, not only with flour and meal, but also with macaroni, vermicelli, &c. (M. Chevallier.)

8. The milky liquid holding the starch in suspension (see Anal., page 749) is poured into a small conical glass, and left at rest for some time; the clear liquid is then decanted, and any remaining water carefully sucked up with a pipette, and the whole left for some time, in order that the deposit may harden. The upper gray layer is next removed with a teaspoon, and the harder and stiffer second layer left undisturbed until it becomes quite solid by drying. When in this state, it may be upset in the form of a cone, upon a lump of dry plaster. The fecula or potato starch (if any is present), being heavier than that of wheat, forms the apex of the cone, and its quantity may be estimated in the following manner:——The operator cuts from the apex of the little cone above mentioned a slice, which he triturates only for a short time in an agate mortar (one of glass, or porcelain, or wedgwood-ware, will not do), and he tests that with aqueous solution of iodine. If it turns blue, it is fecula. Another slice is treated in the same manner, until the operator comes to the wheat starch, which, in the present instance, is not affected by the aqueous solution of iodine. This difference of behaviour of the two species of starch with iodine is due to the friction of the pestle and mortar, which is sufficient to divide or tear the envelopes of the particles of the potato starch, which then become blue when treated by solution of iodine. The particles of wheat starch, on the contrary, are not disaggregated by that treatment, and being therefore protected by their envelope, are not acted upon by the solution of iodine, or, at most, assume only a brown tinge. (M. Robine.)

9. Wheat flour adulterated with plaster of Paris, ground bones, chalk, and potato flour, has a higher specific gravity than a sample of the pure flour. This may be readily ascertained by any person by filling a small vessel with some pure flour, and then with the given sample. “A vessel which will contain 1 lb. of wheat flour will contain 1-1/2 lb. of fecula” (potato flour), and hence “the proportion of this adulteration may be easily estimated.” (Ure.)

10. If to a sample of wheat flour is added a solution of potassa, containing about 1-3/4% of the pure alkali, the granules of potato farina, or of bean meal, or pea meal, present (if any), will acquire 4 or 5 times their original volume, while those of the pure wheat starch will be scarcely affected by it. This change is very perceptible under a microscope of small power. 2 parts of liquor of potassa (Ph. L.) and 5 parts of distilled water form a mixture that answers for the above purpose.

11. By means of the microscope the admixture of the cheaper feculas and meals with wheat flour is readily detected by the characteristic appearance of the starch grains; and when the adulteration exceeds 9% or 10%, its extent may be readily estimated with considerable accuracy. As the range of adulteration is generally from 12% to 27%, this method is applicable in the greater number of cases.

Analysis. The value of wheat flour as an aliment depends upon the quantity of gluten, sugar, starch, and phosphate of lime, which it contains; and its superiority over the flour of the grains of the other cereals is referred to its containing a larger proportion of the first and last of these substances than they do. The quantitative analysis of flour is very simple, and may be easily made by persons unacquainted with chemistry, by attending to the instructions below:——

a. Make 1000 gr. of the sample into a dough with a little water, let it rest an hour and then gently knead it in successive water, until the starchy particles are perfectly removed. Collect the portion (GLUTEN) left in the hand, drain off the water, place it on a piece of filtering or blotting paper, several times doubled, and set it aside.

b. Mix the several waters employed in the preceding process, and set them aside in a tall vessel, to deposit the suspended portion (STARCH). After a sufficient time pour off the clear liquid, and throw the whole of the sediment on a weighed paper filter, placed in a funnel, observing to remove the portion adhering to the bottom of the vessel by means of a little clean water, that none may be lost.

c. Evaporate the decanted liquid, as well as what runs from the filter, until it becomes curdy, then filter it through a piece of weighed blotting paper, and preserve the sediment (ALBUMEN); next evaporate the residuum to the consistence of a syrup, agitate it with 10 times its weight of alcohol, and filter, observing to wash the paper filter clean with a little alcohol after the solution has passed through it. The substance on the paper is PHOSPHATE OF LIME and GUM, and must be set aside. By subsequent digestion in water, filtration, and evaporation, the two may be obtained separately.

d. Evaporate or distil off the spirit from the solution and washings, as above; the residuum is SUGAR.

e. Dry the substances educed as above, by a gentle heat, and weigh them. The weight of the albumen may be taken with that of the gluten, as it possesses about the same nutritive value, and also because it has been asserted by some persons that the former substance is in reality gluten, and not albumen. By dividing the given weights by 10, the per-centage value of the sample is obtained. The pieces of filtering paper employed should be carefully dried and weighed before using them, and the same degree of heat should be employed for this purpose as that to which they will be afterwards exposed in the drying of the substances resulting from the operations.

Obs. The above method of ascertaining the actual value of any sample of flour as an article of food, though not strictly accurate, approximates sufficiently to the truth for all practical purposes, and is well adapted to the wants of the baker and large purchaser. In many cases it will only be necessary to perform the first part of the process (a), which will give the per-centage of the most important constituent of the flour; the rest being of minor consequence.

In addition to what has been already stated in the article on BREAD, it may be useful to mention that a pound of the best flour, from thoroughly dried wheat, will take 10 fl. oz. of water to form it into ordinary dough, or 9 fl. oz. to form it into bread dough. Under the old parliamentary acts, a sack of flour (280 lbs.) was presumed to produce 80 loaves (quartern or quarter-peck), the weight of which, within 48 hours after being baked, was to be 4 lbs. 5-1/2 oz. each. At the present time fully 92 loaves, weighing 4 lbs. each, are produced by the London bakers from one sack of flour, when honest weight is given; but as the latter is rarely the case, and the bread is frequently ‘slack’ or ‘under-baked,’ and thus contains more water than good bread ought to do, a much larger product is commonly obtained. The dough loses about 1/7th of its weight in baking, if in batches; but fully 1/6th, if baked in small loaves, and placed in the oven separately. The best bread contains about 1/4-1/6th of its weight of added water; and common bread, often much more than 1/4th. The proportion of water in the London bread has greatly increased during the last few years, owing to the introduction of the fraudulent plan of making the dough with rice jelly or moss jelly. This is the reason why the bread of some bakers suffers such a loss of weight in a few hours after being taken from the oven. A 4 lbs. loaf of bread purchased from a baker at Lambeth, after remaining on the sideboard of a sitting-room for 24 hours, was found to have lost no less than 6-1/2 oz. by evaporation, and in two days longer its interior cells were covered with green mould, and the whole was unfit for food. The bakers, aware of these facts, are particularly careful not to bake more bread than they can dispose of whilst ‘new,’ and are in the habit of refusing to weigh their bread before selling it, when it is more than 10 or 12 hours old, although they are liable to be ‘fined’ for such a refusal. See BREAD, CAKES, FARINA, &c., also below.

=Flour, Baked.= Syn. FARINA TOSTA, F. TRITICI TOSTA, L. Prep. From wheat flour, carefully baked in a ‘slack’ oven, until it acquires a pale-buff hue. Astringent; used to make food for infants troubled with diarrhœa. See FARINA.

=Flour, Barley (Prepared).= Syn. FARINA HORDEI PREPARATA, L. Prep. (Ph. Bor.) From barley flour, compressed into a tin cylinder until the vessel is 2-3rds full, which is then suspended at the upper part of a still 2-3rds filled with water, and after the ‘head’ is fitted on, the water is kept boiling for 30 hours (2 days of 15 hours each). Lastly, the upper layer being removed, the rest is reduced to powder, and kept in a dry place.

=Flour, Boiled.= Syn. TRITICINA, FARINA PREPARATA, L. Prep. From fine flour, tied up in a linen cloth as tight as possible, and after it has been frequently dipped into cold water, the outside of the cloth is dredged over with flour, until a crust is formed round it, to prevent the water soaking into it whilst boiling; it is then boiled for a long time, and when cold, it is divided into small oblong pieces. For use, it is reduced to powder, either by grinding or grating it, and is then prepared like arrow-root. It forms a good diet for children, in diarrhœa, &c.; and as it may be easily prepared at home, it has the advantage of being free from adulteration.

=Flour, Jones’s Patent.= Prep. From kiln-dried flour, 1 cwt.; tartaric acid, 10-1/2 oz.; mix thoroughly; after 2 or 3 days, add, of bicarbonate of soda, 12 oz.; lump sugar, 1/2 lb.; common salt, 1-1/2 lb.; mix, and pass the compound through the ‘dressing-machine.’ It is necessary that the whole of the ingredients should be perfectly dry, and separately reduced to fine powder before adding them to the flour. By simply mixing it with cold water, and at once baking it, it produces light, porous bread.

Obs. We have already had occasion to pay a passing tribute to the excellence and usefulness of Jones’s Patent Flour.[314] It is, indeed, invaluable to every household, as furnishing the means of producing, with great economy, and extemporaneously, not merely cakes, puddings, pastry, and fancy bread, but the ‘staff of life’ itself, household bread, of a purity, flavour, and lightness, seldom, if ever, met with in that purchased of the bakers.

=Flour, Sewell’s Patent.= a. (No. 1.) Flour, 1 sack (280 lbs.); hydrochloric acid (sp. gr. 1·14), 45 oz.; mix, by adding the acid in a ‘spray,’——b. (No. 2.) To the last, add (expertly) bicarbonate of soda, 39 oz.; mix thoroughly, and pass the whole through a sieve or ‘dressing machine.’

Obs. This flour is used as the last, to which, however, it is inferior in quality. No. 1 will keep 5 weeks. No. 2 will keep a month. Jones’s flour will keep good in a dry place for years. If No. 1 is alone employed for the dough, to each pound of the flour, 65 gr. of bicarbonate of soda, with salt q. s., must be added. The patentee claims for his invention the merit of the soda and acid being converted into culinary salt in the process of making up the flour and baking the dough.[314]

[Footnote 314: See UNFERMENTED BREAD.]

=FLOWER DEW= (F. J. Weber, successor of Rau, Bamberg). A flat bottle with the name of Rau moulded on it; its gross weight is more than 80 grammes, but it contains scarcely 22 grammes of a nearly colourless but slightly yellow fluid, consisting of a pleasant aromatic solution of oils of bergamot, lemon, orange flowers, and rose in strong spirit.

=FLOWERS.= Syn. FLORES, L. These beautiful and fragrant ornaments of our gardens and our dwellings are too highly esteemed by all classes of the community to require anything in favour of their cultivation to be said here. Our remarks will, therefore, chiefly refer to their collection, improvement, and preservation.

‘Full’ or ‘double flowers,’ or those in which the internal organs become petals, are so much more beautiful than the ‘single flowers’ of the corresponding species and varieties, that their production, with tolerable ease and certainty, has long been a desideratum with both the professional and amateur florist. Various plans have been proposed having this object in view, among which are the following:——1. The use of the best seed only, but not before it is at least 3 or 4 years old. 2. The selection of the outer row of seed only, and its careful preservation intact for at least 2 seasons before sowing it. We are assured that this method is particularly successful with dahlias. 3. The removal of the plants to a shady situation as soon as the flower-buds begin to develop themselves, and stinting them with water and nourishment for a few weeks. In this method a few only of the buds are permitted to mature; the rest being snipped off with a pair of scissors as early as possible. 4. The use of small pots and a scanty supply of water until the flowers are partly developed, when water is supplied in abundance, with or without the addition of a little liquid manure.

To hasten the blooming of flowers, it is a common practice with some gardeners to grow them in as small pots as is consistent with their healthy existence, and carefully to avoid transplanting them to larger pots, for several weeks before their usual time of blossoming. A plant on the point of flowering, if transferred to a larger pot and a richer soil, immediately commences making roots and leaves, whilst the embryo flowers either wholly decay, or their development is checked until the usual season of their production has passed over.

The following liquid has been used with great advantage to promote the vigorous growth and the early flowering of plants:——Sulphate or nitrate of ammonia, 4 oz.; nitrate of potassa, 2 oz.; sugar, 1 oz.; hot water, 1 pint; dissolve and keep it in a well-corked bottle. For use, put 8 or 10 drops of this liquid into the water of a hyacinth glass or jar, for bulbous-rooted plants, changing the water every 10 or 12 days. For flowering plants in pots, a few drops must be added to the water employed for them. The preference should be given to rain water for this purpose. The fluid sold under the name of liquid guano may be used in the same manner.

Flowers may be preserved in a fresh state for a considerable time, by keeping them in a moist atmosphere. When growing on the parent stem, the large amount of evaporation from the surface of their leaves is compensated for by an equivalent proportion of moisture supplied by the roots; but when they are plucked, the evaporation from the surface continues, while the supply of moisture is cut off. To supply, in part, this loss of moisture by evaporation, has arisen the almost universal practice of placing flowers in water; but their mutilated stems possess a far inferior power of sucking up fluids to that of the roots, and thus their decay is only deferred for a time. To preserve them more effectually, or at least to render their existence less ephemeral, we may surround them with a moist atmosphere, by which the loss of water from the surface of their leaves will be reduced to the smallest possible amount. “It is now eighteen years ago since we first saw, in the drawing-room of a gentleman, in the hot dry weather of the dog-days, flowers preserved day after day in all their freshness by the following simple contrivance——A flat dish of porcelain had water poured into it. In the water a vase of flowers was set; over the whole a bell-glass was placed, with its rim in the water. This was a ‘Ward’s case’ in principle, although different in its construction. The air that surrounded the flowers being confined beneath the bell-glass, was kept constantly moist with the water that rose into it in the form of vapour. As fast as the water was condensed it ran down the sides of the bell glass back into the dish; and if means had been taken to inclose the water on the outside of the bell-glass, so as to prevent its evaporating into the air of the sitting-room, the atmosphere around the flowers would have remained continually damp. We recommend those who love to see plenty of fresh flowers in their sitting-rooms in dry weather to adopt this method. The experiment can be tried by inverting a tumbler over a rose-bud in a saucer of water.” (‘Gardener’s Chron.’)

Another method by which some flowers may be preserved for many months is to carefully dip them, as soon as gathered, in perfectly limpid gum water, and after allowing them to drain for 2 or 3 minutes, to set them upright, or arrange them in the usual manner in an empty vase. The gum gradually forms a transparent coating on the surface of the petals and stems, and preserves their figure and colour long after they have become dry and crisp.

Yet another method (given in the ‘Pharmaceutical Journal’) is as follows:——“A vessel with a movable cover is provided, and having removed the cover from it, a piece of metallic gauze of moderate fineness is fixed over it, and the cover replaced. A quantity of sand is then taken sufficient to fill the vessel, and passed through a sieve into an iron pot, where it is heated with the addition of a small quantity of stearin, carefully stirred so as to thoroughly mix the ingredients.

“The quantity of stearin to be added is at the rate of half a part to 100 parts of sand. Care must be taken not to add too much, as it would sink to the bottom and injure the flowers. The vessel with its cover on and the gauze beneath it is then turned upside down, and the bottom being removed, the flowers to be operated upon are carefully placed on the gauze and the sand gently poured in, so as to cover the flowers entirely, the leaves being thus prevented from touching each other. The vessel is then put in a hot place, such, for instance, as the top of a baker’s oven, where it is left for 48 hours. The flowers thus become dried, and they retain their natural colours. The vessel still remaining bottom upwards, the lid is taken off, and the sand runs away through the gauze, leaving the flowers uninjured.

Faded flowers may be generally more or less restored by immersing them half-way up their stems in very hot water, and allowing them to remain in it until it cools, or they have recovered. The coddled portion of the stems must then be cut off, and the flowers placed in clean cold water. In this way a great number of faded flowers may be restored, but there are some of the more fugacious kinds on which it proves useless.

Flowers may be produced in winter by taking up the plants, trees, or shrubs in the spring, at the time when they are about to bud, with some of their own soil carefully preserved around the roots, and placing them upright in a cellar till Michaelmas; when, with the addition of fresh earth, they are to be put into proper tubs or vessels, and placed in a stove or hot-house, when they must be treated in the usual manner. By this method, in the month of February, fruits or roses will appear. Flowers sown in pots about Michaelmas may thus be made to bloom at Christmas.

The apparently instantaneous flowering of plants, exhibited a few years ago by M. Herbert to an astonished audience, was, we believe, effected by the heat generated by fragments of quicklime concealed in the mould close to, but not in immediate contact with, the roots. The plants selected by M. Herbert——a group of geraniums and a rose tree——were planted in two rather deep boxes of garden mould, and were covered with glass shades. The operator commenced by pouring over the roots, from a small watering-pot, a liquid which, uniting to the ingredients already in the earth, caused a great heat, as was shown by an intense steam or vapour, which was evolved within the shades, and allowed, to some extent, to escape through a small hole in the top, which at first was kept closed. The effect upon the geraniums was certainly almost instantaneous; the buds beginning to burst in about five or six minutes, and the plants being in full bloom within ten minutes, when the blossoms were gathered by M. Herbert, and distributed amongst the ladies present. With the rose tree the exhibitor was less fortunate. The invention may prove useful where ladies require to decorate their drawing-rooms or boudoirs with the beauties of the floral world somewhat earlier in the season than they can otherwise be obtained. It must not, however, be forgotten that the plants are, as it were, parboiled during the process, and die after a few days.

As regards the sanitary value of flowers, Mantegazza, of Pavia, states that ozone is generated in larger quantities by certain plants possessing spicy aromatic odours, than by the action of electricity upon the air. He says that in some plants this ozone is developed by the direct rays of the sun, whilst in others the action, once begun in solar light, is continued in darkness; and that cherry-laurel, clove, lavender, mint, lemon, fennel, narcissus, heliotrope, hyacinth, mignonette, &c., all produce ozone largely on exposure to the rays of the sun.[315] He also finds that whilst the ozonigenic properties of flowers reside mainly in their perfumes, the most odoriferous yielding the largest amount of ozone, certain others possessing no particular perfume, have extraordinary ozonigenic power; as, for instance, the sunflower, broad belts of which were planted by the late Commodore Maury around the grounds of the national observatory at Washington, to the effect of which he attributed the after immunity of his family from intermittent fevers.[316]

[Footnote 315: The experiments of Mr Kingzetti on the limited oxidation of essential oils, lead to the inference that instead of ozone, peroxide of hydrogen is the body evolved.——ED.]

[Footnote 316: Recent researches seem to have shown that the hygienic properties of the sun-flower, like those of the Eucalyptus, are chiefly, if not wholly due to the power the plant possesses of abstracting enormous quantities of moisture from the soil, and thus removing from certain localities an active element in the production of malaria.——ED.]

The collection and preservation of flowers for medicinal purposes and distillation, will be found noticed under VEGETABLES.

=Flowers, Artificial.= The beauty and value of these pleasing articles of personal decoration mainly depend upon the taste and ingenuity of the maker. The delicate fingers of woman, and her ready powers of imitation and invention, combined with her natural affection for the chaste and beautiful, have enabled her the more especially to excel in this manufacture. The productions of the female artificial florists of the French capital are justly admired everywhere.

The French employ velvet, kid, and fine cambric for the petals, and taffeta for the leaves. Very recently thin plates of bleached whalebone have been used with great success for some portions of artificial flowers.

As colours and stains, the following are employed in Paris:——

BLUE. Indigo dissolved in oil of vitriol, and the acid partly neutralised with salt of tartar or whiting.

GREEN. A solution of distilled verdigris.

LILAC. Liquid archil.

RED. Carmine dissolved in a solution of salt of tartar, or in spirits of hartshorn.

VIOLET. Liquid archil, mixed with a little salt of tartar.

YELLOW. Tincture of turmeric.

The above colours are usually applied to the petals with the fingers.

=Flowers.= Syn. FLORES, L. Among chemists, this term is applied to various pulverulent substances obtained by sublimation, as flowers of antimony, benzoin, zinc, sulphur, &c. The term has been discarded from modern chemical nomenclature, but is still commonly employed in familiar language and trade.

=FLUID CAM′PHOR.= Prep. (Sir J. Murray.) From camphor (in powder), 1 dr.; freshly precipitated carbonate of magnesia, 2 dr.; cold distilled water, 1 pint; the solution is effected by forcing in carbonic acid gas under pressure. Each fl. oz. contains 3 gr. of camphor, and 6 gr. of carbonate of magnesia. See ESSENCE OF CAMPHOR.

=FLUID MAGNE′SIA.= Syn. LIQUOR MAGNESIÆ CARBONATIS, L. M. BICARBONATIS, L. The preparations sold under this name are mere solutions of freshly precipitated carbonate of magnesia in water, formed by means of carbonic acid gas, under powerful pressure, and long agitation. Those best known are Sir J. Murray’s and Mr Dinneford’s, each fl. oz. of which is said to contain about 17-1/2 gr. of the carbonate, but their actual richness in the latter seldom exceeds 10 or 12 gr., and by the time they reach the consumer is often as low as 5 or 6 gr. Recently precipitated carbonate of magnesia placed in a bottle or other suitable vessel, which is then filled by means of a soda-water apparatus with water fully charged with carbonic acid gas, readily dissolves on slight and cautious agitation, and the aërated water becomes saturated with magnesia. A scruple of carbonate of magnesia put into a soda-water bottle, and thus treated, is all taken up in from 20 minutes to half an hour, and the beverage continues beautifully clear.

=FLUID-OZON= (J. Krohn, Munich, with a certificate from Justus von Liebig). A mouth wash and toilet water. An aqueous solution of permanganate of soda, 1 in 9, contaminated with traces of sodium sulphate and chloride. (Wittstein.)

=FLUM′MERY.= A species of thick hasty-pudding made with oatmeal or rice, flavoured with milk, cream, almonds, orange flowers, lemons, &c., according to fancy.

Prep. 1. (DUTCH FLUMMERY.) From blancmange and eggs, flavoured with lemon peel and sweetened with sugar.

2. (FRENCH FLUMMERY.) From equal parts of blancmange and cream, sweetened, and flavoured. The above are poured into forms, and served cold, to eat with wine, spirit, cider, &c.

3. (A. T. Thomson.) Take oatmeal or groats, 1 quart; rub it for a considerable time with hot water, 2 quarts; and let the mixture stand until it becomes sour; then add another quart of hot water, and strain through a hair sieve. Let stand till a white sediment is deposited, decant the fluid portion, and wash the sediment with cold water. This is now to be boiled with fresh water, until it forms a mucilage, stirring the whole time. A light and nutritious food, during early convalescence.

=FLUOBORIC ACID.= Syn. BOROFLUORIC ACID. This may be easily prepared by saturating hydrofluoric acid with boracic acid, keeping the mixture cool, and then concentrating it in platinum vessels till dense fumes arise.

=FLUOHYDRIC ACID.= See FLUORIDE OF HYDROGEN.

=FLU′ORIDE OF HYDROGEN.= HF. Syn. FLUOHYDRIC ACID; HYDROFLUORIC ACID; A. HYDROFLUORICUM, L. An acid composed of hydrogen and fluorine. It was discovered by Scheele, but was first obtained in a pure state by Gay-Lussac and Thénard, in 1810.

Prep. Pour concentrated sulphuric acid on half its weight of fluor spar, carefully separated from siliceous earth, and reduced to fine powder. The mixture must be made in a capacious leaden retort, and a gentle heat only applied, and the evolved gas must be collected in a leaden receiver, surrounded by ice.

Prop., &c. A colourless fluid below 59° Fahr., which speedily evaporates in dense white fumes when exposed to the air. Its affinity for water exceeds that of sulphuric acid, and its combination with that fluid is accompanied with a hissing noise, and a considerable increase of its sp. gr. up to a certain point. It attacks glass and silica, for which reason it cannot be preserved in glass vessels. Bottles of lead, silver, platinum, or pure gutta percha, are used to keep it in. It is highly corrosive, instantaneously destroying the skin on contact, and producing deep and serious ulcerations; its vapour is pungent, irritating, irrespirable, and poisonous. With the bases it unites to form FLUORIDES.

In the arts, hydrofluoric acid is used for etching on glass.

=FLU′ORIDES.= Compounds of fluorine with metals and other basic radicals. The fluorides of the metals are, with the exception of those of the alkaline metals, insoluble in water, while the fluorides of hydrogen, boron, and silicon, are gaseous, condensing at a low temperature to volatile liquids.

=FLU′ORINE.= F. Syn. FLUORINIUM, L. An element that has not yet been isolated, owing to its attacking and combining with every element or compound that at present has been exposed to it, except oxygen. It is presumably gaseous, and of a pale greenish-yellow colour.

=FLU′OSILICIC ACID.= Syn. FLUORIDE OF SILICON AND HYDROGEN; HYDROFLUOSILIC ACID. Prep. From powdered fluor spar, and siliceous sand or powdered glass, of each 1 part; concentrated sulphuric acid, 2 parts: mix in a glass retort, apply a gentle heat, and pass the evolved gas into water through a layer of mercury. Decomposition ensues, silica being deposited in a gelatinous state, and hydrofluosilicic acid or fluosilic acid remains in solution. The acid liquor is used as a test for potassium and barium, with whose salts it yields nearly insoluble precipitates.

=FLUX.= Syn. FLUXUS, FLUOR, L. In medicine, a term formerly applied to several diseases attended with a copious discharge, as diarrhœa (FLUX), dysentery (BLOODY FLUX), English cholera (BILIOUS FLUX), fluor albus (WHITE FLUX), &c. These terms are still current among the vulgar.

=Flux.= In metallurgy, &c., a term applied to various substances of easy fusibility, which are added to others which are more refractory, to promote their fusion.

Prep. 1. (BLACK FLUX.) Nitre, 1 part; crude tartar or cream of tartar, 2 parts; mix, and deflagrate, by small quantities at a time, in a crucible, heated to dull redness. The product consists of carbonate of potassa, mixed with charcoal in a finely divided state. Used for smelting metallic ores. It exercises a reducing action, as well as promotes the fusion. It must be kept in a dry corked bottle.

2. (CHRISTISON’S FLUX.) Carbonate of soda (cryst.), 8 parts; charcoal (in fine powder), 1 part; heat the mixture gradually to redness. For reducing arsenic.

3. (CORNISH REDUCING FLUX.) Crude tartar, 10 parts; nitre, 4 parts; borax, 3 parts; triturate together.

4. (CORNISH REFINING FLUX, WHITE FLUX.) Crude tartar and nitre, equal parts, deflagrated together. See BLACK FLUX.

5. (CRUDE FLUX.) Same as BLACK FLUX, omitting the deflagration. Reducing.

6. (FRESENIUS’S FLUX.) Carbonate of potassa (dry), 3 parts; cyanide of potassium, 1 part. For the arsenical compounds.

7. (LIEBIG’S FLUX.) Carbonate of soda (dry) and cyanide of potassium, equal parts. As the last. See ARSENIOUS ACID.

8. (MORVEAU’S REDUCING FLUX.) Powdered glass (free from lead), 8 parts; calcined borax and charcoal, of each, 1 part; all in fine powder, and triturated well together. Used as BLACK FLUX.

9. (WHITE FLUX.) See above.

10. (FLUXES FOR ENAMELS.) See ENAMELS.

11. (Various.) Borax, tartar, nitre, sal-ammoniac, common salt, limestone, glass, fluor spar, and several other substances, are used as fluxes in metallurgy.

Obs. On the large scale, crude tartar is employed in the preparation of fluxes; on the small scale, commercial cream of tartar or bitartrate of potassa.

=FLY.= The common house-fly (Musca domestica) causes considerable annoyance to the person in hot weather, as well as damage to handsome furniture, especially to picture frames, gilding, and the like. The best way to exterminate them is to expose on a plate one or other of the mixtures given under FLY POISON (below). The blow-fly (Musca vomitoria), and other insects, may be kept from attacking meat by dusting it over with black pepper, powdered ginger, or any other spice, or by skewering a piece of paper to it on which a drop or two of creasote has been poured. The spices may be readily washed off with water before dressing the meat.

It is a fact not generally known, that flies will not pass through a netting made of fine silk, thread, or wire, even though the meshes may be an inch apart, unless there is a window or light behind it. This affords us a ready means of excluding these insects from all our apartments which have windows only on one side of them, without keeping the latter closed. It is merely necessary to have an ornamental netting stretched across the opening, when, although flies may abound on the outside, none will venture into the room so protected. If, however, there is a window on the other side of the room, they will fly through the netting immediately. See below.

=Fly-blow in Sheep.= Oil of turpentine, 3 oz.; oil of amber, 1 oz.; corrosive sublimate, 1 dr. The sublimate must be first dissolved in a pint of whey, and then mixed with the oils.

=Fly Papers.= Those papers which, a few years ago, were sold about the streets of London by harsh-voiced cries of “Catch ′em alive-oh!” and which might be seen in many shop-windows covered with dead and dying flies, were prepared by rubbing factitious birdlime over sheets of paper. It would be difficult to conceive a more cruel or more offensive mode of catching flies than that of glueing their living bodies to an adhesive surface. A preferable kind of fly-paper is that called ‘PAPIER MOURE,’ which contains a large quantity of arsenic in its substance.[317] This paper is kept wet when in use, and the flies, by sipping the moisture, are poisoned.

[Footnote 317: Mr Plowman, in a letter to the ‘Pharm. Journ.,’ June 22nd, 1878, says that in a specimen of “Papier Moure” examined by him he failed to detect the least trace of arsenic.]

=Fly Poison.= Prep. 1. A strong solution of white arsenic (say 1 dr. to the pint), sweetened with moist sugar, treacle, or honey. Sold under the name of ‘FLY WATER,’

2. Treacle, honey, or moist sugar, mixed with about 1/12th their weight of King’s yellow or orpiment.

Obs. Both the above are dangerous preparations, and should never be employed where there are children.

3. (Redwood.) Quassia chips (small), 1/4 oz.; water, 1 pint; boil 10 minutes, strain, and add of treacle, 4 oz. “Flies will drink this with avidity, and are soon destroyed by it.”

4. Black pepper, 1 teaspoonful; brown sugar, 2 teaspoonfuls; cream, 4 teaspoonfuls. See below.

=Fly Powder.= The dark grey-coloured powder (so-called ‘sub-oxide’) obtained by the free exposure of metallic arsenic to the air. Mixed with sweets, it is used to kill flies.

=Fly Water.= See FLY POISON (above).

=FOG.= The influence of very intense foggy weather upon the death-rate is well illustrated by a reference to the Registrar-General’s returns for 1873. From the 8th to the 12th of December of that year an unprecedently thick fog prevailed in London. The mortality in the metropolis for the week ending December 6th was twenty-three persons per thousand; in the week following, during which the fog occurred, the death-rate rose to twenty-seven; and in the week after that, when the full effects of the fog could be estimated, the deaths were found to be thirty-eight in the thousand. In the same periods the deaths from phthisis and diseases of the respiratory organs were respectively 520, 764, and 1112. That this increased death-rate was not the result of the inclement weather by which the fog was accompanied is evidenced by the circumstance that in large provincial towns, where the weather was equally severe, but in which no fog occurred, the increase in the mortality, when compared to London, was slight.

The mean of the deaths registered in London, in the two weeks ending December 20th, showed an increase of 41 per cent. upon the number returned in the first week of the month; whilst during the same date the deaths in seventeen large English towns were only 8 per cent. This fatal fog occurred during the London cattle-show week, and killed a great number of the animals sent for exhibition.

In a specimen of the air of Manchester, obtained during the visitation of that city by a very dense fog, Dr Angus Smith discovered it contained a diminished amount of oxygen when compared with a favorable sample of air.

=FOILS.= These are thin leaves of polished metal, placed under precious stones and pastes, to heighten their brilliancy, or to vary the effect. Foils were formerly made of copper, tinned copper, tin, and silvered copper, but the last is the one wholly used for superior work at the present day.

Foils are of two descriptions:——white, for diamonds and mock diamonds, and——coloured, for the coloured gems. The latter are prepared by varnishing or lacquering the former. By their judicious use the colour of a stone may often be modified and improved. Thus, by placing a yellow foil under a green stone that turns too much on the blue, or a red one under a stone turning too much on the crimson, the hues will be brightened and enriched in proportion.

Prep. 1. (CRYSTAL, DIAMOND, or WHITE FOIL.)——a. This is made by coating a plate of copper with a layer of silver, and then rolling it into sheets in the flatting mill. The foil is then highly polished, or covered with crystal varnish.

b. The inside of the socket in which the stone or paste is to be set is covered with tin foil, by means of a little stiff gum or size; when dry, the surface is polished and the socket heated, and whilst it is warm, filled with quicksilver; after repose for two or three minutes the fluid metal is poured out, and the stone gently fitted in its place; lastly, the work is well fitted round the stone, to prevent the alloy being shaken out.

c. The bottom of the stone is coated with a film of real silver, by precipitating it from a solution of the nitrate in spirit of ammonia, by means of the oils of cassia and cloves.[318] This method vastly increases the brilliancy both of real and factitious gems, and the work is very permanent.

[Footnote 318: See SILVERING.]

2. (COLOURED FOILS.) The following formulæ produce beautiful coloured effects, when judiciously employed:——

a. (Amethyst.) Lake and Prussian blue, finely ground in pale drying oil.

b. (Blue.) Prussian blue (preferably Turnbull’s), ground with pale, quick-drying oil. Used to deepen the colour of sapphires.

c. (Eagle marine.) Verdigris tempered in shell-lac varnish (alcoholic), with a little Prussian blue.

d. (Garnet.) Dragon’s blood dissolved in rectified spirit of wine.

e. (Vinegar garnet.) Orange lake finely tempered with shell-lac varnish.

f. (Green.)——α. From pale shell-lac, dissolved in alcohol (lacquer), and tinged green by dissolving verdigris or acetate of copper in it.

β. From sesquiferrocyanide of iron and bichromate of potassa, of each 1/2 oz.; ground to an impalpable powder, first alone, and then with gum mastic (clean and also in fine powder), 2 oz.; a little pyroxilic spirit is next added, gradually, and the whole again ground until the mass becomes homogeneous and of a fine transparent green. The beauty increases with the length of the grinding. The predominance of the bichromate turns it on the yellowish green; that of the salt of iron on the bluish green. For use it is to be thinned with pyroxilic spirit. (‘Chem.,’ iii, 231.) Used for emeralds.

g. (Red.) Carmine, dissolved in spirit of hartshorn, or in a weak solution of salt of tartar, and a little gum (dissolved) added.

h. (Ruby.)——α. From lake or carmine, ground in isinglass.

β. Lake ground in shell-lac varnish. Both are used when the colour turns on the purple.

γ. From bright lake ground in oil. Used when the colour turns on the scarlet or orange.

i. (Yellow.)——α. Various shades of yellow may be produced by tinging a weak alcoholic solution of shell-lac or mastic, by digesting turmeric, annotta, saffron, or socotrine aloes in it. The former is the brightest, and is used for topazes.

β. From hay saffron digested in 5 or 6 times its weight of boiling water until the latter becomes sufficiently coloured, and a little solution of gum or isinglass added to the filtered liquor. When dry, a coating of spirit varnish is applied.

Obs. By the skilful use of the above varnishes, good imitations of the gems may be cheaply made from transparent white glass or paste; and by applying them to foils set under coloured pastes (FACTITIOUS GEMS), a superior effect may be produced. The pigments employed must be reduced to the finest state possible by patient grinding, as without this precaution transparent and beautiful shades cannot be formed. The palest and cleanest mastic and lac, dissolved in alcohol, and also the palest and quickest drying oil should alone be used when these substances are ordered. In every case the colour must be laid on the foil with a broad soft brush; and the operation should be performed, if possible, at once, as no part should be crossed, or twice gone over, whilst wet. If the colour turns out too pale, a second coat may be given when the first one has become quite dry, but this practice should be avoided if possible.

=FOMENTA′TION.= Syn. FOMENTATIO, FOMENTUM, FOTUS, L. A liquid, either simple or medicated, used for local bathing. Fomentations are distinguished from lotions chiefly in being applied in a heated state, and in larger quantities, and for a longer period at a time.

Fomentations are chiefly employed to allay pain or irritation, or to promote suppuration or the healthy action of the parts. As the intention is to convey heat, combined with moisture, to the part fomented, the utmost care must be taken to manage the application so as to promote the object in view as much as possible. Flannel cloths wrung out of the hot or boiling liquid, by means of two sticks, turned in opposite directions, form the best vehicles for fomentations. If they are shaken up, and laid lightly over the part, they involve a considerable quantity of air, which, being a bad conductor, retains the heat in them for a considerable time. “In every process of fomenting there should be two flannels, each (say) three yards long, with the ends sewed together, to admit of the boiling water being wrung out of them; and the one flannel should be got ready whilst the other is applied. The fineness or the coarseness of the flannel is not a matter of indifference. The coarser it is the less readily does it conduct heat, and the longer it retains its warmth; therefore it is more efficient for fomenting. White flannel also retains the heat longer than coloured flannel.” (Dr R. E. Griffith.) More harm than good is frequently done by allowing the patient to become chilled during the application. “If only one (flannel) is used, the skin becomes chilled during the time occupied in removing the flannel, soaking it in the water, wringing it out, and reapplying it; but if two are used, one of them is ready, and can be applied the moment the other is taken off, by which means the part is never exposed to the air, no matter how long the fomentation is continued. In some diseases (rheumatism, peritonitis, &c.), the patient is scarcely conscious of a degree of heat which scalds the nurse’s hands. In this case the fomenting flannels should be put in a towel, by which means they may be wrung out without being handled by the nurse, and may be applied far hotter than can be done by any other method.” (Dr J. B. Nevins.)

The quantity of liquid forming a fomentation, as well as the size of the cloths employed, must entirely depend upon circumstances. In some cases (as in slight affections of the face, &c.) the application may be effectually made by holding the part in the steam of the hot liquid, and bathing it continually by means of a sponge or cloth. In some instances 1/2 pint to a pint of liquid may be found a sufficient quantity; whilst in others several quarts will be required. Under all circumstances, care must be taken to keep the fomentation as near as possible at the temperature ordered, during the whole time of its application; and, as soon as the operation is finished, to quickly wipe the part dry, and to cover it with ample clothing, in order that the reaction set up may not be prematurely checked.

Fomentations usually consist of simple water, or the decoction of some simple vegetable substance, as chamomiles, elder flowers or mallows; but, occasionally, the leaves and flowers of aromatic and narcotic plants, and saline matter, are employed under this form. The following formulæ are given as examples:——

=Fomentation, Acetic.= Syn. FOTUS ACETICUS (Paris Codex). Fomentations of vinegar are sometimes prepared with white, with rose, or with aromatic vinegar (Paris Codex) in the proportion of one of vinegar to four of water.

=Fomentation, An′odyne.= Syn. FOTUS ANODYNUS, FOMENTATIO ANODYNA, FOMENTUM ANODYNUM, L. Prep. 1. Simple decoction of poppy-heads.

2. (Hosp. F.) Poppy-heads (without the seeds), 1-1/2 oz.; water, 3-1/2 pints; boil to 2-1/2 pints; add of elder flowers, 3/4 oz.; boil to a quart and strain. Used to allay pain.

3. (Pierquin.) Opium, 1 oz.; wine, 1 quart; boil to a pint and strain. Used in severe gouty, rheumatic, neuralgic, and syphilitic pains.

4. Opium, 1 oz.; water, 1 quart; boil to 3/4 pint, add pyroligneous acid, 2 fl. oz.; boil for 10 minutes longer, then further add of sherry wine, 3/4 pint; and as soon as the whole again boils, strain it for use. Superior to the last, and cheaper.

=Fomentation, Antineural′gic.= Syn. FOMENTATIO ANTINEURALGICA, L. Prep. 1. (Mialhe.) Acetate of morphia, 2 gr.; acetic acid, 2 or 3 drops; eau de Cologne, 2 or 3 dr.; dissolve. In facial neuralgia.

2. (Trousseau and Reveil.) Cyanide of potassium, 1 dr.; distilled water, 6 fl. oz.; dissolve and keep it in a well-closed bottle in the dark. Used in neuralgia, especially in that of the face (tic douloureux). A compress of lint or soft linen is dipped in it and applied to the part. It must not be used internally or applied to a wounded surface, as it is very poisonous. See FOMENTATIONS, ANODYNE, Nos. 3 and 4 (above), also FOMENTATION, STIMULANT.

=Fomentation, Antiseptic.= Syn. FOMENTATIO ANTISEPTICA, L. Prep. 1. Decoction of mallows, 4 pints; sal ammoniac, 2 oz.; dissolve, and add of disulphate of quinine, 20 gr., dissolved in camphorated spirit, 4 fl. oz.

2. (Hosp. F.) Decoction of bark, 1 quart; infusion of chamomile, 1 pint; camphorated spirit, 2 fl. oz.; hydrochloric acid, 1 fl. dr. Both are used when there is a tendency to gangrene or putrescence.

=Fomentation of Ar′nica.= Syn. FOMENTATIO ARNICÆ, L. Prep. 1. Flowers of arnica, 1 oz.; water, 3 pints; boil to a quart, and strain. Used in contusions.

2. (Graefe.) Flowers of arnica, 2 oz.; rue (leaves), 1 oz.; boiling water, q. s. to strain 12 fl. oz. of infusion after an hour’s maceration at nearly the boiling temperature. Used in contusions and extravasations, especially as an application to black eyes.

3. (Radius.) Flowers of arnica, 1/2 oz.; boiling vinegar, q. s. to strain 6 fl. oz. of infusion, in which dissolve of carbonate of ammonia, 2 dr. Used in œdema of the scrotum.

=Fomentation, Aromat′ic.= Syn. FOMENTATIO AROMATICA, FOTUS AROMATICUS, L. Prep. 1. Sea wormwood, southernwood, and chamomiles, of each 1 oz.; laurel leaves, 1/2 oz.; water 5 pints; boil to half gall., and strain. In rheumatism, cutaneous affections, colic, &c.

2. (Augustin.) Rosemary, 1/2 oz.; red wine, and water, of each 3 fl. oz.; infuse and strain with expression. In contusions, especially black eyes.

3. (Hosp. F.) Cloves and mace, of each 1 oz.; opium, 20 gr.; red wine (boiling), 1 pint; digest at near boiling for 1 hour, and strain. Used as both the last.

4. (Rideau.) Bay leaves, rosemary, southernwood, and wormwood, of each 1 oz.; water, 2 quarts; boil 5 minutes, and strain. As No. 1.

=Fomentation, Astrin′gent.= Syn. FOTUS ASTRINGENS, F. ROBORANS, L. Prep. 1. Decoction of oak bark.

2. To each quart of the last add of alum 1 dr.

3. (Ph. Chirur.) Bruised galls, 1 oz.; boiling water, 2-1/2 pints; digest 1 hour, and strain.

4. (Ricord.) Tannin, 2-1/2 dr.; aromatic wine (hot), 1/2 pint; dissolve.

5. Bistort and pomegranate peel, of each 2 oz.; sal ammonia, 1/4 oz.; red wine, 1 pint.; infuse at a gentle heat. The above are used in hæmorrhages, piles, prolapsus, &c.

=Fomentation of Belladon′na.= Syn. FOTUS BELLADONNÆ, L. Prep. (Ophthalmic Hosp.) Extract of belladonna, 1 dr.; boiling water, 1 pint. Used to dilate the pupil in certain affections of the eye; it is usually applied on the forehead.

=Fomentation of Bitter-sweet.= Syn. DECOCTUM DULCAMARÆ, L. Prep. Bitter-sweet stalks, 10 dr.; water, 1-1/2 pint; boil to a pint, and strain.

=Fomentation of Cham′omile.= Syn. FOMENTATIO ANTHEMIDIS, L. Prep. Chamomiles, 2 oz.; water, 3 pints; boil 10 minutes, and strain with expression. Emollient.

=Fomentation, Com′mon.= Syn. FOTUS COMMUNIS. (L. 1744.) Prep. Dried southernwood, sea wormwood, chamomile, of each 1 oz.; dried bay leaves, 1/2 oz.; water, 5 pints; boil slightly, and strain.

=Fomentation, Compound of Hemlock.= (Guy’s Hosp.) Syn. FOMENTUM CONII COMPOSITUM. Prep. Dried hemlock, 2 oz.; dried chamomiles, 1/2 oz.; boiling water, 1-1/2 pint; macerate for 2 hours, strain, and press.

=Fomentation, Diuret′ic.= Syn. FOMENTATIO DIURETICA, L. Prep. (Trousseau.) Tinctures of squills and foxglove, of each 2 oz.; hot water, 6 fluid oz.; mix. Applied by lint or linen compresses to the insides of the thighs, in dropsies, when the stomach will not bear diuretics.

=Fomentation of El′der Flowers.= Syn. FOTUS SAMBUCI, L. Prep. From elder flowers, 1 oz.; boiling water, 2 quarts; digest in a hot place for 1 hour, and express the liquor. Emollient.

=Fomentation, Emol′lient.= Syn. FOMENTATIO EMOLLIENS. L. Prep. 1. Marshmallow root and poppy heads, of each 1 oz.; water, 3 pints; boil to a quart, and strain.

2. (P. Cod.) Emollient herbs, 1 oz.; boiling water, 1 quart; infuse 1 hour, and strain with expression. (See above.)

=Fomentation, Foxglove.= Syn. FOMENTUM DIGITALIS. Dried foxglove, 1 oz.; boiling water, 1-1/2 pint; infuse, and strain.

=Fomentation of Galls.= Syn FOMENTUM GALLÆ. Prep. Bruised galls, 1/2 oz.; boiling water, 2 lbs.; macerate for an hour and strain.

=Fomentation, Narcot′ic.= Syn. FOMENTATIO NARCOTICA, L. Prep. (P. Cod.) Narcotic herbs, 1 oz.; boiling water, 1-1/2 pint; infuse as last.

=Fomentation, Poppy.= Syn. FOMENTUM PAPAVERIS. As DECOCTION OF POPPIES.

=Fomentation, Resol′vent.= Syn. FOTUS RESOLVENS, L. Prep. (Richard.) Fomentation of elder flowers, 8 fl. oz.; liquor of diacetate of lead, 1/2 fl. dr.; mix. Used to discuss tumours, &c.

=Fomentation, Stim′ulant.= Syn. FOMENTATIO STIMULANS, L. Prep. 1. Sesquicarbonate of ammonia, 1 oz.; tincture of cantharides, 2 fl. oz.; warm water, 1 pint.

2. Household mustard, 4 oz.; hot water, 1-1/2 pint; mix. Both the above are rubefacient and counter-irritant, and excellent in rheumatism, neuralgia, &c.

=Fomentation, Tannin.= Syn. FOMENTUM TANNINI. (Ricord.) Prep. Tannin, 2 dr.; aromatic wine, 8 oz.

=Fomentation, Ver′mifuge.= Syn. FOMENTATIO VERMIFUGA, FOTUS ANTHELMINTICUS, L. Prep. Leaves and flowers of tansy, wormwood, and chamomile, of each 3 oz.; water, 1 quart; boil to 1-1/2 pint, and strain. Applied to the abdomen, &c., in worms.

=Fomentation, Wine.= Syn. FOTUS VINOSUS (Par. Cod.) Prep. Red wine, 2 pints; honey 4 oz.

=FOOD.= Syn. CIBUS, MATERIA ALIMENTARIA, L. Anything which feeds or promotes the natural growth of organic bodies, by supplying them with materials which, by assimilation, may be converted into the substances of which they are composed; or which, by its decomposition or slow combustion, maintains the temperature, or some other essential condition of life, at the proper standard. The numerous articles employed as food are all compounds; and in many cases they consist of mechanical mixtures or chemical combinations of two or more compounds. Organized matter, or that which has possessed either animal or vegetable life, or which has been produced by living organs, seems to be alone capable of assimilation, to any extent, by the animal system; and hence it is from the organic kingdom that our aliments are necessarily derived. Water, iron, earthy phosphates, chloride of sodium, and other salts, which form the inorganic constituents of the body, though not of themselves nourishing, are also assimilated when taken in conjunction with organic aliments, and then contribute essentially to nutrition. In the animal and vegetable substances employed as food, these inorganic compounds are provided in small but sufficient quantities to meet the requirements of the healthy body, and in this state of combination alone can they be regarded in the light of aliments. A complete consideration of this subject embraces, not only all the substances used as food, but also those things which when taken with them improve their flavour, promote their digestion, and render them more wholesome and nutritive; and also their preparation for the table in its various relations with health and disease.

The following ‘BILLS OF FARE,’ for which we are indebted chiefly to Soyer, Rundell, and others, exhibit the various articles in season at different periods of the year.

FIRST QUARTER. January.——Poultry and game: Pheasants, partridges, hares, rabbits, woodcocks, snipes, turkeys, capons, pullets, fowls, chickens, and tame pigeons.——Fish: Carp, tench, perch, lampreys, eels, cray-fish, cod, soles, flounders, plaice, turbot, thornback, skate, sturgeon, smelts, whitings, lobsters, crabs, prawns, and oysters.——Vegetables: Cabbage, savoys, colewort, sprouts, leeks, onions, beet, sorrel, chervil, endive, spinach, celery, garlic, scorzonera, potatoes, parsnips, turnips, brocoli (white and purple), shalots, lettuces, cresses, mustard, rape, salsafy, and herbs of all sorts (some dry and some green); cucumbers, asparagus, and mushrooms are also to be had, though not in season.——Fruit: Apples, pears, nuts, walnuts, medlars, and grapes.

February and March.——Meat, fowls, and game, as in January, with the addition of ducklings and chickens.——Fish: As the last two months (cod is not thought so good from February to July, although it is still sold at the fishmonger’s).——Vegetables: The same as the previous months, with the addition of kidney-beans.——Fruit: Apples, pears, and forced strawberries.

SECOND QUARTER. April, May, and June.——Meat: Beef, mutton, veal, lamb, and venison (in June).——Poultry: Pullets, fowls, chickens, ducklings, pigeons, rabbits, and leverets.——Fish: Carp, tench, soles, smelts, eels, trout, turbot, lobsters, chub, salmon, herrings, cray-fish, mackerel, crabs, prawns, and shrimps.——Vegetables: As before; and in May, early potatoes and cabbages, peas, radishes, kidney-beans, carrots, turnips, cauliflowers, asparagus, artichokes, and numerous salads (forced).——Fruit: (in June) strawberries, cherries, melons, green apricots, and currants and gooseberries for tarts; pears, grapes, nectarines, peaches, and some other fruit.

THIRD QUARTER. July, August, and September.——Meat, as before.——Poultry, &c.: Pullets, fowls, chickens, rabbits, pigeons, green geese, leverets, and turkey poults. Two former months, plovers and wheat-ears (in September), partridges, geese, &c.——Fish: Cod, haddocks, flounders, plaice, skate, thornback, mullets, pike, carp, eels, shellfish (except oysters), and mackerel (during the first two months of the quarter, but they are not good in August).——Vegetables: Of all sorts, beans, peas, French beans, &c.——Fruit: (In July)——Strawberries, gooseberries, pine-apples, plums (various), cherries, apricots, raspberries, melons, currants, and damsons. (In August and September)——Peaches, plums, figs, filberts, mulberries, cherries, apples, pears, nectarines, and grapes. (During the latter months)——Pines, melons, strawberries, medlars, and quinces. (In September)——Morella cherries, damsons, and various plums.

FOURTH QUARTER. October, November, and December.——Meat, as before, and doe venison.——Poultry and Game: Domestic fowls, as in first quarter; pheasants (from the 1st of October); partridges, larks, hares, dotterels (at the end of the month), wild-ducks, teal, snipes, widgeon, and grouse.——Fish: Dories, smelts, pike, perch, halibuts, brills, carp, salmon-trout, barbel, gudgeons, tench, and shellfish.——Vegetables: (As in January), French-beans, last crops of beans, &c.——Fruit: Peaches, pears, figs, bullace, grapes, apples, medlars, damsons, filberts, walnuts, nuts, quinces, services, and medlars. (In November)——Meat, &c.: Beef, mutton, veal, pork, house-lamb, doe venison, and poultry and game as in the last month.——Fish: As the last month.——Vegetables: Carrots, turnips, parsnips, potatoes, skirrets, scorzonera, onions, leeks, shalots, cabbage, savoys, colewort, spinach, chardbeats, chardoons, cresses, endive, celery, lettuces, salad-herbs, and various pot-herbs.——Fruit: Pears, apples, nuts, walnuts, bullace, chestnuts, medlars, and grapes. (In December)——Meat, &c.: Beef, mutton, veal, house-lamb, pork, and venison.——Poultry and Game: Geese, turkeys, pullets, pigeons, capons, fowls, chickens, rabbits, hares, snipes, woodcocks, larks, pheasants, partridges, sea-fowls, guinea-fowls, wild ducks, teal, widgeon, dotterels, dun-birds, and grouse.——Fish: Cod, turbot, halibuts, soles, gurnets, sturgeon, carp, gudgeons, codlings, eels, dories, and shell-fish.——Vegetables: As in last month. Asparagus, &c., forced.——Fruit: As before, except bullace.

=Food, Inspection of.= The Public Health Act enacts that——

“Any medical officer of health or inspector of nuisances may at all reasonable times, inspect and examine any animal, carcase, meat, poultry, game, flesh, fish, fruit, vegetables, corn, bread, flour, or milk exposed for sale, or deposited in any place for the purpose of sale, or of preparation for sale, and intended for the food of man, the proof that the same was not exposed or deposited for any such purpose, or was not intended for the food of man, resting with the party charged; and if any such animal, carcase, meat, poultry, game, flesh, fish, fruit, vegetables, corn, bread, flour, or milk, appears to such medical officer or inspector to be diseased, or unsound, or unwholesome, or unfit for the food of man, he may seize and carry away the same himself or by an assistant, in order to have the same dealt with by a justice.” (P. H., s. 116.)

“If it appears to the justice that any animal, carcase, meat, poultry, game, flesh, fish, fruit, vegetables, corn, bread, flour, or milk so seized is diseased, or unsound, or unwholesome, or unfit for the food of man, he shall condemn the same and order it to be destroyed, or so disposed of, as to prevent it from being exposed for sale, or used for such food; and the person to whom the same belongs or did belong at the time of sale, or of exposure for sale, or in whose possession, or on whose premises the same was found, shall be liable to a penalty not exceeding £20 for every animal, carcase, or fish, or piece of meat, flesh, or fish, or any poultry or game, or for the parcel of fruit, vegetables, corn, bread, or flour, or for the milk so condemned, or at the discretion of the justice, without the infliction of a fine, to imprisonment for a term of not more than three months.

“The justice who, under this section, is empowered to convict the offender, may be either the justice who may have ordered the article to be disposed of or destroyed, or any other justice having jurisdiction in the place.” (P. H., s. 117.)

“Any person who in any manner prevents any medical officer of health or inspector of nuisances from entering any premises and inspecting any animal, carcase, meat, poultry, game, flesh, fish, fruit, vegetables, corn, bread, flour, or milk exposed or deposited for the purpose of sale, or of preparation for sale, and intended for the food of man, or who obstructs or impedes any such officer or inspector, or his assistant, when carrying into execution the provisions of this Act, shall be liable to a penalty, not exceeding £5.” (P. H., s. 118.)

“Any complaint made on oath, by a medical officer of health, or by an inspector, or other officer of a local authority, any justice may grant a warrant to any such officer, to enter any building, or part of a building in which any such officer has reason for believing that there is kept or concealed any animal, carcase, meat, poultry, game, flesh, fish, fruit, vegetables, corn, bread, flour, or milk which is intended for sale for the food of man, and is diseased, unsound or unwholesome, or unfit for the food of man and to search for, seize, and carry away any such animal, or other article, in order to have the same dealt with by a justice under the provisions of this Act.

Any person who obstructs any such officer in the performance of his duty, under such warrant shall, in addition to any other punishment to which he may be subject, be liable to a penalty not exceeding £20.” (P. H., s. 119.)

=FOOL.= Cooks give this name to a species of jam made of boiled and crushed fruit, mixed with milk or cream, and sweetened.

=Fool, Ap′ple.= From the peeled and cored fruit, placed in a jar, with moist sugar, q. s. to render it palatable, and a very little cider or perry; the jar is set in a saucepan of water over the fire, and the heat continued until the apples become quite soft, when they are pulped through a colander, and a sufficient quantity of milk, a little cream, and some sugar, added to bring them to the proper ‘palate.’

=Fool, Goose′berry.= From gooseberries, as the last. Those which are unripe are generally preferred. These preparations, when nicely made, are very pleasant and wholesome.

=FOOT (Human).= See FEET.

=FOOTS.= Coarse moist sugar. The scrapings of the sugar hogsheads, refuse sugar, waste, and dirt, is also sold to the publicans under this name, who use it in the adulteration of their beer; chiefly to make it stand more water, and to impart ‘briskness.’

=FORCE′MEAT.= Syn. FARCE, STUFFING. A species of sausage meat, either served up alone, or employed as an ingredient in other dishes.

Mrs Rundell truly remarks that “at many tables, where everything else is done well, it is common to find very bad forcemeat or stuffing.” To avoid this error, care should be taken to so proportion the ingredients that “no one flavour should predominate; yet if several dishes be served the same day, there should be a marked variety in the tastes of the forcemeats as well as of the gravies. A general fault is, that the tastes of lemon peel and thyme overcome all others; therefore they should only be used in small quantities.” Forcemeats should be just consistent enough to cut with a knife, but not dry and heavy. Herbs are very essential ingredients; and it is the copious and judicious use of them that chiefly gives the cookery of the French its superior flavour. “To force fowls, meat, &c., is to stuff them.” (Mrs Rundell.)

=FOR′CING.= Horticulturists apply this term to the art of accelerating the growth of plants, so as to obtain fruits or flowers at unusual seasons. Dung-beds, bark-beds, and frames, pits, and houses, with glass roofs, are commonly employed by the gardeners for this purpose.

=FORGERIES, PROTECTION FROM.= See PAPER, PROTECTIVE.

=FORMATE.= Syn. FORMIATE. Salts, in which one atom of hydrogen in formic acid is replaced by a metal or other basic radical. They are best obtained either by direct saturation of the acid, or by double decomposition; most of them are very soluble, and are decomposed by hot oil of vitriol. Formate of ammonium crystallises in square prisms; formate of sodium, in rhombic prisms; formate of potassium is deliquescent, and crystallises with difficulty; the formates of barium, calcium, magnesium, and strontium, form small prismatic crystals; formate of lead assumes the shape of small colourless needles, soluble in 40 parts of water; the formates of cobalt, iron, manganese, nickel, and zinc, are easily crystallisable, whilst that of copper forms very beautiful, large, bright-blue rhombic prisms; formate of silver is less soluble than the salt of lead, and is decomposed at a gentle heat.

=FORMIC ACID.= HCHO_{2}. Syn. HYDROGEN FORMIATE. An organic acid, obtained by oxidizing many organic substances, and found in the red ant.

Prep. Sugar, 1 part; water, 2 parts; binoxide of manganese, 3 parts; mix in a retort capable of holding fully 10 times the bulk of the ingredients, and add, cautiously, oil of vitriol, 3 parts, diluted with an equal weight of water; as soon as the first violent effervescence has subsided, heat may be applied, and the product collected and purified, as below.

Formate of lead in fine powder is introduced into a long glass tube, one end of which is connected with an apparatus evolving sulphuretted hydrogen, and the other with a receiver. As soon as the salt is entirely decomposed (blackened) a very gentle heat is applied, and the distilled liquid collected; the product is, lastly, boiled for a minute or less, to expel any adhering sulphuretted gas. This furnishes chemically pure formic acid.

From wood spirit, 1 part; bichromate of potassium and sulphuric acid, of each 3 parts; the sulphuric acid, diluted with an equal weight of water, being gradually added last. A portion of wood spirit distils over with the acid, and may be again treated with bichromate of potassium and sulphuric acid, when a fresh portion of formic acid will be produced. This process yields a large product.

Prop., purific., &c. The products of the above processes are limpid and colourless; the stronger ones fume slightly in the air, and possess an extremely penetrating odour. The acid obtained by the second process boils at 209° Fahr., crystallises in brilliant scales below 32°, and has the sp. gr. 1·2353. Its vapour is inflammable, and burns with a blue flame. It is extremely corrosive, and rapidly destroys the texture of living organic substances. The products of the other processes are very dilute, and possess the above properties in only a minor degree. They may all be purified and concentrated by saturating them with pure carbonate of sodium or of potassium, and after subjecting the liquid to a gentle heat for a short time, and liberating the formic acid from the salt by means of dilute sulphuric acid, finally submitting the mixture to distillation, when the hydrated acid will come over perfectly pure.

Formic acid reduces the salts of mercury and silver, and forms salts with the bases termed formiates.

Formic acid is readily distinguished from acetic acid, which in many points it resembles, by heating it with a little solution of oxide of silver or mercury; the metal is reduced, and precipitated in a pulverulent state, while carbonic acid is extricated. The odours of the two acids also vary.

=FORMICA.= Syn. THE ANT. The following are the principal species of the genus Formica. F. flava, the yellow ant. Many careful observers say this species keeps in its nest the Aphis radicans, which when its abdomen is touched by the ant, excretes a saccharine substance on which the ants feed. F. rufa, or large red ant, F. fusca; or brown ant, Polyergus rufescens, and F. sanguinea. These two latter are sometimes called amazon ants, from their pugilistic propensities. They have been known to make regular raids against other species of ants, and to carry off their larvæ and pupæ to their own nests, where they rear the insects that come of them, and afterwards employ them as slaves, causing them to excavate passages, to collect food, to carry larvæ and (so dependent do the masters become on the exertions of their bondsman) even to feed them; it being a well-attested fact that the slave holders would starve if left to themselves. See ANT.

=FORMOBENZOIC ACID.= (HC_{7}H_{6}O,CHO_{2}). Syn. FORMIATE OF HYDRIDE OF BENZOYLE. MANDELIC ACID. When the distilled water of bitter almonds (containing hydrocyanic acid and the essential oil) is boiled with hydrochloric acid, a curious reaction occurs; the hydrocyanic acid is decomposed——into ammonia which unites with the hydrochloric acid, and formic acid which enters into combination with the oil of almonds——producing a new body possessed of acid properties, and termed Formobenzoic acid. On evaporating the solution the acid may be obtained in mixture with ammonia hydrochlorate, from which it may be separated by ether; the ethereal solution deposits it in rhomboidal tables. It has a sour taste and is easily soluble in alcohol. When heated it fuses at a low temperature, emitting an agreeable odour of hawthorn blossoms. (Miller.)

=FORM′ULA.= [L.] In pharmacy and medicine, a short form of prescription; a recipe. By chemists the term is applied to a grouping of symbols, expressing the composition of a body; thus, HCl (standing for 1 atom of hydrogen united to 1 atom of chlorine) is the formula for hydrochloric acid. A chemical formula is termed empirical when it merely gives the simplest possible expression of the composition of the substance to which it refers. A rational formula, on the contrary, aims at describing the exact composition of molecule, or combining weight of the substance, but stating the absolute number of atoms of such of the elements essential to that object, as well as the mere relations existing between them. The empirical formula is at once deduced from the analysis of the substance, reckoned to 100 parts; the rational formula requires, in addition, a knowledge of its combining quantity, which can only be obtained by direct experiment, by synthesis, or by the careful examination of one or more of its most definite compounds. Thus, the composition of acetic acid is expressed by the formula CH_{2}O, which exhibits the simplest relations of the three elements; if we want to express the quantities of these, in atoms required to make up one molecule of acetic acid, we have to adopt the formula C_{2}H_{4}O_{2} or HC_{2}H_{3}O_{2}.

=FOR′MYL.= Syn. FORMYLE. A hypothetical organic radical, having the composition C_{2}H. Its existence was inferred from the constitution of certain organic compounds which are now referred to the methyl-series. Formic acid was supposed to be an oxide of formyl; and chloroform, the terchloride of formyl.

=FOXGLOVE.= Syn. DIGITALIS (B. P.), L. A genus of plants belonging to the natural order Scrophulariacæ. The leaves of the uncultivated ‘Digitalis purpurea,’ or purple foxglove, are officinal in our pharmacopœias. They must be gathered before the terminal flowers have expanded. “The petiole and midrib of the leaf being cut off, dry the lamina.” (Phar. L.) The seeds (DIGITALIS SEMINA), which were ordered, as well as the leaves, in former pharmacopœias, are said to be in many points preferable to them. When good, the leaves are of a dull-green colour, and possess a feeble narcotic odour, and a bitter, unpleasant taste. Both the dried leaves and the powder should be preserved in corked bottles covered with dark-coloured paper, or in well-closed tin canisters, and kept in a dark cupboard; and the stock should be renewed yearly, as age considerably diminishes the medicinal activity of digitalis.

Action, uses, &c. Foxglove is diuretic, sedative, and antispasmodic, and exerts a specific action over the cerebro-spinal system, promoting the functions of the absorbents, and reducing the force of the circulation in a remarkable manner. It is administered in fevers and inflammations, to reduce the frequency of the pulse, and to allay excessive vascular excitement; in dropsy (unless the habit is full and pulse tight and cordy), as a diuretic, either alone, or combined with squills, calomel, salines, or bitters; in internal hæmorrhages, as a sedative, when the pulse is full, hard, and throbbing; in diseases of the heart and great vessels, and in phthisis, to reduce the force and velocity of the circulation; in epilepsy and insanity, to repress vascular excitement; and in spasmodic asthma, scrofula, and several other diseases, with one or other of the above intentions.

The greatest caution is required in the use of foxglove, as its effects accumulate in the system, and the unwary practitioner is occasionally surprised at the sudden demise of his patient, even after he has left off the use of this drug.——Dose, 1/2 gr. to 1-1/2 gr., in powder, every 6 hours. See EXTRACT, INFUSION, TINCTURE, &c.

=FOX′ING.= See MALT LIQUORS.

=FRACT′URE.= Syn. FRACTURA, L. The breaking or disrupture of a bone. When the bone is nearly divided into two parts, it is called a SIMPLE FRACTURE; when the integuments are also lacerated, a COMPOUND FRACTURE; and when the bone is splintered, a COMMINUTED FRACTURE.

=FRAGRANT PAIN-CURER= (Five-minute). Dr Walter Scott, New York. A remedy to remove all kinds of pain in five minutes. A clear colourless fluid containing ether, 6 grammes; glycerin, 21 grammes; common salt, 3·4 grammes; distilled water, 170 grammes. (Hager.)

=FRANK′INCENSE.= Syn. COMMON FRANKINCENSE; THUS (Ph. L.), L. The turpentine which exudes from the bark of Abies excelsa (Norway spruce fir) and Pinus palustris (pitch or swamp pine), hardened by the air. (Ph. L.) The gum-resin olibanum, which is the produce of the Boswellia thurifera, is the ‘odorous frankincense’ of commerce.

=Prepared Frankincense.= Syn. THUS PRÆPARATUM (Ph. L.), L. Prep. (Ph. L.) Frankincense, 1 lb.; water, q. s. to cover it; boil until the resin is melted, and strain through a hair sieve; when the whole has cooled, pour off the water, and keep the frankincense for use. Resembles common resin in its general properties.

=FRAX′ININ.= Syn. FRAXIN; FRAXINA, L. A peculiar bitter, neutral, and crystallisable substance, soluble in boiling water, extracted from the bark of Fraxinus excelsior, or common ash. It is febrifuge.

=FREC′KLES.= These are round or oval-shaped yellowish spots, similar to stains, developed on the skin. There are two varieties——FRECKLES, or SUMMER FRECKLES, resulting from the action of the sun and heat during the summer season, and disappearing with the hot weather or exposure; and——COLD FRECKLES, which occur at all times of the year. The former are chiefly confined to persons of fair complexion, whilst the latter attack persons of all complexions indifferently, and sometimes assume a lively yellow or greenish colour.

Treatment. Common freckles may generally be removed by the frequent application of dilute spirits, acids or alkaline solutions; the last two just strong enough to prick the tongue. Cold freckles commonly occur from disordered health, or some general disturbance of the system, to which attention should be chiefly directed. In both varieties the solution of bichloride of mercury (Ph. L.), or Gowland’s lotion, will be found a most useful external application. See below.

=Freckles, Lotion for.= Prep. 1. Bichloride of mercury, 5 gr.; hydrochloric acid, 30 drops; lump sugar, 1 oz.; rectified spirit of wine, 2 oz.; rose water, 7 oz.; agitate together until the whole is dissolved.

2. Petals or leaves of red roses, 1 oz.; hot water, 12 fl. oz.; infuse an hour, and strain, with expression, 1/2 pint; add of citric acid, 30 gr.; dissolve, and in a few hours, decant and clear.

3. Rose leaves (dried), 1/4 oz.; lemon juice (freshly expressed) and rum or brandy, of each 1/4 pint; digest 24 hours, and squeeze out the liquor for use.

4. (Kittoe’s.) Sal ammoniac, 1 dr.; spring water, 1 pint; lavender water or eau de Cologne, 1/4 oz; mix. The above are applied with the fingers night and morning, or oftener.

=Freckles, Pomade for.= Prep. 1. Citrine ointment, 1 dr.; simple ointment, 7 dr.; otto of roses, 3 drops.

2. Elder flower ointment, 1 oz.; sulphate of zinc (levigated), 20 gr.; mix by porphyrization, or by trituration in a wedgwood-ware mortar. Both the above, applied night and morning, are excellent for either cold or summer freckles.

=FREEZ′ING MIXTURES.= See ICE and REFRIGERATION.

FRENCH BER′RIES. Syn. PERSIAN BERRIES, AVIGNON B.; GRAINES D’AVIGNON, Fr. The unripe berries or fruit of the Rhamnus infectorius. They are imported from France and Persia; those from the latter country being esteemed the best. Some writers state that the Persian berries are the product of a distinct species, namely, R. amygdalinus. They are chiefly used for dyeing morocco leather yellow. Their decoction dyes cloth, previously mordanted with alum, tartar, or protochloride of tin, of a yellow colour; with sulphate of copper, an olive; and with red sulphate of iron, an olive-green colour.

=FRENCH POL′ISH.= Several varnishes are used under this name. That most generally employed is a simple solution of pale shell-lac in either methylated spirit or wood naphtha. Sometimes a little mastic, sandarac, or elemi, or copal varnish, is added to render the polish tougher.

Prep. 1. From pale shell-lac, 5-1/2 oz.; finest wood naphtha, 1 pint; dissolve.

2. Pale shell-lac, 3 lbs.; wood naphtha, 1 gall. Methylated spirit (68 o. p.) may be substituted for the naphtha in each of the above formulæ.

3. Pale shell-lac, 5 oz.; gum sandarac, 1 oz.; spirit (68 o. p.), 1 pint.

4. Pale shell-lac, 5-1/2 oz.; gum elemi, 3/4 oz.; spirit, 1 pint.

5. Pale shell-lac, 1-1/4 lbs.; mastic, 1/4 lb.; spirit, 2 quarts.

6. Pale shell-lac, 2-1/4 lbs.; mastic and sandarac, of each 3 oz.; spirit, 1 gall.; dissolve, add copal varnish, 1 pint, and mix by roughly agitating the vessel. All the above are used in the manner described below.

7. Shell-lac, 12 oz.; wood naphtha, 1 quart; dissolve, and add of linseed oil, 1/2 pint.

8. Shell-lac, 1/2 lb.; gum sandarac, 1/4 lb.; spirit, 1 quart; dissolve, add of copal varnish, 1/4 pint; mix well, and further add of linseed oil, 1/2 pint. The last two require no oil on the rubber.

Obs. The preparation of French polish is precisely similar to that of other spirit or naphthalic varnishes. Sometimes it is coloured, in order to modify the character of the wood. A REDDISH TINGE is given with dragon’s blood, alkanet root, or red sanders wood; and a YELLOWISH TINGE, by turmeric root or gamboge. When it is simply desired to DARKEN the wood, brown shell-lac is employed to make the polish; and when the object is to keep the wood LIGHT COLOURED, a little oxalic acid (2 to 4 dr. to the pint) is commonly added. These substances are either steeped in or agitated with the polish, or with the solvent, before pouring it on the ‘gums,’ until they dissolve, or a sufficient effect is produced. French polish is not required to be so clear and limpid as other varnishes, and is, therefore, never artificially clarified. See VARNISH, and below.

=FRENCH POL′ISHING.= This process, now so generally employed for furniture and cabinet work, is performed as follows:——The surface to be operated on being finished off as smoothly as possible with glass paper, and placed opposite the light, the ‘rubber’ being made as directed below, and the polish (see above) being at hand, and preferably contained in a narrow-necked bottle, the workman moistens the middle or flat face of the rubber with the polish, by laying the rubber on the mouth of the bottle and shaking up the varnish against it, once, by which means the rubber imbibes the proper quantity to cover a considerable extent of surface. He next encloses the rubber in a soft linen cloth, doubled, the rest of the cloth being gathered up at the back of the rubber to form a handle. The face of the linen is now moistened with a little raw linseed oil, applied with the finger to the middle of it, and the operation of polishing immediately commenced. For this purpose the workman passes his rubber quickly and lightly over the surface uniformly in one direction, until the varnish becomes dry, or nearly so, when he again charges his rubber as before, omitting the oil, and repeats the rubbing, until three coats are laid on. He now applies a little oil to the rubber, and two coats more are commonly given. As soon as the coating of varnish has acquired some thickness, he wets the inside of the linen cloth, before applying the varnish, with alcohol, or wood naphtha, and gives a quick, light, and uniform touch over the whole surface. The work is, lastly, carefully gone over with the linen cloth, moistened with a little oil and rectified spirit or naphtha, without varnish, and rubbed, as before, until dry.

The RUBBER for French polishing is made by rolling up a strip of thick woollen cloth (list) which has been torn off, so as to form a soft elastic edge. It should form a coil, from 1 to 3 inches in diameter, according to the size of the work.

=FRES′CO-PAINTING.= See PAINTING.

=FRICANDEAU.= [Fr.] Among cooks, a ragoût, or fricassée of veal. The same term is also sometimes applied to stewed beef, highly seasoned.

=FRICASSEE.= [Fr.] A dish prepared by stewing or semi-frying, highly flavoured with herbs, spices, or sauce. Small things, as chickens, lamb, &c., and cold meat, are usually formed into fricassees.

=FRIC′TION=. In a general sense, the act of rubbing one body against another; attrition.

=Friction.= In mechanics this is the resistance which the surface of a moving body meets with from the surface of the body on which it moves. To lessen the amount of friction in machines, various unctuous substances, as oil, tallow, soap, black-lead, &c., are used by engineers. These substances act by imparting smoothness to the points of contact, and thus reduce their resistance to each other. The full consideration of the subject belongs to engineering.

=Friction.= In medicine, friction, whether simple or conjoined with liniments, is a therapeutical agent of considerable power. By it the circulation is promoted in debilitated parts, and medicinal substances (iodine, mercurials, opium, &c.) are made to penetrate the pores of the skin. “The benefit of friction, which consists of motion and heat, whether or not the same be raised by rubbing the body with a coarse cloth or the flesh-brush, has advantages inconceivable and scarcely credible, by which the obstructions of the pores and cutaneous glandules are opened, their stagnating juices broken into small particles, dissolved, and rendered fit to be carried off in perspiration, in the room of which, as my Lord Verulam well observes, new juice will succeed with new vigour to the body; and longevity, saith that great naturalist, is this way most certainly promoted” (Daniel Turner).

Simple friction is performed by the hand alone, or with a piece of flannel, a hair glove, or a flesh-brush. “If it be properly performed——namely, by short, brisk strokes with the tips of the fingers, and with great celerity, when the naked hand is the agent; and if it be continued for an hour or upwards, and repeated several times a day——its influence in reducing swelled glands and swellings of the joints, as well as in alleviating rheumatic pains, is very great; but, besides being well performed, the friction should be continued for (at least) half an hour, in order to render it useful.” (Dr R. E. Griffith.)

Gentle, slow, and equable friction, by producing a continued repetition of an agreeable impression on the nervous system, acts both as an anodyne and hypnotic. For this purpose “the operator should sit by the side of the bed, and introducing the hand under the bedclothes, rub the legs or the arms (or other parts) gently with equally lengthened but slow movements. When the invalid is a child, its influence is more powerful when aided by a monotonous, but a soft tune, which, although it operates upon a distinct sense, yet, by combination, renders the friction more soporific.” (Griffith.)

When the friction is accompanied with the use of any acrid or irritating substance, or is intended to introduce any active remedy into the system, the rubbing should be brisk, and of sufficient force to slightly abrade and inflame the cuticle; and should be continued until the substance, which is usually in the form of an ointment, either wholly or partially disappears, owing to its absorption by the skin. The hand of the operator should, in most cases, be guarded by a glove; otherwise he is likely to share with the patient the effects of the medicine, a result not always agreeable or even safe.

=FRIGORIFIC MIXTURES.= See REFRIGERATION.

=FRIT.= The pulverulent materials of glass, heated until they coalesce without melting. See ENAMEL, GLASS, &C.

=FRIT′TERS.= Fried batter. A species of pancake, containing fruit, sweetmeats, poultry, meat, or fish.

Prep. 1. (M. Alexis Soyer.) “The following is thirty receipts in one:”——Soak crum of bread, 1 lb., in cold water, q. s.; take the same quantity of any kind of boiled or roasted meat (a little fat), and chop it into fine dice; press the water out of the bread; put into the pan butter, lard, or dripping, 2 oz., with chopped onions, two teaspoonfuls; fry two minutes, add the bread, stir with a wooden spoon until rather dry, then add the meat, and season with salt, 1 teaspoonful, pepper, 1/2 do., and a little grated nutmeg if handy; stir till quite hot; then further add two eggs, one at a time, mix very quickly, and pour it on a dish to cool; next roll it into the shape of small eggs, then in flour, ‘egg’ them, and bread-crum them; lastly, fry in abundance of fat to a nice yellow colour, and serve either plain or with any sharp or other savory sauce you fancy. Innumerable dishes can be made in this way; in fact, from everything that is eatable, and at any season of the year——from the remains of meat, poultry, game, fish, vegetables, &c. The same can be done with chopped, dried, or preserved fruits, simply using a 1/4 lb. more bread, and sifting powdered sugar and cinnamon over them. Cream may also be used for fruit, or curds.

Fritters are also (and more commonly) fried in ordinary batter, instead of bread-crumbs. “There is no end to what may be done with these receipts.” “They can be ornamented and made worthy the table of the greatest epicure if the bread be soaked in cream, and spirits or liquor introduced into them.” (Soyer.)

2. Mrs Rundell:——a. (APPLE FRITTERS.) See FRUIT FRITTERS.

b. (BUCKWHEAT FRITTERS, B. CAKES, BOCKINGS.) Made by beating up buckwheat flour to a batter with some warm milk, adding a little yeast, letting it rise before the fire for 30 or 40 minutes, then beating in some eggs and milk or warm water, as required, and frying them like pancakes. Buckwheat fritters, when well prepared, are excellent. Made without eggs and served up with molasses, they form a common dish in almost every breakfast in North America.

c. (CURD FRITTERS.) From dried curd, beaten with yolk of egg and a little flour, and flavoured with nutmeg.

d. (FRENCH FRITTERS.) Common pancakes, beaten up with eggs, almonds, and flavouring sugar, orange-flower water, and nutmeg, and the paste dropped into a stew- or frying-pan half full of boiling lard, so as to form cakes the size of large nuts, which are cooked till brown.

e. (FRUIT FRITTERS.) From the sliced fruits, with rich batter.

f. (SOUFFLÉ FRITTERS.) Rich pancakes, flavoured with lemon.

g. (SPANISH FRITTERS.) From slices of French rolls soaked in a mixture of cream, eggs, sugar, and spices, and fried brown.

=FROG.= The esculent variety, in Europe, is the common green or gibbous frog, the Rana esculenta of Linnæus. As an aliment, it is much esteemed on the Continent, the hind legs only being eaten. Its liver is among the simples of the Ph. L. 1618, and was once considered a useful remedy in certain forms of ague.

The Americans eat the bull-frog (the Rana taurina). This variety of the edible frog, which is a native of the Northern States and is much prized as a table delicacy, has been lately introduced into France by the Société d’Acclimatisation. Its flesh, when cooked, is said to have a taste very like that of turtle. In South Africa, a large frog called Matlamétlo is eaten. Frogs are also favourite food with the natives of China and Australia.

=FROG OINTMENT or Thrush Mixture.= Brown syrup, 90 grammes; verdigris, 6 grammes; strong acetic acid, 10 grammes; solution of perchloride of iron, 2 grammes. (Hager.)

=FROST-BITES.= When those parts of the body in which the circulation of the blood is most languid are exposed to extreme cold, they quickly become frozen, or, as it is called, ‘frost bitten.’ The fingers, toes, ears, nose, and chin are most liable to this attack. The remedy is long-continued friction with the hands or cold flannel, avoiding the fire, or even a heated apartment.

=FROSTBEULENTINCTUR, FROSTBEULENWASSER——Chilblain Tincture, Chilblain Water.= Manufactured by a chiropodist of Munich. It is a solution of 2 grammes zinc sulphate in 60 grammes water. (Wittstein.)

=FROSTSALBE——Frost Ointment= (Wahler, Kupferzell). Mutton tallow, 24; hog’s lard, 24; iron oxide, 4; heat it in an iron vessel, stirring continually with an iron rod until the whole has become black; then add 4 parts Venice turpentine, 2 parts bergamot oil, and 2 parts Armenian bole rubbed smooth with olive oil.

=FRUIT.= Syn. FRUCTUS, L. Among botanists this is the mature ovary or pistil, containing the ripened ovules or seeds. In familiar language, the term is applied to any product of a plant containing the seed, more especially those that are eatable.

Fruits are extensively employed as articles of diet by man, both as luxuries and nutriment. The fruit of the cereals furnishes our daily bread; that of the vine gives us the well-known beverage, wine, whilst other varieties enrich our desserts, and provide us with some of our most valuable condiments and aromatics. The acidulous and subacid fruits are antiseptic, aperient, attenuant, diuretic, and refrigerant. They afford little nourishment, and are apt to promote diarrhœa and flatulency. They are, however, occasionally exhibited medicinally, in putrid affections, and are often useful in bilious and dyspeptic complaints. The farinaceous fruits (grain), as already stated, furnish the principal and most useful portion of the food of man. The oleo-farinaceous (nuts, &c.) are less wholesome and less easy of digestion than those purely farinaceous. The saccharine fruits, or those abounding in sugar, are nutritious and laxative, but are apt to ferment and disagree with delicate stomachs when eaten in excess. Stone fruits are more difficult of digestion than the other varieties, and are very apt to disorder the stomach and bowels.

As a rule, fruit should never be eaten in large quantities at a time, and only when quite ripe. It then appears to be exceedingly wholesome, and to be a suitable corrective to the grossness of animal food. It also exercises a powerful action on the skin, and is a specific for scurvy in its early stages. Many cutaneous diseases may likewise be removed by the daily use of a moderate quantity of fruit, or other fresh vegetable food. Cases are not uncommon which, after resisting every variety of ordinary medical treatment, yield to a mixed fruit or vegetable diet.

Fruits should be gathered in dry weather, and preferably about noon, because the dew and moisture deposited on them during the night and earlier part of the morning has then evaporated. They should be quite ripe when gathered, but the sooner they are removed from the tree after this point is arrived at, the better. Immature fruit never keeps so well as that which has ripened on the tree; and overripe fruit is liable to be bruised and to lose flavour. The less fruit is handled in gathering the better. Some of them, as PEACHES, NECTARINES, GRAPES, PLUMS, &c., require to be treated with great delicacy, to avoid bruising them or rubbing off the bloom. Some fruit, as a few varieties of APPLES, PEARS, and ORANGES, &c., are gathered before they are fully ripe, in order that they may the better undergo the perils of transit and storage.

Pres. Ripe fruits are commonly preserved in the fresh state by placing them in a cool dry situation, on shelves, so that they do not touch each other; or by packing them in clean, dry sand, sawdust, straw, bran, or any similar substance, with like care, to preserve them from the action of air and moisture. An excellent plan, commonly adopted for dessert fruit in this country, is to wrap each separately in a piece of clean, dry paper, and to fill small, wide-mouthed jars or honey-pots with them. The filled pots are then packed one upon another (see engr.) in a dry and cold place (as a cellar), where the frost cannot reach them. The space (a) between the two pots may be advantageously filled up with plaster of Paris made into a paste with water. The joint is thus rendered air-tight, and the fruit will keep good for a long time. The mouth of the top jar is covered with a slate. For use, the jars should be taken one at a time from the store-room as wanted, and the fruit exposed for a week or ten days in a warm dry room before being eaten, by which the flavour is much improved.

Fruit is preserved on the large scale for the London market by placing in a cool situation first a layer of straw or paper, and so on alternately, to the height of 20 or 25 inches, which cannot be well exceeded, as the weight of the superincumbent fruit is apt to crush or injure the lower layers. Sometimes alternate layers of fruit and paper are arranged in baskets or hampers, which are then placed in the cellar or fruit-room. The baskets admit of being piled one over the other without injury to the fruit. The use of brown paper is inadmissible for the above purposes, as it conveys its peculiar flavour to the fruit. Thick white-brown paper is the cheapest and the best.

=Fruit Essences (Artificial).= These remarkable products first attracted attention at the Exhibition of 1851. To speak somewhat generally, they are mixtures of amylic, butyric, pelargonic, valerianic, and other ethers, in alcohol. By judicious mixture, the flavour of almost any fruit can be more or less perfectly imitated. The artificial essences are generally coloured to represent the juice of the fruit from which they are supposed to be derived. The ESSENCE OF JARGONELLE PEAR and the ESSENCE OF APPLE, which are, perhaps, the best of all the artificial essences, are respectively formed from the ACETATE and VALERIANATE OF AMYLE. See AMYLE, ESSENCE, &c.

=FRU′MENTY.= Wheat boiled in water until quite soft, then taken out, drained, thinned with milk, sweetened with sugar, and flavoured with nutmeg. When currants and eggs are added, it forms ‘SOMERSETSHIRE FRUMENTY,’ Some persons boil the wheat like rice. “Eaten with milk, in the evening, for some time, it will often relieve costiveness.” (Griffith.)

=FRY′ING.= “The frying-pan is, without doubt, the most useful of all kitchen implements, and, like a good-natured servant, is often imposed upon and obliged to do all the work, while its companion, the gridiron, is quietly reposing in the chimney corner.” “The usual complaint of food being rendered greasy by frying is totally remedied by sautéing the meat in a small quantity of fat, butter, or oil, which has attained a proper degree of heat, instead of placing it in cold fat, and letting it soak while melting.” “According to the (common) mode in which all objects are cooked which are called fried, it would answer to the French word ‘sauté,’ or the old English term ‘frizzle,’ but to fry any object, it should be immersed in very hot fat, oil, or butter.” “To frizzle, sauté, or, as I will now designate it, semi-fry, is to place in the pan any oleaginous substance, so that, when melted, it shall cover the bottom of the pan by about two lines; and when hot, the article to be cooked is to be placed therein. To do it to perfection requires a little attention, so that the pan shall never get too hot. It should also be perfectly clean——a great deal depends on this.” (Soyer.)

According to the writer quoted above, a chop or steak, for frying, should be chosen 3/4 of an inch thick, and should “never exceed one inch, nor be less than half an inch, and to be as near as possible of the same thickness all over.” “An ill-cut chop (or steak) never can be but ill-cooked; you can always equalise them (when badly cut) by beating them out with a chopper.”

“The motive of semi-frying food is to have it done quickly; therefore, to fry a whole fowl, or even half (for example), is useless, as it could be cooked in a different way in the same time; but to semi-fry a fowl (in joints or pieces), with the object of having it quickly placed on the table, in order to satisfy a good, and perhaps fastidious appetite, it should be done in a similar way to that practised in Egypt some 3000 years since, and of late years for the great Napoleon——that is, cooked in oil. In France this dish is called ‘Poulet à la Marengo,’ It is related that the great conqueror, after having gained that celebrated victory, ate three small chickens at one meal done in this way, and his appetite and taste were so good, and he approved of them so highly, that he desired that they may always be served in the same way during the campaign.”

“For many objects I prefer the frying-pan to the gridiron; that is, if the pan is properly used. As regards economy, it is preferable, securing all the fat and gravy, which is often lost when the gridiron is used.” “This simple batterie de cuisine” may be employed “equally as well in the cottage as in the palace, or in the bachelor’s chamber as in the rooms of the poor.” (Soyer.)

=FUCH′SIN.= See TAR COLOURS.

=FUCUS′AMID, FU′CUSINE, and FU′CUSOL.= Compounds obtained by Dr Stenhouse from several varieties of FUCUS by treatment with sulphuric acid, as in the preparation of FURFURINE (which see).

=FU′EL.= Matter used for the production of heat by burning. The principal substances employed as fuel are——ANTHRACITE, CHARCOAL, COAL GAS, COKE, OIL, SPIRIT, PITCOAL, TURF, and WOOD.

The heating power of almost every description of fuel has been determined by the direct experiments of Lavoisier, Regnault, Andrews, and others; the general principle of their methods consisting in the use of an apparatus wherein the entire heat of combustion was absorbed by a known weight of water, the whole arrangement being protected from the influence of external changes of temperature, and the increase of the temperature of the water being known by the simultaneous indication of several delicate thermometers suspended in it. The real value of such determinations is simply relative. The imperfect character of most boiler and furnace arrangements, and the large quantity of fuel which passes into the ‘ash-pit’ unconsumed, together with the irregular ‘draught,’ and the amount of heat absorbed by excess of cold air, result practically in an enormous loss of heating power, even under the most careful management. The mechanical condition of a fuel must be considered in estimating its value. In a series of trials instituted by the Government it was a sine quâ non that the toughness of each kind of coal must be such, for naval use, as to resist, without crumbling, the constant friction in the ship’s hold, at the same time that its ‘fracture’ must be such that it packs into the smallest possible space.[319]

[Footnote 319: For full information on coal and other fuels, refer to Ure’s ‘Dict. of Arts, Manufactures, &c.,’ Percy’s ‘Metallurgy,’ and Watt’s ‘Dict. of Chemistry.’]

In the chemical laboratory COAL GAS is now generally employed as fuel. It is cheap and manageable, and, with proper apparatus, may be made to supply almost any amount of heat. Where gas cannot be conveniently procured, OIL and SPIRIT are used as fuel for lamps. See ANTHRACITE, CHARCOAL, COKE, FURNACE, PITCOAL, &c., also below.

=Fuel, Econom′ical.= Various mixtures have been recommended under this name. The following is one of the best:——

Prep. Small coal, charcoal, or sawdust, 1 part; clay, loam, or marl, 1 part; sand, or ashes, 2 parts; water, q. s.; make the mass up wet into balls. For use, these balls are piled on an ordinary fire to a little above the top bar. They are said to produce a heat considerably more intense than that of common fuel, and ensure a saving of one half the quantity of coals, whilst a fire thus made up will require no stirring, nor fresh fuel for ten hours. The quantity of the combustible ingredient in them should be doubled, when they are intended to be used with a very little foundation of coal.

Obs. Of late years simple FIRE-CLAY BALLS have been much used for radiating heat from parlour-grates, and so effecting saving in the consumption of fuel. They are very useful for partially filling up those roomy, old-fashioned, badly-constructed grates, which are still to be found in many private houses.

PEAT and TURF, both recent and charred, are commonly used as fuel by the lower classes, in neighbourhoods where they are plentiful. FIR CONES or TOPS contain a great quantity of solid woody in addition to the resinous matter, and are well adapted for domestic fires.

=Fuel, Prepared.= Syn. COMPRESSED FUEL, PATENT F., STEAM F. Many artificial fuels are now in use. The greater number have one character in common——they are composed of small coal cemented by some bituminous matter. The following are the principal kinds:——

FUEL, ABERDARE PATENT STEAM. From the ‘small’ of the South Wales Steam Coal mixed with coal, pitch, and compressed by hydraulic machinery. The pitch is broken up, and thoroughly mixed with the small coal over a furnace, in iron pans, in which shafts with obliquely attached blades are continually revolving. The mixture is afterwards pressed into iron moulds by a force equal to about 2-1/2 tons per inch. The weight of a cubic foot of this excellent fuel is 80 lbs.; the space occupied by 1 ton, 28 cubic feet.

FUEL, CASE AND MORRIS’S PATENT. From the ‘small’ of the ‘best steam coal,’ ground moderately fine, treated so as to absorb a certain portion of liquid coal tar, and then pressed by machinery into blocks. It is said to occupy less space by about 10% than ordinary coal.

FUEL, GRANT’S PATENT. This is formed of coal dust, 1 cwt., and coal-tar pitch, 20 lbs., melted together by a heat of 220° Fahr., and moulded into blocks the size of common bricks, under a pressure of 5 or 6 tons. These are, lastly, whitewashed. It is heavier than common steam coal, and is said to go fully one third further, by which facility of transport and economy is combined.

FUEL, PURIFIED BLOCK. This is prepared by the torrefaction of washed coal dust, and is said to possess in a remarkable degree the advantages of both coke and steam coal.

=FU′LIGOKA′LI.= Prep. (Dr Polya.) Caustic potassa, 1 part; water, q. s.; dissolve; add of wood soot, 5 parts; boil 1 hour, dilute with water, filter, evaporate the filtrate to dryness, and put the product at once into warm, dry bottles.——Dose, 2 to 3 gr., thrice a day, made into pills, which must be coated with gum and kept from the air. (See below.)

=Fuligokali, Sulphuretted.= Syn. FULIGOKALI SULPHURETUM, L. Prep. (Dr Polya.) Caustic potassa, 7 parts; sulphur, 2 parts; water, q. s.; dissolve with heat, add of fuligokali, 30 parts, evaporate to dryness, and preserve it in well-corked dry bottles.——Dose, &c. As the last.

Obs. M. Gibert states that he has tried both fuligokali and sulphuretted fuligokali on his patients at the Hospital Saint-Louis, both internally and externally, with manifest advantage in various obstinate chronic skin diseases. He made a pomade of 30 grammes (say 1 oz.) of lead ointment, and 1 or 2 grammes (say 20 to 25 gr.) of fuligokali, in which he recognised positive resolvent, detersive, and stimulant properties. See ANTHRACOKALI.

=FULLER’S EARTH.= Syn. CIMOLIA, C. TERRA, L. A soft, unctious, friable, greenish or yellowish-grey species of clay, containing 53% of silica, 10% of alumina, and about 9% of oxide of iron. After being dug out of the earth it is thoroughly dried in ovens, and then thrown into cold water, where it soon falls to powder, and is purified by the common process of edulcoration or washing-over. It is extensively used to extract oil and grease from cloth in the process of ‘fulling,’ it forms an excellent filtering powder for oils, and is applied as a cooling and healing dressing by the poor to inflamed breasts, excoriations, &c.

=FUL′MINATING COMPOUNDS.= These are numerous, and are scattered through several distinct classes of bodies. Among the most powerful and dangerous are the chloride and iodide of nitrogen and the fulminates of silver and mercury.

=Fulminating An′timony.= Syn. PYROPHORUS OF ANTIMONY, L. Prep. Tartar emetic (dried), 100 parts; lampblack or charcoal powder, 3 parts; triturate together, put it into a crucible that it will three fourths fill (previously rubbed inside with charcoal powder), cover it with a layer of dry charcoal powder, and lute on the cover; after 3 hours’ exposure to a strong heat in a ‘reverberatory furnace,’ and 6 or 7 hours’ repose to allow it to cool, &c., cautiously transfer the solid contents of the crucible, as quickly as possible, without breaking it, to a wide-mouthed stoppered phial, where, after some time, it will spontaneously crumble down into a powder.

Obs. When the above process is properly conducted, the resulting powder contains potassium, and fulminates violently on contact with water. A piece the size of a pea introduced into a mass of gunpowder explodes it on being thrown into water, or on its being moistened in any other manner.

=Fulminating Bis′muth.= Prep. From bismuth, 120 parts; carburetted cream of tartar, 60 parts; nitre, 1 part. Very rich in potassium.——Prop., &c., resemble those of the last. We have been assured that this is the compound used by the late Capt. Warner for some of his secret fusees.

=Fulminating Cop′per.= Syn. FULMINATE OF COPPER. Prep. Digest copper (in powder or filings) with fulminate of mercury or of silver, and a little water. It forms soluble green crystals that explode with a green flame.

=Fulminating Gold.= Prep. Recently precipitated peroxide of gold is digested in strong liquor of ammonia for 24 hours, and the resulting product is dried in the open air or at a temperature below 180° Fahr., care being taken to avoid the slightest friction, lest it should explode. A deep olive-coloured powder.

Obs. This compound can only be safely made in very small quantities at a time, as without great care it explodes with extreme violence. This is caused by the slightest friction or sudden increase of heat. Its fulminating property may be destroyed by boiling it in pearlash lye, or weak oil of vitriol; and by heating the residuum after washing it in water, pure gold will be obtained.

=Fulminating Mer′cury.= Syn. FULMINATE, FULMINATE OF MERCURY. Prep. 1. Mercury, 1 part; nitric acid (sp. gr. 1·375), 12 parts; dissolve, add at intervals, to this solution, alcohol (sp. gr. ·850), 16·3 parts; apply heat till the effervescence and cloud of gas disappears, adding, gradually, on the action becoming violent, 16·3 parts more of alcohol.——Product. 112% of the mercury employed.

2. Mercury, 100 parts; nitric acid (sp. gr. 1·4), 1000 parts (or 740 parts by measure); dissolve by a gentle heat, and when the solution has acquired the temperature of 130° Fahr., slowly pour it through a glass funnel tube into alcohol (sp. gr. ·830), 830 parts (or 1000 parts by measure); as soon as the effervescence is over, and white fumes cease to be evolved, filter through double paper, wash with cold water, and dry by steam (not hotter than 212°) or hot water. The fulminate is then to be packed in 100 gr. paper parcels, and these stored in a tight box or corked bottle.——Product, 130% of the weight of mercury employed.

Prop., &c. Small brownish-grey crystals, which sparkle in the sun; entirely soluble in 130 parts of boiling water, and deposited as the solution cools under the form of beautiful pearly spangles. It greatly resembles fulminate of silver in its appearance and general properties. It explodes violently by both friction and percussion, but unlike the silver-salt, merely burns with a sudden and almost noiseless flash when kindled in the open air.

Obs. The second formula is not only the cheapest, but the best and safest. The first is more expensive and dangerous. There is no little hazard in pouring the alcohol into the nitric solution; for at each effusion an explosive blast takes place; whereas, by pouring the solution into the alcohol, no danger whatever is incurred. This preparation is used for priming the copper percussion caps for fowling-pieces, muskets, &c. Dr Ure, in his first report to the Board of Ordnance, recommended the use of a spirituous solution of gum sandarac, as the best substance for diluting the fulminate, and fixing it in the caps; but in a subsequent report to the same Board, he stated that a solution of mastic in spirit was to be preferred. At the present time the following composition is applied to the interior of percussion caps in quantities varying from ·2 to ·3 of a grain:——Chlorate of potassium, 26 parts; nitre, 30; fulminate of mercury, 12; sulphur, 17; ground glass, 14; gum, 1, making altogether 100 parts. (Watts.)

Caution. Fulminate of mercury should only be dried in small parcels at a time, and these should be placed at a distance from each other. The dreadful explosion which occurred some years ago at Apothecaries’ Hall, and by which Mr Hennel, the talented chemist of the Apothecaries’ Company, lost his life, was occasioned by the spontaneous detonation of this substance.

=Fulminating Plat′inum.= Syn. PLATINUM FULMINANS, L. Prep. By acting on binoxide of platinum with pure ammonia. It is analogous to the gold and silver ammonio-compound.

=Fulminating Powder.= Syn. DETONATING POWDER; PULVIS FULMINANS, L. Prep. 1. Nitre, 3 parts; carbonate of potash (dry), 2 parts; flowers of sulphur, 1 part; reduce them separately to fine powder, before mixing them. A little of this compound (20 to 30 gr.), slowly heated on a shovel over the fire, first fuses and becomes brown, and then explodes with a deafening report.

2. Sulphur, 1 part; chlorate of potassa, 3 parts. When triturated, with strong pressure, in a marble or wedgwood-ware mortar, it produces a series of loud reports. It also fulminates by percussion.

3. Chlorate of potassa, 6 parts; pure lampblack, 4 parts; sulphur, 1 part. A little placed on an anvil detonates with a loud report, when struck with a hammer. No. 1 is the substance commonly known as ‘FULMINATING POWDER,’ See BLASTING POWDER.

=Fulminating Sil′ver.= Syn. ARGENTUM FULMINANS, L. Two very distinct compounds are known by this name, the one containing oxide of silver and ammonia, and the other being a true fulminate of silver.

Prep. 1. (AMMONIA-COMPOUND OF SILVER, BERTHOLLET’S FULMINATING SILVER.)——a. Digest oxide of silver (recently precipitated and dried by pressure between bibulous paper) in concentrated liquor of ammonia, for 12 or 15 hours, pour off the liquid, and cautiously dry the black powder in the air, in divided portions. The decanted ammoniacal liquor, when gently heated, yields, on cooling, small crystals, which possess a still more formidable power of detonation than the black powder, and will scarcely bear touching, even whilst under the liquid.

b. Dissolve chloride of silver in strong liquor of ammonia, cautiously add pure potassa (in fragments), and when effervescence ceases, decant the fluid portion, and wash and dry the powder, as before.

2. (FULMINATE OF SILVER, BRUGNATELLI’S FULMINATING SILVER; ARGENTI FULMINAS, L.)——a. Pour alcohol, 1 oz., on nitrate of silver (in fine powder), 100 gr., previously placed in a capacious flask or beaker glass, and shortly afterwards add strong nitric acid, 1 oz.; as soon as all the powdered nitrate assumes the form of white clouds, add cold distilled water, q. s. to suspend the ebullition, and next collect the powder on a filter, and otherwise proceed as with the ammonia-compound (above).

b. (Fownes.) Metallic silver, 40 to 50 gr.; nitric acid (sp. gr. 1·37), 3/4 fl. oz.; dissolve by the aid of a gentle heat, add, whilst the solution is still hot, alcohol, 2 fl. oz., and again apply heat until reaction commences; the fulminate slowly separates from the hot liquid under the form of small, brilliant, white, crystalline plates, which, after being slightly washed with a little cold distilled water, are to be distributed upon separate pieces of filtering paper, in portions not exceeding 1 or 2 gr. each, and left to dry in the air. When dry, the papers are to be folded up, and carefully preserved in a box or bottle. A sixpence and the strongest commercial nitric acid and rectified spirit answer for the above purpose.

c. (Liebig.) Grain silver, 1 part; nitric acid (sp. gr. 1·36 to 1·38), 10 parts; dissolve at a gentle heat, and add the solution to alcohol of 85%, 23 parts; apply a gentle heat till the liquid begins to boil, then remove it from the fire and set it aside to cool; the fulminate of silver is deposited in lustrous, snow-white, acicular crystals, and when washed and dried, equals in weight that of the silver employed.

Prop., &c. The properties of both compounds are very similar. Those of the true FULMINATE OF SILVER (No. 2) need only be considered here. This dissolves in 36 parts of boiling water, but the solution deposits the greater portion of the fulminate as it cools. It is one of the most dangerous substances for which we are indebted to modern chemistry. It explodes with unparalleled violence by friction or percussion, or when strongly heated, or when touched with strong sulphuric acid; the metal is reduced, and a large volume of gaseous matter suddenly liberated. Strange to say, though its explosive tendency is so great that it can be hardly made, handled or kept, with safety, it may, when very cautiously mixed with oxide of copper, be burned in a tube to determine its composition, in a similar manner to that employed in the analysis of other organic substances. Many frightful accidents have happened from the spontaneous explosion of this substance. 1 or 2 gr. are the most that can be exploded with safety in a building or confined space.

=Fulminating Zinc.= Syn. FULMINATE OF ZINC; ZINCUM FULMINANS, ZINCI FULMINAS, L. Prep. From fulminate of silver, zinc filings, and a little water, digested together, as FULMINATING COPPER.

=FULMINA′TION.= Syn. FULMINATIO, L. Detonation. A sudden explosion, accompanied with a loud report and extreme violence. Some chemists, without sufficient reason, have endeavoured to confine the application of the term to the explosion of a fulminate.

=FUMIGA′TION.= Syn. FUMIGATIO, SUFFUMIGATIO, L. Fumigations (FUMIGATIONES) are vapours of gases extemporaneously extricated for the purpose of destroying contagious or noxious miasmata or effluvia, or to mask unpleasant odours, or to produce a medicinal action on those parts of the body with which they are brought in contact.

Fumigations, for the purpose of obviating or masking unpleasant odours in the sick chamber, must never be employed to the neglect of cleanliness and ventilation; for most of them, instead of purifying the air, actually render it less fit for respiration. The common practice of burning scented paper, pastilles, sugar, juniper berries, benzoin, cascarilla, &c., so as to create an odoriferous smoke, is of this character. As disinfecting agents, they are probably useless, and are relics of an ancient custom of burning frankincense and other odorous substances in vitiated air, to overcome the fetor which is more or less present. The fumes thus diffused through the atmosphere “disguise unpleasant odours; but they accomplish nothing more. The infection remains not only unaltered by the diffusion of the most powerful aromatic vapours, but its deleterious properties are sometimes augmented by them.”[320]

[Footnote 320: We deem it right to remark that a different opinion respecting the disinfecting power of odoriferous smoke is now held by many scientific men. According to this opinion, the minute particles of aromatic substances do really destroy or render inert the noxious miasmata.]

Among the various substances used as DISINFECTING FUMIGATIONS, chlorine, by almost general consent, holds the first place. Dr Carmichael Smyth recommended nitrous acid, which is even now preferred by Dr Christison to chlorine; whilst Prof. Graham regarded the fumes of burning sulphur as more efficacious than either of these substances. The vapours of hydrochloric acid and of vinegar, and the smoke of gunpowder, which once had their advocates, have now justly sunk into disfavour.

No apartment should be submitted to fumigation until it is vacated; as until then its thorough disinfection is impossible, and but little benefit or immunity from contagion is conferred by any aërial disinfecting agent, the presence of which fails to cause discomfort to the patient.

Of all common diseases, scarlet fever appears to be the one most requiring fumigation. For this purpose, chlorine gas or heat should be employed. The infectious matters of certain diseases, especially scarlet fever, are either dissipated or destroyed at a heat slightly above that of boiling water. (Dr Henry.) Contagious diseases are very commonly propagated in this metropolis by persons having their linen washed by laundresses who perform their operations in the same sinks of dirt and misery in which they live. See CIGARS (in pharmacy), DISINFECTANT, INHALATION, &c., and below.

=Fumigation, Ace′tic.= Syn. FUMIGATIO ACETICA, L. The fumes of strong vinegar or acetic acid, obtained by heating the liquid over a lamp, or by sprinkling it on a hot shovel. Aromatic vinegar in this way yields very refreshing fumes, and was formerly thought more efficacious than simple acetic acid.

=Fumigation, An′odyne.= Syn. FUMIGATIO ANODYNA, L. Prep. (Trousseau & Reveil.) Stramonium and sage, equal parts, sufficient to fill a small pipe. Smoked in spasmodic asthma, irritating coughs, &c.

=Fumigation, Aromat′ic.= See BALSAMIC FUMIGATION.

=Fumigation, Balsam′ic.= Syn. AROMATIC FUMIGATION; FUMIGATIO AROMATICA, F. BALSAMICA, L. Prep. 1. From gum benzoin, either alone or mixed with olibanum or styrax, thrown on hot cinders or a heated shovel.

2. (Dr Dohrn.) Gum olibanum, 4 parts; gum benzoin, styrax, and flowers of roses and lavender, of each 1 part; to be reduced to powder, and used as before.

3. Amber, mastic, and olibanum, of each 3 oz.; benzoin and styrax, of each 1 oz.; camphor, 1 dr. As last. The above are used in hooping-cough, asthma, &c.; a small quantity only being employed at a time.

=Fumigation, Belladon′na.= Syn. FUMIGATIO BELLADONNÆ, L. Prep. (M. Schroeder.) From dried belladonna leaves, 1 to 2 dr.; as before. In spitting of blood, asthma, tickling cough, &c.

=Fumigation, Chlorine.= Syn. DISINFECTING FUMIGATION, GUYTON-MORVEAU’S F.; FUMIGATIO CHLORINII, L. Prep. 1. (P. Cod.) Common salt, 3 parts; water and sulphuric acid, of each 2 parts; black oxide of manganese 1 part; mix in a shallow vessel, placed in the centre of the apartment. This is used to disinfect unoccupied rooms.

2. Hydrochloric acid and powdered black oxide of manganese mixed in proportions so as to make a thin paste. Used as directed under 1.

3. Chloride of lime, either sprinkled on the floor (if uncarpeted) or (if carpeted) placed about the room in shallow dishes. Used for inhabited rooms, and on shipboard, &c.

4. A solution of chloride of lime (1 oz. of the chloride to each quart of water). Used as the last but more freely.

Obs. Chlorine fumigations, although so popular, and so much relied on by many medical practitioners, are apparently useless in preventing the progress of certain contagious diseases. “In Moscow, chlorine was extensively tried and found unavailing, nay, even injurious, in cholera.” (Dr Pereira.) “At the time that the cholera hospital was filled with clouds of chlorine, then it was that the greatest number of the attendants were attacked.” (Dr Albers.) At the Smallpox Hospital, where chlorine was tried, with the view of arresting the progress of erysipelas, “all offensive smell was removed, but the power of communicating the disease remained behind.” (‘Lond. Med. Gaz.’) Notwithstanding these marked failures, the confidence of many eminent members of the profession continues unabated. “As a fumigating agent, disinfectant and antiseptic, chlorine, I believe, stands unrivalled.” “For destroying miasmata, noxious effluvia, and putrid odours, it is the most powerful agent known.” (Dr Pereira.) Our own experience leads us to the conclusion that chlorine is more useful in neutralising the contagious or morbific matter of fevers (especially of scarlet fevers) and putrid diseases generally, than of the other diseases in which it has been employed.

=Fumigation, Hydrochlo′′ric.= Syn. MURIATIC FUMIGATION; FUMIGATIO MURIATICA, F. ACIDI HYDROCHLORICI, L. Prep. From common salt placed in a cup or saucer, and an equal weight of sulphuric acid poured over it. Now seldom used. It rapidly neutralises ammoniacal fumes.

=Fumigation, I′odine.= Syn. FUMIGATIO IODINII, L. Prep. 1. From iodine, 5 to 25 gr., or more, according to extent of surface, placed on a heated iron contained in a box or case in which the limb is enclosed. In the usual skin diseases in which the use of iodine is indicated. Iodine may be readily diffused through the atmosphere by placing a small quantity on a hot plate. Duroy says iodine powerfully arrests putrefaction.

2. (Compound; FUMIGATIO IODINII COMPOSITA——Sellers.) Iodine, 20 gr.; red sulphide of mercury, 40 gr.; sulphur, 6 dr.; mix, and divide into 12 powders. One to be used, as the last, 3 times daily; in lepra, psoriasis, &c.

=Fumigation, Mercu′′rial.= Syn. FUMIGATIO MERCURIALIS, L. Prep. (Bouchardat.) Olibanum (in powder), 2 parts; red sulphide of mercury, 3 parts. A little is sprinkled on red-hot coals or a heated shovel held beneath the part; or the fumes are inhaled. Obs. Abernethy used the black oxide of mercury (1-1/2 to 2 dr.), and applied it to the whole body, excepting the head, in a similar way to the sulphur bath, and continued the application for about a quarter of an hour. See CANDLES, (Mercurial), and No. 2 (above).

=Fumigation, Mu′riatic.= See HYDROCHLORIC F. (above).

=Fumigation, Ni′trous.= Syn. FUMIGATIO NITROSA. Prep. (P. Cod.) Sulphuric acid, diluted with half its weight of water, is placed in a porcelain cup (any shallow vessel of glass or earthenware will do), placed over heated cinders, and small quantities of powdered nitre added to it from time to time.

Obs. Heat causes the gas to be evolved more rapidly, and thus renders the fumes more offensive, without increasing their efficacy. Equal weights of oil of vitriol and water are the proportions usually employed, 1/4 oz. of nitre is said to be sufficient for a small room. (Dr Bateman.) The vessel containing the ingredients should be placed in an elevated position in the centre of the apartment.

Dr Carmichael Smith, who introduced nitrous acid gas as a fumigation (1799), received a reward of £5000 from Parliament for publishing his formula.

=Fumigation, Sulphu′rous.= Syn. FUMIGATIO SULPHUROSA, F. SULPHURIS, L. Prep. 1. The gas produced by burning sulphur, sulphurous anhydride, or, as Mr Keates has suggested, by burning bisulphide of carbon.

To guard against the danger arising from fire, when sulphur is burnt for the purposes of fumigation, the operator is advised to proceed as follows:——Having closed the fireplace, windows, &c., of the apartment to be disinfected, procure a common pail or a large earthenware pan, and place it in the centre of the room; then into the middle of the pail or pan put upside down an ordinary flower-pot. Then pour water into the pail or pan (as the case may be) until it nearly reaches to the top of the inverted flower-pot. Now stand on the flower-pot a plate or saucer of earthenware or common crockery, sufficiently large to hold the quantity of sulphur required; place this quantity of sulphur in the plate or saucer, and put on it a few live coals; then close the door of the apartment, and leave it undisturbed for six or eight hours. At the expiration of this time the door may be opened, as well as the windows, the barricade being at the same time removed from the fireplace; a thorough draught of air being thus established, the sulphurous smell will soon disappear. During the fumigation all articles within the room should be spread out so as to expose as great a surface as possible. “The cubic space to be thus disinfected should be calculated by multiplying the length, height, and breadth together, and taking an ounce and a half of sulphur for every 100 cubic feet. For a small bedroom one pound of sulphur would be sufficient. Indeed, eighteen ounces would suffice for a room measuring 12 ft. × 10 ft. × 10 ft.”[321]

[Footnote 321: ‘Water, Air, and Disinfectants,’ by Noel Hartley.]

2. Flowers of sulphur, 7 parts; nitre, 4 parts; benzoin and olibanum, of each 2 parts; camphor, 1 part; pressed into the bowls of tobacco-pipes, and lighted with a quick-match. See BATH and DISINFECTANT.

=Fumigation, Tar.= Syn. FUMIGATIO PICEA, SUFFUMIGATIO PICIS LIQUIDÆ, L. Prep. 1. Vegetable tar, 1 part; water, 7 or 8 parts; mix, and let it simmer in an open vessel set over a spirit lamp placed near the centre of the apartment.

2. (Sir A. Crichton.) Norway tar, 1 lb.; powdered carbonate of potash, 1/2 oz. or 1 oz.; mix, and heat it as last. The potash is added to neutralise any volatile acid. Formerly highly thought of in bronchitis and pulmonary consumption.

=Fumigation, Tooth′ache.= Syn. FUMIGATIO ODONTALGICA, F. ANTI-NEURALGICA, L. Prep. 1. From henbane seeds, powdered and thrown into a basin of boiling water, and the affected part held in the steam. Sometimes a little of the seed is placed on a heated iron spoon, and the part exposed to the fumes.

2. (Beasley.) A popular remedy is to throw henbane seed on hot cinders, inverting a cup over them to receive the smoke and empyreumatic oil produced. The cup is then filled with hot water, and the steam conveyed to the affected side of the mouth.

=FU′′MING LIQUORS.= See AMMONIUM SULPHYDRATE, ARSENIC TRICHLORIDE, TIN BICHLORIDE, &c.

=FUNG′I.= In botany, a natural order of cellular plants, producing their fructification in the air; growing in or upon decaying or living organic substances, and nourished through their vegetative structure called the spawn or mycelium. Fungi have very variable properties. Some are medical, others edible, others are deadly poisons. The various diseases of plants known as blight, mildew, rust, smut, vine-mildew, potato-disease, ergot, &c., are either caused by or accelerated by the agency of fungi. See AGARIC, MUSHROOM, &c.

=FUR′NACE.= An enclosed fireplace for obtaining a high degree of heat. Furnaces vary much in construction and size, according to the particular manufacture in which they are employed. They may be broadly divided into two classes——WIND-FURNACES and BLAST FURNACES. In the former a high temperature is produced without the aid of bellows by means of a powerful draught. In the latter heated air is blown in through a pipe or pipes at the bottom. For many metallurgic and large chemical operations REVERBERATORY FURNACES are employed. A furnace of this kind is usually long, with a low roof to keep down the flame and hot air upon the ‘hearth’ or space between the fireplace and the flue.[322] For the smaller operations in chemistry, a variety of furnaces have been invented, and the introduction of coal-gas as a fuel by Develle, Griffin, Gore, Fletcher, and others, has wrought a complete change in the arrangements of the laboratory. The GAS-FURNACES of Mr J. J. Griffin are adapted for almost every operation performed by the aid of heat. Those more recently introduced by Mr W. Gore are very compact and portable, and will rapidly produce a ‘white heat,’ without the help of bellows or high chimney, by means of ordinary coal-gas and atmospheric air. The first and smallest size consumes 33 cubic feet of gas (value seven farthings) per hour, and is suitable for assayers, jewellers, analytical chemists, experimentalists, dentists, and others. It is capable of fusing eight ounces of copper or six ounces of cast iron, copper begins to melt in it in about twelve minutes from the time of lighting. The second-sized one consumes about twice that quantity of gas, is suitable for manufacturing jewellers generally, and for a great variety of practical persons who require to melt small quantities of gold, silver, copper, german silver, brass, cast iron, glass, and other substances, or require a small crucible heated to high temperatures. It is capable of melting 45 ounces of copper, or 40 ounces of cast iron, and with its heat up it melts one pound of copper in eight minutes; copper begins to melt in about twenty minutes from the time of lighting.

[Footnote 322: For an illustration of this kind of furnace, see SODIUM, Carbonate of.]

Fletcher’s[323] UNIVERSAL FURNACES for high temperatures, which are said to require neither blast nor attention, are intended for laboratory purposes, enamel burning, heating soldering irons, and for jewellers’ and dentists’ work. These furnaces are made in two distinct types; one with a perforated cover to the crucibles and muffles to attain the maximum heat; the other with a slide chimney and a double lid over the crucible.

[Footnote 323: Manufactured by Thos. Fletcher, Museum Street, Warrington.]

The power and rapidity of working depend in each case on the length of the chimney used. A furnace with a four-feet chimney will melt a crucible of cast-iron in thirty-five minutes; a furnace with an eight-feet chimney will melt the same quantity of iron in about twenty minutes, starting with the furnace cold. The stove with the side chimney, although more convenient in use, is slower in working, taking about twice as long to obtain the same temperature.

The following are varieties of Fletcher’s UNIVERSAL FURNACE:——

1. SMALL LABORATORY FURNACE for crucibles, with nickel-plated burner tubes. This takes crucibles up to 2-1/2 by 2-1/4 inches outside, and with a three-feet chimney, as supplied with the furnace, will, it is stated, melt copper, gold, silver, &c., in about ten minutes, or cast-iron in thirty-five minutes from the time the gas is lighted. Small muffle fittings, with muffles 2-1/4 by 3 by 2-1/2 inches inside, can be supplied with this furnace.

2. SMALL CRUCIBLE FURNACE, with fixed chimney. This furnace is more especially designed for gold, silver, copper, &c., and, as sent out with a four-feet chimney and a single lid, is amply powerful, and practically of a very convenient form.

3. SMALL MUFFLE FURNACE, with three feet chimney. This requires about eighteen inches longer chimney than the small crucible furnace to obtain the same temperature in the same time, owing to a slight loss of heat by radiation from the stoppers.

4. a. LARGE MUFFLE FURNACE. This is identical in design and construction with the smaller one. The clear working space inside the muzzle is 3-7/8 by 5 inches, by about 3 inches deep. This is recommended as a useful furnace for watch dial enamellers, assayers, photo-enamel burning, and for all purposes where exact temperatures are required not exceeding the fusing point of cast iron.

The burner of this furnace is twice the size of the small laboratory furnace, and requires a gas supply from a pipe and tap of half-an-inch bore. The burner is the same shape as the muffle, and is unfit for crucible work.

b. EXTRA LARGE MUFFLE FURNACE 4-1/2 by 3-3/4 by 7 inches clear inside working space. This will take a No. 3 plumbago pot, and with half an inch gas pipe, giving a supply of about 35 feet per hour, will, it is affirmed, melt 3 or 4 lbs. of brass in about 25 minutes, and the same quantity of cast iron in 60 or 70 minutes from the time the gas is first lighted, without the slightest trouble or attention.

5. LADLE FURNACE. This takes ladles up to 6-1/2 inches diameter, and will melt 6 or 8 lbs. of zinc in about 15 minutes, or the same quantity of lead, tin, &c., in about half the time. It is said to be a convenient and powerful arrangement for dentists, heating soldering-irons, making granulated zinc, sand baths, &c.

6. SMALL LABORATORY FURNACE, complete for crucibles, muffles, ladles, and sand baths.

7. FLETCHER’S INJECTOR GAS FURNACE (with Blast). This furnace is intended for general purposes, and for the treatment of refractory substances at high temperatures. The patentee states “that it will burn perfectly in the same space any available gas supply from 10 to 50 feet per hour, or more, if required, giving temperatures in exact proportion; and any operation may be repeated at any time by taking a note of the position of the air slide which governs the combustion of the gas.”

Mr Fletcher gives the power of the small furnace as follows:——With an 1/2 inch gas supply-pipe, day pressure, starting with the furnace cold, it will melt silver in 3 minutes, cast iron in 8 minutes, cast steel in 25 minutes.

With a supply of 50 feet per hour, the same results are stated to be obtained in a little over half the time, and so on in proportion with a greater or less gas supply. It is also said to work satisfactorily for gold, &c., melting it with a supply of gas too small for any other furnace, and the maximum temperatures obtained are limited, only by the available gas supply and the fusibility of the casing. The highest temperature as obtained by measuring by Wedgwoods’ Pyrometer, is said to be 9000 Fahrenheit. This furnace is stated to be particularly suited for gold and silver melting, and refining, iron assays, and general crucible work, and safe in the hands of the most careless workman. It is adapted for crucibles not exceeding 4 inches by 2-1/4, 5 inches by 3-1/2, 7-1/2 inches by 5. For further information respecting furnaces intended for use in the laboratory and assay office, the reader is referred to ‘Watt’s Dictionary of Chemistry,’ also to ‘Ure’s Dictionary of Arts, Manufactures, and Mines,’ for description of the furnaces employed in the different metallurgical operations; and to the ‘Chemical News’ (June 30th, 1876, and February 2nd, 1877), for a description of a new decomposing furnace. See ASSAYING, CHIMNEYS, COPPER, CRUCIBLE, FUEL, &c.

=FUR′NISHING.= It is essential for the sake of neatness, and for a pleasing effect to the eye, that there should be a harmony of colours, and also a similarity of style, in the main articles of furniture. The tints of the carpet, of the paper or paint of the walls, and of the window-curtains, should be all in harmony in each room; that is, either possess a general resemblance of colour, or various colours in pleasing contrast and harmony with each other. If the preponderating colour of the curtains is scarlet, and the colour of the walls or carpet blue, a most inharmonious and unpleasing effect is produced; but brown and green, or green and gold, will be in harmony, and may, therefore, be placed together. Carpets being the most expensive articles, it is safest to buy them first, and then to let their colour guide us in the tone and style of the curtains, paper-hangings, chair-covers, hearth-rugs, and the various minor articles. It is also economical to buy carpets of the same pattern for several rooms, because in the event of removal to a house with different sized apartments, a piece of one carpet may be taken to alter the size of another.

=FUR′NITURE.= See FRENCH POLISHING, OIL, POLISH, VARNISH, &c.

=FURS.= Of these the most valuable are Ermine and Sable. Fur skins, when unprepared, or merely dried, go under the name of ‘Peltry.’ (Brande.)

Furs may be preserved from moths and other insects by placing a little colocynth pulp (bitter apple), or spice (cloves, pimento, &c.), wrapped in muslin, among them; or they may be washed in a very weak solution of corrosive sublimate in warm water (10 to 15 gr. to the pint), and afterwards carefully dried. As well as every other species of clothing, they should be kept in a clean, dry place, from which they should be taken out occasionally, well beaten, and exposed to the air, and re-turned.

=FU′SEL-OIL.= Syn. FOUSEL OIL, POTATO-OIL, OIL OF POTATO SPIRIT, GRAIN OIL, GRAIN-SPIRIT OIL, MARC-BRANDY OIL, CRUDE HYDRATED OXIDE OF AMYL. Source. An offensive, strong-smelling oil, produced along with alcohol during the fermentation of grain, potatoes, &c., on the large scale, and which gives the peculiar and disagreeable flavour and odour to raw whiskey. It is found chiefly in the last portion of the spirit which passes over, called the ‘faints,’ to which it imparts its characteristic odour and flavour. By rectifying the faints at a very gentle heat, most of the alcohol and water first pass over together with only a little fusel oil, whilst the latter forms the residuum in the still. Various names (as above) are given to the crude oil thus obtained, according to its source. In each case it essentially consists of hydrated oxide of amyl, but trifling and variable quantities of other organic compounds are mixed with it, which slightly modify its character, more particularly its odour and flavour. The oil of potato spirit is the purest form of crude fusel oil.

Obs. The exertions of the distiller are directed, as much as possible, to lessen the formation of fusel oil during the fermentation of his ‘worts,’ and to eliminate, during the distillation and rectification of his liquors, the greatest possible proportion of that with which they may be contaminated.

Prop., &c. Fusel oil is a nearly colourless volatile liquid, with a rather high boiling point, a durable, penetrating, offensive smell, and an acrid, burning taste; when swallowed, it occasions nausea, giddiness, headache, &c.; in slightly larger quantities, vomiting, delirium, oppressive respiration, and lessened sensibility to pain; its vapour also produces these effects. In quantity, it is a narcotic poison. The greater intoxicating power of whiskey, more especially that from raw grain, than other spirit, is due to the larger quantity of fusel oil which it contains. This appears to be well known to the lower class of whiskey drinkers in these countries, and to the consumers of corn brandy in some of the northern parts of Europe. The last are said to frequently demand to be served with “a glass of good fusel.” In England fusel oil is chiefly used for lamps and varnishes.

Purific. The AMYLIC ALCOHOL (ALCOHOL AMYLICUM) of the Dublin College is thus prepared. Introduce the ordinary fusel oil of the distilleries into a small still or retort, connected with a condenser, and apply heat; as soon as the oil begins to flow over, unmixed with water, the receiver should be changed, and the distillation resumed, and carried nearly to dryness; the product in the second receiver, and the oily matter which separates from the water in the first receiver, are to be reserved for use. It is employed in the preparation of VALERIANATE OF SODA. See AMYL.

=FU′SIBLE ALLOY′.= Syn. FUSIBLE METAL. Prep. 1. Bismuth, 2 parts; lead, 5 parts; tin, 3 parts. Melts in boiling water.

2. (D’Arcet’s.) Bismuth, 8 parts; lead, 5 parts; tin, 3 parts. Melts below 212° Fahr.

3. (Walker.) Bismuth 8, tin 4, lead 5 parts; antimony, 1 part. The metals should be repeatedly melted and poured into drops, until they are well mixed.

4. (Onion’s.) Lead, 3 parts; tin, 2 parts; bismuth, 5 parts. Melts at 197° Fahr.

5. To the last, after removing it from the fire, add of quicksilver (warm), 1 part. Liquid at 172°, solid at 140° Fahr.

Obs. The first four of the above are used to make TOY-SPOONS, to surprise children by their melting in hot liquors. A little mercury may be added to lower their melting points. Nos. 2 and 3 are specially adapted for making ELECTROTYPE MOULDS. The beautiful casts of the French medals known to all electrotypers as Clichée moulds are in the alloy No. 3. The above alloys are also used to form PENCILS for writing on asses’ skin, or paper prepared by rubbing burnt hartshorn into it, &c.; also as a METAL BATH in the laboratory. The last is used for ANATOMICAL INJECTIONS.

=FU′SION.= Syn. FUSIO, L. The liquefaction of solid bodies by the action of heat. The term AQUEOUS FUSION has been applied to the melting of salts in their combined water when heated; and the term IGNEOUS FUSION, to the liquefaction of bodies by heat alone.

The vessels in which substances are fused are formed of various materials and shapes, according to the properties of the solid operated on, and principally with reference to the degree of heat required for its fusion. In every case the containing vessel should be capable of sustaining the proper degree of heat, without either melting or cracking, and should also be unacted on by the substances melted in them. See CRUCIBLE, FURNACE, &c.

=FÜRSTENBALSAM, Bamberger für Frauen=——BAMBERG PRINCE’S BALSAM FOR WOMEN. An embrocation for strengthening women after confinement. A hexagonal eau de Cologne bottle containing about 100 grammes of a clear reddish-brown fluid, which is a filtered mixture of equal parts of spirit of lavender (Sp. Lavand. Co.) and spirit of soap, mixed with a little camphor and ammonia. (Hager.)

=FUS′TIC.= Syn. FUSTIC WOOD. Two distinct dye-stuffs are known by this name, but are distinguished by the adjectives ‘old’ and ‘young.’

=Fustic, Old.= Syn. BOIS JAUNE, Fr. The wood of the Maclura tinctoria. Its decoction dyes woollens yellow of different shades, according to the ‘mordant.’ Alum, tartar, and spirits of tin brighten the tint; acetate and sulphate of iron and common salt darken it; with sulphate of iron it gives olives and browns; with the indigo vat and sulphate of indigo green. These colours are very permanent. Its yellow turns on the lemon when pale, and on the orange when darker. 1 lb. of old fustic will dye 3 to 5 lbs. of wool.

=Fustic, Young.= Syn. YELLOW FUSTIC; FUSTET, Fr. The wood of the Rhus Cotinus or Venice sumach. It gives a yellow turning on the green, but its colours are not very permanent. It is chiefly used in combination with other dye-stuffs.

=GAL′BANUM.= Syn. GUM GALBANUM; GALBANUM (B. P.), L. “A gum-resin derived from an unascertained umbelliferous plant. In irregular tears about the size of a pea, usually agglutinated into masses; of a greenish-yellow colour, translucent, having a strong disagreeable odour, and an acrid bitter taste.” (B. P.) Its properties are similar to the other fetid antispasmodic gum-resins. It ranks between ASSAFŒTIDA and AMMONIACUM.

=Galbanum, Strained.= Syn. PREPARED GALBANUM; GALBANUM COLATUM, G. PRÆPARATUM (Ph. L.), L. From crude galbanum, as prepared ammoniacum. Formerly the common practice was to melt it in the dry state, by heat cautiously and quickly applied, and to strain it through a piece of coarse canvas stretched across a wooden frame or ‘horse.’ The ‘strained galbanum’ of the shops is seldom pure. The following forms are current in the trade for its ‘reduction,’ as this species of adulteration is technically termed:——

1. Galbanum (true), 9 lbs.; strain as above, then add, towards the end black resin (clean), 3 lbs.; and when the whole is melted, further add of Venice turpentine, 2 lbs.——Product. 12 lbs.

2. Strained galbanum and black resin, of each 6 lbs.; melt, and add, of strained assafœtida, 2 oz.; Venice turpentine, 3 lbs.——Prod. 14-1/2 lbs.

=Galbanum, Facti′′tious Strained.= Syn. GALBANUM COLATUM FACTITIUM, L. Prep. 1. From black resin, 4 lbs.; melt, and add of Venice turpentine, 2 lbs.; assafœtida, 2-1/2 oz.; oils of juniper and fennel, of each 1-1/2 dr.; water, 1/2 pint.

2. As the last, adding soft soap, 5 oz. Sometimes the small and ‘waste’ of the chests are added to the above to improve them.

=GALÈNE-EINSPRITZUNG——Galen’s Injection= (J. F. Schwarzlose Söhne, Berlin). According to Hager:——Gum Arabic, 25 grammes; water, 65·5 grammes; sugar of lead, 4·5 grammes; tinct. opii with saffron, 5 grammes. According to Schädler:——Sulphocarbolate of zinc, 3 grammes; gum Arabic, 20 grammes; tinct. opii, 2 grammes; water, 100 grammes.

=GALL.= Syn. BILE; BILIS, CHOLE, FEL, L. A bitter fluid secreted by the liver; in part flowing into the intestines, and in part regurgitating into the gall-bladder. Its uses in the animal economy appears to be——to separate the chyle from the chyme, to promote digestion of oleaginous substances, and to assist in exciting the peristaltic action of the intestines. The fæces appear to owe their colour chiefly to the presence of bile, since, without, they appear of a dirty pipe-clay colour.

The gall of various animals was formerly used in medicine. From whatever source it was obtained, it was believed to be calefacient, desiccant, detergent, discutient, and parturifacient; but besides these properties, each variety was conceived to possess virtues peculiarly its own. Thus, bear-gall (fel ursi) was reputed anti-epileptic; eel-gall (fel anguillarum), parturifacient; hare-gall (fel leporis), “good in cataract;” and ox-gall (fel bovis), “sovereign against stiff joints, rheumatics, angry ulcers, and stomach colics.” The gall of the bat, goat, hen, hog, partridge, silurus, &c., were also employed as remedies. At the present time ox-gall is the only one used in medicine and the arts.

Ox-gall has been recently reintroduced into medicine by Dr Allnatt and others, and in certain cases of dyspepsia and biliary derangement appears to be a valuable remedy.

Crude ox-gall is extensively employed by the scourers of woollen cloth, clothes renovators, &c. It rapidly extracts grease and oil from textile fabrics without injuring the colour. See CONSTIPATION, DYSPEPSIA, OX-GALL, &c.

=Gall, Glass.= See SANIVER.

=GAL′LATE.= Syn. GALLAS. L. A salt of gallic acid. The alkaline gallates are soluble. They rapidly suffer decomposition in the presence of excess of the base, and the liquor gradually acquires a blackish colour. The gallates of most of the other metallic oxides are insoluble.

=GALLEN-MIXTUR FÜR PFERDE=——GALL MIXTURE FOR HORSES (F. Barth, veterinary surgeon, Freibach-by-Altenhofen, Carinthia). A clear decanted solution of 8 parts wood tar in 92 parts common kienöl (ol. pini). (Hager.)

=Gallen-Mixtur=——GALL MIXTURE (Ph. Barth, Marburg in Steiermark). The same preparation as the above, coloured with 3/4 per cent. of dragon’s blood. (Wittstein.)

=Gallen-Tinctur=——GALL TINCTURE (Dr G. Krieger, Garz). 5 parts wood tar, 10 parts water, 30 parts spirit, 1 part corrosive sublimate, and 1/20 part rosanilin, mixed with a gentle heat, allowed to deposit, and filtered. (Hager.)

=GAL′LIC ACID.= H_{3}C_{7}H_{3}O_{5}.Aq. Syn. ACIDUM GALLICUM (B. P.), L. “A crystalline acid prepared from galls.” (B. P. L.) It may be also obtained from other vegetable substances. It appears to be a product of the oxidation of tannic acid, and probably does not exist ready formed in recent vegetables.

Prep. 1. (Dumas.) Nut-galls, reduced to powder, are moistened with water, and exposed to the action of the air, in a warm situation (say 70° to 80° Fahr.), for two or three months, adding more water, from time to time, to make up for that lost by evaporation. At the end of the above period the mouldy, dark-coloured mass is strongly pressed in a cloth, and the solid portion boiled in a considerable quantity of water. The solution (filtered whilst hot) deposits, on cooling, crystals of gallic acid, which, after being thoroughly drained and pressed dry between bibulous paper, are purified by boiling them along with about 1/6th of their weight of prepared animal charcoal in 8 parts of water, and filtering, &c., as before.

2. (Graham.) A strong infusion or decoction of galls is precipitated with sulphuric acid in the cold; the resulting thick mass is mixed with dilute sulphuric acid (cold), and the liquid expressed; the ‘marc’ is next treated with sulphuric acid diluted with twice its weight of water, and after boiling the mixture for some minutes the whole is allowed to cool; the resulting crystals are purified as before.

3. (Liebig.) A strong aqueous solution of tannic acid (tannin) is added to sulphuric acid as long as a precipitate falls; the powder is collected, washed, and dissolved by the aid of heat in dilute sulphuric acid; the solution, after being boiled for a few minutes, deposits, on cooling, crystals of gallic acid in considerable quantity.

4. (Scheele.) A filtered decoction of galls is exposed for some months in an open vessel; after a time it grows mouldy, and becomes covered with a thick, glutinous pellicle; in two or three months the sides of the vessel and the under portion of the pellicle are found to be covered with small yellow crystals of gallic acid, which are purified as directed above. (See No. 1.)

5. (Ph. D., B. P.) The Dublin contains two formulæ for gallic acid, the one being based on that of Dumas or Scheele, the other on that of Graham or Liebig.——a. From galls (in coarse powder), 1 lb.; water, q. s. to make a stiff paste; a porcelain dish is ordered, and the exposure in the moistened condition is to be continued for 6 weeks; the solution of the first crop of crystals is to be made in 10 fl. oz. of boiling water, and when the filtrate has cooled to 80° Fahr., it is to be poured off from the crystals which have formed, which are then to be washed with ice-cold water, 3 fl. oz., and dried——first in blotting paper, and finally by a steam or water heat. By boiling the undissolved portion of the galls with 45 fl. oz. of fresh water, more crystals may be obtained.

b. Powdered gall-nuts, 1 lb., are steeped for 24 hours in water, 1 pint, and after being placed in a porcelain displacement apparatus, are treated with water, 1-1/2 pint, added in successive portions; oil of vitriol, 5 fl. oz., diluted with an equal volume of water, and allowed to cool, is now added to the percolated infusion, and after thorough admixture the liquid is filtered from the viscid precipitate which forms; oil of vitriol, 5 fl. oz. (diluted as before), is then added to the filtrate, the precipitates, enveloped in calico, are submitted to powerful pressure, and subsequently dissolved in oil of vitriol, 16 fl. oz., previously diluted with water, 56 fl. oz.; the solution is boiled for 20 minutes, and set aside for a week; at the end of this time the deposit which forms is dissolved in three times its weight of boiling water, and the solution treated as before.

Prop. Gallic acid forms small, feathery, and nearly colourless crystals, which have a beautiful silky lustre; that of commerce is usually of a pale-yellow colour; it is soluble in 100 parts of cold water, and in 3 parts of boiling water; it is also soluble in alcohol, and slightly so in ether; the aqueous solution is decomposed by exposure to the air; dissolved in hot oil of vitriol, it forms a deep, rich, red solution, which, when thrown into water, drops the gallic acid, deprived of some of its water. This substance is soluble in the alkalies, and dyes cloth like madder. When strongly heated, gallic acid is converted into metagallic acid, or into pyrogallic acid, according to the manner in which the heat is applied.

Tests. Gallic acid is distinguished from tannic acid by not affecting solutions of gelatin, the protosalts of iron, or the salts of the alkaloids, and by giving a deep bluish-black precipitate with the sesquisalts of iron, which disappears when the liquid is heated. It is distinguished from pyrogallic acid by its inferior insolubility in water, and by its not affecting the solutions of the protosalts of iron. To detect gallic acid mixed with tannic acid, the latter should be removed, either by digesting the substance in ether, or by immersing for some time in its solution a piece of skin depilated by lime, previously to applying the tests.

Pur. Free from colour; decomposed by heat; soluble in water and in rectified spirit. It turns preparations of the sesquioxide of iron, dissolved in water, of a bluish black colour, but throws down nothing from a solution of isinglass.

Uses, &c. The principal use of pure gallic acid is in the art of photography. It has recently been employed in medicine, as an internal astringent, in doses of 3 to 10 gr., thrice a day, or oftener; in hæmorrhage and fluxes, as well as for checking the night sweats in phthisis. Dr Todd says, that in all cases of internal hæmorrhage, or hæmorrhagic tendency, it is the best astringent or styptic we possess. As an external astringent, it is greatly inferior to tannic acid. It has been given in doses of 15 to 30 gr. in tape-worm, “but without any benefit.” (Pereira.)

Purification. Gallic acid, as obtained by either of the above forms, is never quite pure; but it may be rendered absolutely pure by combining it with oxide of lead, and decomposing the compound (gallate of lead) by sulphuretted hydrogen. The sulphuret of lead acts like animal charcoal in removing the colour. (Liebig.) Commercial gallic acid “may be rendered nearly white by dissolving it in 20 times its weight of boiling distilled water, and causing the solution to traverse a stratum of prepared animal charcoal, spread upon a calico filter. When the liquid passes through colourless, it should be evaporated to 1-6th its volume, and then suffered to cool, in order to the separation of the crystallised acid.” (Ph. D.)

=GALLIC FERMENTATION.= This name has been given to the peculiar process by which tannic acid is converted into gallic acid, under the joint influence of moisture and atmospheric oxygen. According to the researches of M. Antoine Larocque, the peculiar ferment of nut-galls which operates this change also converts sugar into alcohol and carbonic acid, in the same way as yeast does; whilst beer yeast, muscular flesh, and caseous matter change tannin into gallic acid. The similarity of the gallic and vinous fermentation may hence be reasonably inferred.

=GALLIUM.= A new metal discovered in August, 1875, by means of the spectroscope, by M. Lecoq Boisbaudran, in a specimen of blende from the mines of Pierrefitte, in the Pyrenees. The new element was named gallium in honour of France, the discoverer’s native country.

Gallium gives a spectrum composed of two bands in the violet, one of the bands being brilliant, and of wave length 417, and the other, a feeble one of wave length, 403·3.

The Pierrefitte blende contains one part of gallium in four hundred thousand. It is, however, found much more abundantly in a black blende from Bensberg, on the Rhine, one hundred thousand parts of this latter yielding one part of gallium.

Gallium resembles lead in appearance, but is less blue in colour. Exposed to moist air it tarnishes slightly. It is a little harder than lead, is flexible, malleable, and may be easily cut with a knife. If melted and poured upon glass, it adheres to it, and forms a mirror which is whiter than that caused by mercury. A red heat fails to volatilise it to any appreciable extent, and it is only slightly oxidised at that temperature; therefore it is not tarnished when exposed to the air. Hot nitric acid dissolves it, but the cold acid has scarcely any action on it. It melts at 30·15 C. When once fused, it preserves the liquid condition even for several months at 0° C.,[324] until it is touched by some solid body, or by a piece of solid gallium, when it congeals to a crystalline solid, having a specific gravity of 5·93; when fused it has a specific gravity of 6·08. It crystallises in square octohedra. In properties gallium is more or less intermediate between the metals aluminium and indium.

[Footnote 324: In consequence of this curious property gallium was first described as a liquid metal.]

Chemical reactions of gallium:——The following are the chief reactions of the salts of gallium when in solution. With ammonia they give a white gelatinous precipitate, soluble, but not readily in excess of the precipitant; potash gives a similar precipitate, soluble in excess; acetate of ammonia, on boiling in a solution free from excess of acid, precipitates a basic compound; barium carbonate readily precipitates gallium salts in the cold. A sulphate and a chloride of gallium have already been obtained. These salts are both very soluble; the sulphate is a non-deliquescent substance, the chloride, on the contrary, is excessively so, and decomposed by a large excess of water. Gallium also forms an alum consisting of the double sulphate with ammonium. Gallium alum is a beautifully crystalline body, more soluble in cold than in hot water.

At a meeting of the ‘Academie des Sciences’ in March, 1878, M. de Baubradon stated that he had determined the atomic weight of gallium. The mean of two experiments showed it to be 69·9.

The ‘Comptes Rendus’ for February, 1878 (No. 7), contains a communication from MM. Lecoq de Boisbaudran and E. Jungfleisch, on the extraction of gallium from the ores in which it is found associated with indium.

The following is the process given by the authors:——The blende of Bendsberg is pulverised and then roasted in a Perret furnace, by which treatment the greater part of the indium is volatilised. The residue is treated with sulphuric acid in quantity sufficient to dissolve almost all the zinc, and there is thus obtained a residue which is treated with excess of sulphuric acid.

The persalts of iron present are then reduced by means of metallic zinc, and the filtrate fractionally precipitated with carbonate of sodium; the precipitates are redissolved in sulphuric acid, and the reduction with zinc and the fractional precipitation repeated, the latter operation being in both cases watched by the spectroscope.

The precipitate containing the gallium concentrated in a small bulk, is redissolved in acid, and the excess of the latter reagent removed by evaporation, after which it is boiled with much water. The filtrate separated from the sediment containing titanic acid, which form is treated with sulphuretted hydrogen, then mixed with acetate of ammonium and again treated with sulphuretted hydrogen, which throws down the galliferous sulphide of zinc free from alumina. Again the precipitate is dissolved in sulphuric acid, and the solution fractionally precipitated with carbonate of sodium, which operation, guided as it is by spectral examination, entirely removes the zinc. By once more dissolving in the exactly necessary amount of sulphuric acid, and treating with sulphuretted hydrogen, cadmium, lead, indium and zinc are removed, and the filtrate is then largely diluted with water and boiled. The bulky sub-salt of gallium which separates at this temperature is treated with potash, which leaves iron, indium, &c., undissolved, and the alkaline liquor when treated with sulphuretted hydrogen, and subsequently with sulphuric acid to slight acidity, yields a deposit consisting mainly of sulphide of indium.

The slightly acid liquid is then boiled with much water, and the deposit of sub-salt of gallium thus obtained is dissolved in potash, and the solution subjected to electrolysis, by which means a metallic deposit of gallium is obtained.

It is interesting to note how accurately many of the chemical physical properties to gallium had, previously to its discovery, been predicted by the Russian chemist, Mendelejeff, by reasoning on the so-called “periodic law,” which he thus defines:——“The properties of the simple bodies, as also the properties and constitution of their combinations, are periodic functions of the atomic weights of the elements.”

In 1864 an English chemist named Mr Newlands, observing certain relations existing between the atomic weights of many of the elements, was the first to arrange them in such a manner or serial form as to suggest that when certain gaps were observed in the atomic weights of a series, new elements might be assumed to exist. Guided by this theory, Mendelejeff affirmed that the “periodic law” not only indicates vacancies in the classificatory scheme of the known elements, but enables us to predict the properties of elements as yet undiscovered, and of their compounds. Thus, of one of the vacancies observable in the table of the elements arranged according to his classification, Mendeljeff asserted, that should the element (which he named Eka aluminium) with the corresponding atomic number be discovered, it would possess the following characteristics:——It would most probably, like indium and thallium, be discovered by the aid of spectrum analysis. Gallium, as we have seen, was found by this means. The formula of its oxide would be El_{2}O_{3}; the oxide of gallium is best represented by Ga_{2}O_{3}.

The salts would have the general formula ElX_{3}; the salts of gallium have most probably the general formula GaX_{3}. It will form an alum isomorphous with common alum, this we have seen gallium does. Its salts would be precipitable by barium carbonate; the gallium salts are thrown down by this reagent. It would not oxidise in the air; gallium does not tarnish upon exposure to the air. It would decompose water at a red heat; gallium readily does this at high temperatures. Its specific gravity (and this is very remarkable) would be about 5·9; gallium has a specific gravity of 5·93. Its atomic weight would be about 68; that of gallium is 69·9.

The hypothetical Eka aluminium of Mendelejeff appears therefore to correspond with the gallium of Boisbaudran.

=GALLS.= Syn. GALL-NUTS, NUT-GALLS; GALLA (B. P.); GALLÆ (Ph. E.). “Excrescences on Quercus infectoria caused by the puncture and deposited ova of Diplolepis Gallæ tinctoriæ.” The best galls are blueish-black, heavy, and not yet perforated; intensely astringent. They are imported from Aleppo, and are known in commerce as black or blue galls (GALLÆ NIGRÆ, G. CŒRULÆ). The next quality is termed, from their colour, green galls (GALLÆ VIRIDES). Both are gathered before the insect has escaped, and are styptic and powerfully astringent. White galls (GALLÆ ALBÆ) are lighter, less astringent, and inferior.

Uses, &c. Galls are extensively employed in the art of dyeing, and constitute one of the principal ingredients in all the shades of black, and are also employed to fix or improve several other colours. A decoction of galls, to which a little green copperas and gum Arabic has been added, forms common writing ink. In medicine they are used as an astringent, in hæmorrhages and fluxes, in doses of 10 to 20 gr.; and topically, under the form of infusion or decoction, as a gargle in relaxation of the uvula; as an injection in gleet and leucorrhœa; as a lotion or fomentation in flabby ulcers, prolapsus ani, &c.; and as an ointment in piles, watery ulcers, &c. The infusion or decoction is also used as an antidote to poisoning by the alkaloids, and was formerly given as a tonic in intermittents. See GALLIC ACID, INK, &c.

=GALL′STONE.= Syn. CALCULUS BILIOSUS, C. CYSTICUS BOVINUS, L. Formed in the gall-bladder of neat cattle in winter, when they are fed upon dry food. Used as a yellow pigment, and in medicine——Dose, 1 gr.; in dyspepsia and flatulency. Man is also subject to gall-stone, the presence or passage of which is attended with the most acute pain, frequently accompanied with nausea and sickness. In no case should a patient suffering from a paroxysm such as above described delay to seek immediate medical aid. The following treatment is recommended for the benefit of those only who, like emigrants and others, may be unable to obtain professional assistance.

The pain and spasm should be endeavoured to be alleviated by full doses of laudanum, given in soda water. If there be much sickness, the laudanum should be given in the form of an enema. If the paroxysm be excessive, the cautious inhalation of ether or chloroform should be tried. When the pain is of long duration, leeching should be had recourse to. Ice applied freely to the pit of the stomach has sometimes been found to give relief. See CALCULUS.

=GALV′ANIZED IRON.= See IRON and ZINCING.

=GAM′BOGE.= Syn. (CAMBOGE; CAMBOGIA, L. B. P.) GAMBOGIA, L. “A gum-resin obtained from Garcinia Morella.” (B. P.) Gamboge is an active hydragogue and drastic purgative, which occasionally proves useful in torpor of the abdominal and pelvic viscera; but which is highly dangerous in an irritable or inflammatory state of the stomach or bowels, and during pregnancy. It is very apt to induce nausea and vomiting. In large quantities it is a violent poison. “The deaths which have occurred from the use of enormous quantities of Morrison’s pills are mainly ascribable to the gamboge contained in those medicines.” (Pereira.)——Dose, 1 to 5 gr., made into pills or mixture, every 4 to 6 hours; in obstinate constipation, in dropsies, in apoplexy and like cerebral affections, and in worms (especially tape-worm), either alone or combined with other cathartics. See COMPOUND EXTRACT OF COLOCYNTH.

=GAME.= The flesh of game is believed to possess strengthening qualities superior to that of poultry. It also contains less fat. Game is tender and easy of digestion, and it has a delicate and marked flavour. It forms a valuable diet for the invalid, by reason of its easy digestibility.

Respecting the choice and preservation of game, Eliza Acton writes——“Buck venison, which is in season only from June to Michaelmas, is considered finer than doe venison, which comes into the market in October, and remains in season through November and December; neither should be cooked at any other part of the year.

“The greater the depth of fat upon the haunch the better the quality of the meat will be, provided it be clear and white, and the lean of a dark hue.

“If the cleft of the hoof, which is always left on the joint, be small and smooth, the animal is young; but it is old when the marks are the reverse of these.[325] Although the haunch is the prime and favourite joint of venison, the neck and shoulder are also excellent, dressed in various ways, and make much-approved pasties. A free current of air in a larder where venison is kept is always a great advantage.

[Footnote 325: Venison is not in perfection when young.]

“All moisture should be wiped daily, or even more frequently, from the venison with soft cloths, when any appears upon the surface, and every precaution must be taken to keep off the flies when the venison is not hung in a wire safe. Black pepper thickly powdered on it will generally answer the purpose.

“Hares and rabbits are stiff when freshly killed, and if young the ears tear easily, and the claws are smooth and sharp. A hare in cold weather will remain good for ten or fourteen days; care only must be taken to prevent the inside from becoming musty, which it will do if it has been emptied in the field. Pheasants, partridges, and other game, may be chosen by nearly the same tests as poultry——by opening the bill the staleness will be detected easily if they have been kept too long by the hardness of the bill. With few exceptions game depends almost entirely for the fine flavour and the tenderness of its flesh, on the time which it is allowed to hang before it is cooked, and it is never good when very fresh; but it does not follow that it should be sent to table in a really offensive state.”

=Game, Hashed.= Ingredients.——The remains of cold game, one onion stuck with three cloves, a few whole peppers, a strip of lemon peel, salt to taste, thickening of butter and flour, one glass of port wine, one tablespoonful of lemon juice, one tablespoonful of ketchup, and one pint of water or weak stock.

Proceed as follows:——Cut the remains of cold game into joints, reserve the best pieces, and put the inferior ones and the trimmings into a stewpan with the onion, pepper, lemon peel, salt, and water or weak stock; stew these for about an hour, and strain the gravy; thicken it with butter and flour; add the wine, lemon juice, and ketchup; lay in the pieces of game, and place them by the side of the fire until they are warmed through, avoiding boiling, otherwise the game will become too hard. Just on the point of simmering serve, and garnish the dish with sippets of toasted bread. Time. Altogether, an hour and a quarter.

⁂ The above recipe applies to any kind of game.

If desirable, the flavour may be varied by adding flavoured vinegars, curry powder, &c.; these, however, cover the gamey taste of the dish, and are, therefore, not to be recommended.

=Grouse, to Roast.= Ingredients.——Grouse, butter, a thick slice of toasted bread. Mode.——Let the birds hang as long as possible; pluck and draw them; wipe (but do not wash them) inside and out, and truss them without the head, the same as for a roast fowl. Put them down to a sharp clear fire, keep them well basted the whole of the time they are cooking, and serve them on buttered toast, soaked in the dripping-pan, with a little melted butter poured over them, or with bread sauce and gravy. Time. Half an hour; if liked thoroughly done, thirty-five minutes. Seasonable from the 12th of August to the beginning of December. (Mrs Beeton.)

=Hare, Jugged.= Ingredients.——One hare, a bunch of sweet herbs, two onions, each stuck with three cloves, six whole allspice, half a teaspoonful of black pepper, a strip of lemon peel, thickening of butter and flour, two table-spoonfuls of mushroom ketchup, quarter of a pint of port wine. Mode.——Wash the hare nicely, cut it up into joints (not too large), and flour and brown them; then put them into a stewpan with the herbs, onions, cloves, allspice, pepper, and lemon peel; cover them with hot water, and when it boils carefully remove all the scum, and let it simmer gently till tender, which will be in about 1-3/4 hour, or longer should the hare be very old. Take out the pieces of hare, thicken the gravy with flour and butter, add the ketchup and port wine, let it boil for about ten minutes, strain it through a sieve over the hare, and serve. A few fried forcemeat balls should be added at the moment of serving, or, instead of frying them, they may be stewed in the gravy, about ten minutes before the hare is wanted for use. Do not omit to serve red-currant jelly with it. Time. Altogether, two hours. Seasonable from September to the end of February. (Mrs Beeton.)

=Hare, to Roast.= Ingredients.——Hare, forcemeat, a little milk, and butter. To be eaten in perfection, the hare must hang for some time. After it is skinned wash it well, and soak it for an hour in warm water to draw out the blood. Make a forcemeat, wipe the hare dry, fill the belly with it, and sew it up. Bring the hind and fore legs close to the body towards the head, run a skewer through each, fix the head between the shoulders by means of another skewer, and be careful to leave the ears on. Put a string round the body from skewer to skewer and tie it above the back. Mode.——The hare should be kept at a distance from the fire when it is first laid down. Baste it well with milk for a short time, and afterwards with butter; and particular attention must be paid to the basting, so as to preserve the meat on the back juicy and nutritive. When it is almost roasted enough, flour the hare, and baste well with butter. When nicely frothed dish it, remove the skewers, and send it to table with a little gravy in the dish, and a tureen of the same. Red-currant jelly must be served with it. If the liver is good it may be parboiled, minced, and mixed with the stuffing; but it should not be used unless quite fresh. Time. A middling-sized hare an hour and a quarter; a large hare one and a half to two hours. (Mrs Beeton.)

=Partridges, to Roast.= Let the birds hang as long as they can possibly be kept without becoming offensive; pick them carefully, draw and singe them, wipe the insides thoroughly with a clean cloth, truss them with the head turned under the wing and the legs drawn close together, not crossed. Flour them when first laid to the fire, and baste them plentifully with butter. Serve them with bread sauce and good brown gravy; a little of this last should be poured over them. Time. 30 or 40 minutes. In preparing them for the spit the crop must be removed through a slit cut in the back of neck, the claws clipped close, and the legs held in boiling water for a minute, that they may be skinned more easily. (Eliza Acton.)

=Pheasant, to Roast.= Let it hang as many days as possible without becoming tainted. Pluck off the feathers carefully, cut a slit in the back of the neck to remove crop, then draw the bird in the usual way, and either wipe the inside very clean with a damp cloth, or pour water through it; wipe the outside also, but with a dry cloth; cut off the toes, turn the head of the bird under the wing, with the bill laid straight along the breast; skewer the legs, which must not be crossed; flour the pheasant well, lay it to a brisk fire, and baste it constantly and plentifully with well-flavoured butter. Send bread sauce and good brown gravy to table with it. Time. Three quarters of an hour, a few minutes less if liked very much underdone, five or ten more for thorough roasting, with a good fire in both instances. In season from October to the end of January. (Eliza Acton.)

=Rabbit, to Boil.= Rabbits that are three parts grown, or, at all events, which are still quite young, should be chosen for boiling. Wash them well, truss them firmly, with the heads turned and skewered to the sides, drop them into sufficient boiling water to keep them quite covered until they are cooked, and simmer them gently from thirty to forty-five minutes; when very young they will require even less time than this. Cover them with rich white sauce mixed with livers parboiled, finely pounded, and well seasoned with cayenne and lemon juice; or with white onion sauce, or with parsley and butter, made with milk or cream instead of water (the livers, minced, are often added to the last of these), or with good mushroom sauce. Time. 30 to 45 minutes. (Eliza Acton.)

=Rabbit, to Roast.= This is much improved by having the backbone taken out. When this is done line the inside with thin slices of bacon, fill it with forcemeat, sew it up, truss, and roast it at a clear, brisk fire, and baste it constantly with butter. Flour it well soon after it is laid down. Serve it with good brown gravy, and with currant jelly, when this last is liked. Time. 3/4 hour to 1 hour; less if small. (Eliza Acton.)

=Venison, Haunch of, to Roast.= To prepare the venison for the spit wash it slightly with tepid water, or merely wipe it thoroughly with damp cloths, and dry it afterwards with clean ones; then lay over the fat side a large sheet of thickly-buttered paper, and next a paste of flour and water about three quarters of an inch thick; cover this again with two or three sheets of stout paper, secure the whole well with twine, and lay the haunch to a sound, clear fire; baste the paper immediately with butter or clarified dripping, and roast the joint from three hours and a half to four and a half, according to its weight and quality. Doe venison will require half an hour less time than buck. Twenty minutes before the joint is done remove the paste and paper, baste the meat in every part with butter, and dredge it very lightly with flour; let it take a pale-brown colour, and send it to table as hot as possible, with gravy in a tureen and good currant jelly. Time. 3-1/2 to 4-1/2 hours. The kind of gravy appropriate to venison is a matter on which individual taste must decide. (Eliza Acton.)

=Venison, Hashed.= Ingredients.——The remains of roast venison, its own or mutton gravy, thickening of butter and flour. Mode.——Cut the meat from the bones in neat slices, and, if there is sufficient of its own gravy left, put the meat into this, as it is preferable to any other. Should there not be enough put the bones and trimmings into a stewpan with about a pint of mutton gravy; let them stew gently for an hour, and strain the gravy. Put a little flour and butter into the stewpan, keep stirring until brown, then add the strained gravy, and give it a boil up; skim and strain again, and when a little cool put in the slices of venison. Place the stewpan by the side of the fire, and when on the point of simmering serve. Do not allow it to boil. Send red-currant jelly to table with it. Time. Altogether, an hour and a half. A small quantity of Harvey sauce, ketchup, or port wine, may be added to enrich the gravy.

=GAN′GRENE.= See MORTIFICATION.

=GAN′TEINE.= A composition used to clean kid and other leather gloves.

Prep. 1. (M. Buhan.) Curd soap (in small shavings), 1 part; water, 3 parts; mix with heat, and stir in of essence of citron, 1 part.

2. (SAPONINE,——Duvignau.) Soap (in powder), 250 parts; water, 155 parts; dissolve with heat, cool, and add, of eau de javelle, 165 parts, solution of ammonia, 10 parts, and rub the whole to a smooth paste. Patent. A small portion of either of the above is rubbed over the glove with a piece of flannel (always in one direction), until it is sufficiently clean. See GLOVES.

=GARAN′CINE.= See MADDER RED.

=GAR′DENING.= See HORTICULTURE.

=GAR′GLE.= Syn. GARGARISM, THROATWASH; GARGARISMA, GARGARISMUS, GARGARISMUM, L. A liquid medicine applied to the back part of the mouth or upper part of the throat. Gargles are applied by allowing a small mouthful to run as much as possible over the affected part, by holding the head backwards and breathing through it, by which means the liquid is agitated and its action promoted.

Gargles are not to be swallowed. It often happens, however, that patients, either by accident or from negligence, do swallow a certain quantity, notwithstanding the instructions given them to the contrary. Care should therefore be taken to avoid making gargles of such substances as may occasion unpleasant symptoms in small doses, though they may not, perhaps, amount to poisoning.

Gargles usually have for their basis either simple water, or milk, wine, or vinegar, diluted with water, to which, in both cases, sugar, honey, or syrup is generally added. Their other ingredients vary with the indication, but must, in all cases, be either in the liquid form, or soluble in the liquid used as the excipient.

Gargles are commonly dispensed in mixture bottles. The quantity used at a time, under ordinary circumstances, may be about 2-3rds of a wine-glassful.

=Gargle.= Syn. GARGARISMA, G. COMMUNE, G. SIMPLEX, L. Prep. 1. (St. B. Hosp.) Honey or honey of roses, 1-1/2 fl. oz.; strong vinegar, 2-1/2 fl. oz.; barley water, 1 pint.

2. (St. George’s.) Oxymel, 1 fl. dr.; decoction of barley, 5 fl. dr. In common sore throats, &c. The formulæ of several other hospitals are similar.

=Gargle of Ac′etate of Ammo′′nia.= Syn. GARGARISMS AMMONIÆ ACETATIS, L. Prep. (Wendt.) Solution of acetate of ammonia and honey of roses, of each 1 fl. oz.; elder-flower water, 8 fl. oz.; mix. In the ulcerated sore throat of scarlet fever.

=Gargle of Acetate of Manganese.= Syn. GARGARISMA MANGANESII ACETATIS. Prep. Acetate of Manganese, 1 drachm; water, 7 fluid ounces; clarified honey, 1 oz. The chloride and sulphate of manganese are also used, about 1/2 drachm or 2 scruples to 6 oz. of barley water.

=Gargle of Ace′tic Acid.= Syn. OXYMEL GARGLE; GARGARISMA ACIDI ACETICI, L. Prep. 1. (St. B. Hosp.) Acetic acid, 1 dr.; oxymel, 2 fl. dr.; water to make up 4 fl. oz.

2. Barley water, 12 fl. oz.; acetic acid, 1-1/2 fl. oz.; honey, 6 dr. Antiseptic. For sore throat.

=Gargle of Aluminium Chloride.= Syn. GARGARISMA ALUMINII CHLORIDI. Prep. (Throat Hosp.) Solution of chloride of aluminium 12 minims, water 1 fl. oz. Astringent and antiseptic.

=Gargle of Al′um.= Syn. GARGARISMA ALUMINIS, L. Prep. 1. (Augustin.) Oak-bark (in powder), 1 oz.; water, 1-1/2 pint; boil to a pint, filter, cool, and add, of alum, 1/2 dr.; brandy, 2 fl. oz. In inflammation of the mouth and throat.

2. (Cavarra.) Alum, 3 dr.; water, 6 fl. oz.; dissolve. In offensive breath.

3. (Foy.) Alum, 1 dr.; tincture of myrrh, 2 fl. dr.; tincture of bark, 4 fl. dr.; honey of roses, 2 oz.; laudanum, 20 drops; wine, 2/3 pint. In scurvy.

4. (Grant.) Alum, 1 oz.; tincture of myrrh, 1/2 fl. oz.; peppermint water, 7 fl. oz. In relaxation of the uvula, &c.

5. (Mid. Hosp.) Alum, 1 dr.; honey, 2 dr.; water to make 6 fl. oz. As No. 4.

6. (P. Cod.) Alum, 40 gr.; honey of roses, 1 oz.; infusion of roses, 6 fl. oz. As the last.

7. (Ratier.) Alum, 1 oz.; infusion of red roses and barley water, of each 3 fl. oz.; honey of roses, 2 oz. As No. 4.

8. (Westm. Hosp.) Alum, 1 dr.; dilute sulphuric acid, 1 fl. dr.; treacle, 4 dr.; water to 15 fl. oz.

9. (Ph. Wirtem.) Alum and nitre, of each 3 oz.; cream of tartar, 4 oz.; dilute acetic acid, 4 lbs.; dissolve, evaporate to dryness, and powder the residuum. For use, 1/2 oz. of the powder is dissolved in water, 8 fl. oz. Highly recommended in inflammation of the fauces and tonsils. This forms Zobel’s ‘SPECIFIC FOR QUINSY,’

=Gargle, Antiscorbu′tic.= Syn. GARGARISMA ANTISCORBUTICUM, L. Prep. (P. Cod.) Bitter species, 1 dr.; boiling water, 8 oz.; macerate 1 hour, strain, and add, syrup of honey, 2 oz.; antiscorbutic tincture, 1 oz.

=Gargle, Antisep′tic.= Syn. GARGARISMA ANTISEPTICUM, L. Prep. (Fr. Hosp.) Decoction of bark, 6 oz.; camphor, 20 gr.; sal-ammoniac, 12 gr. In putrid sore throat, &c.

=Gargle, Astrin′gent.= Syn. GARGARISMA ASTRINGENS, L. Prep. 1. (Collier.) Tincture of galls, 2 fl. dr.; honey, 1/2 oz.; water, 6 fl. oz. In relaxation of the uvula and fauces.

2. (Collier.) Honey, 4 dr.; tincture of myrrh, 3 dr.; powdered alum, 40 gr.; compound infusion of roses, 5-1/2 fl. oz. As the last, and in fetid sore throat.

3. (Sir A. Cooper.) Alum, 2 dr.; decoction of bark, 12 oz.; honey of roses, 1-1/2 oz.

4. (Dr A. T. Thomson.) Infusion of roses, 7 fl. oz.; dilute sulphuric acid, 1 fl. dr.; tincture of catechu, 6 fl. dr.; laudanum, 1-1/2 fl. dr. For relaxation of the uvula. See GARGLE OF ALUM.

=Gargle of Bo′′rax.= Syn. GARGARISMA BORACIS, L. Prep. 1. (Ellis.) Borax, 1 dr.; tincture of myrrh, 4 fl. dr.; clarified honey, 1 fl. oz.; rose water, 4 fl. oz.

2. (Fr. Hosp.) Borax, 2 dr.; honey or capillaire, 1 oz.; rose water, 7 fl. oz.

3. (Guy’s Hosp.) Borax, 2 dr.; honey of roses, 1 oz.; barley water, 7 fl. oz.

4. (Mid. Hosp.) Borax, 1 dr.; simply oxymel, 2 dr.; water to make 3 fl. oz. The above are used in thrush or aphthous sore mouth, ptyalism, &c.

=Gargle of Bromide of Potassium.= Syn. GARGARISMA POTASSII BROMIDI. Prep. (Throat Hosp.) Bromide of potassium, 10 grains; water, 1 fl. oz. Sedative.

=Gargle of Cap′sicum.= Syn. GARGLE OF CAYENNE PEPPER; GARGARISMA CAPSICI, L. Prep. 1. (Dr Griffith.) Tincture of capsicum, 1/2 fl. oz.; rose water, 8 fl. oz.

2. (St. B. Hosp.)——a. Capsicum, 3 dr.; common salt, 1 oz.; boiling water, 1 pint; macerate for 12 hours, strain, and add of distilled vinegar, 1 pint.

b. Tincture of capsicum, 1 fl. dr.; compound infusion of roses, 8 fl. oz.

3. (U. C. Hosp.) Tincture of capsicum, 1 fl. dr.; honey, 6 dr.; water to 4 fl. oz. Used in ulcerated sore throat, scarlet fever, &c.

=Gargle of Carbolic Acid.= Syn. GARGARISMA ACIDI CARBOLICI. Prep. (Throat Hosp.). Carbolic acid, 2 gr.; glycerin, 25 minims; water, 1 fluid ounce. Stimulant and antiseptic.

=Gargle of Chlo′′rate of Potas′sa.= Syn. GARGARISMA POTASSÆ CHLORATIS, L. Prep. (Beasley.) Chlorate of potassa, 1 dr.; honey of roses, 1 oz.; water, 7 oz. Used in malignant sore throat, scarlatina, &c.

=Gargle of Chlo′′ride of Lime.= Syn. GARGARISMA CALCIS CHLORINATÆ, L. Prep. From chloride of lime, 1 dr.; water, 1/2 pint; agitate together for 10 minutes, filter through linen, and add of simple syrup, 1 fl. oz. Used in putrid sore throat, scarlet fever, &c.

=Gargle of Chloride of So′da.= Syn. GARGARISMA SODÆ CHLORINATÆ, L. Prep. 1. (Copland.) Liquor of chloride of soda, 12 fl. dr.; honey, 1/2 oz.; water, 6 fl. oz.

2. (Hosp. Form.) Chlorinated solution of soda, 4 fl. dr.; water to 4 fl. oz. Used as the last.

=Gargle of Chlo′′rine Water.= Syn. GARGARISMA CHLORINII, L. Prep. 1. (Fr. Hosp.) Chlorine water, 1/2 fl. oz.; syrup, 1 fl. oz.; water, 4-1·2 fl. oz.

2. (Mid. Hosp.) Chlorine water, 2 fl. oz.; distilled water, 10 fl. oz. Use. As the last.

=Gargle of Cincho′na Bark.= Syn. GARGARISMA CINCHONÆ, L. Prep. 1. From decoction of cinchona, 7 fl. oz.; simple oxymel, 1 fl. oz. Antiseptic and astringent in relaxation, &c.

2. (Acidulated; GARGARISMA CINCHONÆ ACIDUS, L.) Hydrochloric acid, 1-1/2 fl. dr.; honey, 1-1/2 oz.; decoction of bark to make up 8 fl. oz.

=Gargle, Com′mon.= Syn. GARGARISMA COMMUNE, L. Prep. 1. (Ed. Hosp.) Water, 6 fl. oz.; nitre, 1 dr.; honey of roses, 1 oz. For ordinary sore throat, &c.

2. (Lond. Hosp.) Alum, 1 dr.; dilute sulphuric acid, 2 fl. dr.; tincture of myrrh, 4 fl. dr.; water to 12 fl. oz.

=Gargle of Cy′anide of Mercury.= Syn. GARGARISMA HYDRARGYRI CYANIDI, L. Prep. 1. (Brera.) Cyanide of mercury, 10 gr.; honey of roses, 1 oz.; barley water, 1 pint.

2. (Cullerier.) Cyanide of mercury, 10 gr.; linseed tea, 1 pint. Used in the same cases as mercurial gargle.

=Gargle, Deter′gent.= Syn. GARGARISMA DETERGENS, L. Prep. 1. (P. Cod.) Alcoholised sulphuric acid, 1 fl. dr.; honey of roses, 2 oz.; barley water, 8 oz.

2. (Dr A. T. Thomson.) Nitre, 2 dr.; honey of roses, 4 fl. dr.; infusion of roses, 5-1/2 fl. oz. In inflammatory sore throat.

=Gargle, Emol′lient.= Syn. GARGARISMA EMOLLIENS, L. Prep. 1. (Buchan.) Marshmallow root, 1 oz.; figs, 2 oz.; water, 1 quart; boil to a pint and strain. Demulcent, soothing.

2. (Trousseau & Reveil.) Barley water, 8 oz.; honey, 1-1/2 oz. Both are used in inflammatory affections of the throat and mouth.

=Gargle of Horserad′ish.= Syn. GARGARISMA ARMORACIÆ, L. Prep. (Collier.) Compound spirit of horseradish, 1 fl. oz.; honey, 2 oz.; water, 4 fl. oz. A good gargle for scurvy of the fauces and pharynx, vulgarly called the ‘inward scurvy.’

=Gargle of Hydrochlo′′ric Acid.= Syn. MURIATIC ACID GARGLE; GARGARISMA ACIDI HYDROCHLORICI. L. Prep. 1. (Guy’s Hosp.) Hydrochloric acid, 30 drops; honey of roses, 2 oz.; barley water, 6 fl. oz.

2. (Ratier.) Hydrochloric acid, 2 fl. dr.; clarified honey, 2 fl. oz.; barley water, 1 pint.

3. (St. B. Hosp.) Red-rose leaves, 2 dr.; boiling water, 1 pint; hydrochloric acid, 1-1/2 fl. dr.; digest 1 hour, and strain. In inflammatory sore throat, ulcerations of the mouth, scarlet fever, &c.

=Gargle of I′odine.= Syn. GARGARISMA IODINII, L. Prep. 1. Iodine, 10 gr.; iodide of potassium, 12 gr.; rectified spirit and simple syrup, of each, 1 fl. oz.; water, 5 fl. oz. In chronic enlargement of the tonsils, in scrofulous habits.

2. (Dr Ross.) Tincture of iodine, 1-1/2 fl. dr.; tincture of opium, 1 fl. dr.; water, 6 fl. oz.

3. (St. T. Hosp.) Compound tincture of iodine, 2 fl. dr.; water, 5 fl. oz. In ulceration of the tonsils.

=Gargle, Mercu′′rial.= Syn. GARGARISMA HYDRARGYRI, G. MERCURIALE, L. Prep. 1. (G. HYD. BICHLORIDI.) Corrosive sublimate, 2 to 5 gr.; barley water, 1 pint; honey of roses, 2 fl. oz. For syphilitic ulcers in the throat.

2. (Plenck.) Calomel, 6 gr.; quicksilver, 30 gr.; powdered gum, 3 dr.; syrup of poppies, 1/2 oz.; triturate till the globules of metal disappear, and add of decoction of clematis, 26 fl. oz.; honey of roses, 1 oz.; essence of myrrh, 1 dr. (or tincture of myrrh, 1 fl. oz.). In syphilitic and putrid sore throat.

=Gargle of Mustard.= Syn. GARGARISMA SINAPIS. Prep. (Fleury). Black mustard seed, bruised 4 ounces; salt, 4 scruples; vinegar, 8 scruples; warm water, 7 ounces. Digest and filter.

=Gargle of Myrrh.= Syn. GARGARISMA MYRRHÆ, L. Prep. 1. (Ainslie.) Tincture of myrrh, 6 fl. dr.; vinegar, 1 fl. dr.; honey of roses, 1-1/2 fl. oz.; barley water, 12 fl. oz.

2. (Ph. Chirur.) Tincture of myrrh, 1/2 oz.; honey of roses, 1-1/2 oz.; lime water, 6 fl. oz. In scarlatina and putrid sore throat. See ASTRINGENT GARGLE, &c.

=Gargle of Ni′tre.= Syn. GARGARISMA SALIS NITRI, G. POTASSÆ NITRATIS, L. Prep. 1. Nitre, 2 dr.; honey or syrup, 1/2 oz.; rose water, 5-1/2 fl. oz.

2. (Brande.) Nitre, 2 dr.; oxymel, 1 fl. oz.; barley water, 7 fl. oz. In inflammatory sore throat. See COMMON GARGLE.

=Gargle of Oak-Bark.= Syn. GARGARISMA CORTICIS QUERCÛS, L. Prep. 1. Oak-bark, 2 dr.; boiling water, 6 fl. oz.; macerate 1 hour, and strain.

2. (Ellis.) Decoction of oak-bark, 1 pint; alum, 1/2 dr.; brandy, 2 fl. oz. In chronic sore throat, relaxation of the uvula, &c.

=Gargle of Oxide of Manganese.= Syn. GARGARISMA MANGANESII OXIDI. Prep. (Pareira). Black oxide of manganese, 2 dr.; decoction of barley, 5 fl. oz.

=Gargle of Pel′litory.= Syn. GARGARISMA PYRETHRI. Prep. 1. Pellitory root, 4 dr.; water, 16 fl. oz.; boil to 8 fl. oz., and add of liquor of ammonia 2 fl. dr.

2. (Swediaur.) Infusion of pellitory, 1 pint; vinegar, 3 fl. oz.; sal-ammoniac, 3 dr. To promote the maturation and healing of throat ulcers.

=Gargle of Permanganate of Potash.= Syn. GARGARISMA POTASSÆ PERMANGANATIS. Prep. (Throat Hosp.) Solution of permanganate of potash (B. P.), 6 minims; distilled water, 1 fl. oz. Antiseptic.

=Gargle of Ro′′ses.= Syn. GARGARISMA ROSÆ, G. ROSARUM, L. Prep. (Kendrick.) Conserve of roses, 3 oz.; boiling water, 16 fl. oz.; infuse 1 hour; add of dilute sulphuric acid, 2 fl. dr., and strain. Antiseptic, astringent; used in several indications.

=Gargle of Subacetate of Lead.= Syn. GARGARISMA PLUMBI SUBACETATIS. Prep. (Ratier.) Liquid subacetate of lead, 1/2 dr.; barley water, 1 lb.; syrup, 1 fl. oz.

=Gargle of Turpentine.= Syn. GARGARISMA TEREBINTHINATUM. Prep. (Geddings.) Oil of turpentine, 2 dr.; mucilage, 6-1/2 fl. oz. In salivation.

=Gargle, Spirit.= Syn. GARGARISMA SPIRITUOSUM, G. SPIRITÛS VINI, L. Prep. 1. (Dr Watson.) French brandy, 1 fl. oz.; water, 1/4 pint.

2. (St. George’s.) Proof spirit, 1 fl. oz.; oxymel, 5 fl. dr.; decoction of barley, to make up 6 fl. oz. In relaxations and salivation.

=Gargle, Stim′ulant.= Syn. GARGARISMA STIMULANS, L. Prep. (Dr Copland.) Infusion of roses, 6-1/2 fl. oz.; dilute hydrochloric acid, 40 drops; tincture of capsicum, 1-1/2 fl. dr.; honey, 3 dr. See GARGLE OF CAPSICUM.

=Gargle of Tan′nin.= Syn. GARGARISMA ACIDI TANNICI, L. Prep. 1. (Beral.) Tannin, 1 dr.; honey of roses, 2 oz.; rose water, 2 fl. oz.; distilled water, 8 fl. oz.

2. (Jannart.) As the last, but using only half the quantity of tannin. In salivation and aphthous ulcerations.

=Gargle of Verd′igris.= Syn. GARGARISMA ÆRUGINUS, G. CUPRI ACETATIS, L. Prep. (Guy’s Hosp.) Oxymel of verdigris, 4 dr.; honey of roses, 2 oz.; barley water, 3-1/2 fl. oz. Used as a detergent for ulcers in the throat. If swallowed it produces violent vomiting. The addition of 2-1/2 oz. of water to the above produces a gargle sufficiently strong for most cases.

=Gargle of Vin′egar.= See GARGLE OF ACETIC ACID.

=Gargle of Zinc.= Syn. GARGARISMA ZINCI, G. Z. SULPHATIS, L. Prep. (Dr Copland.) Sulphate of zinc, 20 gr.; oxymel, 1 fl. oz.; rose water, 7 fl. oz. In aphthous sores, relaxations, ulceration of the tonsils, &c.

=GAR′LIC.= Syn. ALLIUM, L. The Allium sativum of botanists. It is diaphoretic, diuretic, expectorant, stimulant, and tonic; and externally, irritant, rubefacient, and even vesicant.——Dose, 1/2 dr. to 1-1/2 dr.; in enfeebled digestion, chronic diarrhœa, old chronic coughs, atonic dropsies, and worms. An antispasmodic and counter-irritant liniment is made of the juice, which was formerly esteemed in chest diseases and infantile convulsions. A small clove of garlic, or a few drops of the juice, was formerly introduced into the ear in certain forms of deafness. As a condiment its properties resemble those of the onion, than which it is much more powerful.

=GAR′NET.= In mineralogy, one of the precious stones or gems. The finest specimens of noble garnet (SYRIAN or ORIENTAL GARNET) are brought from Pegu. According to chemical analysis, the garnet is a double silicate of alumina and lime, coloured with iron and manganese.

=Garnet, Facti′′tious.= See PASTES.

=GA′RUM.= [L.] A species of pickle or sauce prepared of fish, in a state of incipient putrefaction, strongly salted and seasoned with aromatics. According to Pliny, the Romans used a species of lobster for this purpose.

=GAS.= Syn. GAZ, Fr. A permanently elastic aëriform fluid. In English the term ‘air’ is now usually restricted to the gaseous mixture forming the atmosphere, but it was formerly used as a synonym for ‘gas.’ The principal gases are the elementary bodies hydrogen, chlorine, oxygen and nitrogen, and the compounds ammonia, carbonic acid, carbonic oxide, carburetted hydrogen, hydrochloric acid, phosphoretted hydrogen, protoxide of nitrogen, sulphuretted hydrogen, and sulphurous acid. See these substances under their respective heads.

=Gas.= Syn. COAL GAS, ILLUMINATING G. The term ‘gas’ is popularly applied to the important mixture of hydrocarbons produced by the destructive distillation of pit-coal, and now employed as a source of artificial light in most of large towns of Europe and America. Although artificial illumination by means of coal-gas was, previous to 1819, used in Great Britain in isolated cases, and had been employed for the occasional lighting up of the mansion of Culrose Abbey in Scotland, by Lord Dundonald, as far back as 1787; and by Murdoch, in 1798, for lighting the foundry of Boulton and Watts in Soho, it does not appear to have been generally adopted in London, and the other large towns of England and Scotland until that year; since which time to the present artificial gas illumination has steadily progressed, and increased to so enormous an extent, that some works are now delivering millions of cubic feet of coal-gas a day. The apparatus used in the manufacture of gas on the large scale consists essentially of a system of closed retorts (a) of cast iron or fire-clay, generally having the form of a flattened cylinder, and arranged in sets of three or five, and heated by the same coal fire, as shown in the accompanying drawing.

The quantity of coal required to charge each retort is about two bushels, and it takes about four hours for the coal to give off all its gas. When it has done this the resulting coke is removed from the retort, and a fresh charge of coal is thrown into it, the mouth of the retort being then closed with a thick iron plate, and luted with clay. An iron pipe ascends from the upper side of the front of the retort, projecting from the furnace, and after describing a curve at its upper extremity, this iron pipe opens into a much wider tube, called the hydraulic main (b), which latter passes horizontally along the front of the range of furnaces, the tubes from all the retorts dipping into it. The hydraulic main is always kept half full of the water and the tar which condenses from the ascending gas; owing to which arrangement the opening into each retort is effectually closed by a water-valve, and thus permits a fresh charge of coals to be thrown in, and of coke to be withdrawn in any one or more of the retorts, without interfering with the distillation going on in the others.

The aqueous portion of the liquid deposited in the hydraulic main, which is known as the ammoniacal liquor, and forms the principal source of the commercial salts of ammonia, consists principally of solution of carbonate of ammonium, but contains also sulphide, cyanide, and sulphocyanide of ammonium. After it leaves the hydraulic main, the gas passes into the condenser (e), which is composed of a series of bent iron tubes (shown in the plate), these being kept cool either by the large surface they expose to the air, or, if necessary, by means of a stream of cold water applied to the outside.

Any of the volatile hydrocarbons or salts of ammonia escaping condensation in the hydraulic main are arrested in the condensers, but not always; hence it is necessary to afterwards carry the gas through a scrubber (not figured in the plate) or case containing pieces of coke, over which a stream of water being made to trickle, absorbs any remaining ammoniacal vapours. The gas next passes through the lime purifier (f), an iron box fitted with shelves, on which is placed slaked lime, which absorbs the carbonic acid, and part, but not the whole of, the sulphuretted hydrogen contained in the gas. Of the many methods devised for the removal of the sulphuretted hydrogen, none appears to be so successful and economical as that which consists in passing the gas over a mixture of sulphate of iron, slaked lime, and sawdust.

The gas, after it has become purified by the foregoing processes, is passed into the gasometer (g) (part of which is represented in the plate), whence it passes into the mains, by which it is conveyed to the various condensers. Another prejudicial impurity formed in gas is carbon disulphide, which when burned gives rise to small quantities of sulphuric acid, and this in time attacks certain kinds of furniture, as well as the bindings of books.

Dr Angus Smith effects the removal of the disulphide by passing the gas through a solution of plumbic oxide in caustic soda, diffused through sawdust.

The quality of coal-gas is largely dependent upon the temperature employed in its manufacture. If the retorts are insufficiently heated, the result will be the formation of certain easily-condensable hydrocarbons, which not only diminish the bulk of the gas, but cause considerable inconvenience by collecting in and blocking up the pipes. On the contrary, should too much heat be used, the gas becomes partially decomposed by contact with the red-hot retort, and deposits on its sides the substance known as “gas carbon,” thus not only removing to a certain extent the constituent to which the gas owes its illuminating power, but impoverishing its lighting qualities still more, by diluting it with an unnecessary quantity of liberated hydrogen. These latter effects are forcibly illustrated in the following analysis of the gas collected from Wigan cannel coal at different periods of the distillation.

The best gas is said to be produced when the retorts are heated to a bright cherry red.

In 100 Volumes. 1st Hour. 5th Hour. 10th Hour.

Olefiant gas and volatile hydro-carbons 13·0 7·0 0·0 Marsh gas 82·5 56·0 20·0 Carbonic oxide 3·2 11·0 10·0 Hydrogen 0·0 21·3 60·0 Nitrogen 1·3 4·7 10·0

“The value of gas as an illuminating agent may be said to depend on the amount of hydrocarbons present, and on the relation which the carbon bears to the hydrogen in these substances. In marsh gas, CH_{4}, which is, practically speaking, non-luminous, the per-centage composition is, carbon 75, and hydrogen 25. In olefiant gas, C_{2}H_{4}, the carbon is 85·7, and the hydrogen 14·3, and the gas possesses a correspondingly greater amount of illuminating value. In acetylene, C_{2}H_{2}, we have a gas of still greater illuminating value, the proportion of carbon to hydrogen being also greater, the per-centage composition being, carbon 92·3, and hydrogen 7·7. In benzol, C_{6}H_{6}, we have the same per-centages; while in naphthalene, C_{10}H_{8}, a still higher ratio between the carbon and hydrogen exists, and a corresponding increased value in light-giving power. It was formerly taken as an axiom that the illuminating value of a mixture of gases was also proportionate to the relation between the carbon and hydrogen, but although this is very good as a rough criterion in practice, the statement must not be accepted as strictly true. The illuminating power of a mixture of gases is known now to depend far more on the nature of the particular compounds present, than upon the absolute proportion between the hydrogen and carbon; for while on the one hand it is possible to have a gas (marsh gas) containing as much as 75·4 per cent. of carbon, and yet which is valueless for illuminating purposes; it is also possible to have a mixture of gases in which the per-centage of carbon is far less, although the illuminating value is much greater.”[326]

[Footnote 326: ‘Chemistry, Theoretical, Practical, and Analytical,’——Mackenzie.]

Coal gas consists of a mixture of the following bodies:

Marsh gas (light carbonetted hydrogen). Olefiant gas (heavy ” ” ). Hydrogen. Carbonic oxide. Nitrogen. Vapours of liquid hydro-carbons. Vapour of bisulphide of carbon.

The yield of gas, and also the illuminating power of the product, vary greatly with different kinds of coal. The average yield may be roughly estimated at 10,000 cubic feet of gas per ton of coal.[327]

[Footnote 327: For practical details respecting the manufacture of this product, see the article COAL GAS in ‘Ure’s Dictionary of Arts, Manufactures, &c.,’ ‘Wagner’s Chemical Technology,’ and ‘Chemistry, Theoretical, Practical, and Analytical.’]

Anthracite is by no means suited for a gas coal. The best coals for this purpose are those which are bituminous; they comprise caking coal, parrot coal, and certain varieties of cannel coal. London gas (which is generally deficient in illuminating power) is manufactured principally from Durham and Newcastle coal.

In addition to the elementary composition of the coal, the amount and nature of the volatile matter contained in it is an important factor in its value as a source for gas. It should also yield a small amount of ash, and be as free as possible from sulphur, besides which its ultimate analysis should show a comparatively small proportion of oxygen. If there be an excess of this latter element, the production of the hydrocarbon illuminants will be diminished, since the hydrogen which would go to their formation would unite with the oxygen to form useless water.

The late Charles Mansfield proposed to increase the illuminating power of ordinary coal-gas, and to render water gas or even atmospheric air luminiferous, by passing them through sponges or over trays containing mineral naphtha or benzole; and a patent was taken out for this purpose. The gas so treated imbibes or dissolves a portion of the liquid, and burns with increased brilliancy. The method of saturating the gas with the liquid hydrocarbon is as follows:——“The apparatus consists of a brass reservoir or chamber attached to the end of the gas-pipe, near the burner. This reservoir may be in the shape of an oil-flask, made air-tight, with a screw-joint, or other means of supplying any highly volatile oil, turpentine, or mineral naphtha, and should be kept about half full. Into this reservoir the gas-pipe ascends a little above the surface of the oil; a very small jet-pipe of gas, regulated by a stop-cock, is branched off below this chamber, to supply a minute flame, so as to cause a sufficient evaporation from the oil to unite with the gas in the flask receiver. The whole is, of course, surmounted with the usual burner and lamp-glass.”

The naphthalising of gas did not work well on a large scale. Recently, however, an attempt was made to get up a company in England to work a French patented process, which differed only from that of Mansfield’s in the substitution of another hydrocarbon (probably a petroleum product) for benzol. The chemical and technical journals exposed this invention, and prevented the sinking of capital in a worthless undertaking. On a small scale, simple ‘naphthalisers’ appear to work very well.

The illuminating power of gas, as well as of other sources of light, may be directly ascertained by what is termed the ‘comparison of shadows,’ or indirectly, and more conveniently, by chemical analysis.[328] See AIR GAS, ILLUMINATION.

[Footnote 328: See ‘Watts’s Dictionary of Chemistry,’ vol. i.]

=GASTROPHAN= (Apotheker J. Fürst, Prague). For strengthening the digestion and improving the appetite. Quassia, 30 grammes; orange berries, 15 grammes; galangal, 4 grammes; cardamoms, 2 grammes; star anise oil, 10 drops; orange-peel oil, 10 drops; spirit, 180 grammes; water, 120 grammes; digested and filtered. (Hager.)

=GASTROPHILE= (Dr Borchard). There are several numbers of this preparation. Soda water, containing common salt, perhaps in some of the numbers mixed with Glauber’s salts.

=GAZ′OGENE.= [Fr.] Syn. AËRATING MACHINE. A portable apparatus for aërating water and other liquids. Many forms have been given to this instrument, but in all the principle is the same. Powders for generating carbonic acid gas are placed in a separate compartment, and the liquid to be aërated in another. The two compartments are connected by a suitable tube, and a second tube, furnished with a spring tap, affords an exit for the aërated liquid. By the aid of the gazogene, water, wine, ale, &c., may in a few minutes be fully saturated with carbonic acid gas, and so rendered brisk and piquant. By using fruit syrups, manufactured from English and foreign fruits, the most delicious aërated summer beverages can be made, resembling those so much esteemed by travellers in the South of Europe and the sea-board cities of the Western world.

The following are the proportions of soda and acid required for charging gazogenes:

For 2 pints, powdered tartaric acid, 280 grains; bicarbonate of soda, 340 grains.

For 3 pints, powdered tartaric acid, 340 grains; bicarbonate of soda, 420 grains.

For 5 pints, tartaric acid, 620 grains; carbonate of soda, 760 grains.

Put the acid and soda in different coloured papers.

=GEDACHTNISS-LIMONADE——Mnemonic Lemonade= (manufactured by G. M. Raufer, Vienna). A mixture of 15 parts phosphoric acid, 15 parts glycerin, 70 parts water. (Schädler.)

=GEHOR INSTRUMENT.= Instrument for deafness (Apotheker F. Brunner, Troppau). A little tube of silver plate, 2 centimètres long and as thick as a straw, with a small mussel-shaped widening at one end, which is wrapped in cotton wool, to be inserted in the ear.

=GEHOR LIQUOR=, Schweizer——Swiss Cure for Deafness (Raudnitz). Water mixed with a little coarse brandy. (Wittstein.)

=GEHOROL——Oil for Deafness= (C. Brockelmann, Soest). Provence oil adulterated with sunflower oil and mixed with very small traces of camphor and cajeput, sassafras, and rosemary oils. (Hager.)

=GEL′ATIN.= Syn. GELATINE; GÉLATINE, Fr.; GELATINA, L. Animal jelly, obtained by the prolonged action of boiling water on the organic tissue of the bones, tendons, and ligaments, the cellular tissue, the skin, and the serous membranes. Glue and size are coarse varieties of gelatin, prepared from hoofs, hides, skins, &c.; and isinglass is a purer kind, obtained from the air bladders of some other membranes of fish.

Prop., &c. Gelatin is insoluble in cold water, but dissolves with greater or less readiness on the application of heat, according to the source where it is obtained, and in this state forms a tremulous and transparent jelly on cooling; it is insoluble in both alcohol and ether, and is decomposed by the strong alkalies and acids; with tannic acid it forms an insoluble compound of a buff colour, which is the basis of leather; when acted on by cold concentrated sulphuric acid, it yields glycocoll or gelatin sugar; and when boiled with strong alkalies, it yields glycocoll and leucine. Chlorine passed into a solution of gelatin occasions a dense white precipitate (chlorite of gelatin), which ultimately forms a tough, elastic, pearly mass, somewhat resembling fibrin.

Tests. Its aqueous solution is recognised as follows:——1. It gelatinises on cooling. 2. It is precipitated by alcohol. 3. Bichloride of mercury gives a whitish flocculent precipitate. 4. Tannic acid or infusion of galls gives a copious yellowish-white, curdy precipitate, which, on being stirred, coheres into an elastic mass, insoluble in water, and incapable of putrefaction, and which, when dried, assumes the appearance of over-tanned leather. 5. The gelatinising property is destroyed by nitric acid. 6. It is not affected by either alum or acetate of lead. In this respect it differs from chondrin.

Qual. The goodness of commercial gelatin intended for food is readily proved by pouring boiling water over it, and digesting the two together for a short time. If it is pure and wholesome, its colour remains unaltered, and during its solution it continues entirely free from smell. The resulting solution and jelly are also odourless, neutral to test-paper, free from unpleasant taste, and perfectly transparent. If it forms a yellow gluey-looking mass, and evolves an offensive odour, it should be rejected as of inferior quality, and unfit for culinary purposes.

Uses, &c. Gelatin is largely employed as an article of food, as in soups, jellies, &c.; but its value in this respect has been, perhaps, overrated.[329] Animals fed exclusively on gelatin die of starvation. But when mixed with other food, especially with substances abounding in albumen, casein, or fibrin, gelatin may be useful as an aliment, and serve directly to nourish the gelatinous tissues. (Liebig.) Hence gelatin is a fitting substance to form part (but only a part) of the diet of convalescents, as it conveys nutrition directly to these tissues, without tasking the diminished powers of life for its conversion; but its use should be accompanied by a proper quantity of azotised animal food to supply the elements to the blood, for the support and increase of the muscular tissue, or fleshy portion of the body. In France gelatin obtained from bones is employed as a part of the diet in hospitals with the best effect, materially abridging the period of convalescence; but when given alone, all animals soon become disgusted with it, and die if not supplied with other food. (D’Arcet.) See GLUE, ISINGLASS, and below.

[Footnote 329: The reader interested in this subject should consult a paper by Carl Voit in the ‘Zeitschrift für Biologie,’ viii, 297-388.]

=Gelatin, Bone.= Obtained from crushed bones by boiling with water, or by the action of steam and water successively, either with or without pressure; or by maceration in dilute hydrochloric acid, to extract the phosphate of lime, the remaining gelatinous mass being well washed in cold water, and afterwards dissolved in boiling water in the usual manner. A little carbonate of soda is commonly added to the last water. Gelatin has even been extracted from fossil bones. “A soup was prepared from one of the bones of the great mastodon by the préfet of one of the departments of France.” (Pereira.) Butchers’ meat contains, on an average, 24% of dry flesh, 56% of water, and 20% of bone. The last will yield, by proper treatment, nearly 1-3rd of its weight of dry gelatin, or a quantity equal to about 6% of the meat from which it is cut. This, as well as other varieties of gelatin, is frequently blanched by sulphurous acid or animal charcoal, and tinged of various colours with the ordinary vegetable dyes. Thus, blue is given with sulphate of indigo or the juice of blue berries; green, with the juice of spinach; and red, with juice of red-beet.

=Gelatin, French.= Syn. CAKE GELATIN. Gelatin made up into small thin cakes, like the finer sorts of glue. A good deal of it is prepared in Paris from the cuttings of the skins used in making kid gloves and slippers.

=Gelatin, Patent.= Various qualities of gelatin are manufactured from glue pieces, or cuttings of the hides of beasts and skins of calves, and from inferior isinglass. According to Mr Nelson’s specification, the crude materials, freed from hair, wool, flesh, and fat, after being thoroughly washed and ‘scored,’ are macerated for 10 days in a lye of caustic soda, and are then placed in covered vessels at a temperature varying from 60° to 70° Fahr., until they become tender; they are next washed to free them from alkali, and are then exposed to the vapour of burning sulphur until they acquire a sensibly acid reaction; they are now dissolved in water contained in earthen vessels heated to 150° Fahr., and the solution, after being strained, is put into ‘settling vessels,’ and heated to 100° to 120° Fahr., for 8 or 9 hours; at the end of this time the clear liquor is drawn off, and poured on the ‘cooling slabs,’ to the depth of about 1/2 an inch. As soon as the jelly is cold, it is cut into pieces, and washed in water until perfectly free from acid. It is then redissolved in water at about 85°, the solution poured out on slabs as before, and when cold, it is cut up, and, lastly, dried on nets.

According to another specification (Rattray’s Patent) glue-pieces are steeped in water until they begin to putrefy, then washed with water, drained, and put from 12 to 24 hours into water strongly soured with sulphurous acid; they are afterwards washed first with cold water, and then in water at 120° Fahr., and are lastly converted into size by digestion for 24 hours in water at 120° Fahr., the resulting solution being filtered through bags of double woollen-cloth.

Patent gelatins are often sold cut up in imitation of ‘picked isinglass,’ to which, for the preparation of jellies, soups, and blancmanges, they are not much inferior.

=Gelatin, Rough.= Syn. GELATINE BRUT, Fr. From the skulls of oxen, the spongy insides of the horns and ribs, and from several other soft bony parts (deprived of fat), by washing them in water, digesting in an equal weight of hydrochloric acid of 6° Baume, in cold weather, and 4° or 5° in summer, for 10 days, then in acid of only 1° Baume for 24 hours longer; afterwards soaking and washing in successive portions of cold water until all the acid is washed out, adding an ounce of carbonate of soda to the last water. Used to make glue, &c. A similar article is prepared from the bones of sheep. The pieces, after being treated as above, are steeped in boiling water for a few minutes, wiped dry, and shaken together in a bag to remove the internal pellicle; after which they are cut into squares or dice to disguise them, and finally dipped into a hot solution of gelatin to varnish them. In this state the article is called ‘GELATINE BRUT FIN,’ Used to make soup. It keeps better than the cakes of portable soup. When less carefully prepared, it is also used to make glue for fine work. See BONE GELATIN.

=GELEE (pour le Goitre).= See LINIMENT OF IODIDE OF POTASSIUM.

=GELSEMIUM SEMPERVIRENS.= Syn. GELSEMIUM NITRIDUM, GELSEMIUM SEMPERVIRENS, GELSEMIUM LUCIDUM, ANONYMUS SEMPERVIRENS, BIGNONIA SEMPERVIRENS; LISANTHUS SEMPERVIRENS. The YELLOW JASMINE, or WOODBINE. The CAROLINA JASMINE.

Different botanists have placed the plant in different natural orders. De Candolle assigns it to the Loganiaceæ; Decaisne to the Apocynaceæ; Chapman to the Rubiaceæ.

The root, which is the only part of this plant employed in medicine, and of which a fluid extract has been introduced into the United States Pharmacopœia, as met with in English commerce occurs in two states; either in packets prepared by the shakers of New Lebanon, which contain the root in small pieces, formed into a compact mass by hydraulic pressure, and in which state it is difficult to powder; or it is simply sold cut up into pieces varying from two to eight inches in length, and one-third to three fourths of an inch in diameter. It is frequently mixed with about half its bulk of long, wiry, pale-brown rootlets.

The so-called gelsemium root consists chiefly of subterranean stem with a small proportion of true root, occasionally a slender piece of the aërial stem may be found intermixed, and is readily distinguished by its purplish colour and hollow centre, and by the silky and tow-like fibre, rendered visible when the epidermis is peeled off (fig. 1 e).

The true root is hard and woody, slightly undulated in outline, very sparingly branched, except in the slender pieces, externally of a pale brown colour, nearly smooth, and furnished with a thin scurfy cuticle, which is slightly cracked longitudinally. When a transverse section is examined with a lens, the bark of the root is seen to be very thin, and to consist of two layers, the inner one being usually almost as pale as the woody portion, and of somewhat soft texture, the outer one is darker and more compact (fig. 1 b, c).

The meditullium, or woody portion of the root occupies nearly its whole diameter, is of a pale yellowish bright colour, the yellow tint becoming much more distinct when the root is wetted. The medullary rays are white and very distinct, and the woody tissue between the rays is very porous, the pores being very small, but visible to the unaided eye, especially when the root is broken instead of cut (fig. 1 d). There is no pith or central cavity in the root. The root has a bitter taste and pleasant flavour, somewhat between those of senega and green tea; this is more readily perceived in the tincture.

The subterranean stem (fig. 1 a) is also furnished with rootlets, but is easily distinguished from the root by the presence of a small, dark coloured, central cavity representing the pith, and by the external surface being rougher, and frequently variegated with dark longitudinal lines, which are the remains of the same purplish cuticle which presents so marked a feature in the aërial stem. The bark is thicker than that of the true root, and the inner layer is usually dark brown. If the subterranean stem is broken slowly and carefully, a thin row of silky fibres projects fully a quarter of an inch from the broken edge. The fibres do not appear when the bark of the root is broken, and thus serve to distinguish the stem of this drug from the root. Experiments as to the relative value of the bark of the root and stem are wanting. The bark of the stem has the same bitter taste as that of the root, and if it be hereafter shown that it is equally active, the above character of scattered strong fibres, taken in conjunction with the flavour of the drug and its porous structure, will serve to distinguish it from all other roots and stems used in materia medica.[330]

[Footnote 330: Holmes.]

Medicinal properties.——The American medical journals record the successful administration of gelsemium in a great number and variety of diseases, including intermittent, remittent, typhoid, and yellow fevers, the irritative fevers of childhood, inflammation of the lungs and pleura, dysentery, rheumatism, and other inflammatory affections, neuralgia, obstinate menstruation, delirium tremens, morbid wakefulness, St. Vitus’ dance, hysteria, epilepsy, spasmodic stricture of the urethra, and gonorrhœa. Dr Hurd, an American physician, reports very favorably of the drug as a cardiac sedative, and considers it more efficient than any other remedy in the palpitation and the difficult breathing that accompany heart disease; and Dr Hill, of Maine, finds it when combined with bromide of potassium useful in irritable bladder.

Its principal use, however, in American medical practice has been as a febrifuge. In periodic fevers it has been employed with great advantage, as well as in cases of intermittent fever, which having failed to yield to quinine alone, succumbed, when this latter medicine was combined with gelsemium.

In England gelsemium has been successfully employed for the relief of facial neuralgia, or of the pain caused in the face and jaws by decayed teeth; as well as in obscure nervous affections and severe headaches. It is given principally in the form of tincture; but sometimes in powder in doses of from one to two grains.

The therapeutic action of gelsemium is believed to be due to the sedative effect it exercises on the nervous and arterial systems——hence its power in controlling the nervous irritability so prevalent during fever. In moderate doses it causes a sensation of agreeable langour, accompanied with muscular relaxation; in larger doses, dizziness, dilated pupil, double vision, general muscular debility and prostration; these symptoms being accompanied by a diminution in the force and frequency of the pulse as well as in the respiration. At the same time the patient becomes insensible to pain; but is free from stupor and delirium. These symptoms are said to pass off, after a time, and to be attended with no unpleasant results.

The ‘Lancet’ as well as many of the American medical journals record several cases of poisoning arising from giving an overdose of this drug. The symptoms are a great prostration of nervous energy, accompanied by paralysis of sensation and motion. When death occurs it is probably owing to syncope. The antidotes are, first, an emetic, and after this has acted, stimulants, such as carbonate of ammonia with brandy, or aromatic spirits of ammonia. In cases accompanied with insensibility, recourse should be had to electricity.

Kollock, in the ‘American Journal of Pharmacy’ for 1855, states that he found the root on analysis to yield volatile oil, dry acrid resin, fatty resin, fixed oil, gallic acid, starch, pectic acid, albumen, extractive matter, lignin, gum, a yellow colouring matter, mineral matter (chiefly salts of potassium, calcium, magnesium, iron and silica), and an alkaloid, to which the name gelseminine or gelsemia has been given. Kollock also states that the leaves and flowers contain the same ingredients as the root, although in much smaller quantities.

Eberle, in the ‘American Journal of Pharmacy’ for 1864, says he failed to obtain gelseminine from the root. In a paper contributed to the ‘American Journal of Pharmacy,’ for January, 1870, by Dr Wormley, the author stated that he said he not only succeeded in obtaining pure gelseminine from the root, but also a peculiar acid which he calls gelseminic, or gelsemic[331] acid; which he regards as existing in combination with the gelsemia, forming the gelsemate of gelsemia.

[Footnote 331: Professor Sonneschien, having submitted the so-called Gelseminic Acid to analysis thinks there can be no doubt that it is perfectly identical with æsculin, a glucoside obtained from the bark of the horse-chesnut——the Esculus hippocastanum.]

Probably the alkaloid gelseminine may at some future time be introduced into medicine, since it would appear to be the chief ingredient to which the root owes its activity. It is strongly poisonous. Dr Wormley injected one eighth of a grain under the skin of a large cat, which in 40 minutes exhibited great prostration, and died in an hour and a half from the time of the injection of the poison. The properties of the gelseminic acid, the resin, the volatile oil, and other ingredients of the root, have not been fully investigated. See TINCTURE OF GELSEMIUM, GELSEMININE.

In the ‘American Journal of Pharmacy’ for April, 1877, Dr Wormley gives the following directions for the preparations of gelseminic acid, and gelsemine:——A given volume of fluid extract, acidulated with acetic acid, is slowly added with constant stirring to about eight volumes of water; after the separated resinous matter has completely deposited, the liquid is filtered, and the filtrate concentrated on a water bath, to something less than the volume of fluid extract employed. The gelseminic acid is then extracted from the concentrated fluid by ether, after which the liquid is treated with slight excess of carbonate of sodium, and the gelsemine extracted with ether or chloroform. For the extraction of the first of these principles, it is not essential that the liquid should be acidulated, but in the presence of a free acid the results are more satisfactory.

=GEMS=. Syn. JEWELS; GEMMÆ, L. “Gems are precious stones, which, by their colour, limpidity, lustre, brilliant polish, purity, and rarity, are sought after as objects of dress and decoration. They form the principal part of the crown jewels of kings, not only from their beauty, but because they are supposed to comprise the greatest value in the smallest bulk; for a diamond, no larger than a nut, or an acorn, may be the representative sign of the territorial value of a whole country, the equivalent in commercial exchange for a hundred fortunes, acquired by severe toils and privations.” “Among these beautiful minerals mankind have agreed in forming a select class, to which the title of gems or jewels has been appropriated; while the term precious stone is more particularly given to substances which often occur under a more considerable volume than fine stones ever do. Diamonds, sapphires, emeralds, rubies, topazes, hyacinths, and chrysoberyls, are reckoned the most valuable gems;——crystalline quartz, pellucid, opalescent, or of various hues, amethyst, lapis lazuli, malachite, jasper, agate, &c., are ranked in the much more numerous and inferior class of ornamental stones.” (Ure.)

Tests. The only tests applicable to gems and precious stones are the determination of their relative hardness and their specific gravity. By the first test, pastes or factitious gems are readily detected; but beyond this, owing to the difficulty of applying it, it ceases to be useful to persons unconnected with the trade. The determination of the specific gravity is, however, of more general application, as gems are generally dismounted when offered for sale, or are so set that they may be removed from their ‘mountings’ without injury or inconvenience. See SPECIFIC GRAVITY, and below.

Obs. The relative hardness of the different substances is measured by the power they possess of cutting or scratching the other substances having a smaller number attached to them in the table. Thus, no gem but the DIAMOND (20) will scratch either the RUBY (17) or the SAPPHIRE (16); and, for the same reason, a blue stone that will cut the EMERALD or the TOPAZ can be no other than the SAPPHIRE. The sp. gr. is ascertained in the usual manner, and will be found sufficiently indicative of the true nature of the stone when considered in connection with its other characteristics. The index of refraction is a certain key to the quality of the stone, in the hands of those who are capable of determining it, and may be applied to either mounted or unmounted gems. The most convenient instrument for the purpose is Wollaston’s ‘REFLECTING-GONIOMETER,’

=Gems, Facti′′tious.= These, with few exceptions, are made of very pure, fusible, highly transparent, and dense glass, usually termed ‘PASTE’ or ‘STRASS,’ which is generally formed of oxide of lead, potassa, and silica, with small quantities of other ingredients to increase the brilliancy and clearness. The characteristic tints are imparted by the addition of metallic oxides. The beauty of artificial stones and gems depends, chiefly, upon the tint of the real stones being exactly imitated, and upon proper care and skill being exercised in the cutting, polishing, and mounting them. All the coloured glasses, and enamels, may be worked up into artificial gems.

TABLE of the Hardness, Specific Gravity, and Refractive Power of the principal GEMS and PRECIOUS STONES, and some other MINERALS; compiled expressly for this work.

---------------------------------------------------------------------------------- | Name. | Relative | Specific Gravity. | Index of Reflection. | | | Hardness. | | | ---------------------------------------------------------------------------------| | Agate | 12 | 2·6 | | | Amethyst (occidental) | 11 | 2·7 | | | Calcareous spar | 6 | 2·7 | | | Chalk | 3 | 2·7 | | | Chrysolite | 10 | 3·7 | | | Cornelian | 11 | 2·7 | | | Crystal | 11 | 2·6 | | | Diamond (bluish) | 19 | 3·3 | } | | ” (cubic) | 18 | 3·2 | } | | ” (from Ormus) | 20 | 3·7 | } 2·439 | | ” (pink) | 19 | 3·4 | } | | ” (yellowish) | 19 | 3·3 | } | | ” (average colourless)| 19 to 20 | 3·3 to 3·55 | } | | Emerald | 12 | 2·8 | | | Fluor spar | 7 | 3·5 | 1·434 | | Garnet | 12 | 4·4 | 1·815 | | Glass | { } | 2·3 to 3·62 | 1·525 to 2·028 | | ” (crystal or flint) | {various} | 3·0 ” 3·6 | 1·830 ” 2·028 | | ” (plate) | { } | 2·5 ” 2·6 | 1·514 ” 1·542 | | Gypsum | 5 | 2·3 | | | Jasper (green) | 11 | 2·7 | | | ” (reddish yellow) | 9 | 2·6 | | | Onyx | 12 | 2·6 | | | Opal | 10 | 2·6 | | | Quartz | 10 | 2·7 | 1·548 | | Ruby | 17 | 4·2 | } 1·779 | | ” (pale, from Brazil) | 17 | 3·5 | } | | ” (spinelle) | 13 | 3·4 | 1·764 | | Sapphire (deep blue) | 16 | 3·8 | } 1·794 | | ” (paler) | 17 | 3·8 | } | | Sardonyx | 12 | 2·6 | | | Schoerl | 10 | 3·6 | | | Topaz | 15 | 4·2 | | | ” (Bohemian) | 11 | 2·8 | | | ” (whitish) | 14 | 3·5 | | | Tourmaline | 10 | 3·0 | | | Zeolite | 8 | 2·1 | | | Zircon | —— | —— | 1·961 | ----------------------------------------------------------------------------------

MM. Fremy and Feil have lately succeeded in manufacturing artificial corundum, ruby and topaz, having a composition the same as the natural stones. The process by which they have effected this consists in fusing together at a red heat, in the furnace of a glass works for a considerable time, a fusible aluminate (such as aluminate of lead), and some silicious body.

The silica is found to unite with the lead, and to liberate the alumina in the crystalline form. When equal weights of alumina and red lead are heated together in a crucible made of some refractory silicious substance, the above conditions if the temperature has been maintained sufficiently long and high ensue, and there is found in the crucible at the end of the operation a layer of silicate of lead, and very frequently another of pure crystallised alumina or corundum.

The ruby colour is given by adding to the mixture in the crucible two or three per-cent. of bichromate of potash, the blue being produced by the addition of a small quantity of oxide of cobalt, with a trace only of bichromate of potash. A film of silicate of lead very frequently adheres to the ruby crystals, and this has to be removed.

In some instances, however, the crystals occur nearly pure, and are precisely similar to the natural gems in crystalline form, composition, hardness, and lustre.

Upon being heated, the artificial ruby, like the natural one, loses its rose colour, and recovers it again on cooling. It is said that the factitious gems hitherto obtained are not, as a rule, equal in lustre to the natural ones, and are consequently not so well suited for jewellers’ work; also that they do not present to the lapidary conditions favorable to cleavage or cutting. They are, however, very well adapted for the works of watches. See ENAMELS, PASTES, &c.

=GENE′VA.= See GIN and HOLLANDS.

=GEN′TIAN ROOT.= Syn. GENTINÆ RADIX, L. The dried root of Gentiana lutea, or ‘yellow gentian.’ Dose, 10 to 30 gr.; as a simple bitter tonic, and stomachic, in dyspepsia, loss of appetite, gout, &c. It was formerly a favourite remedy in agues. “Joined with galls or tormentil, and given in sufficient quantity, it has not failed in any intermittents in which I have tried it.” (Dr Cullen.) In excessive doses it is apt to relax the bowels and disturb the system. When taken for some time, it imparts its bitter flavour to the perspiration and urine. See DECOCTION, EXTRACT, &c.

=GEN′TIANIN.= Syn. GENTIANINE; GENTIANINA, L. A substance obtained by MM. Henry and Caventou from the root of common gentian.

Prep. 1. Gentian root (in powder) is digested for 2 or 3 days in cold ether, with agitation, and the filtered tincture evaporated to dryness; the residuum is dissolved in rectified spirit, and the solution is again evaporated; the semi-crystalline mass is, lastly, redissolved in either alcohol or ether, and crystallised by careful evaporation.

2. (Magendie.) The ethereal extract is exhausted with cold alcohol (rectified spirit), as before, and the resulting tincture is evaporated to dryness; the residuum is dissolved in water, calcined magnesia added in excess, and the whole boiled and filtered; the sediment is digested in ether, and the ethereal tincture allowed to crystallise by slow evaporation.

Prop., &c. Gentianin forms golden-yellow needles, scarcely soluble in cold water, but very soluble in alcohol and ether. It is a powerful bitter and stomachic.——Dose, 1/2 gr. to 2 gr.

=GER′MAN PASTE.= Prep. From pea-meal, 2 lbs.; sweet almonds (blanched), 1 lb.; fresh butter or lard, 1/4 lb.; moist sugar, 5 oz.; hay saffron, 1/2 dr.; beat to a smooth paste, adding cold water q. s., granulate the mass by passing it through a colander, and expose the product to the air in a warm place, until quite hard and dry. The addition of 2 or 3 eggs improves it. Used to feed larks, nightingales, and other insectivorous birds. It will keep good for 12 months in a dry place.

=GER′MAN SILVER.= Syn. ALBATA, ARGENTAN, Electrum, NICKEL SILVER, TUTENAG, VIRGINIAN PLATE, WHITE COPPER. A well-known alloy, the finer varieties of which nearly equal silver in whiteness and susceptibility of receiving a high polish, whilst they surpass it in hardness and durability. The following formulæ are from the highest authorities, or are the results of actual analysis of the finest commercial samples:——

Prep. 1. Copper, 50 parts; nickel, 20 parts; zinc, 30 parts. Very malleable, and takes a high polish.

2. Copper, 50 parts; nickel, 26 parts; zinc, 24 parts. Closely resembles silver; an excellent sample.

3. Copper and zinc, of each 41 parts; nickel, 18 parts. Rather brittle.

4. (M. Gersdorff.) Copper, 50 parts; nickel and zinc, of each 25 parts. Very white and malleable, and takes a high polish. Recommended as a general substitute for silver.

5. (Gersdorff.) Copper, 60 parts; nickel and zinc, of each 20 parts. For castings, as bells, candlesticks, &c.

6. (Gersdorff.) Copper, 60 parts; nickel, 25 parts; zinc, 20 parts. For rolling and wire. Very tough and malleable.

7. (Sample made from the ore of Hilburghausen.) Copper, 40-1/2 parts; nickel, 31-1/2 parts; iron, 2-1/2 parts; zinc, 25-1/2 parts. Equal to the best Chinese sample.

8. (Pelouze.) Copper and nickel, equal parts. Recommended by M. Pelouze as superior to any of the alloys containing zinc.

9. (Pelouze.) Copper, 2 parts; nickel, 1 part. Not so white as the last, but more malleable.

10. (White Copper from China.)——a. Copper, 30 parts; nickel, 36 parts; zinc, 34 parts.

b. (Said to be prepared from native ore.) Copper, 41 parts; nickel, 32 parts; iron, 2-1/2 parts; zinc, 24-1/2 parts. Silvery white, takes a high polish, very sonorous, malleable both cold and at a dull-red heat, and may be rolled into leaves or formed into wire.

11. (White metal spoon, sold as ‘German Plate.’) Copper, 55 parts; nickel, 24 parts; zinc, 16 parts; tin, 3 parts; iron, 2 parts.

Anal. This may be briefly described as follows:——a. 100 gr. of the alloy is digested in nitric acid q. s., diluted with a little water. If the sample is unequally attacked by the acid, and a white external shell is observed which dissolves more slowly than the internal portion, it is ‘plated’ on those parts with silver. If this silver shell or casing has a polished surface on both sides, the article has been ‘electro-plated,’ if the contrary is the case, it has most probably been plated in the usual way.

b. The solution being completed, heat is applied to expel the excess of acid, and the remainder is largely diluted with distilled water; dilute hydrochloric acid is now dropped in as long as it occasions a precipitate, and the whole, after being moderately heated for a short time, and cooled, is thrown upon a small paper filter; the precipitate on the filter is next washed with distilled water, carefully dried, and ignited in a small porcelain crucible, the filter itself being separately burnt on the cover of the crucible, and the ashes added to its contents prior to ignition. Every 143-1/2 gr. of the resulting fused chloride is equal to 108 gr. of metallic silver.

c. The filtered liquid (see b) is next treated with a stream of sulphuretted hydrogen, and the black precipitate is collected, washed, and digested in strong nitric acid; when the solution is complete sulphuric acid is dropped in to precipitate the lead (if any is present); if a precipitate is formed, the whole is evaporated to dryness, and the excess of sulphuric acid expelled by a rather strong heat applied towards the end; the dry mass is now collected on a filter, washed with a mixture of water and alcohol, dried, and exposed to slight ignition in a porcelain crucible. Every 152 gr. of the resulting dry sulphate is equal to 104 gr. of lead.

d. The liquor filtered from the sulphate of lead, or (in its absence) the nitric solution of the precipitate produced by the sulphuretted hydrogen (see c), is next treated with potassa, &c., as described under the analysis of brass. Every 40 gr. of the dry protoxide thus obtained represents 32 gr. of pure copper.

e. The liquor which was filtered from the precipitate produced by the sulphuretted hydrogen (see c) is boiled until it loses its offensive odour, and is then precipitated with carbonate of soda, in slight excess, and again boiled for a few minutes; the precipitate (mixed oxides of nickel and zinc) is collected, washed, and redissolved in dilute acetic or nitric acid, in excess; a current of sulphuretted hydrogen is next passed through the solution, the precipitate collected on a filter, washed, redissolved in hydrochloric acid, and the solution again treated with carbonate of soda; the last precipitate (oxide of zinc) is washed, dried, and gently ignited. Every 40 gr. of this oxide is equivalent to 32 gr. of metallic zinc.

f. The washings of the precipitated oxides and the liquid filtered from the precipitate occasioned by the sulphuretted hydrogen (see e) are mixed together, pure solution of ammonia added in considerable excess, and the mixture agitated for some time; the undissolved portion of the precipitate is then collected on a filter, washed with distilled water, redissolved in dilute nitric acid, again precipitated with solution of potassa, and this last precipitate (ferric oxide) washed, dried, ignited, and weighed. Every 80 gr. represents 50 gr. of metallic iron.

g. The ammoniacal solution filtered from the precipitate of sesquioxide of iron (see f) is precipitated with pure solution of potassa, boiled for a few minutes, and, when cold, thrown on a filter; the precipitate is, lastly, washed with hot water, dried, ignited, and weighed. Every 37-1/2 gr. of the oxide thus obtained is equal to 29-1/2 gr. of metallic nickel.

Obs. The manufacture of nickel or German silver has of late acquired an importance which is second only to that of silver plate itself. The superior quality of this alloy, and the graceful patterns which it is often made to assume in the hands of the accomplished artist cannot fail to have attracted the admiration of the majority of our readers. The value of correct information regarding the preparation of this alloy, and of a ready method of determining the composition of the most improved commercial samples will, therefore, be fully appreciated by every metallurgist who wishes to throw his wares into the arena of public competition. Much that is vended under the name of GERMAN SILVER is little better than the BRITANNIA METAL or PLATE PEWTER formerly so plentiful in every establishment in this country. German silver has quite superseded copper as the basis of ‘electro-plated goods.’[332]

[Footnote 332: See ELECTROTYPE.]

The union of the metals in the above formulæ is effected by heat with the usual precautions. When iron is ordered, it is generally added under the form of ‘tin plate.’ See ALLOY, BRASS, BRITANNIA METAL, BRONZE, &c.

=GER′MAN TIN′DER.= See AMADOU.

=GERMINA′TION.= The growth or vegetation of a seed by which a young plant is produced. The conditions essential to germination are the presence of warmth, air, and moisture. The most favorable temperature is between 60° and 85° Fahr., according to the habitat of the respective plants. Below 40° Fahr. most of the more perfect seeds either refuse to vegetate, or vegetate slowly and feebly; and at or near the freezing-point none of them undergo this change. At a temperature above 100° Fahr. the young germ is usually injured, and at about 125°, if it forms, it soon withers and dies. See MALTING, SEED, &c.

=GERMS.= The ‘germ theory of disease’ may be briefly stated to be that which supposes the cause of epidemic and contagious maladies to be due to the agency of specific, inconceivably small germs,——different germs giving rise to different diseases.

These disease germs gaining an entrance by means of air, water, or food into the healthy body, and being possessed of extraordinary powers of increase and subdivision, are supposed to set up the particular disease, and at the same time to multiply to an incredible extent by feeding upon the tissues best suited for their support. Further, they are conceived to be thrown off into the atmosphere from the body of the patient, whence they are conveyed as before described into other healthy animal organism, in which, comporting themselves as in the previous case, they set up a similar disease. See BACTERIA AS ORIGINATORS OF DISEASE.

=GHEE.= A sort of butter used by the natives of India. Prep. Milk is boiled in large earthen pots for an hour or two, then allowed to cool, a little curdled milk called ‘dhye’ being added, in order to make the whole coagulate. After a lapse of some hours the contents of each to the depth of 5 or 6 inches are removed and placed in a larger earthenware utensil, in which they are churned by means of a piece of split bamboo for about half an hour; then hot water is poured in, and the churning continued for half an hour longer, after which time the butter is found to be formed. When this becomes rancid, it is melted in an earthen vessel, and boiled until all the water has evaporated; after which a little salt or betel-leaf is put into it, and finally it is poured off into suitable vessels in which it can be preserved from the air. Bottles are commonly used for this purpose. See BUTTER.

=GHER′KINS.= Syn. GIR′KINS. Small cucumbers adapted for pickling. See PICKLES.

=GILD′ING.= Syn. DORURE, Fr. The art or process of covering the surfaces of bodies with a thin film of gold, for the purpose of increasing their durability or improving their appearance. For the sake of brevity we shall briefly notice the leading varieties of gilding, and their applications, in alphabetical order.

GILDING, BURNISHED. This is distemper gilding to which a ‘face’ has been given with the ‘burnisher.’ It is chiefly employed for the polished portions of the frames of pictures and mirrors, the more prominent parts of statuettes, &c.

GILDING, CHEMICAL. Those varieties in which the film of gold is formed on the surface through the agency of chemical affinity, in opposition to mechanical gilding, in which the gold is made to adhere by the intervention of some glutinous substance.

GILDING, COLD. The articles (copper or brass) to be gilded, after being softened, annealed, and polished in the usual manner, are rubbed with a little gilding powder by means of a piece of cork moistened with a solution of salt in water; after which the work is burnished with a piece of hematite or polished steel. (See below.)

GILDING, DISTEMPER. This is applied to wood, plaster, marble, &c. It is commonly performed in this country by giving the wood, first, a coating of good size, and next, several successive coats of size thickened with finely powdered whiting, Spanish white, or plaster of Paris until a good face is produced; observing to let each coat become quite dry, and to rub it perfectly smooth with fine glass paper, before the application of the following one. When the proper ‘face’ is obtained, the surface is thinly and evenly gone over with gold size, and when this is nearly dry, the gold leaf is applied, and afterwards burnished with an agate or dog’s tooth. The process, as adopted by the Parisian artists, who greatly excel in this species of gilding, is very complicated, and is divided into at least 17 distinct operations, each of which they declare to be essential to its excellence.

GILDING, ELECTRO-. See ELECTROTYPE.

GILDING, GRECIAN. In this variety sal-ammoniac and corrosive sublimate, equal parts, are dissolved in nitric acid, and a solution of gold made with this menstruum; after slight concentration the liquid is applied to the surface of silver, which immediately becomes black, but on being heated exhibits a rich gilded surface.

GILDING, JAPANNER’S. The surface is covered with oil size thinned with spirits of turpentine, and gold, in powder, is gently dabbed on with a puff of wash leather. This gives the appearance of ‘frosted gold.’ A coating of varnish is next given, followed by exposure to a gentle heat in the ‘stove.’

GILDING, LEAF. This term is commonly applied to the gilding of paper, vellum, &c., by applying leaf gold to the surface, previously prepared with a coating of gum water, size, or white of egg. It is usually burnished with an agate or dog’s tooth.

GILDING, MECHANICAL. See CHEMICAL GILDING (above).

GILDING, MERCURIAL. See WASH GILDING (below).

GILDING, OIL. This species of gilding may be divided into several operations. The following are the abridged instructions of a Parisian artist on the subject:——1. The surface is prepared by a coating of white lead in drying oil.——2. Another coat is given, made with calcined white lead or massicot, ground in linseed oil and turpentine. 3 or 4 coats of this mixture are often given, at intervals of at least 23 hours, observing to carefully smooth off each coat with pumice stone or shave grass before the application of the following ones.——3. The ‘Gold Colour,’ or paint, is next applied. It is usually very adhesive gold size, or the bottom of the pot or dish in which painters wash their brushes. For this purpose it is thoroughly ground and strained.——4. When the gold colour becomes partially dry and sufficiently tenacious, the gold leaf is applied, and pressed on with a wad of cotton-wool or a soft brush. It is now left for several days to harden.——5. A coat of spirit varnish is next given, and the object is cautiously passed over a chafing-dish of charcoal, observing to avoid stopping the motion of the piece whilst doing so, as the work would then become discoloured and blistered.——6. The work is ‘finished off’ with pale oil varnish. For out-door gilding and common work the varnishing process is generally omitted. This species of gilding is applied to woodwork, plaster, metal, &c.

GILDING, VARNISH. This is a mere variety of oil gilding, applied to equipages, furniture, mirror and picture frames, &c., the surface being highly varnished and polished before it receives the size or gold colour; and after the gilding has become quite dry, a coat of spirit varnish, fumed with the chafing dish as above, is applied, followed by 2, 3, or more coats of the best copal varnish, at intervals of 3 or 4 days each. The whole is, lastly, carefully polished with tripoli and water.

GILDING, WASH, AMALGAM G., MERCURIAL G., WATER G. This consists in the application of a thin coating of amalgam of gold to the metallic surface (brass, bronze, or copper) to be gilded, and the subsequent volatilisation of the mercury by heat. It is the usual method of gilding articles of copper and its alloys, and possesses great beauty and durability when skilfully executed. The occupation is, however, an unhealthy one, owing to the continual exposure of the workman to the fumes of mercury. The furnace invented by M. D’Arcet obviates this evil, as the whole of the volatilised mercury is carried off, and again condensed for further use. It should, therefore, be adopted by every water-gilder who studies economy and the health of those in his employ.

The process of water gilding consists in several distinct operations, and can only be successfully performed by those who have been schooled in the art by an apprenticeship to the trade. It would, therefore, be waste of space to enter into details here. Formulæ for several of the articles employed for the purpose will be found in the alphabetical places in this work.

GILDING, WATER. See above.

Among the applications of the process of gilding that deserve a separate notice are the following:——

The gold letters and figures on the covers of BOOKS are thus formed:——Gum mastic, in fine powder, is dusted over the surface to be gilded; an iron or brass tool bearing the design upon its face is then heated to a proper temperature, and gently pressed upon a piece of leaf gold, which slightly adheres to it; the two are then transferred to the cover, and the tool is gently pressed on it, by which means the mastic softens and retains the gold. The loose gold and powdered mastic are then dusted off with a brush. Gold leaf will adhere to leather without the use of mastic, but not so firmly as when it is employed.

The edges of the leaves of books and paper are first cut perfectly smooth, and then washed over with a solution of isinglass in weak spirit, or with a varnish made of Armenian bole, 4 parts, and powdered sugar-candy, 1 part, mixed up to a proper consistence with strained white of egg. The coating is allowed to dry, and is then smoothed with a wet rag, after which the gold leaf is applied and polished with the burnisher.

BRASS BUTTONS, formerly so much in demand, are covered by a rough species of wash gilding. The buttons are polished in the lathe and thrown into a pan with a little amalgam of gold, and as much aquafortis diluted with water as will wet them all over. Here they are well stirred up, until they assume a silvery appearance, when they are washed with clean water. They are then submitted to a sufficient heat in a suitable apparatus, until the mercury is volatilised. The buttons are next cooled, and well tossed and rubbed about with a painter’s brush; and are, lastly, burnished by washing them well with beer or ale grounds.

Twelve dozen (1 gross) of buttons, of 1 inch in diameter, may be perfectly gilded on both sides with only 5 gr. of gold. By an Act of Parliament, which is still unrepealed, this is the smallest quantity of gold permitted to be used for a gross of buttons of the above size.

GLASS, PORCELAIN, and EARTHENWARE, are gilded by blending powdered gold with gum-water and a little borax, and applying the mixture by means of a camel-hair pencil; the article is then heated in an oven or furnace, by which means the gum is burnt, and the borax, vitrifying, cements the gold to the surface. It is afterwards polished with a burnisher. Names, dates, or any fancy device, may thus be permanently and easily fixed on glass, china, earthenware, &c.

JAPANNED WORK is gilded by the method explained as ‘Japanner’s gilding’ (above).

LEATHER is gilded in the same way as the covers of books. (See above.) For common work, silver leaf, or even tin foil, is applied to the surface, previously covered with size or white of egg, and after being burnished down and dried, is washed over with gold-coloured lacquer.

The LETTERS of sign-boards and the ornamental gilding for out-door work are done by first covering the design with yellow paint, then with oil gold-size, and when this is nearly dry applying the leaf gold, observing to shield it properly from the wind, lest it be blown away or become crumpled before being properly attached. The work is, lastly, varnished.

POLISHED METALS may be gilded by one or other of the methods already noticed. Articles in silver, copper, brass, and bronze, are usually coated by the process of wash or water gilding; or, directly, by the application of gold leaf, as follows:——The piece or article is heated to a bluish tint, and gold leaf pressed gently and carefully on it with the burnisher; heat is again applied, and the process repeated with fresh leaves of gold until the gilding has acquired the proper thickness and tone. The surface is lastly polished with the burnisher, or is coloured in the usual manner at the stove. This succeeds with iron, steel, silver, copper and its alloys, &c. Another method for polished articles in iron and steel, which, however, is less durable than the preceding, is to apply an ethereal solution of gold to the surface with a camel-hair pencil. The ether flies off and leaves the surface coated with gold, which is then polished as before. In this way, any fancy device or writing may be executed on steel or iron with extreme facility.

SILKS, SATINS, WOOLLENS, IVORY, BONE, &c., may be readily gilded by immersing them in a solution of neutral terchloride of gold (1 of the salt, and 3 to 6 of water), and then exposing them to the action of hydrogen gas. The latter part of the process may readily be performed by pouring some dilute sulphuric acid on zinc or iron filings, in a wide-mouthed bottle, and placing it under a jar or similar vessel, inverted, at the top of which the articles to be gilded are suspended. Flowers or other ornamental designs may be produced by painting them on the surface with a camel-hair pencil dipped in the solution. The design, after a few minutes’ exposure to the hydrogen, shines with all the splendour of the purest gold, and will not tarnish on exposure to the air, or in washing.

GILDED THREAD or GOLD THREAD is merely a thread of yellow silk covered with a very thin flatted wire of gold, by means of a revolving wheel.

WIRE (copper, silver, or brass) is occasionally gilded, in coils, by a similar process to that adopted for BUTTONS; but more frequently as follows:——Rods (usually of silver) are covered with gold foil of a thickness proportionate to the quality of the intended wire, and the compound bar is then drawn into wire, in the usual way. 100 gr. of gold was formerly the lowest legal quantity that could be employed for 1 lb. of silver.

Patents. Among the varieties of chemical gilding may be mentioned

1. (Elkington’s patent——GERMAN GILDING, Bonnet’s GILDING PROCESS.) The articles to be gilded, after being perfectly cleaned from scale or grease, and receiving a proper ‘face,’ are suspended, by means of wires, in the gilding liquid (boiling hot), and moved about therein for a period varying from a few seconds to a minute, or longer; the precise time required depending on the newness and strength of the liquid. When sufficiently gilded, the articles are withdrawn from the ‘solution of gold,’ washed in clean water, and dried; after which they undergo the usual operation of ‘colouring,’ &c. A dead gold appearance is produced by the application to the articles of a weak solution of nitrate of mercury previously to the immersion in the gilding liquor; or the deadening may be given by applying a solution of the nitrate to the newly gilded surface, and then expelling the mercury by heat.

The gilding liquor.——Take of fine gold, 5 oz. (troy); nitro-muriatic acid, 52 oz. (avoirdupois); dissolve by heat, and continue the heat until red or yellow vapours cease to be evolved; decant the clear liquid into a suitable vessel; add of distilled water, 4 galls.; pure bicarbonate of potassa, 20 lbs.; and boil for 2 hours. The nitro-muriatic acid is made with pure nitric acid (sp. gr. 1·45), 21 oz.; pure muriatic acid (sp. gr. 1·15), 17 oz.; and distilled water, 14 oz.

This process, though patented by Mr Elkington in England, was in reality discovered and first practised by M. Bonnet, a foreigner. Articles thus gilded do not bear friction and the operations of being put in colour (mise en couleur) so well as those gilded by the mercurial process, or by the methods of cold or leaf gilding as applied to polished metals.

2. (Talbot’s patent.) By this process polished metallic articles are gilded by simple immersion in a solution of gallic acid in water, ether, or alcohol, to which a solution of gold has been previously added. SILVERING and PLATINISING may be effected in the same manner, by using a solution of either of these metals instead of one of gold.

⁂ These and other chemical processes have been almost completely superseded by the certain and economical process of ELECTRO-GILDING. See ELECTROTYPE.

=Gilding Amalgam.= See AMALGAM.

=Gilding Liquor.= This name has been given to various solutions of gold, and to other liquids employed in gilding. The former are noticed elsewhere. Among the latter are the following:

DEADING AQUAFORTIS. From mercury, 1 part; aquafortis (sp. gr. 1·33), 3 parts; dissolve, and add of soft water, 7 parts. Used to produce a dead-gold effect. It is applied (diluted) to the articles, before spreading the amalgam over them, in water gilding; or before placing them in the ‘gilding liquor,’ in the chemical processes.

MERCURIAL SOLUTION. From mercury, 10 parts, dissolved in aquafortis (sp. gr. 1·33), 11 parts, and the solution diluted with 25 times its weight of water. Used to moisten the scratch brush before drawing it over the amalgam, in mercurial gilding; also to deaden the gilded surface, by moistening the latter with it, and then exposing the piece to a heat sufficiently high to drive off the mercury.

GILDER’S PICKLE. From alum and common salt, of each 1 oz.; nitre, 2 oz.; dissolved in water, 1/2 pint. Used to impart a rich colour to gold surfaces, especially of trinkets. Its application should not be too long continued, as it dissolves a small portion of the gold. For common purposes it is best used largely diluted with water.

VERMEIL, VERMEIL COATING, OR-MOLU C. From annotta and salt of tartar, of each 1 oz.; dragon’s blood, 1/2 oz.; water, 1 quart; simmer down to about one fourth, add saffron, 20 gr., and when merely tepid, strain through fine muslin into a bottle. Used to give lustre and fire to distemper gilding. A little is floated over the surface with a very soft, flat, camel-hair brush.

=Gilding Metal.= The metal employed as a base for gilding is usually brass, or a mixture of brass and copper. The following proportions have been recommended:——

1. Copper, 6 parts; brass, 1 part. 2. Copper, 4 parts; Bristol brass, 1 part. 3. Copper, 13 parts; old Bristol brass, 3 parts; tin, 14 parts.

=Gilding Powder.= Prep. 1. Pure gold, 5 dr.; pure copper, 1 dr.; aqua regia, 10 oz.; dissolve, moisten clean linen rags with the solution, dry them, and burn them to ashes. The latter contain the gold in a state of minute division, and must be carefully collected.

2. Grain gold, 1 dr.; rose copper, 15 gr.; aqua regia, 2 fl. oz.; proceed as last. Used in ‘Gold Gilding.’

3. See Gold (in powder).

=Gilding Shells.= See GOLD SHELLS.

=Gilding Size.= See GOLD SIZE.

=Gilding Wax.= Syn. GILDING VARNISH, GILDER’S WAX. Prep. 1. From beeswax, 4 oz.; verdigris and sulphate of copper, of each 1 oz.; melted together.

2. Beeswax, 4 oz.; verdigris, red ochre, and alum, of each 1 oz. Used to give a red gold colour to water gilding.

=GIN.= Syn. GENE′VA. Corn spirit flavoured with either oil of juniper or oil of turpentine.

Gin was originally and, for some time, wholly imported from Holland, and was a rich, soft spirit, flavoured, chiefly, with juniper berries; on which account it had obtained the name of ‘GENEVA,’ from ‘GENIÈVRE,’ the French for juniper. After a time the distillation of an imitation geneva sprung up in this country, when the foreign spirit came to be called ‘HOLLANDS,’ or ‘HOLLANDS GENEVA,’ to distinguish it from the spirit of home manufacture. The English monosyllable ‘GIN’ is a corruption of geneva, the primary syllable of which, as in numerous other instances, was seized on by the vulgar, and adopted as a short and convenient substitute for the whole word.

The liquor at present known by the name of ‘gin’ in this country is a very different article to that imported from Holland, and consists of plain corn-spirit, flavoured with oil of turpentine and small quantities of certain aromatics. The thousand and one receipts for this article, which have from time to time been printed in books, produce a flavoured spirit bearing no resemblance to the more esteemed samples of English gin; and, if possible, the products are even more unlike genuine Hollands. Any persons may easily satisfy himself of the truth of this assertion by actual experiment on the small scale. The cause of this incongruity has arisen chiefly from the writers not being practically acquainted with the subject, and from the disinclination of well-informed practical men to divulge, gratuitously, what they conceive to be valuable secrets. Hence the utter failure of any attempts to produce either gin or Hollands from the receipts usually published. The authors appear to have all imbibed a juniper-berry mania——probably from the imbibition of their favourite beverage. Oil of juniper, in the hands of these gentlemen, appears to be a perfect aqua mirabilis, that readily converts whisky into gin, and imparts the rich creamy flavour of ‘Schiedam Hollands’ to crude corn or molasses spirit. But theory and experiment sometimes disagree. In practice, it is found that the true flavour of foreign geneva cannot be imparted to spirit by juniper alone, and that the English gin of the present day depends for its flavour on no such a substance. The following formulæ are merely given as specimens; and it is proper to remark, that every distiller has his own receipt for this notorious beverage. Hence it is that the gins of no two distillers are of precisely the same flavour; and this difference is still more marked when the distillers reside in parts of the country remote from each other. Booth’s, Smith’s, and Nicholson’s gins have each a characteristic flavour, readily perceived by their respective votaries; whilst the difference between ‘Plymouth’ or ‘Bristol gin,’ and the ‘gin of the metropolis,’ is as remarkable as that between ‘Barclay’s XXX’ and ‘Guinness’s bottled stout.’ These variations in flavour generally depend on the use of more or less flavouring matter, or of a spirit more or less clean or free from taint; and, less frequently, on the addition of a small quantity of some peculiar aromatic, which exercises a modifying influence on the chief flavouring ingredient. In many cases the flavour has originated from accident, but the consumers having become accustomed to, and hence relishing, that particular ‘palate,’ it is found to be unwise or commercially impossible to alter it. Any change in these matters is therefore looked upon in every distillery as a dangerous innovation, which would prove more prejudicial to the prosperity of its exchequer than the repeal of the duty on French wines and brandy, or even a frightful conflagration. The distillers, like the brewers, are thorough conservatives in all matters connected with the flavour of their liquors.

In the preparation of gin, both sweetened and unsweetened, and indeed of liquors generally, the greatest possible care must be taken to avoid an excess of flavouring. The most esteemed samples are those that consist of very pure spirit, slightly flavoured.

Prep. 1. Clean corn spirit, at proof, 80 galls.; newly rectified oil of turpentine, 1-1/4 pint; mix well by violent agitation, add culinary salt, 14 lbs., dissolved in water, 40 galls.; again well agitate, and distil over 100 galls., or until the faints begin to rise. Product. 100 galls. of gin 22 u. p., besides 2 galls. contained in the faints. If 100 galls. at 17 u. p. are required, 85 galls. of proof spirit, or its equivalent at any other strength, must be employed.

2. Proof spirit (as above), 8 galls.; oil of turpentine, 1 fl. oz.; salt, 1-1/2 lb., dissolved in water, 4 galls.; draw over 10 galls., as before. 22 u. p.

3. Clean corn spirit, 80 galls.; oil of turpentine, 1 pint; pure oil of juniper, 3 fl. oz.; salt, 21 lbs.; water, 35 galls.; draw over 100 galls., as before. 22 u. p.

4. To the last, before distillation, add, of oil of caraway, 1/2 fl. oz.; oil of sweet fennel, 1/4 fl. oz.; cardamoms (ground), 8 oz.

5. To No. 3 add, of essential oil of almonds, 1 dr.; essence of lemon, 4 dr.

6. To No. 1, before distillation, add of creasote, 3 fl. dr.

7. To No. 3 add of creasote, 2 dr.

8. Proof spirit, 80 galls.; oil of turpentine, 3/4 pint; oil of juniper, 1/4 pint; creasote, 2 dr.; oranges and lemons, sliced, of each 9 in no.; macerate for a week, and distil 100 galls. 22 u. p.

9. To No. 1 add of rectified fusel oil, 1/2 pint.

10. To No. 1 add of oil of juniper, 1/2 pint.

Concluding Remarks. The oil of turpentine for this purpose should be of the best quality, and not that usually vended for painting, which always contains resin and often fixed oil. Juniper berries, bitter almonds, and the aromatic seeds, may be used instead of the essential oils; but the latter are the most convenient. Turpentine conveys a plain-gin flavour,——juniper berries or oil gives a Hollands flavour,——creasote imparts a certain degree of smokiness, or whiskey flavour,——lemon and the other aromatics, a creaminess, fulness, and richness. The flavour imparted by cardamoms, when used judiciously, is peculiarly agreeable and appropriate. That from caraways is also in general esteem. Cassia in extremely small proportions also tells well. Fusel oil gives a whiskey-gin flavour; and in conjunction with creasote or crude pyroligneous acid, a full whiskey flavour. The only danger in the employment of all these articles is using too much of them. When this misfortune happens, the remedy is to add sufficient plain spirit to reduce the flavour to the proper standard. The creaminess and smoothness so much admired in ‘foreign geneva’ results chiefly from age. The English rectifier endeavours to imitate this by the addition of a little sugar. A rich mellowness, that combines well with gins turning on the ‘Hollands flavour,’ is given by a very small quantity of garlic, and with Canadian balsam or Strasburg turpentine. The peculiar piquancy, or the property of ‘biting the palate,’ regarded as a proof of strength and quality by the ignorant gin-drinker, is imparted to the liquor by the addition of a little caustic potassa. Sliced horseradish gives piquancy as well as mellowness. Grains of paradise, cayenne pepper, and sulphate of zinc, are also commonly added by fraudulent dealers.

Although gin is always prepared on the large scale by distillation, it may also be made by the simple solution or digestion of the flavouring ingredients in the spirit; but it is, of course, better for distillation. If made in the former way, no salt must be employed. The gin produced by the above formulæ is that denominated in the trade ‘UNSWEETENED GIN,’ ‘GROG GIN,’ &c.; but the gin usually sold in the metropolis is a sweetened spirit, and hence is technically distinguished by the terms ‘SWEETENED,’ or ‘MADE UP,’ The generality of London gin-drinkers prefer the latter article, even when weaker and inferior, which it usually is, as the addition of sugar permits adulteration and watering to an enormous extent with absolute impunity. Sweetened spirit cannot be easily tested for its strength, and is taken by the Excise at the strength which it is declared to possess by the dealer. To ascertain whether gin is sweetened or not, a little may be evaporated in a spoon, over a hot coal or a candle, when, if it is pure, it will leave the spoon scarcely soiled; but if, on the contrary, it has been sweetened, a small quantity of syrupy liquid, or sugar, will be obtained, the sweetness of which may be easily recognised by tasting it.

The whole of the casks and utensils employed for gin should be perfectly clean, and properly prepared, so as not to give colour; as, if this spirit acquires the palest coloured tint, its value is lessened, and if much coloured it is rendered unsaleable. When gin has once become much stained, the only remedy is to re-distil it; when it is only slightly stained, the addition of a few lbs. of acetic acid (B. P.) to a pipe or butt, a spoonful or two to a gallon, or a few drops to a decanterful, will usually decolour it, either at once or as soon as it is mixed with water to make grog. See ALCOHOLOMETRY, CASKS, DISTILLATION, HOLLANDS, SPIRITS, &c., and below.

=Gin, Cor′dial.= This is gin sweetened with sugar, and slightly aromatised.

Prep. Good gin (22 u. p.), 90 galls.; oil of almonds, 1 dr.; oils of cassia, nutmeg, and lemon, of each 2 dr.; oils of juniper, caraway, and coriander, of each 3 dr.; essences of orris root and cardamoms, of each 5 fl. oz.; orange-flower water, 3 pints; lump sugar, 56 to 60 lbs.; dissolved in water, 4 galls. The essences are dissolved in 2 quarts spirit of wine, and added gradually to the gin until the requisite flavour is produced, when the sugar (dissolved) is mixed in, along with a sufficient quantity of soft water, holding 4 oz. of alum in solution, to make up 100 galls. When the whole is perfectly mixed, 2 oz. of salt of tartar, dissolved in 2 or 3 quarts of hot water, are added, and the liquor is again well rummaged up; after which the cask is bunged up, and allowed to repose. In a week, or less, it will have become brilliant, and may be either ‘racked,’ or drawn from the same cask. Product. 100 galls., about 30 u. p.

=Gin, Sweetened.= Prep. From unsweetened gin (22 u. p.), 95 galls.; lump sugar, 40 to 45 lbs., dissolved in clear water, 3 galls.; mix well, and fine it down as above. Product. 100 galls., at 26 u. p. This, as well as the last, is usually ‘permitted’ at 22 or 24 u. p., which is also done when the gin has been further lowered with water so as to be even 30 or 35 u. p. See SPIRITS, and above.

=GIN′GER.= Syn. GINGER ROOT; ZINGIBERIS RADIX, ZINGIBER (B. P.), L. “The scraped and dried rhizome” (rootstock or underground stem) of “Zingiber officinale”——(B. P.). Ginger is an aromatic stimulant and stomachic, very useful in flatulence and spasms of the stomach and bowels, and in loss of appetite and dyspepsia, arising from debility, or occurring in old or gouty subjects. A piece chewed an hour before dinner tends to provoke the appetite; as a masticatory, it often relieves toothache, relaxation of the uvula, tender gums, and paralytic affections of the tongue. Made into a paste with warm water, and spread on paper, it forms a useful and simple ‘headache-plaster,’ which frequently gives relief when applied to the forehead or temples. As a condiment and flavouring ingredient, it is perhaps one of the most wholesome of the aromatic kinds, and is less acrid than the peppers.——Dose, 10 gr. to 1/2 teaspoonful, stirred up in any simple liquid.

Pur., &c. The best is that known in commerce as ‘UNBLEACHED JAMAICA GINGER,’ which is an uncoated pale variety, occurring in large, bold, fleshy pieces (‘RACES’), which cut soft, bright, and pale-coloured. The inferior varieties occur in smaller pieces, and are darker-coloured, flinty, and shrivelled. The dealers frequently ‘dress up’ the common dark-coloured gingers by washing them in water, drying them, and then ‘rouncing’ them in a bag with a little calcined whiting or magnesia (WASHED GINGER); or they bleach them by dipping them into a solution of chloride of lime, or by exposing them to the fumes of burning sulphur (BLEACHED GINGER); or they dip them into a milk formed of quicklime or whiting and water (WHITE-WASHED GINGER). The last has a chalk-white surface, which cannot be mistaken for the natural one. POWDERED GINGER is with difficulty obtained pure and good. The common adulterants are wheat-flour, or East Indian arrow-root, and plantain-meal. The first may be detected by the microscope, the others by the flavour and action of hot water. See LOZENGES, &c.

=GINGERIN.= Syn. OLEORESINA ZINGIBERIS. Prep. (Pharm., U. S.) Put 1 lb. (Troy) of ginger in fine powder into a percolator, and pour on it 12 ounces (old measure) of pure ether. When this has been absorbed, add rectified spirit until 12 ounces (old measure) have been obtained. Recover the greater part of the ether by distillation over a water bath, and expose the residue in a porcelain dish until the volatile part has evaporated. Keep it in a stoppered bottle.

=GINSENG.= The root of the Panax Schinseng (Ginseng) is greatly esteemed in China, where it is regarded as a panacea for nearly all diseases, and where it realises a high price in consequence. This opinion of its therapeutic value is not shared by British and American practitioners, who look upon it as a comparatively inert substance. An allied species, the Panax quinquefolium, is sold in America, less for the sake of its very feeble demulcent properties, than to supply the demand of those who have acquired a taste for it. “The root has a somewhat bitter taste, and is somewhat mucilaginous. It occurs in pieces usually about three or four inches long, often partially divided, being joined together at the base; when clean it has a semi-transparent appearance.”[333]

[Footnote 333: ‘Gardener’s Chronicle.’]

=Preserved Ginger.= Syn. CONDITUM ZINGIBERIS, L. An excellent stomachic sweetmeat or preserve. It is chiefly imported from the West Indies and China. See CANDYING, &c.

=A Factitious Preserved Ginger= is sometimes met with, prepared from the stalks of lettuces just going to seed, using a concentrated syrup, strongly flavoured with Jamaica ginger. See CANDY, &c.

=GIN′GER BEER.= See BEER.

=GIN′GERBREAD.= Prep. 1. (Dr Colquhoun.) Flour, 1 lb.; carbonate of magnesia, 1/4 oz.; mix; add, of treacle, 1/2 lb.; moist sugar, 1/4 lb.; melted butter, 2 oz.; tartaric acid (dissolved in a little water), 1 dr.; make a stiff dough, then add of powdered ginger and cinnamon (cassia), of each 1 dr.; grated nutmeg, 1 oz.; set it aside for half an hour or an hour before putting it into the oven. Obs. It should not be kept longer than two or three hours at the utmost, before being baked.

2. Flour and treacle, of each 1 lb.; butter, 1-1/2 oz.; carbonate of magnesia, 1 oz.; add spices (ginger, cinnamon, nutmeg, allspice, cayenne, corianders, &c.) to taste; mix as last. Obs. Fit for baking in from four to six hours.

3. Flour, 2 lbs.; carbonate of magnesia, 1/2 oz.; mix; add, treacle, 1-1/2 lb.; butter, 2 oz.; spice, q. s.; tartaric acid, 1/4 oz.; mix quickly, and make it into forms. Obs. Ripe for the oven in half an hour to one hour.

4. Instead of tartaric acid in the last formula, use cream of tartar (dissolved in water), 2 oz. Obs. Ripens in 40 or 50 minutes.

5. Flour or fine pollard, 1 lb.; treacle, 3/4 lb.; salt of tartar, 1/2 oz., dissolved in water, q. s., butter, 1 oz.; spices, to palate. Obs. Takes several days to ripen; sometimes a fortnight.

6. (Extemporaneous.)——a. From flour, 1-1/4 lb.; moist sugar and treacle, of each 1/2 lb.; butter, 2-1/2 oz.; baker’s salt (carbonate of ammonia), 1/4 oz., dissolved in cold water, q. s.; ginger, 3 dr.; nutmeg, 2 dr.; cassia, 1 dr.; cayenne pepper (best), 1/2 dr.

b. From flour, 6 lb.; powdered ginger, 2-1/2 oz.; caraway seeds, 1 oz. (and other spices to palate); candied lemon and orange peels, of each 2 oz.; moist sugar and melted butter, of each 1/2 lb.; treacle, 4 lb.; volatile salt, 2 oz.; water, q. s.; mix as above. May be baked at once.

c. From Jones’s patent flour, 2 lbs.; treacle, 1 lb.; moist sugar, 3/4 lb.; butter, 2-1/2 oz.; spice, q. s.; mix as quickly as possible, and bake it instantly. If the dough is expertly mixed up, the quality of the product is fully equal, if not superior, to that of any of the preceding formulæ.

Obs. Gingerbread is either rolled out into thin sheets and cut into cakes or nuts (GINGERBREAD NUTS) with the top of a wine-glass or canister, or is formed into thick cakes, which are baked in ‘batches’ (ordinary GINGERBREAD). Both varieties require a pretty brisk oven; the thinner kinds (nuts, &c.), especially, must be baked as crisp as possible, without being burnt. The varieties called LEMON GINGERBREAD, CARAWAY G., &c., have a perceptible predominance of these flavouring ingredients. The addition of a little alum, dissolved in water, makes the bread both lighter and crisper, and causes it to ripen quicker, but at the same time lessens its wholesomeness.

=GIN′GER CAN′DY.= See CANDYING.

=GIN′GER DROPS.= See DROPS (Confectionery).

=GLAIRE.= White of egg. See ALBUMEN and EGG.

=GLAN′DERS.= Syn. FARCINOMA, L. A contagious disease, generally confined to the horse, ass, and mule, but communicable to man, in whom it assumes a highly malignant and often fatal character. This disease appears under two forms——1. SIMPLE ACUTE GLANDERS, marked by copious discharge of foul mucous matter from the nostrils and adjacent parts; and——2. FARCY, FARCIN, or FARCY GLANDERS, when it attacks the lymphatics of the skin, either generally, producing a distended appearance of the vessels, like moles or buttons (LEAD or BUTTON FARCY), or locally, when it takes the form of dropsical accumulations in the legs (WATER FARCY).

Treat. Mr Youatt considers it useless to attempt the cure of glandered horses; but that farcy in its earlier stages and milder forms may be often successfully treated. “All the mercurials have been used with benefit in farcy; but they must be discontinued as soon as the mouth is sufficiently affected, or sickness, loss of appetite, and like symptoms, are produced.” (Blaine.) Feeding the animal entirely on green food appears to be the best mode of treatment in both varieties. The buttons are generally removed with caustic or a red-hot iron.

“Glanders is quite incurable, but by generous diet, good stabling, and mineral tonics, life, except in extremely acute cases, may be prolonged for many weeks. This, however, is not desirable; for it involves great risk, not only to other horses, but also to the attendants.” (Finlay Dun.)

=GLASS.= Syn. VITRUM, L. This well-known substance is essentially a mixture of silicates with an excess of silica or silicic acid. It generally contains the silicates of potassa, soda, lime, baryta, magnesia, alumina, and lead, coloured by small portions of iron, manganese, cobalt, uranium, copper, or gold. In its usual form it is brittle, transparent, noncrystalline, insoluble, and fusible; but it sometimes exhibits other properties.

The manufacture of glass is one of the highest beauty, and, considering the comparative worthlessness of the materials of which it is made, and the various purposes of a useful, ornamental, and scientific nature which it subserves, it may be regarded as, perhaps, the most important in the history of inventions. The principle of its production is very simple, although great skill and experience are necessary to ensure its excellence. Silica (commonly under the form of sand) is heated with carbonate of potassa or of soda, and slaked lime or oxide of lead, until the mixture fuses, and combination takes place. After a time the melted mass becomes perfectly limpid and free from air-bubbles, when it is allowed to cool until it assumes the peculiar tenacious condition proper for working. The operation of fusion is conducted in large crucibles of refractory fire-clay, which, in the case of ‘lead-glass,’ are covered with a dome at the top, and have an opening at the side by which the materials are introduced, and the melted glass withdrawn.

The manufacture of glass is only conducted on the large scale, and the precise character and proportions of the ingredients used by the glass-maker must necessarily greatly depend upon the nature of the raw materials furnished by his locality, or otherwise at his command. The attention of the manufacturer should be directed to the use of his materials in such proportions as will furnish, in the melting-pot, the proper quantities of the essential ingredients, as determined from the known composition of the best commercial samples. The purity of the raw materials and the accuracy of his proportions and quantities are proved or disproved by the excellence of the product; and the cause of error (if any) may be at once determined by carefully ascertaining the quality of the ingredients employed, and the composition of the defective glass.

A writer (in ‘Chem. Centr.,’ 1872, 528) points out that very generally the soda used in glass making, contains sulphate, and that when this is so a poor glass is produced. The addition of ·75-1 part of wood charcoal for every 100 parts of true soda——improves the quality of the glass.

Prep. The following formulæ exhibit the composition of the leading commercial glasses, as shown by chemical analysis, together with the proportions of the raw materials used in their production.

BOTTLE GLASS. Sp. gr. 2·700 to 2·735.——

a. Composition by analysis:——

1. Silica, 53·55%; lime, 29·22%; mixed alkali, 5·48%; alumina, 6·01%; oxide of iron, 5·74%. Dark green.

2. Silica, 52%; baryta, 21·6%; soda, 26·1%; oxides of iron and manganese, ·3%. Pale green; very superior.

b. Raw materials used:——

1. Yellow sand, 20%; kelp, 8%; lixiviated wood-ashes, 30%; fresh wood-ashes, 8%; pale clay, 16%; ‘cullet’ (broken glass), 18%. This is the common mixture for coarse bottles, in Belgium, France, and Germany.

2. To the last add of black oxide of manganese, 2-1/2 to 3%. Has a rich yellowish colour; used for Rhenish-wine bottles.

3. Pale sand, 51%; lixiviated wood-ashes, 33%; pearl-ashes (dried), 8%; common salt, 7-1/2%; white arsenic, 1/2%; charcoal, q. s. Very pale green.

4. Siliceous sand (pale), 68-1/2%; potash (or its equiv.), 4%; lime, 23-1/2%; heavy spar, 2-1/2%; peroxide of manganese, 1-1/2%. This forms the celebrated ‘flask-glass’ of St. Etienne.

GLASS, BROAD, SPREAD WINDOW GLASS. Sp. gr. 2·642.——

a. By analysis:——

Silica, 69·70%; lime, 13·30%; soda, 15·25%; oxide of iron (and loss), 1·75%.

b. Materials used:——

1. White sand, 50%; dried sulphate of soda, 22%; charcoal (in powder), 9%; ‘cullet,’ 41%; peroxide of manganese, a little. Pale.

2. White sand, 60%; potashes (good), 24%; common salt, 10%; nitre, 5%; white arsenic, 1%; peroxide of manganese, a little (1/12 to 1/10%); pale ‘cullet,’ at will (10 to 30%). Very pale. This is the ‘spread’ or ‘sheet window-glass’ in common use.

GLASS, CHEMICAL. Sp. gr. 2·390 to 2·396.——

a. By analysis:——

1. Silica, 72·80%; potassa, 16·80%; lime (with a trace of alumina), 9·68%; magnesia, 40%; traces of oxide of manganese and iron (and loss) ·32%. This is the difficultly fusible ‘Bohemian tube-glass,’ so valuable in chemical manipulations.

2. Silica, 69·3%; potassa, 15·8%; soda, 3%; lime, 7·6%; alumina, 1·2%; magnesia, 2%; oxide of iron, ·5%; oxide of manganese (and loss), ·6%. English chemical glass (without lead). More fusible than the last.

b. Materials used:——

1. Quartz (hyalin, in powder), 60%; calcined purified pearlash, 30%; fresh-burnt lime (very pure), 9%; nitre (dried), 3/4%; arsenious acid or peroxide of manganese, 1/4%. Said to be the proportions used in the production of a, 1 (above).

2. (M. Peligot.) Quartz, 71-1/2%; carbonate of potassa (or its equiv., dry), 20%; quicklime, 8-1/2%; (manganese, a little). Said to be the formula for the hardest and least fusible ‘Bohemian tube-glass.’ It is very intractable and infusible, except at a very high temperature; but the addition of an exceedingly small quantity of boracic acid, borax, or arsenious acid, causes it to flow into a glass possessing great brilliancy and hardness, and capable of being wrought at the highest heat of the ordinary furnace.

GLASS, CROWN, WHITE WINDOW-GLASS. Sp. gr. 2·486 to 2·488.——

a. By analysis:——

1. Silica, 62·8%; potassa, 22·1%; lime, 15·5%; alumina (with traces of oxide of iron and manganese), 2·6%. Crown-glass of Bohemia, according to Dumas. Very beautiful.

2. Silica, 72·5%; soda, 17·75%; lime, 9·75%. English crown-glass; excellent quality, but not so white as the last.

b. Materials used:——

1. Finest white siliceous sand, 64%; purified potashes (dry), 23%; lime, 12%; white arsenic, 3/4%; oxide of manganese, 1/4%. Said to be used in Bohemia.

2. (Schweigger.) Pure sand, 57%; dry sulphate of soda, 28-1/2%; quicklime, 11-1/2%; powdered charcoal, 3 or 4%. Corresponds to a, 2, above (nearly).

3. Pure sand, 40%; soda ash, 24%; lime, 5%; white ‘cullet,’ 31%, Rather superior to the last.

CRYSTAL, CRYSTAL GLASS. The ‘crystal glass’ of England is flint glass’ of superior quality; that of Bohemia is noticed under TABLE GLASS.

GLASS, FLINT, CRYSTAL. Sp. gr. 3·000 to 3·620.——

a. By analysis:——

1. (Berthier.) Silica, 59·19%; oxide of lead, 28·68%; potassa, 12·13%; oxides of iron and manganese, traces. Finest colourless English crystal.

2. (Brande; Faraday.) Silica, 52%; oxide of lead, 34%; potassa, 34%. Crystal.

3. (Faraday.) Silica, 44·30%; oxide of lead, 43·05%; potassa, 11·75%; alumina, ·50%; oxides of iron and manganese, ·12%; (loss 28%). Heaviest of three samples of flint glass examined.

b. Materials used:——

1. Finest Lynn-sand (calcined, sifted, and washed), 51%; litharge (purest), 28% (or red lead, 29%), refined pearlashes (calcined before being weighed), 16%; nitre (purified), 4-3/4% arsenious acid and peroxide of manganese, of each, 1/8%. Very fine crystal.

2. (M. Payen.) Fine sand, 46%; red lead, 31%; purified carbonate of potash, 23%. French crystal.

3. (Geddes.) White Lynn-sand, 51%; red lead or litharge, 33%; refined pearlashes, 13%; nitre, 3%; a very little arsenious acid and peroxide of manganese. Ordinary English flint-glass. Crystal ‘cullet’ may be added at will to the above. This glass was originally prepared from powdered flints, a fact to which it owes its common name.

GLASS, OPTICAL. 1. (Crown glass.) Purest siliceous sand, 55%; carbonate of soda (dry), 12%; chalk (dry), 11%; carbonate of baryta, 22%.

2. (Flint glass.)——

a. By analysis:——

Silica, 44·30%; oxide of lead, 43·05%; potassa, 11·75%. This is Guinand’s ‘dense optical glass.’

b. Materials used:——

1. Purest quartz, 42%; red lead (finest), 42%; purified potash, 14-3/4%; purified nitre, 1-1/4%. These are the proportions used for the last.

2. (Korner.) Finest quartz (reduced to powder, treated with hydrochloric acid, washed, and dried), 47-1/2%; red lead, 38-1/4%; cream of tartar, 14-1/2%. The above are used by opticians in the construction of achromatic object-glasses.

GLASS, PLATE. Sp. gr. 2·488 to 2·600.——

a. By analysis:——

1. (Dumas.) Silica, 75·9%; soda, 17·5%; lime, 3·8%; alumina, 2·8%. French mirror-glass.

2. (Mitscherlich.) Silica, 60%; potassa, 25%; lime, 12·5%; loss, 2·5%(?). Finest Bohemian plate.

b. Materials used:——

1. Finest siliceous sand, 45%; dried carbonate of soda, 25%; lime, 5%; nitre (purified), 2%; plate-glass cullet, 23%; peroxide of manganese and cobalt azure, a very little. Ordinary English plate.

2. Whitish quartz sand, 60%; purified carbonate of soda (dried), 20%; lime (slaked by exposure to the air), 9%; plate-glass cullet, 11% (or more). Sometimes as much cullet as sand is used; but in all cases 1% to 1-1/2% of its weight in carbonate of soda is added with it, besides that ordered in the formula, to compensate for loss of alkali by remelting. Used at the celebrated plate-glass works at Saint-Gobain, France. The product possesses an amount of excellence which British manufacturers have yet failed to equal.

GLASS, TABLE BOHEMIAN CRYSTAL. Sp. gr. 2·6 to 2·8.——

a. By analysis:——

1. (M. Berthier.) Silica, 71·7%; potassa, 12·7%; soda, 2·3%; lime, 10·3%; alumina, ·4%; oxides of iron and manganese (and loss), 2·6%. Very white, hard, and beautiful table glass.

2. (Dumas.) Silica, 70%; potassa, 20%; lime, 4%; alumina, 5%; oxide of iron, ·6%; peroxide of manganese, ·4%. A beautiful white wineglass.

b. Materials used:——

1. Finest sand, 50%; purified potashes, 25%; chalk, 10%; nitre, 2%; crystal cullet, 27%; manganese, a little (say 1/16%). Used in England recently for table glass.

2. Quartz (hyalin, in powder), 63%; purified potashes, 26%; slaked lime (carefully sifted), 11%; manganese, a little; crystal cullet, at will. Used in Bohemia.

3. (M. Perdonnet.) Powdered quartz, 44%; carbonate of potassa, 33%; quicklime (in fine powder), 22%; nitre, 1%; and a very small quantity of arsenious acid and peroxide of manganese. Said to be the formula used at Neuwelt for the glass a, 1 (above).

Qual., &c. These are denoted by its hardness, transparency, homogeneity, strength, and power of resisting the action of water, air, light, and the stronger acids and alkalies. The power of glass to resist the action of menstrua is readily tried by exposing it to boiling oil of vitriol, and hot but dilute solution of caustic potassa. Neither of these tests should cause the glass to lose its transparency or to become dim.

Swallowed glass. Glass and enamel, both in fragments and in powder, have occasionally been swallowed, with different results. These bodies are insoluble in the fluids of the body, and, consequently, any injurious action they may exert upon the system whilst they are retained in it must entirely depend upon mechanical attrition or irritation. As treatment, we must administer an emetic, and assist its action by thick mucilaginous liquids, and afterwards have recourse to antiphlogistics, if necessary.

Anal.——a. A portion of the sample for examination is heated to dull redness, and then suddenly thrown, whilst still hot, into a vessel of cold water. It is next dried, and reduced to fine powder in an agate or hardened-steel mortar.

b. 100 gr. of the prepared powder is thoroughly mixed with 200 gr. of pure potassic hydrate, and the whole is exposed to heat in a silver or platinum crucible or capsule until perfect fusion takes place; when cold, the crucible and its contents are boiled in about half a pint of distilled water; nitric acid is added to the resulting solution, in excess, and the mixture, together with any sediment, is evaporated to dryness, after which the heat is gradually increased to 400° or 500° Fahr.; the dry residuum is next reduced to powder, and digested in water acidulated with nitric acid, until exhausted of soluble matter; the insoluble portion is then carefully dried, gently ignited and weighed. The weight in grains represents the per-centage of silica in the sample examined.

c. The mixed liquid and washings of b is next acidulated with nitric acid, and treated to a stream of sulphuretted hydrogen, which, if it produces a precipitate, is continued for some time; the precipitate is collected on a very small filter, washed, and dried; the filter with the precipitate next placed in a beaker glass, and strong fuming nitric acid is cautiously added, drop by drop, until complete solution takes place; after boiling the solution for a few minutes, diluting with distilled water, and allowing it to cool, it is precipitated with sulphuric acid, in excess; this precipitate (sulphate of lead) is washed, dried, slightly ignited in a porcelain crucible, and weighed. The weight in grains, multiplied by ·7369, gives the per-centage of oxide of lead or litharge.

d. The filtered liquid from c is evaporated to dryness, and redissolved in water acidulated with hydrochloric acid, and treated with a solution of ammonium chloride, and afterwards with ammonia, in excess; the precipitate (alumina and oxide of iron) is collected, washed, and boiled in a solution of potassium hydrate; the undissolved portion is collected on a filter, washed with boiling water, ignited, and weighed. This gives the per-centage of peroxide of iron.

e. The liquid filtered from the oxide of iron holds the alumina (if any) in solution; a solution of carbonate of ammonium is dropped in; the resulting precipitate is washed, dried, ignited, and weighed. This gives the per-centage of alumina.

f. The filtrate from the alumina and oxide of iron (see d), after being evaporated to dryness, is redissolved in a large quantity of distilled water, and is treated with a solution of oxalic acid (a solution of oxalate of ammonium is preferable when no baryta is present); the precipitate is washed, dried, gently ignited, and weighed. The weight of the resulting carbonate of calcium, in grains, multiplied by ·56292, gives the per-centage of lime required.

g. The filtrate from f is now mixed with carbonate of potassium, in considerable excess, and boiled for a long time; the resulting precipitate (if any) is then collected on a filter, slightly washed with hot water, dried, and exposed to a full red heat for some time (say 2 hours); the residuum of the calcination is then weighed. This furnishes the per-centage value of the sample in magnesia.

h. The filtrate from f is treated with dilute sulphuric acid or the solution of a sulphate, as long as a precipitate falls; the precipitate (sulphate of barytum,) is washed, dried, gently ignited, and weighed. The weight, in grains, multiplied by ·6589, gives the per-centage of baryta in the sample.

The above may be varied by gently concentrating the liquid filtered from the precipitate of alumina and oxide of iron (see d), and precipitating it with dilute sulphuric acid; the mixed precipitate is exhausted by digestion in water holding chloride of ammonium in solution; the undissolved residuum (sulphate of barytum,) is washed, dried, and otherwise treated as before; whilst the solution with the washings is treated with a solution of carbonate of ammonium; the precipitate is carbonate of calcium, which is to be washed, &c., as directed under f. The liquor, &c., filtered from the lime, is lastly tested for magnesia. (See g.)

i. A second 100 gr. of the powdered glass (see a) is mixed with 200 gr. of fluor spar, also in powder; the compound is placed in a platinum or leaden capsule, 500 gr. of strong sulphuric acid are added, and the whole cautiously stirred together with a silver stirrer or spoon, care being taken to avoid inhaling the fumes; the heat of a spirit lamp is next applied, and at first is kept at about 212° Fahr., but towards the conclusion of the process is raised to 300° Fahr., or even higher, and is continued for at least 2 hours, or until fumes entirely cease to be evolved; 5 or 6 fl. oz. of distilled water are next poured on the residuary mass, and, after thorough agitation, the whole is thrown on a filter, more water being at last poured on to wash out any remains of soluble matter; to the filtrate, carbonate of ammonium is added in excess, and after a time the earthy salts are removed by filtration; the filtered liquor is now evaporated to dryness, and ignited to dull redness for 2 or 3 minutes; the residuum (sulphate of potassium or sodium, or of both), after being weighed (the weight being carefully noted down), is redissolved in distilled water; a solution of chloride of barium is then added as long as it disturbs the liquor, and after a time the whole is again filtered; the filtrate is concentrated by evaporation, and solution of bichloride of platinum added in excess; the whole is now gently evaporated to dryness, mixed with alcohol, collected on a filter, carefully washed with weak alcohol, dried at a temperature under 212° Fahr., and weighed. The weight, in grains, multiplied by ·1940, gives the per-centage of potassa sought.

k. The weight of sulphate of potassium in the ignited residuum in i is calculated from that of the potassium last found (47 parts of the one being equal to 87 parts of the other), and this weight is deducted from the gross weight of the ignited sulphates; the remainder represents the quantity of sulphate of sodium present. The weight of the latter, in grains, multiplied by ·4367, gives the per-centage of pure soda required.

Concluding Remarks. One of the chief points to which the skilful glass manufacturer directs his attention, is the quality of the materials. Great care is exercised in the selection of the sand for all the finer varieties of glass. The usual practice is to test it before using it, by exposing it to a very high temperature. The purest sand is that which is the whitest and freest from iron, and which, consequently, suffers the least alteration by this treatment. The alkalies (potash, soda) employed are purified by solution and crystallisation. The red lead and litharge must be pure and absolutely free from oxide of copper (a common contamination), which gives a green tint to the glass. The former, which is the most costly, is preferable to the finest crystal. Care must also be taken that the lime, clay, &c., are respectively of proper purity; and that the ‘cullet,’ or broken glass, which is almost always remelted with the other materials, is of proper quality, and of the same kind as that to which it is added. Potassa produces a better glass than soda, although the latter is now very generally employed, from its lower price. It is, however, quite inadmissible as an ingredient in the manufacture of the better class of crystal and plate glass, as, however pure it may be, it imparts to the product a slight greenish tinge more or less destructive of its beauty. When sulphate of soda (Glauber salt) is used as a source of soda, it is gently calcined to dissipate its water of crystallisation, and requires the addition of about 8% of charcoal to effect its reduction in the melting-pot. Common salt is also employed as a source of soda in the same manner. Sometimes native sulphide of lead (galena) is used to decompose the sulphate of soda, and in lieu of part of the oxide of lead; in which case about 5 parts of the sulphuret are taken for every 9 parts of the calcined sulphate.

To anticipate the results of his processes, and to carry out with certainty his various intentions, the glass manufacturer, perhaps more than any other person, requires the aid of science and experience. All his most essential operations depend on chemical principles. The products of his furnaces are not formed by the mere mechanical admixture of their several ingredients whilst in the state of fusion, but result from the play of delicate affinities which only act under certain conditions, and when the materials are presented to each other in uniform and definite proportions. Chemically speaking, the glasses are mixed super-silicates of the respective bases which enter into their composition (potassium, calcium, lead, &c.), and, like all other compounds which are formed by elective attraction, obey the common laws of combination, as developed by Dalton, and now so successfully applied in almost every department of industrial art. It has been shown by the most careful analysis, that in all the more valuable and beautiful commercial glasses the relative proportions of the materials are conformable to these laws, and that several of them are true atomic compounds, as perfect in this respect as the crystalline bodies commonly denominated salts. In some of the harder glasses of Bohemia the number of atoms or equivalents of silica are to each of the bases with which it is united, nearly as 5 to 1; whilst in a softer glass of German manufacture the proportions of the two are found to be as 4 to 1. The celebrated plate glass of St. Gobain is an atomic compound formed of 1 equivalent of trisilicate of soda united to 1 equivalent of trisilicate of lime, with a small per-centage of alumina in combination with silicic acid, also in atomic proportion. Glasses in which the ingredients bear no atomic ratio to each other are never homogeneous, but always more or less striated and of unequal colour and refractive power. The absence of atomic proportion between the substances entering into its composition appears to be the only reason why the best English plate and mirror glass is so greatly inferior to that of France and Germany, that comparison of the two becomes absurd. The only variety of glass in the production of which the English manufacturer excels is flint glass or crystal, and here he certainly surpasses all his numerous competitors. The subject is doubtless involved in difficulty, owing to the precise temperature necessary to effect the perfect combination of the bases with the silicic acid, varying with the character of the compound, and not being satisfactorily settled by observation or experience. The modifying influence of temperature is shown by the fact that the lower the heat employed in the process, the smaller the quantity of silica which enters into the composition of the resulting glass; whilst at higher temperatures a part of the base is dissipated in fumes, until such proportions of base and acid result as are required to produce a permanent atomic compound corresponding to the temperature employed. If the heat is excessive or improperly continued, the loss of base produces an opposite effect, and an opaque, semi-vitrified mass is formed, resembling ‘Reaumur’s porcelain.’ The quality of the resulting glass depends on this change being more or less complete. If the furnace yields the right temperature, and the duration of the exposure to its action is neither too short nor too prolonged, nature makes up for the unskilful conduct of the operative, and removes the stumbling blocks which his ignorance had placed in the way of his own attempts at excellence. The proceedings and their results are accidental; but being once obtained, the first are repeated without further trouble or inquiry. This accounts for the same mixture of materials yielding products of different qualities at different times, and in different works, which the operative contents himself with referring to the ‘going of the furnace.’ The common plan in this country is to regulate the proportions and firing by experience only, rather than by theory and practice combined. Now, although the chemist has much yet to learn on the precise constitution of the glasses, and although theory may not be able to ensure unvarying success, it is nevertheless certain that, in all cases, it can afford much valuable assistance in that direction. Indeed, it has been asserted by one of the leading Continental chemists, that ingredients that will yield the proper equivalent proportions in the melting pot cannot produce a bad glass, if exposed to such a temperature as to permit of perfect combination taking place.

It is found that those glasses which contain a predominance of alkali are acted on by water, and when this is in great excess they are perfectly soluble in that fluid. Ordinary flint glass is affected by long coction in water, whilst crown glass, which contains less alkali, is unaltered by that trial. Glass which contains any considerable quantity of lead is acted on by sulphuretted hydrogen. This is the cause of the surface of flint glass, under certain circumstances, becoming opaque and iridescent. Glasses made of silica and alkali alone are incapable of permanently resisting the action of water. The addition of lime or oxide of lead appears to be necessary to give them this quality. Glasses that have a slight greenish or bluish tint may be often whitened, or rendered colourless, by exposure to light and air. This arises from the peroxidation of the iron, to whose protoxide they owe their tint. Other glasses become purpled by exposure, owing to the peroxidation of the manganese.

Different colours are communicated to glass by the addition of metallic oxides. Thus, oxide of manganese gives an amethyst; oxide of cobalt, a blue; oxide of iron, a brown; black oxide of copper, a green; oxide of gold, a purple; suboxide of copper, a ruby-red; oxide of tin, a white; oxide of silver, a yellow, &c. These substances are either added to the melted contents of the glass-pot, as in preparing artificial gems, &c., or they are applied in a thin layer to the surface of the object, which is then heated until fusion of the coloured compound occurs, as in enamelling and painting on glass.

Glass is FORMED or FASHIONED into articles by the processes of blowing, casting, drawing, rolling, or spreading. In the process of BLOWING GLASS the workman begins by collecting a proper quantity of glass in a soft, pasty state, at the end of his blow-pipe (an iron tube, five or six feet in length, terminated by a mouth-piece of wood), which he then commences blowing through, by which the lump is expanded into a kind of flask, susceptible of having its form modified by the position in which it is held, and the velocity of rotation continually given to the iron tube. If an open-mouthed vessel is to be made, an iron rod, called a ‘pontil’ or ‘puntil,’ is dipped into the glass-pot and applied to the bottom of the flask, to which it thus serves as a handle, the blow-pipe being removed by the application of a cold iron to the neck. The vessel is now re-heated, and the aperture enlarged, and the vessel otherwise altered in figure by the aid of a few simple tools until completed. It is then detached, and carried to the ‘annealing oven,’ where it undergoes slow and gradual cooling during many hours. In this way bottles, flasks, carboys, and an almost infinite variety of other articles, are formed. The large circular tables of CROWN-GLASS are made by a joint process of BLOWING and SPREADING. The globular flask at first produced, transferred from the blow-pipe to the ‘pontil,’ is suddenly made to assume the form of a flat disc by the centrifugal force of the rapid rotatory movement given to the rod. SPREAD or BROAD GLASS is formed into sheets in a nearly similar manner. PLATE-GLASS is cast upon a flat metal table, and, after very careful annealing, is ground and polished by suitable machinery. TUBES are made by rapidly drawing out a hollow cylinder; and from these a great variety of useful small apparatus are constructed with the help of a lamp and blowpipe, or, still better, the bellows-table of the barometer-maker. GLASS BEADS are made from small tubes chopped into pieces of suitable lengths, which are stirred first in a mixture of sand and wood-ashes, in the cold, and afterwards in an iron pan over the fire until they assume a rounded form. SMALL TUBES are bent in the flame of a spirit lamp or gas-jet, and cut by a file, a scratch being made, and the two portions pulled or broken asunder in a way easily learned by a few trials. LARGE TUBES require the heat of a powerful blowpipe and lamp, or that of a furnace.

The following hints respecting the MANAGEMENT OF GLASS may prove useful to the inexperienced:——

ANNEALING. The process of annealing glass has been briefly referred to before. The extreme brittleness of imperfectly annealed wrought glass may generally be remedied on the small scale by immersing the articles in a bath of oil, or a concentrated solution of chloride of calcium, or common salt, and heating the whole gradually and cautiously to the boiling-point, and letting it again cool——the slower the better. By this treatment the glass will be enabled to bear any alterations of temperature between the two extremes to which it has been exposed.

BLOWING. By the ingenious art of GLASS-BLOWING and GLASS-DRAWING, as practised on the small scale, with a blowpipe lamp furnace, a variety of articles of ornament and utility may be made, their number being limited only by the ingenuity of the artist. The details of the various operations are, however, too lengthy to describe here.

CLEANING. 1. Windows, looking-glasses, &c., may be quickly cleaned as follows:——Dip a slightly moistened rag or flannel into whiting, fuller’s earth, wood-ashes, or rotten-stone, in impalpable powder, with which smear the glass, and wipe it off with a dry, soft cloth. This does well when the surface is very dirty. In other cases, a little thumb blue, whiting, or chalk, in fine powder, tied up in muslin, may be dusted on the glass, which should then be cleaned off with chamois leather. This gives a fine polish.

2. The vessel to be cleansed, is filled, or, if large, rinsed, with a moderately dilute solution of permanganate of potash, contact being prolonged till a film of hydrated manganic oxide has been deposited; the solution is then poured away, and the glass vessel rinsed with some strong hydrochloric acid.

CUTTING. Glass may be easily cut with a common well-hardened steel file, provided it be moistened with oil of turpentine, or plunged under water. It may be also perforated with a common steel brad-awl in the same way. GLASS VESSELS, as bottles and tubes, may be readily cut or shortened by placing a heated iron ring over the spot, or a piece of loose string or cotton dipped in oil of turpentine and set on fire, and immediately on the withdrawal of either applying cold water to the part. Glass vessels or tubes thus treated will generally crack round, and may be readily divided into two parts. In this manner a common Florence oil-flask may be converted into an evaporating dish and a funnel. By a little practice a crack may be led in almost any direction, or a new one made, by the point of a red-hot poker or a spring coal (an ignited crayon of prepared charcoal). The parts may then be separated by a little force or a smart rap, and the divided edges smoothed by the flame of a blowpipe, or by grinding them with powdered emery and water on a flat stone. In this way many broken articles in glass may be converted into others scarcely less useful.

ETCHING ON GLASS has been already noticed under the head of Etching.

GILDING OF GLASS. Gold chloride is dissolved in boiling water; the solution is filtered, and the filtrate so far diluted, that 200 cubic centimètres contain 0·0648 gram of the metal, and it is then made alkaline with soda. The reducing agent is alcohol saturated with marsh gas; this is diluted with its own volume of water. 25 cubic centimetres of this solution are mixed with the alkaline gold chloride solution, and this mixture is poured between the perfectly well-cleaned plate to be gilded, and another sheet of glass placed at a distance of 3 mm. under the first. After two to three hours’ rest the gilding is effected. The plate is removed and washed. (‘Dingler’s Journal.’)

GRINDING. This, on the large scale, like glass-cutting, forms a distinct occupation. On the small scale, glass may be roughed or ground by friction with powdered emery and water and a flat rubber of wood; care being taken that the article, if a plate, is laid on a perfectly flat surface, or, if hollow, is supported by a core of cement or plaster. The frosted appearance of ground glass is given to the panes of windows by gently dabbing the glass over with a piece of glazier’s putty, stuck on the ends of the fingers. When applied with a light and even touch, the resemblance is considerable. Another method is to dab the glass over with thin white paint, or flour paste, by means of a brush, but the effect is much inferior to the above.

GLASS, PACKING. This subject will be considered under the general head of PACKING.

WRITING ON GLASS may be performed by a piece of French chalk or crayons prepared for the purpose; or even with a common pen held nearly perpendicular. Indian ink, or, when the article will be exposed to damp, shell-lac ink or varnish, thickened with a little Vermillion, or lampblack, is best adapted to this purpose. Common ink is not sufficiently opaque.

GLASS, TO PREVENT THE CRACKING OF, BY BOILING WATER. When new, all glass and earthenware should be placed in cold water in a saucepan, and after some hours the saucepan containing the vessel or vessels, should be placed over the fire, until the water reaches the boiling point.

=Glass.= This term was applied by the older chemists to various substances to which a vitreous appearance has been given by heat. Thus we have ‘GLASS OF ANTIMONY,’ ‘GLASS OF BORAX,’ &c. It is now obsolete.

=Glass, Iridescent.= The inventor of the process by which this beautiful variety of glass is made is M Clémandot.

The ‘Chemical News’ states that the principle observed in its manufacture consists in submitting the glass articles to the action of dilute hydrochloric, sulphuric, or other acid, under a pressure of from two to six atmospheres. M Clémandot claims to be able to imitate the nacreous films which are seen on ancient glass which has been exposed to combined atmospheric influences for thousands of years.

=Glass, Pow′dered.= Syn. VITRUM PULVERISATUM, L. Prep. Heat the glass red hot, throw it into cold water, dry, and powder it. Used to filter acids, and glued upon paper as a polishing powder; also to wear down corns upon the feet, after the feet have been well soaked, and dried.

=Glass, Sol′uble.= Syn. WATER GLASS; VITRUM SOLUBILE, L. An impure alkaline silicate. Prep. Silica, 1 part; carbonate of potassium or of sodium, 2 parts; fused together.

Carbonate of sodium (dry), 54 parts; carbonate of potassium (dry), 70 parts; silica, 192 parts; as last. Soluble in boiling water, yielding a fine, transparent, semi-elastic varnish.

Carbonate of potassium (dry), 10 parts; powdered quartz (or sand free from iron and alumina), 15 parts; charcoal 1 part; fused together. Soluble in 5 or 6 times its weight of boiling water; and the filtered solution, evaporated to dryness, yields a transparent glass, permanent in the air.

M. F. Capitaine, who, acting upon a suggestion made by Liebig, some twenty years since, has recently taken up the subject of the manufacture of soluble glass, and silicate of potash, from farine fossile (an infusorial earth), has published an account of his researches in ‘Dingler’s Polytechnic Journal.’[334]

[Footnote 334: See ‘The Journal of the Society of Arts’ for January 11th, 1878.]

Although M. Capitaine does not think that the farine will be able to compete in cheapness with flint (where this latter is abundant) for the preparation of the alkaline silicates, he states that it possesses the advantage over flint of being much more soluble, and of yielding a far more neutral glass; added to which the production of the silicate is said to be effected with much less trouble than when flint is employed. An important condition is, that the farine must be first well calcined, since if the least trace of organic matter be left in it, the resulting solution will have a yellowish or brownish tint, which will make it unsaleable.

“The lyes being prepared partly with caustic soda, and partly with carbonate of soda, had densities ranging from 1·22 to 1·24 which were found to be most advantageous. A reservoir furnished with mechanical agitators, was about two thirds filled with lye, and the necessary quantity of calcined farine added, the stirring being kept up continually. The proportion of farine is easily calculated on the datum, that one part of hydrate of soda dissolves about 2·8 parts of chemically pure farine, the quality of which varies but little. Lye of the density indicated produces a rather light solution, which presents little resistance to the agitators. If steam is afterwards introduced the solution becomes very rapid, when the pressure reaches about three atmospheres, and at the end of about three hours the silica is completely dissolved.

“For the preparation of silicate of potash for surgical purposes the farine fossile is said to be peculiarly adapted. In this case the boiling must be continued for one or two hours longer than in the case of soluble glass, with an addition of 10 to 15 per cent. of farine.”

Uses. &c. Soluble glass, in solution, has been used to render textile fabrics less combustible, as a varnish to protect stone, and as a vehicle in fresco-painting, The soda compound (silicate of sodium) is largely used as a dung-substitute in calico-printing, and by soap manufacturers in place of the resinates formerly in use. 10 or 12 tons are produced weekly in the district of South Lancashire. The potassa compound (silicate of potassium) has been recommended as a remedy for gouty concretions by Mr Ure.——Dose, 10 to 15 gr., in 6 or 8 fl. oz. of water twice a day. See DUNGING, VARNISH, &c.

=Glass, Toughened.= Syn. VERRE TREMPÉ. M. de la Bastie’s process for converting ordinary, into toughened, tempered, or hardened glass, may in general terms be said to consist in heating the glass to a certain temperature, and then plunging it into an oleaginous bath. For the process, however, to be successful, the observance of a number of minute details is essential; if these be neglected failure is certain to ensue. Thus it is found, that if the glass be insufficiently heated it will, when immersed in the bath, fail to be affected by it, and will consequently experience no alteration in properties. Again, if overheated, it will then get out of shape; or, further it may be heated to the right temperature, and yet be spoilt as it is being transferred to the bath. Moreover, the exact composition of the bath itself, and its temperature constitute very important conditions, the most trifling departure from which may give rise to unsatisfactory results. All these obstacles appear to have been overcome by M. de la Bastie, who has designed plant in the shape of furnaces and baths, by means of which the tempering process can be carried out, without chance of failure. When the glass is brought to the required temperature, all that is necessary is that they should be plunged into the bath, and instantly withdrawn. The cost of the operation is stated to be very small.

“The process as carried out at New York is thus described:——The glass after being run from the furnaces and moulded as usual, instead of being put into annealing pans, is immersed in a hot bath consisting of three parts of flaxseed oil, and one part of tallow. The bath stands at about 320°; and after remaining in this the ware is removed to a second, and similar bath, by which it is cooled down to about 200°. Finally the pieces are immersed in a water bath, and then dipped into a quantity of ordinary refined burning oil. They are then cleaned, ready for packing, with plaster of Paris powder. The work is but in its infancy, and but one small furnace is used in the experiments. Improvements will doubtless be made, by which the cleaning can be done more rapidly than by the powdered plaster, probably some chemical being used for the purpose. It is supposed that the oil works into the pores of the hot glass, and thus toughens it. Great care has to be exercised in the final cooling by water, as too long a contact with the air in changing from one bath to another, makes the ware crack. Articles cooled entirely in oil retain the oil on the surface, but are thus rendered stronger than otherwise.

This new process is very much employed in the manufacture of lamp chimneys, though they have the disadvantage of flying into small pieces, and with violence when they do break, which sometimes does occur.”[335]

[Footnote 335: Supplement to ‘Ure’s Dictionary of Arts, Manufactures, &c., 1878.]

The results so far obtained when glass is subjected to M. de la Bastie’s process are variable. In some cases the articles subjected to it possess great toughness, and the glass bears a blow without experiencing any fracture. In other instances, however, a slight fall or blow shivers it to atoms. When the toughened glass under any circumstances breaks, it possesses a disadvantage over ordinary broken glass, in distributing itself into a great number of small, sharply angular fragments.

Another process for toughening glass, which has been patented by Herr F. Siemens, consists in heating, and then pressing, and suddenly cooling the glass to be hardened; but when the articles are such as are usually moulded, the hardening and tempering are accomplished at the same time as the pressing; thus the molten glass is run into suitable moulds, and while still highly heated, is squeezed, the moulds effecting the necessary cooling, a proceeding which renders the employment of the oleaginous bath unnecessary. Mr Bauer’s method for toughening glass consists in heating ordinary glass plates so strongly that they begin to bend from softening, and then plunging them into a liquid paraffin bath having a temperature of 200°.

Toughened glass is liable to rupture under circumstances that have not yet been accounted for.

M. de la Bastie conceives that the fragile nature of glass is due to the weakness of the cohesion of its particles, and that if this cohesive power can be increased, the strength of the material will be improved in proportion. M. de la Bastie first tried to obtain this end by forcibly compressing the glass while in a plastic or fluid condition, but without success; and it was only after various experiments that he was enabled to harden the glass, by dipping it into oil or any other liquid that permitted of being heated to a temperature considerably above that of water.

=GLAZE.= Syn. GLAZING. Any coating or varnish applied to a surface to render it smooth and glassy; any factitious, shining exterior. The following applications of this term are the following:——

=Glaze.= In cookery, is commonly understood to be gravy or clarified soups boiled until it gelatinises on cooling. It is used as a species of varnish to cover various dishes for the table, and may be spiced and flavoured according to the fancy of the cook. White of egg is generally used as a glaze for pastry.

=Glaze.= In the porcelain and earthenware manufacture, the vitreous coating which is so essential to the beauty and utility of potter’s ware. Glazes are either white or coloured. The former, by the addition of the colouring ingredients used for enamels, are converted into the latter.

a. For EARTHENWARE:——

Prep. 1. (With lead.) White lead (pure), 53 parts; quartz or ground flints, 36 parts; Cornish stone, or felspar, 16 parts; white flint glass, 5 parts; reduce the whole to an impalpable powder. For common earthenware.

2. (Without lead.) Fine washed sand, 10 parts; purified potash, 8 parts; nitre, 1 part; slaked lime, 2 parts; nitre, 4-3/4%; powder, mix, heat the mixture in a blacklead crucible in a reverberatory furnace, till the mass flows into a clear glass; let this cool, then reduce it to fine powder. For glazing pharmaceutical and chemical vessels.

b. For PORCELAIN:——

Prep. (Rose.) Felspar, 27 parts; borax, 18 parts; finest siliceous sand, 4 parts; nitre, soda, and purest china clay (Cornish), 3 parts; mix, heat to a ‘frit,’[336] powder, and add of calcined borax, 3 parts.

[Footnote 336: A technical term for the half-fused mass formed by heating together the materials of which glass is composed.]

c. For STONEWARE:——

1. (Ure.) White felspar, 26 parts; soda, 6 parts; nitre, 2 parts; borax, 1 part; ‘frit’ together as last. Of the product take 13 parts; red lead, 50 parts; white lead, 40 parts; flints, 12 parts; reduce the whole to powder as before. For painted stoneware.

2. From common salt, which is thrown into the heated furnace containing the ware. It is volatilised and decomposed by the joint agency of the silica of the ware and of the vapour of water always present; hydrochloric acid and soda are produced, the latter forming a silicate, which fuses over the surface of the ware, and gives a thin but excellent glaze. ‘SALT-GLAZED STONEWARE’ is now generally used for large chemical vessels, drain-pipes, &c.

Obs. Glazes must be reduced to very fine powder. For use, they are ground with water to a very thin paste or smooth cream, into which the articles, previously baked to the state called ‘biscuit,’ are then dipped; they are afterwards exposed to a sufficient heat in the kiln to fuse the glaze. Another method of applying them is to immerse the biscuit in water for a minute or so, and then to sprinkle the dry powder over the moistened surface.

=GLI′ADIN.= Syn. GLUTIN, VEGETABLE GELATIN. One of the proximate principles of wheat gluten, soluble in alcohol.

=GLIADINPFLASTER= (A. L. Klose, Berlin). For rheumatism. A thin paper on which is spread a solution of gelatin containing spirit and some acrid substance, such as cantharides or euphorbium.——Hager.

=GLOB′ULIN.= Syn. CRYSTALLIN. An albumenoid body existing in the crystalline lens of the eye.

=GLOVE POW′DER.= Prep. 1. From Castile soap, dried by exposure to a warm dry atmosphere for a few days, and then reduced to fine powder in a mortar. Used to clean gloves.

2. Pipe-clay, coloured with yellow ochre, umber, or Irish slate q. s., and afterwards scented with a little powdered orris root or cloves. Used to colour gloves made of doe-skin and similar leather.

=GLOVES.= Syn. GANTS, Fr. Although gloves constitute a less costly article of dress at the present day than they did during the Middle Ages, the following information may nevertheless be sometimes found of value to their wearers:——

GLOVE CLEANING. 1. (KID GLOVES.)——a. Damp them slightly, stretch them gently over a wooden hand of appropriate size, and clean them with a sponge dipped in benzol, recently rectified oil of turpentine, or camphine; as soon as they are dry, withdraw them gently from the stretcher, and suspend them in a current of air for a few days, or until they cease to smell of the cleaning liquid used. The smell of benzol passes off very quickly. Heat must be avoided. The cleaning liquid should be used liberally, and the first dirty portion should be sponged off with clean liquid.

b. By employing a saponaceous compound. See GANTEINE.

2. (DOE-SKIN and WASH-LEATHER GLOVES.)——a. Stretch them on a hand, or lay them flat on a table, and rub into them a mixture of finely powdered fuller’s earth and alum; sweep it off with a brush, sprinkle them with a mixture of dry bran and whiting, and, lastly, dust them well off. This will not do if they are very dirty.

b. Wash them in lukewarm soft water, with a little Castile or curd soap, ox-gall, or bran tea; then stretch them on wooden hands, or pull them into shape without wringing them; next rub them with pipe-clay and yellow ochre, or umber, or a mixture of them in any required shade made into a paste with ale or beer; let them dry gradually, and, when about half dry, rub them well, so as to smooth them and put them into shape; when they are dry, brush out the superfluous colour, cover them with paper, and smooth them with a warm (not hot) iron.

GLOVE DYEING. LEATHER GLOVES, if not greasy, may be dyed with any of the ordinary dyes by brushing the latter over the gloves stretched out smooth. The surface alone should be wetted, and a second or third coat may be given after the former one has become dry. When the last coat has become thoroughly dry, the superfluous colour should be well rubbed out, a smooth surface given them by rubbing them with a polished stick or piece of ivory, and the whole gone over with a sponge dipped in white of egg.

=Gloves, Cosmetic.= Syn. GANTS COSMETIQUES. These are mock kid or lambskin gloves rubbed over, on the inside, with the following composition:——Spermaceti cerate, 3 oz.; melt, add of balsam of Peru, 1/2 dr., stir for 5 minutes, and, after a few minutes’ repose, pour off the clear portion; to this add of oil of nutmeg, 15 drops; oil of cassia and essence of ambergris, of each 6 drops; and stir until cold. Used by ladies to soften the hands and to prevent or cure chilblains and chaps. They are commonly worn all night in bed.

=GLUCI′NUM.= Gl. Syn. BERYL′LIUM. The metallic base of glucina. It was first obtained by Wöhler, in 1828, by a similar process to that adopted for aluminum, a metal which it greatly resembles. See ALUMINUM.

=Gluci′num, Oxide of.= Syn. GLUCINA, BERYLLIA. A pulverent white substance, found as silicate in the beryl, emerald, &c.

Prep. The beryl, in fine powder, 1 part; carbonate of potassium, 3 parts; expose the mixture to a strong red heat for half an hour, dissolve the calcined mass in hydrochloric acid, and evaporate the solution to dryness; redissolve the residuum in very dilute hydrochloric acid, and precipitate with pure ammonia; wash the precipitate well, digest it with a large quantity of carbonate of ammonium, filter, and boil the solution as long as carbonate of glucinum subsides. By exposure to a red heat the carbonic acid may be expelled, and the earth rendered anhydrous.

Prop., &c. Glucina closely resembles alumina, from which, however, it is distinguished by its solubility when freshly precipitated in a cold solution of carbonate of ammonia, from which it is again thrown by boiling. Glucina is classed with the earths. The beryl contains 14% of this substance.

=GLU′COSE.= See SUGAR (Grape).

=GLUE.= Syn. GLUTEN, GLUTINUM, L.; COLLE, COLLE FORTE, Fr. Inspissated animal jelly, or gelatin, used as a cement.

Prep. Glue is principally prepared from the parings and waste-pieces of hides and skins, the refuse of tanneries, and the tendons and other offal of slaughter-houses. These substances, when intended for the glue-maker, are steeped for 14 or 15 days in milk of lime, then drained, and dried by exposure to the air. This constitutes what is termed the ‘cleansing’ or ‘preparation,’ and in this state the ‘glue pieces,’ as they are called, may be kept for a long time, and transported to any distance without suffering decomposition. Before conversion into glue, they are usually again steeped in weak milk of lime, and next well washed and exposed to the air for 24 to 30 hours. They are then placed in a copper boiler two thirds filled with water, and furnished with a perforated false bottom, to prevent them from burning, and as much is piled on as will fill the vessel and rest on the top of it. Heat is next applied, and the whole gently boiled or simmered together, until the liquor on cooling forms a firm gelatinous mass. The clear portion is then run off into another vessel, and a very small quantity of alum (dissolved) added; here it is kept hot by a water bath, and allowed to repose for some hours to deposit its impurities, after which it is run into the ‘congealing boxes,’ and placed in a cool situation. The next morning the cold gelatinous masses are turned out upon boards wetted with water, and are cut horizontally into thin cakes with a stretched piece of brass wire, and then into smaller cakes with a moistened flat knife. The latter are placed on nettings to dry. The dry cakes of glue are next dipped one by one into hot water, and slightly rubbed with a brush wetted with boiling water, to give them a gloss; they are, lastly, stove-dried for sale. This furnishes the palest and best glue.

As soon as the liquor of the first boiling has drained off, the undissolved portion of skins, &c., left in the copper is treated with fresh water, and the whole operation is repeated again and again, as long as any gelatinous matter is extracted. In this way a second and other inferior qualities of glue are obtained. The product from dried glue-pieces is about 50%.

Var. These chiefly depend on the care with which the process is conducted. HATMAKERS’ GLUE is prepared from the tendons of the legs of neat cattle and horses. It is brown, opaque, and soft; and grows moist in damp weather, but it does not render felt brittle like the other varieties. FISH GLUE is made in like manner from various membranous and solid parts of fishes. PARCHMENT GLUE is prepared from shreds or shavings of parchment, vellum, white leather, &c., dissolved by boiling them in water. It is scentless, and nearly colourless.

Qual. The best glue is transparent, nearly colourless, and tasteless, has very little smell, even when melted, and is extremely adhesive. The presence of more than a trace of alum is objectionable; an undue quantity may be easily detected by the usual tests. The strongest glue is that obtained from skins, more especially from the hides of oxen and cows. That obtained from the bones, cartilages, and tendons, is weaker.

=Glue, Liq′uid.= Prep. (Dumoulins.) Soft water, 1 quart; best pale glue, 2 lbs.; dissolve in a covered vessel by the heat of a water bath, cool, and add, gradually, of nitric acid (sp. gr. 1·335), 7 oz.; when cold put it into bottles. Very strong, and does not gelatinise. For the ‘LIQUID GLUE’ sold in the shops, see CHINESE CEMENT.

=Glue, Marine.= Prep. 1. India rubber (cut small), 1 part; coal tar or mineral naphtha, 12 parts; digest in a covered vessel with heat and agitation, and when the solution is complete, add of powdered shell-lac, 20 parts; continue the heat and stirring until perfect liquefaction has taken place, and pour the fused mass, whilst still hot, on slabs of polished metal or stone, so as to form thin sheets. For use, it is heated to its melting-point (248° to 250° Fahr.) in an iron vessel, and applied in the liquid state with a brush. Employed in ship-building, &c.

2. Caoutchouc, 15 to 20 gr.; chloroform, 2 fl. oz.; dissolve, and add of powdered mastic, 1/2 oz. It must be kept well corked and in a cool place, to prevent loss by evaporation. Used for small, fine work.

=Glue, a New.= Ordinary glue is dissolved in nitric ether, and a little bit of caoutchouc added. This solution forms a very strong glue, and does not get thick or pasty. (‘Dengler’s Journal.’)

=Glue, Port′able.= Syn. BANK-NOTE GLUE. MOUTH G., INDIAN G.; COLLE À BOUCHE, Fr. Prep. From the best pale glue, 1 lb.; water, q. s.; dissolve in a double glue-pot or water bath, and of pale-brown sugar, 1/2 lb., continue the heat until the mixture is complete, and pour it into moulds; or pour it on a marble slab, and when cold cut it into small pieces and dry them in the air. This glue is very useful to draughtsmen, architects, &c., as it dissolves almost immediately in warm water, fastens paper, &c., without the process of damping, and may be softened for many purposes with the tongue. When great strength not required, 4 oz. more of sugar may be used.

=GLU′TEN.= Syn. GLUTIN. A peculiar substance found in the grain of wheat. It is composed of true vegetable fibrin and a small quantity of gliadin. It is prepared by washing paste made of the flour of wheat or rye in successive waters until all starchy matter is removed. The paste may be conveniently enclosed in a bag of fine linen during the washing.

Prop., Uses. Gluten is believed to be eminently nutritious. It is the presence of gluten in wheaten flour that imparts to it its viscidity or tenacity, and confers upon it its peculiar excellence for the manufacture of MACARONI, VERMICELLI, and similar pastes. The superiority of wheaten over other bread depends upon the greater tenacity of its dough, which during the fermentation is puffed up by the evolved carbonic acid, and retained in its vesicular texture so as to form a light loaf.

Gluten is greyish coloured, and extensible whilst fresh and moist, like caoutchouc. It turns blue when mixed with guaiacum resin.

=Gluten Bread.= Prep. 1. From wheat flour which has been deprived of about 2-3rds of its starch by washing it with water.

2. From gluten flour. Recommended in diabetes.

=Gluten Choc′olate.= (Gentile’s.) A mixture of cocoa and gluten flour. As a nutritious and appropriate food in diabetes.

=Gluten Flour.= Prep. 1. From the waste gluten of the starch works, washed, dried, and ground.

2. (Gentile’s.) From the last, mixed with about an equal weight of wheat flour.

=GLYC′ERIN.= C_{3}H_{3}O_{3}. Syn. GLYCERIN, HYDRATED OXIDE OF GLYCERYL; GLYCERINUM, L. A sweet syrupy liquid formed during the saponification of oils and fats.

Prep. 1. Olive oil (or other suitable oil), protoxide of lead, and water are heated together until an insoluble soap of lead (lead plaster) is formed. The glycerin remains in the aqueous liquid. As this crude solution of glycerin is produced in great quantities in the manufacture of lead plaster, the operative chemist has only to purify it. This may be done as follows:——

The water and washings from lead plaster are mixed together, filtered, and submitted to the action of a stream of sulphuretted hydrogen to throw down the lead; the supernatant liquor is decanted from the precipitate, filtered, and evaporated to the consistence of a syrup in a water bath. To render it quite pure it is diluted with water, decoloured with a little animal charcoal, filtered, and again evaporated to the consistence of a thin syrup, after which it is further evaporated in vacuo, or over sulphuric acid, until it acquires the sp. gr. 1·265.

2. (M. Bruère-Perrin.) From the sweet liquor of the stearine works (a product of the process of lime-saponification). The quantity of lime present in the sample is first determined by means of oxalic acid, and the proportion of sulphuric acid necessary for its saturation at once calculated and added; the crude liquor is then concentrated in a tinned-copper vessel, evaporation being promoted by brisk agitation, until the sp. gr. sinks to 10° Baumé; it is next cooled and filtered, and accurately neutralised (if it is required) with carbonate of potassa, after which it is evaporated to the sp. gr. 24° Baumé; on cooling, it deposits gelatinous sulphate of potassa; the whole is now filtered, the deposit on the filter washed with a little very weak spirit and water, the filtrate and washings mixed together and evaporated, as before, with agitation, until the sp. gr. 28° Baumé, whilst hot (36° cold), is attained, when the whole is allowed to cool; the clear liquid is, lastly, decanted and filtered. In this state it has an amber colour, but may be rendered colourless and odourless by rediluting it with water, treating it with animal charcoal, filtering, and again evaporating to a proper consistence.

3. By saponifying olive oil with caustic alkali, decomposing the resulting soap with dilute sulphuric or tartaric acid, evaporating the aqueous portion to dryness (nearly), dissolving out the glycerin with cold rectified spirit, and filtering and evaporating the solution as before.

4. The residuary liquor of a soap manufactory is evaporated, and treated with alcohol to dissolve out the glycerin. The spirit is then evaporated off, the glycerin diluted with water, and finally boiled repeatedly with animal charcoal until all colour and odour are removed.

Obs. The products of the above processes are nearly pure, but that of Price’s patent process, described below, is to be preferred to any of them.

5. (Commercial.) From sweet stearin-liquor, by precipitating the lime by a stream of carbonic acid gas, or by a solution of carbonate of soda, carefully avoiding adding the latter in excess; the liquor is then boiled a little, filtered, evaporated to a syrupy consistence, and again filtered. This is the common glycerin of the shops. It may be further purified as above.

6. (PRICE’S GLYCERIN——Patent dated 1854.) Superheated steam of from 550° to 600° Fahr.) is introduced into a distillatory apparatus containing palm oil or other fatty body. The action of the steam effects the decomposition of the fat, and glycerin and the fatty acids distil over together but no longer in combination. In the receiver the condensed glycerin, from its higher specific gravity, sinks below the fatty acids. Sufficient steam must be supplied, and the temperature nicely regulated. The glycerin is concentrated by evaporation, and if discoloured, it is redistilled. It is usually prepared with sp. gr. 1·24, and then contains 94% of anhydrous glycerin. It can, however, be concentrated to sp. gr. 1·26 when it contains 98%.

Prop. Pure glycerin is a colourless, odourless, uncrystallisable liquid, sweet to the taste, and of a syrupy consistence; it mixes with water in all proportions; it is unctuous and emollient, and softens bodies, like oil, but without greasing them; it does not evaporate or change in the air at ordinary temperatures, and is not susceptible of rancidity or spontaneous fermentation; mixed with yeast and kept in a warm place, it is gradually converted into propionic acid; a strong heat decomposes it, with the production of acrolein; it is neutral to test-paper, and possesses neither basic nor acid properties; it is easily charged with the aroma of the essential oils, and may be combined with soap, and many other substances, without undergoing change. Sp. gr., 1·27 (see above).

MM. Champion and Pellet recommend the following methods for testing the purity of glycerin, as being convenient in application, and giving accurate results.

Qualitative Test. The glycerin diluted with twice its weight of water is treated in the cold.

(1.) With tribasic acetate of lead. If an abundant precipitate be formed, and rapidly deposited, the presence of a proportion of foreign matters may be assumed which would make it unsuitable for use in various applications, such as the manufacture of nitro-glycerin, &c. The crude glycerin obtained in treating fats with sulphuric acid is frequently thus contaminated. These foreign matters result from the action of sulphuric acid at a high temperature (about 110° C.) upon the fatty matter itself or on the impurities it may contain.

(2.) Glycerin obtained by calcareous saponification, also may contain oleate of lime. This may be detected with oxalate of ammonia, which throws down the lime as a clearly perceptible precipitate.

The colour of glycerin is in no way an index of the purity of the product. In all cases it is useful to be assured of the neutrality of the glycerin.

The preceding tests are suited for glycerins more or less impure, but not adulterated. According to the authors’ experiments the tribasic acetate of lead separates all the foreign substances due to normal impurity of the product or alteration in the glycerin during its manufacture. Any addition of glucose may be detected by Fehlings’ solution.

Quantitative Test. This test should comprehend the determination of the water, the foreign organic matter, the lime, and the glycerin.

In the following table the authors have given the density of various mixtures of water and glycerin, comparatively with the degrees Baumé, and also the proportions of water corresponding to the densities. They state, that these determinations have been verified by means of pure anhydrous glycerin, prepared by keeping glycerin for several hours at a temperature of 160° C, and terminating the operation in vacuô. The density found was in accord with that given by Berthelot, namely, 1·264.

Estimation of Organic Matter. Fifty grams of glycerin diluted with water are treated with an excess of tribasic acetate of lead, and the precipitate collected on two tared filters, and the lead compound weighed. The whole is then calcined, the residue treated with nitric acid, and then with sulphuric acid, and from the sulphate of lead is calculated the quantity of oxide of lead, that was in combination with organic matters, and consequently the proportion of the latter, which rarely exceeds 1 to 1·5 per cent.

Lime may be estimated in the usual manner by oxalate of ammonia.

------------------------------------------------------------------------ Hydrometer | Areometer | Water, | Hydrometer | Areometer | Water, Weight of | Degrees, | per Cent.| Weight of | Degrees, | per Cent. Litre. | Baumé. | | Litre. | Baumé. | -----------------------------------|------------------------------------ 1264·0 31·2 0·0 | 1235·0 28·6 11·0 1262·5 31·0 0·5 | 1233·5 28·4 11·5 1261·2 30·9 1·0 | 1232·2 28·3 12·0 1260·0 30·8 1·5 | 1230·7 28·2 12·5 1258·5 30·7 2·0 | 1229·5 28·0 13·0 1257·2 30·6 2·5 | 1228·0 27·8 13·5 1256·0 30·4 3·0 | 1227·0 27·7 14·0 1254·5 30·3 3·5 | 1225·5 27·6 14·5 1253·2 30·2 4·0 | 1224·2 27·4 15·0 1252·0 30·1 4·5 | 1223·0 27·3 15·5 1250·5 30·0 5·0 | 1221·7 27·2 16·0 1249·0 29·9 5·5 | 1220·2 27·0 16·5 1248·0 29·8 6·0 | 1219·0 26·9 17·0 1246·5 29·7 6·5 | 1217·7 26·8 17·5 1245·5 29·6 7·0 | 1216·5 26·7 18·0 1244·0 29·5 7·5 | 1215·0 26·5 18·5 1242·7 29·3 8·0 | 1213·7 26·4 19·0 1241·2 29·2 8·5 | 1212·5 26·3 19·5 1240·0 29·0 9·0 | 1211·2 26·2 20·0 1239·0 28·9 9·5 | 1210·0 26·0 20·5 1237·5 28·8 10·0 | 1208·5 25·9 21·9 1236·2 28·7 10·5 | ------------------------------------------------------------------------

The authors consider that industrially the tribasic acetate of lead might be used for the removal of organic matter from crude glycerin.

After separation of the precipitate, excess of the lead salt could be removed by a current of sulphuretted hydrogen, and during the concentration of the glycerin, the acetic acid set free would be volatilized with injury to the product. The lead salt might be regenerated by calcination, and again converted into acetate.[337]

[Footnote 337: ‘Moniteur Scientifique,’ Quesneville [3], vol. iii, p. 1033.]

The following quantitative test which it is said will detect upon concentration of the fluids, one-tenth per cent. of glycerin in beer; one per cent. in sherry, one per cent. in milk, and five per cent. in treacle, is based upon a fact observed by Iles, viz. that borax when treated with glycerin, gives to a Bunsen flame the green colour characteristic of boracic acid. The method of its application as given by Messrs Senier and Lowe is as follows:——The suspected solution is rendered alkaline by dilute soda, and a borax bead placed in it for a short time. The bead is then held in a Bunsen flame, and if the solution contains one per cent. of glycerin a distinct reaction is observed. Erythrite and glycol give the same colour.

If a small quantity of glycerin from which the fatty acids have not been removed, be poured into the palm, and rubbed between the hands, a peculiar fetid, mouse-like odour will be perceived.

Uses, &c. Glycerin is extensively employed as an excipient for medicines (see GLYCEROLES), also, either alone, or in lotions, baths, &c., as a soothing emollient, and is added to poultices and dressings instead of oil, to prevent their hardening. Diluted with water, it often succeeds in allaying itching and irritation of the skin when all other means fail. As a cosmetic, either made into a lotion or added to soap (glycerin soap), or used in small quantities (along with the water employed in washing), it imparts a healthy clearness and a sensation of softness and coolness to the skin, which is very agreeable and refreshing. It is the best remedy known for chapped nipples, hands, lips, &c.; all of which may be prevented by its use as an article of the toilet. Glycerin is sometimes used as a sweetening agent, as a substitute for syrup.

Glycerin is employed for a great variety of purposes other than medicinal; such, for example, as for:——Keeping clay moist for the modeller, for preventing mustard from drying up, for keeping snuff damp, for the preservation of fruit, for sweetening liqueurs, wine, beer, and malt extracts. It is also used as a lubricant for some kinds of machinery, more especially for watch and chronometer works, because it is unaffected by contact with the air, does not thicken at a low temperature, and is without action on such metals as copper, brass, &c. Glycerin is also an ingredient in copying inks. It renders printing ink soluble in water; indeed it is an excellent solvent for many substances, including the Tar-colours (aniline blue, cyanine, aniline violet, and alizarine), and arsenious acid. It is also added to the pulp of paper in order to render it soft and pliable. It is said that leather driving-belts made as they usually are of weakly tanned leather, when kept in glycerin for twenty-four hours are not so liable to fray. A solution of glycerin in water is now largely used instead of water alone for the purpose of filling gas metres, as such a solution does not freeze in winter nor evaporate in summer. It has also been used for the compasses on board screw-steamers, in order to protect the inner compass-box, against the vibrations caused by the motion of the propeller. It is also employed for the preservation of anatomical preparations, and for mounting microscopic specimens; as well as for rendering wooden casks impervious to petroleum or other oils; as well as for the preparation of artificial oil of mustard, or sulpho-cyan-allyl, which is made by treating glycerin with iodide of phosphorus, whereby iodide of allyl is formed, which on being dissolved in alcohol, and next distilled with sulpho-cyanide of potassium, yields sulpho-cyan-allyl. When treated with concentrated nitric acid, glycerin yields nitro-glycerin.[338]

[Footnote 338: Wagner’s ‘Chemical Technology.’]

Even the above long list does not exhaust the many useful purposes to which glycerin is now applied.

=Glycerin Cream for Chilblains.= Equal parts of glycerin, soft soap, and cherry-laurel water, mixed together.

=Glycerin Cream with Camphor.= Glycerin, 2 parts; camphor, 1 part; rectified spirit, 1 part. Mix. For chilblains.

=Glycerin Jelly for Microscopic Mounting.= (‘Ed. Pharm. Journal.’) Soak any quantity of good clean gelatine in cold water for three or four hours. Pour off the superfluous water, and melt the gelatine at a gentle heat; when melted filter through flannel, and to the filtrate add an equal quantity of Price’s gelatin.

The above forms a good firm jelly, requiring little trouble in securing the cover.

=Glycerin Ointment.= Glycerin, 8 parts; spermaceti, 4 parts; white wax, 1 part; oil of almonds (fixed), 16 parts. Add the glycerin to the melted ingredients, and stir briskly till cold. For chaps and excoriations.

=GLYCEROLE.= A pharmaceutical preparation, in which glycerin is employed as the excipient.

=Glycerole of Belladonna.= Syn. GLYCERINUM BELLADONNÆ. Prep. (Par. Codex.) Extract of belladonna, 1 oz., glycerole of starch, 10 oz. (by weight); rub together until perfectly smooth. Glyceroles of hemlock, henbane, and opium are ordered by the Paris Codex to be prepared in the same manner.

=Glycerole of Borax.= (B. P.) Syn. GLYCERINUM BORACIS, L. 1 of borax in 4-1/2 of glycerin.

=Glycerole of Carbolic Acid.= (B. P.) Syn. GLYCERINUM ACIDI CARBOLICI, L. 1 of acid in 4-1/2 of glycerin.

=Glycerole of Gallic Acid.= (B. P.) Syn. GLYCERINUM ACIDI GALLICI, L. 1 of acid in 4-1/2 of glycerin.

=Glycerole of Iodine.= Syn. GLYCERINUM CUM IODINIO. Prep. (Par. Codex.) Dissolve 5 parts of iodide of potassium and 1 part of iodine in their own weight of water, and add to 40 parts of glycerin (by weight). Applied in skin diseases.

=Glycerole of Iodide of Potassium.= Syn. GLYCERINUM POTASSII IODIDI. Prep. (Par. Codex.) Iodide of potassium, 2 parts, glycerole of starch, 15 parts (by weight); dissolve the iodine in its own weight of water, and add to this glycerole of starch.

=Glycerole of Starch.= (B. P.) Syn. GLYCERINUM AMYLI, L. 1 of starch in 8-1/2 of glycerin.

=Glycerole of Tannic Acid.= (B. P.) Syn. GLYCERINUM ACIDI TANNICI, L. 1 of acid in 4-1/2 of glycerin.

=Glycerole of Tar.= Syn. GLYCERINUM PICIS LIQUIDÆ. Prep. (Par. Codex.) Purified tar, 1 oz. (by weight), glycerole of starch, 3 oz. (by weight).

=GLYCOARNICIN.= A radical cure for gangrene and tubercle (Zeller). 40 grammes clarified honey, with 35 grammes of a tincture of fresh arnica herb, made with weak brandy. (Hager.)

=GLYCOBLASTOL= (Professor Kletzinsky, Vienna). An extract of the pericarps of cayenne pepper, made with glycerine, diluted with a little water, and perfumed with a trace of pleasant-smelling oil containing a suspicion of patchouli. (Hager.)

=GLYCOCINE.= Syn. GLYCOLL. SUGAR OF GELATIN. (C_{2}H_{5}NO_{2}). This is one of the products of the decomposition of gelatin when boiled with dilute sulphuric acid; after the acid is removed by means of barium carbonate, the glycocine may be procured in crystals by evaporating the solution.

It may also be obtained by heating gelatin with a solution of potash or of soda. It is, however, most easily separated in a state of purity by boiling hippuric acid for half an hour with hydrochloric acid; as the liquid cools benzoic acid is separated in abundance, and glycocine remains in combination with hydrochloric acid; on the addition of absolute alcohol, after the solution has been concentrated by evaporation and super-saturated with ammonia, pure glycocine is deposited in minute crystals.

Pure glycocine has a sweet taste, inferior to that of cane sugar. It is soluble in about 400 parts of cold water, less soluble in rectified spirit, and insoluble in absolute alcohol and in ether. It is not susceptible of the alcoholic fermentation.

=GLYCYR′RHIZIN.= Syn. LIQUORICE SUGAR. An uncrystallisable variety of sugar obtained from the root of common liquorice (Glycyrrhiza glabra). It is yellow, transparent, soluble in both water and alcohol, and is not susceptible of the vinous fermentation.

=GLYSTER.= See Enema.

=GNATS and MOS′QUITOES.= Smoke and strong fumes of any kind will drive away these insects. If you only burn a piece of brown paper in an enclosed space where they are, they soon after ‘settle,’ and appear to become so stupefied as to remain inactive for some time after. In those parts of the New World where mosquitoes abound, tobacco smoke is commonly had recourse to in-doors, and large fires made of brush-wood or under-wood out-of-doors. Old travellers, when compelled to bivouac during the season in which they are troublesome, are very careful to keep close on the ‘lee’ of these fires.

=GOA POWDER.= See ARAROBA.

=GOITRE.= Syn. DERBYSHIRE NECK; BRONCHOCELE, TRACHEOCELE; HERNIA BRONCHIALIS, L. A tumour on the fore part of the neck. It sometimes occurs in Derbyshire, and is endemic in the Alps and several other mountainous districts. Iodine and the iodides appear to be the only substances capable of curing or even arresting the progress of this disease.

There seems little doubt that goitre arises from drinking water rendered hard by the presence of magnesian and lime salts.

The disease called cretinism, which is a peculiar form of idiocy, is in some countries more particularly frequently associated with goitre. Both these maladies prevail in Wurtemberg, Saxony, Silesia, the Tyrol, Carynthia, Galicia, Austria, and Switzerland. In England, goitre seems principally confined to the magnesian limestone district extending from Nottingham to the Tyne; it also prevails in a smaller degree in Derbyshire, Norfolk, Cambridge, and Somersetshire, where a few scattered cases of cretinism are to be met with. Goitre is very much more general than is usually supposed in France. In Asia, it is to be found amongst the inhabitants of Chinese Tartary, Thibet, and Ceylon, and in India amongst the dwellers in the valleys and extensive plains that lie at the foot of the Himalayan mountains.

The disease is likewise known to exist in many parts of Africa; goitre is also far from uncommon in certain districts of North America; whilst in South America it is met with amongst the people inhabiting the plateaus of New Grenada, which comprise localities differing so greatly in climatic conditions, as deep and humid valleys, and arid plains almost or entirely destitute of verdure.

Goitre is a disease that may be very rapidly and readily set up. Bally says he has known certain waters in Switzerland produce it even in eight or ten days; and the French medical journals contain many similar instances of its early development.

=GOLD.= Au. Syn. AURUM; OR, Fr.; GOLD, Ger.) Gold is the most valuable and, probably, the longest known of all the metals. From the remotest period it has been esteemed for its beauty and permanence, and has been taken as the standard measure of value amongst all civilised nations. An account of the uses of gold in the arts, and its influence on society in all ages, as a symbol of wealth and an article of ornament and utility, would embrace the whole history of mankind. At the present day it alike contributes to the conveniences, comforts, and luxuries of life; as often exciting the baser passions of the human heart as promoting the cause of benevolence and virtue.

Gold is found almost invariably in the metallic state. It occurs as gold dust in the sands of various rivers, and in the alluvial soil of auriferous districts, from both of which it is obtained by the simple process of washing. Traces of it are constantly found in the iron and other pyrites of the more ancient rocks. Sometimes it occurs beautifully crystallised in the cubic form, associated with quartz, oxide of iron, and other substances, in regular veins. In the gold fields of California and Australia lumps of nearly pure gold have been discovered in abundance during the last few years. In the former country a mass of gold weighing 28 pounds was found, whilst in our own colonies one weighing 106 pounds was dug out of a quartz rock, near Bathurst. The latter contained upwards of 91% of pure gold, and nearly 8-1/2% of silver; being as pure as the English sovereign, or, in trade language, ‘22 carats fine.’

Prep. This consists merely in the separation of the gold and its subsequent purification. Formerly, the auriferous sulphides, if very poor, were first roasted, then fused into ‘mattes’ and again roasted; they were next melted with lead, and the alloy thus obtained was refined by cupellation. When the ores were very rich, the preliminary calcination and fusion were omitted, and the alloy of lead at once formed. This method (by fusion) does not answer well with auriferous copper pyrites or ores very poor in gold. At the present time the method of amalgamation is principally followed. When a ‘vein-stone’ is to be wrought for gold, it is reduced to powder (on the small scale by hand, on the large scale in stamping mills), and is shaken in a suitable apparatus with water and mercury; an amalgam of gold is formed, which is then separated from the mixture, and its mercury removed by distillation. The gold is next cast into ‘ingots.’

Refining.——Gold obtained by the first method usually contains a little copper and silver, and frequently tin or iron. Tin may be removed by adding a little corrosive sublimate or nitre to the gold melted in a crucible. The process by amalgamation commonly leaves no other alloy than silver. This metal is removed either in the ‘dry way,’ by fusing the gold with sulphur or sulphide of antimony; or in the ‘wet way,’ by ‘quartation’ and ‘parting.’ At the Royal Mint, “when gold ingots contain a certain quantity of silver” (say 2% or 3%), “instead of leaving it, as formerly, to constitute a part of the standard alloy, it pays to extract it, and to substitute copper in its place. To get the silver out of the said ingots, they are melted with about 3 parts of silver——the resulting alloy is granulated and boiled with sulphuric acid——the gold remains untouched, and all the silver is dissolved and converted into sulphate.... The sulphate of silver is then decomposed by the immersion of copper plates; the silver is precipitated in a fine, crystalline powder, washed, pressed into masses, and melted, and so affords PURE SILVER, which is afterwards made standard by alloying it with copper, and is used for coinage. The resulting sulphate of copper (which exists in the solution) is then crystallised, and sold.” (Brande.) “By first exhausting the gold with nitric acid, and then boiling it in sulphuric acid, some two or three thousandth part of silver which escaped the action of the nitric acid is dissolved out, and perfectly pure gold is obtained.” (Ure.)

By a foreign invention, patented in 1851 by Mr W. E. Newton, the operations of ‘separations’ and ‘refining’ are conducted by one process. The argentiferous substance, whether in the state of ore or bullion, is reduced to a granulated or spongy state, by fusion along with zinc, or some other metal cheaper than silver, and the zinc is subsequently removed, by digesting the resulting granulated, laminated, or pulverulent alloy, in dilute sulphuric acid, or other acid. The zinc, &c., is recovered by the usual means. This process, carefully conducted, produces metal of great ductility and purity, containing 99% to 99-1/2% of pure gold.

Chemically pure gold is obtained by dissolving the metal in nitro-hydrochloric acid, adding a solution of protosulphate of iron, and collecting and washing the precipitate. In this state it is a brown powder, which acquires a metallic lustre by friction or heat.

Prop. The most marked properties of gold are its rich yellow colour, its ductility, malleability, insolubility in all menstrua except ‘aqua regia’ (nitro-hydrochloric acid), aqueous chlorine, and hydrofluoric acid, and its very slight affinity for oxygen. It melts at a bright red heat (2316° Fahr.——Daniell), and the fused metal has a brilliant green colour. It forms compounds with chlorine, iodine, oxygen, sulphur, &c. Sp. gr. of native gold, 13·3 to 17·7; of pure gold, 19·3 (average); its greatest density is 19·5.

Tests. Metallic gold is characterised by its yellow colour, insolubility in nitric acid, and its ready solubility in aqua regia, forming a rich yellow or amber-coloured liquid, which stains the skin purple. Solutions of gold exhibit the following reactions:——Protosulphate of iron gives a brown precipitate, which acquires a metallic lustre when rubbed;——Protochloride of tin (preferably containing a little perchloride) gives a violet, purple, or blackish precipitate, insoluble in hydrochloric acid;——Sulphuretted hydrogen and hydrosulphide, of ammonia give a black precipitate, insoluble in simple acids;——Ammonia gives a reddish-yellow precipitate (‘fulminating gold’), with tolerably concentrated solutions, either at once or on boiling the liquid;——Liquor of potassa gives a reddish-yellow precipitate with neutral solutions of gold, insoluble in excess.

Estim. 1. In the dry way;——

The quantity of gold in an ALLOY is usually estimated by ‘assaying’ the sample. Before proceeding to the assay, it is necessary to form some estimate of the quantity of other metals (copper or silver, or both) in the specimen to be examined, in order to employ the proper proportion of lead in the ‘cupellation.’ The experienced assayer commonly does this by the ‘assay of the touch,’ and, in certain cases, by a rough preliminary assay. The quantity of lead employed may be about 16 times the weight of the copper present in the sample, and when the alloy contains silver an additional allowance of lead, equal to 1/10th of its weight, is made on that account. When no silver is present, or it is not required to be estimated, a much larger proportion of lead may be employed. The weight taken for the assay (‘assay pound’) is usually 12 or 6 gr. The alloy and dose of lead being accurately weighed and separately wrapped in small pieces of paper, the assay may be at once proceeded with.

α. CUPELLATION. This operation, the most important of the whole, has been already described. Unlike silver, gold will bear the highest heat of the furnace without ‘vegetating,’ ‘fuming,’ or being absorbed by the cupel. The loss of weight gives the amount of copper in the alloy.

β. QUARTATION. The cupelled sample is fused with three times its weight of pure silver (called the ‘witness’), by which the gold is reduced to one fourth of the mass, or less, and in this state may be easily removed.

γ. PARTING. The alloy, after quartation, is hammered or rolled out into a thin strip or leaf, curled into a spiral form, and boiled for a quarter of an hour, in a small flask, with about 2-1/2 to 3 oz. of nitric acid (sp. gr. 1·3); and the fluid being poured off, it is again boiled in a similar manner with 1-1/2 to 2 oz. more of nitric acid (sp. gr. 1·2), after which the gold is carefully collected, washed in pure water, and dried. When the operation of ‘parting’ is skilfully conducted, and the acid not too strong, the metal preserves its spiral form; otherwise, it falls into the state of flakes or powder. The second boiling or digestion is technically termed the ‘reprise.’ The loss of weight by ‘parting,’ after deducting that of the ‘witness,’ corresponds to the quantity of silver originally in the specimen.

δ. ANNEALING. This consists in putting the pure gold obtained by the last process into a small porous crucible or cupel, and heating it to redness in the muffle.

ε. WEIGHING. This must be done with the utmost accuracy. The weight, in grains troy, doubled or quadrupled, as the case may be, gives the number of carats fine of the alloy examined, without calculation.

According to the ‘OLD FRENCH METHOD’ of assaying gold, the following quantities are taken:——For the assay pound, 12 gr.; fine silver, 30 gr.; lead, 108 gr. These having been cupelled together, the (perfect) button is rolled into a leaf (1-1/2 × 5 inches), twisted on a quill, and submitted to parting with 2-1/2 oz. and 1-1/2 oz. of nitric acid, sp. gr. 1·16 (20° Baumé). The remainder of the process is similar to that above described. Two assays are made in the same manner, with a third on pure gold or gold of a known fineness; and no conclusion is drawn, unless the assay of the latter comes out accurately, and that of the first two correspond to each other.

For alloys containing platinum, which usually consist of copper, silver, platinum, and gold, the method of assaying is as follows:——The alloy is ‘cupelled’ in the usual way, the loss of weight expresses the amount of copper; and the button, made into a riband and treated with sulphuric acid, indicates, by the portion dissolved, that also of the silver present. By submitting the residuum to quartation, the platinum becomes soluble in nitric acid. The loss after digestion in this menstruum expresses the weight of that metal, and the weight of the portion now remaining is that of the pure gold. Gold containing palladium may be assayed in the same manner.

2. In the wet way:

The richness in gold of any substance, whether liquid or solid, when the quantity is small (and indeed in all other cases), is most simply and economically performed by the common method of chemical analysis. The gold may be thrown down from its solution by adding a solution of protosulphate of iron; the precipitate, after being washed, dried, and gently heated, may be weighed as pure gold.

Pois., &c. The soluble preparations of gold (chlorides) are violent poisons. The symptoms resemble those occasioned by corrosive sublimate, but are somewhat less violent. Metallic gold in a minute state of division is also capable of producing very unpleasant consequences, and even endangering life. The antidote is iron filings or a solution of sulphate of iron, given conjointly with an emetic.

Uses. The numerous applications of gold in the arts and the daily transactions of life need only be alluded to here. In medicine, gold has been given in the form of powder, in scrofula and syphilis, by Chrestein, Niel, and others, with apparent advantage.——Dose, 1/4 gr. to 1 gr., 3 or 4 times a day, in pills, or as a friction on the tongue and gums. An ointment made of 1 gr. of powdered gold and 30 gr. of lard has been applied by Niel to the skin deprived of the epidermis (endermically) in the above diseases.

The more important chemical compounds containing gold, the alloys and commercial forms of the metal, together with certain factitious substances popularly called ‘gold’, are noticed in alphabetical order below:——

=Gold, Alloys and Preparations of:——=

=Gold, Dutch.= MANNHEIM GOLD, MOSAIC G., OR-MOLU, PINCHBECK, PRINCE’S METAL, RED BRASS, SIMILOR, TOMBAC. These names are applied to several varieties of fine gold-coloured brass, differing slightly in tint and in the proportions of copper and zinc. The terms tombac, prince’s metal, similor, and Mannheim gold, are used by some authors to designate alloys consisting of about 85% of copper and 15% of zinc; whereas, according to other authors, prince’s metal and Mannheim gold are synonymous, and are composed of 75% copper and 25% zinc; according to another author, similor consists of about 71-1/2% copper and 28-1/2% zinc, and Mannheim gold of 80% copper and 20% zinc; and, again, according to another author, similor and Mannheim gold are synonymous, and are applied to alloys of copper containing from 10 to 12% zinc and from 6 to 8% tin. Seeing that such inextricable confusion exists in the employment of the terms above mentioned, it is desirable to discard them altogether. At the celebrated works of Hegermühl, near Potsdam, the proportions copper, 11 parts, to zinc, 2 parts, are employed to produce a metal which is afterwards rolled into sheets for the purpose of making Dutch leaf-gold. This alloy has a very rich, deep gold colour. Its malleability is so remarkable that it may be beaten out into leaves not exceeding 1/52900 inch in thickness.

=Gold, Facti′′tious.= Prep. From copper, 16 parts; platinum, 7 parts; zinc, 1 part; fused together. This alloy resembles in colour gold of 16 carats fine, or 2/3, and will resist the action of nitric acid, unless very concentrated and boiling.

=Gold, Grain.= Syn. AURUM GRANULATUM, L. Prep. From cupelled gold, 1 part; silver, 3 parts; melted together, and poured in a small stream into water; the silver being afterwards dissolved out by digestion in boiling nitric acid, and the grains, after being well washed in water, heated to redness in a crucible or cupel. Used to make preparations of gold.

=Gold, Jew′eller’s.= This term is applied to alloys of gold used for trinkets and inferior articles of jewelry, ranging from 3 or 4 carats fine upwards; or which are too inferior to receive the ‘Hall mark’. The lowest alloy of this class is formed of copper, 16 parts; silver, 1 to 1-1/2 part; gold, 2 to 3 parts; melted together. This is worth only from 8_s._ 6_d._ to 9_s._ 6_d._ the oz.

It has recently been found that gold of the quality of 12 carats, or less, if alloyed with zinc instead of the proper quantity of silver, presents a colour very nearly equal to that of a metal at least 2-1/2 to 3 carats higher, or of 8_s._ or 10_s._ an ounce more value; and the consequence has been that a large quantity of jewellery has been made of gold alloyed in this manner; and the same has been purchased by some shopkeepers, very much to their own loss as well as that of the public; inasmuch as a galvanic action is produced, after a time, upon gold so alloyed, by means of which the metal is split into several pieces, and the articles rendered perfectly useless.

=Gold, Leaf.= Syn. GOLD-LEAF. Gold reduced to leaves by hammering it between thin animal membrane. Its preparation constitutes the trade of the goldbeater. These leaves are only 1/28200 of an inch in thickness. Gilt silver is hammered in the same way, but the leaves are thicker. The latter is called party gold. Both are used by artists and gilders, and by druggists to gild pills, &c.

=Gold, Powdered.= Syn. DIVIDED GOLD, GILDING POWDER, GOLD BRONZE, GOLD COLOUR; AURI PULVIS. Prep. Gold, 1 part; mercury, 7 parts; form an amalgam, and expose it to heat until all the mercury is volatilised; or the mercury may be dissolved out with hot nitric acid. In either case the residuum is to be powdered, washed, and dried. If the quantity operated on is considerable, the process should be so conducted as to save the mercury.

From gold leaf and honey ground together, as the last, by means of a stone and muller. This is the plan commonly adopted in the small way by artists.

From a solution of gold in aqua regia precipitated by protosulphate of iron, the resulting powder being washed, dried, and gently heated, This gives pure gold.

Uses, &c. Powdered gold is employed in gilding by japanners and by artists. It is either sold in powder (gold in powder), or made up into shells (gold in shells). Its use in medicine has been already noticed.

=Gold, Standard.= The standard gold of this country is an alloy of pure gold, 11 parts, with pure copper, 1 part. Formerly the alloy consisted partly of silver, as found in some of the older coins now in circulation. It is often spoken of as 22 carats fine.

=Gold, Chlorides of:=

1. =Monochloride.= AuCl. Syn. AUROUS CHLORIDE, PROTOCHLORIDE OF GOLD. A yellowish-white mass, formed when a solution of trichloride of gold is evaporated to dryness, and the residuum is exposed to a heat of about 440° Fahr., until fumes of chlorine cease to be evolved. It is insoluble in water, which decomposes it, slowly when cold, but rapidly by the aid of heat, into metallic gold and the trichloride.

2. =Trichloride.= AuCl_{3}. Syn. AURIC CHLORIDE, TERCHLORIDE OF GOLD, TRICHLORIDE OF GOLD, AURI CHLORIDUM. Prep. Gold, 1 part, dissolved by aid of heat in nitro-hydrochloric acid, 8 parts, and evaporated down to near dryness, and allowed to crystallise.

Prop. Orange-red crystalline needles, or ruby-red prismatic crystals; deliquescent; soluble in water, ether, and alcohol, forming a deep-yellow solution; at the heat of 500° Fahr. it suffers decomposition, chlorine being given off and pure gold left behind. It is reduced by ferrous sulphate, oxalic, sulphurous, formic and phosphorous acids, as well as by most of the metals, to metallic gold. It combines with several of the metallic chlorides, forming a series of double salts, which are mostly yellow when in crystals, and red when deprived of water.

Uses, &c. It has been employed by Duportal, Chrestien, Niel, Cullerier, Legrand, and others, as a substitute for mercury, in scrofula, bronchocele, chronic skin diseases, &c.; also as a caustic.——Dose, 1/20 gr., dissolved in distilled water, or made into a pill with starch; or, in frictions on the gums, in quantities of 1/16 to 1/10 gr. Its most important use, however, is as a reagent in photography, large quantities being manufactured for use as a chief agent in toning photographic prints.

To some extent it is also used for electro-gilding, and mixed with excess of bicarbonate of potassium, it forms a good yielding solution for small articles of copper. These are to be first cleaned with dilute nitric acid, and then boiled for some time in the mixture.

The above is the salt generally referred to under the name of the ‘chloride of gold,’ or in commerce occasionally as the ‘muriate of gold.’

=Gold, Chloride of, and Sodium.= AuCl_{3}. NaCl. 2Aq. Syn. AUROCHLORIDE OF SODIUM; SODII AUROCHLORIDUM. Prep. Auric chloride, 85 parts; chloride of sodium, 16 parts; dissolve in a little distilled water, evaporate until a pellicle forms, then put it aside to crystallise. It forms beautiful orange-coloured rhombic prisms.

Dose, &c. 1/20 to 1/12 gr., made into a pill with starch or lycopodium, in the same cases in which the terchloride is ordered. Mixed with 2 or 3 times its weight of orris powder, it has been used in frictions on the tongue and gums, and an ointment made with 1 gr. of the salt, mixed with 36 gr. of lard, has been applied to the skin deprived of the epidermis by a blister.

=Gold, Cyanide of.= AuCy_{3}. Syn. AURIC CYANIDE. Prep. Add a solution of pure cyanide of potassium to a solution of pure auric chloride as long as a precipitate forms, carefully avoiding any excess; wash, and dry the precipitate.

Prop., Uses, &c. The salt is a pale-yellow powder, insoluble in water, but very soluble in a solution of cyanide of potassium, forming the double cyanide of gold and potassium so largely used in the electrotype process. Cyanide of gold is employed to a certain extent in medicine.——Dose, 1/12 to 1/10 gr., made into a pill, in the usual cases in which gold is administered. The first formula is essentially similar to that of the French Codex.

=Gold, Extraction of, by Sodium Amalgam.= (Crookes’ Method, Patented.) In the extraction of gold by amalgamation serious difficulties are often occurring through the ‘flouring’ or ‘sickening’ of the mercury employed, and the prevention of the amalgamation by a coating of tarnish on the gold. So much is this the case that losses of from 30 to 60 per cent. of the gold are usually incurred, and, in many cases a still more serious loss of mercury.

When certain minerals, as tellurium compounds, pyrites, &c., occur in the gold ore, the mercury is apt, on trituration, to become subdivided into excessively minute globules, which, owing to their tarnished condition, refuse to unite, and are consequently washed away, it being almost impossible to separate them from the heavier portions of the ore. This is technically called ‘flouring,’ ‘granulating,’ &c. Besides this, certain of these minerals affect the mercury in another way, that is, by ‘sickening’ it, or causing it to lose its bright surface and fluidity, and prevents its amalgamating with the gold. Besides the inconvenience and loss thus caused, a further loss of gold takes place from the inability of the ordinary mercury to touch or amalgamate tarnished gold, unless it is ground with it, for a more lengthy period than is found practicable in most cases.

Mr Crookes, F.R.S., has, by means of the addition of a certain proportion of sodium, in the form of an amalgam, to the mercury, effectually prevented this serious loss of gold and mercury. By adding certain quantities of amalgams B and C, an amount which, differing from each ore, is ascertained by experiment, the ‘flouring’ and ‘sickening’ of the mercury is effectually prevented, the mercury remaining throughout in the best condition. The addition of about one tenth per-centage of amalgam A, at intervals of some hours, increases most powerfully the affinity of the mercury for the precious metals, and secures a more thorough amalgamation.

This invention has met with general approval, and experiments conducted at many mines show its great practical value, giving an increase of from 5 to 30 per cent. in the yield of gold, and, in fact, with many pyrites that yielded no gold to the ordinary amalgamation process, gave a considerable yield of gold to the sodium amalgamation process. This has led to its use in most mines, both silver and gold, in America.

=Gold, Iodide of.= AuL_{3}. Syn. AURIC IODIDE, TRI-IODIDE OF GOLD, GOLD TERIODIDE, AURI IODUM. Prep. Add a solution of trichloride of gold to one of iodide of potassium. The resulting precipitate is at first redissolved on agitation, a soluble double iodide being formed; subsequently the iodide of gold is precipitated, leaving the supernatant liquor free of colour.

Prop., Uses, &c. A dark-green powder, easily soluble in hydriodic acid. It is occasionally employed as a medicine, and, like other preparations of gold, is of an alterative character.——Dose. About 1/16th of a grain.

=Gold, Oxides of=:——

1. =Monoxide.= Au_{2}O. Syn. AUROUS OXIDE, PROTOXIDE OF GOLD. Prep. Formed by treating the aurous chloride with strong potassium hydrate. Green powder, somewhat soluble in potassium hydrate solution, and readily decomposing into metallic gold and auric oxide.

2. =Trioxide.= Au_{2}O_{3}. Syn. AURIC OXIDE, OXIDE OF GOLD, PEROXIDE OF GOLD, AURIC ACID, AURI OXIDUM. Prep. Magnesic oxide, 4 parts; auric chloride, 1 part; water, 40 parts; mix, boil, and wash the precipitate with water, dilute nitric acid, and again with water. It must be dried in the shade.

Reddish-yellow powder, easily decomposed by heat; readily soluble in hydrochloric and hydrobromic acids and strong nitric acid, but insoluble in water and the other acids. Forms unstable salts with the alkalies.

Uses, &c. Trioxide of gold has been given in scrofula, &c., in doses of 1/12 to 1/2 gr., or 1 gr., in scrofula, syphilis, &c., made into a pill with extract of mezereon.

=Gold, Ammoni′uret of*.= Syn. AURATE OF AMMONIA, BERTHOLLET’S FULMINATING GOLD; AURUM AMMONIATUM, AMMONIÆ AURAS, L. Prep. By adding ammonia to a solution of gold in aqua regia (trichloride), as long as a reddish-yellow precipitate (fulminating gold) forms; the latter must be collected, washed, and dried with the greatest possible caution.

Obs. Ammonia fails to precipitate trioxide of gold from solutions which are not tolerably concentrated, and in those containing free acid or ammoniacal salts the precipitate only forms upon boiling the solution. Before adding the ammonia, it is, therefore, proper to drive off the excess of acid, if any, by the application of heat. See FULMINATING COMPOUNDS.

=Gold, Sul′phide of.= Au_{2}S_{3}. Syn. SULPHURET OF GOLD, TERSULPHURET OF G.; AURI SULPHURETUM, L. Prep. Transmit a current of sulphuretted hydrogen gas through a solution of terchloride of gold in water; or add hydrosulphuret of ammonia to the same solution; collect the precipitate, wash it with cold distilled water, and dry it in the shade.

=GOLD DETER′GENT.= Prep. (Upton.) Take quicklime, 1 oz.; sprinkle it with a little hot water to slake it, then gradually add boiling water, 1 pint, so as to form a milk. Next dissolve pearlash, 2 oz., in boiling water, 1-1/2 pint; mix the two solutions, cover up the vessel, agitate occasionally for an hour, allow it to settle, decant the clear, put it into flat half-pint bottles, and well cork them down.

Use. To clean gilding, &c., either alone or diluted with water. It is applied with a soft sponge, and then washed off with clean water. It is essentially a weak solution of potassa, and may be extemporaneously prepared by diluting solution of potassa (Ph. L.) with about 5 times its volume.

=GOLD SHELLS.= Gold leaf or powdered gold ground up with gum-water, and spread upon the insides of shells. Used by artists.

=GOLD SIZE.= Syn. GILDING SIZE, GILDER’S S., GOLD COLOUR. Prep. 1. (OIL SIZE.) Drying or boiled oil thickened with yellow ochre or calcined red ochre, and carefully reduced to the utmost smoothness by grinding. It is thinned with oil of turpentine. Improves by age. Used for oil gilding.

2. (WATER SIZE.) Parchment or isinglass size, mixed with finely ground yellow ochre. Used in burnished or distemper gilding.

=GOLD-BEAT′ER’S SKIN= is prepared from the peritoneal membrane of the cæcum of the ox. It is used to separate the leaves of gold whilst under the hammer, as a nearly invisible defensive dressing for cuts, as a fabric for court plaster, &c.

=GOLDEN SEAL.= See HYDRASTIS CANADENSIS.

=GONG METAL.= See BELL METAL.

=GONIOM′ETRY.= The art of measuring the angles of crystals, by means of a GONIOMETER; a most important matter in chemistry and mineralogy. The only accurate and simple instrument of this kind is the REFLECTING GONIOMETER invented by Dr Wollaston. Facility in using this instrument is readily acquired by a few trials.

=GOOSE.= This bird, the Anser domesticus, is a favourite article of food almost everywhere, and may fairly claim a similar position amongst poultry to that occupied by “good Sir Loin” among joints of meat. The vulgar inuendos occasionally heard to its prejudice should be directed against the cook rather than the bird, as it is only when it is unskilfully dressed and too highly seasoned that it is apt to disagree with that “irascible member of the interior,” a delicate or overloaded stomach. Undue susceptibility in that quarter may, however, be generally allayed by an oblation, in the shape of a little ‘eau de vie,’ used as sauce or gravy. Formerly, almost miraculous virtues were attributed to this bird. Its flesh was said to promote longevity, to cure hydrophobia, and to be aphrodisiac. The fat (GOOSE GREASE; ADEPS ANSERIS), mixed with honey, was supposed to be “good against the bitings of a mad dog.” At the present day it is occasionally used in clysters, and, when scented, as a pomade to make the hair grow, for which purpose it is said to be superior to bear’s grease. In quantity it is an emetic of very easy action. The large feathers of the wings (quills) are used for writing. The small feathers form the common stuffing of our beds.

=GOOSE′BERRY.= The fruit or berry of Ribes grossularis. Unripe fruit, cold and acidulous; ripe fruit, wholesome and slightly laxative; but the seeds and skins should not be eaten, as they are very indigestible; the juice of the green fruit is made into wine (ENGLISH CHAMPAGNE); the seeds, washed and roasted, were formerly used as a substitute for coffee (GOOSEBERRY COFFEE). Gooseberries are preserved by simply bottling them, and keeping them in a very cold place. See CHEESE, FOOL, FRUIT, &c.

=GOULARD.= Syn. GOULARD’S EXTRACT. See SOLUTION OF DIACETATE OF LEAD.

=GOUT.= Syn. ARTHRITIS, L. A painful disease that chiefly attacks the male sex, particularly those of a corpulent habit and robust frame. Persons who live temperately and take much exercise are seldom troubled with gout. Indolence, inactivity, luxurious habits of life, and free living, are the chief exciting causes of this disease; but excessive study, grief, watchfulness, exposure to cold, and the too free use of acidulous liquors, also occasionally bring it on. In some persons it is an hereditary disease.

Symp. Gout is generally preceded by unusual chilliness of the feet and legs, and a numbness or a sensation of prickling along the lower extremities; the appetite fails, flatulency, indigestion, torpor, and languor ensue, and extreme lassitude and fatigue follow the least bodily exercise; the bowels become costive, and the urine pallid. The fits usually come on in the night; the patient is awakened by the severity of the pain, generally in the first joint of the great toe, or occasionally in the heel, whole foot, or calf of the leg. The pain resembles that of a dislocated joint, accompanied by a sensation resembling the effusion of cold water; the pain increases, rigors and febrile symptoms ensue, accompanied with local throbbing and inflammation. Sometimes both feet and legs are attacked; at others, only one. Towards morning the patient generally falls asleep, and sinks into a state of copious perspiration, from which he awakes comparatively recovered. This constitutes what is called a ‘fit of gout.’ These fits or paroxysms are apt to return at intervals, commonly every evening, with more or less violence; and when frequent, the disease usually extends its action, the joints become affected, and concretions of a chalky nature (chalk stones, gout stones) are formed upon them, and they become stiff and nearly immovable.

Treat. A plain or vegetable diet, moderate exercise, and the use of warm laxatives, gentle tonics, diaphoretics, and diuretics, are among the best preventives. The moderate use of alkaline remedies, as potassa and magnesia, has also been recommended. To relieve the fit of gout, or to check it at its commencement, the affusion of cold water will be often found effective. The use of the ‘eau médicinale’, or the ‘vinum colchici’ of the Pharmacopœia, may also be had recourse to; a due dose of which taken at bedtime will frequently carry off the paroxysm, and nearly always mitigate the symptoms. The effect of the above remedies do not greatly differ from each other. The action of both medicines is accompanied with great languor, and a deadly nausea or sickness, which terminates in vomiting or a discharge from the bowels, or both. These symptoms have often reached an alarming extent, and in some constitutions follow even a moderate dose. This method of cure should not, therefore, be unadvisedly and incautiously adopted.

Another remedy which has been recommended for gout is lemon juice, but experience has proved that this agent is not to be depended on. The dose proposed by Dr O. Rees, who originated this treatment, was 2 or 3 fl. oz., twice or thrice a day.

To ensure the efficacy of lemon juice, it must be expressed from the fruit into the glass shortly before being taken. That purchased at the shops is generally stale and disagreeable, and is often worse than useless. In some cases it is advisable to take the juice undiluted, but the more common practice is to mix it with about an equal quantity of water. See RHEUMATISM, COLCHICUM, DRAUGHT (Anti-arthritic), LEMON JUICE, VINEGAR OF COLCHICUM, WINE OF COLCHICUM, &c.

=Gout Cor′dial.= Prep. Rhubarb, senna, coriander seed, sweet-fennel seed, and cochineal, of each 2 oz.; liquorice root and saffron, of each 1 oz.; raisins, 2-1/2 lbs.; rectified spirit of wine, 2 gals.; digest for 14 days, press, and filter. Used in gout and rheumatism. Aromatic and slightly laxative.——Dose, 1 to 3 table-spoonfuls.

=Gout Med′icine.= (Duncan’s.) A mixture of wine of colchicum, wine of opium, and tincture of saffron.

=Gout Rem′edy.= (Alexander’s.) According to Dr Paris, this contains——aniseed, cumin seed, ginger, hermodactyles, pepper, and scammony.

=Gout Specific.= (Murray’s.) A mixture of iodide of potassium, sulphate of magnesia, and wine of colchicum, disguised with an aromatic tincture.

=GOUTTES AMERES.= [Fr.] See DROPS (Bitter).

=GRAD′UATOR.= See VINEGAR.

=GRAFTING COM′POST.= Clay tempered with water, to which a little linseed oil is sometimes added. Used to cover the joint formed by the scion and stock in grafting.

=GRAINS OF HEALTH, Dr Franck’s——Gesundheitspillen——Grains de Santé, ou Grains de Vie=, du Docteur Franck. Silvered pills, containing 1 part gamboge and 4 parts aloes. (Hager.)

=GRAINS OF PAR′ADISE.= Syn. GUINEA GRAINS, MELEGUETTA PEPPER. The seeds of the Ammomum meleguetta. Grains of paradise are hot, acrid, and aromatic, and in general properties similar to the other peppers. In some parts of the world they are used as a condiment. They are principally employed in these countries to impart a false strength to wine, beer, spirits, and vinegar.

=GRANIL′LA.= A small inferior variety of cochineal (which see).

=GRANULA′TION.= The act or process of forming, or breaking into, grains or small masses.

The granulation of MEDICINES has of late years received considerable attention from both foreign and British pharmaceutists. In France, granulated powders (POUDRES GRANULÉES) are coming into general use in place of impalpable powders, the most unpleasant of all forms of medicine. The French process consists in enveloping the particles of medicines in syrup by means of heat and constant stirring. Mr Banner, of Liverpool, has lately introduced a method of granulating medicines far preferable to that of the French pharmaceutists. The powder to be granulated is placed in a mortar, and mucilage of gum acacia is gradually added until a crumbly mass is made; this is then rubbed through a wire sieve (about 12 meshes to the inch), and the granules produced are spread out on paper, and left to dry spontaneously, or they are placed in a copper pan, and kept in constant motion over a stove until dry; when perfectly dry, they are placed in a mortar, and sufficient quantity of strong tincture of tolu (3 dr. to 1 oz.) is added to them, until by constant stirring they all appear glossy and shining; they are then dried again by a gentle heat, being kept in constant motion. The granules thus formed keep well, are tasteless, and are much more elegant and agreeable preparations than pills or ordinary powders. Many saline substances are granulated by the simple process of dissolving the salt in water, and evaporating to dryness with constant stirring.

METALS are granulated (reduced to drops, grains, or coarse powder) by pouring them, in the melted state, into water. In many cases they are allowed to run through the holes of a species of colander or sieve to produce minute division; and in order to render the drops spherical, they are allowed to fall from a sufficient height to permit of their acquiring the solid state before striking the water. Lead shot is made in this way. Shot towers are often upwards of 100 feet in height. See COPPER, GUNPOWDER, POWDER, ZINC, &c.

=GRAPES.= Syn. UVÆ, L. The fruit of Vitis vinifera, or the common grape vine. Ripe grapes are cooling and antiseptic, and in large quantities diuretic and laxative. They are very useful in bilious affections and dyspepsia, and in all febrile, putrid, and inflammatory complaints. The skin and seed, which are indigestible, should be rejected. “Grapes which contain a large quantity of sugar are, if taken without the husks, the safest and most nutritive of summer fruits.” (Cullen.) “The subjects of pulmonary affections, who pass the summer in Switzerland, may try the effects of a course of grapes, ‘cure de raisins,’ a remedy held in high estimation in several parts of the Continent.” (Sir J. Clark.)

Grapes, in bunches are preserved by wrapping them in silver paper, and packing them in dry bran. Each bunch is suspended by the stem with the fingers of one hand, whilst the bran is poured round it with the other; the jar being occasionally gently shaken as the process of packing proceeds. Some paper is then laid over the top of the jar, the mouth or cover of which is, lastly, tied firmly over with bladder, to exclude the air and moisture. See FRUIT, &c.

=GRAPH′ITE.= See PLUMBAGO.

=GRATE.= A frame of iron bars used for burning coal as fuel. In the construction of a grate it is desirable to make the perpendicular height of the fuel as great as is consistent with safety. A stratum of burning coal will radiate considerably more heat into an apartment if placed vertically than if arranged horizontally; besides which a great saving of fuel will be effected in proportion to the heat radiated. Hence the faulty construction of the old-fashioned wide grates. The fuel should also be so divided in a fireplace as to be easy of ignition, and so placed as to give free access of air to all its parts, as the smoke is then more likely to be burnt.

=GRAV′EL.= A collection of small pebbles commonly mixed with sand or clay, or both. Gravel for garden walks is chosen for its fine colour and binding properties. The gravel of Kensington and Wimbledon is esteemed the finest in the world. Gravel walks when once in order, may be rendered nearly equal to asphalt by pouring over them tar or a mixture of tar and pitch, absorption being promoted, if required, by the application of a hot iron.

=Gravel.= In pathology, a term popularly applied to calculous matter formed in the kidneys, and passing off in the urine; and sometimes to distinct calculi or concretions in the bladder itself.

An attack of gravel, as commonly understood, is accompanied by a deposit of red, gritty, sand-like particles in the urine, which do not dissolve when the urine is heated. The deposit consists of uric acid. Pains in the loins are a common accompaniment of gravel, and there is also sometimes pain in passing water.

Treat. Give twenty minims of solution of potash (of the B. P.) three times a day in barley water; or twenty grains of bicarbonate of soda, also three times a day. If the attack be attended with much pain a brisk dose of Gregory’s powder should be additionally taken every morning. Vichy Water will also be found a useful remedy. See CALCULUS.

=GRAVIM′ETER.= See HYDROMETER.

=GRAV′ITY.= Syn. GRAVITATION. The attractive force by which bodies fall towards the centre of the earth. Weight is the measure of gravity. The determination of the relative weight of bodies with reference to a given standard, is explained under SPECIFIC GRAVITY.

=GRA′VY.= The juice or liquid matter that drains from dressed meat after it is placed on the dish for serving. The common practice among cooks is to pour a spoonful or two of boiling water or broth over the joint, to increase the quantity. The natural gravy that oozes from the meat after it is cut is the richest and most wholesome. Made gravies are prepared by adding spice and flavouring to the foregoing, or to strong meat soup.

The gravy for roast meat is usually made by sprinkling a little salt on the joint after it is placed in the dish, and then pouring some boiling water over it; this washes off some of the brown, and makes a coloured liquid in the dish.

Another method for making gravy for roast meat is the following:——Take any bones, scraps of cold meat, or trimmings of the joint, put them in a half pint of water, with a little salt and half an onion, let them stew all the time the meat is roasting; colour with a little burnt sugar. When the meat is done, pour the dripping from it carefully into a basin, leaving the gravy at the bottom of the tin; strain the gravy you have made into this, let it boil, and pour round (not over) the meat. If the gravy is liked thick, put a dessert-spoonful of flour, mixed into a smooth paste, with two of cold water, into the saucepan five minutes before you strain it. See SAUCE.

=GRAY.= Syn. GREY; GRIS, Fr. A mixture of black and white. Delicate grays result from mixture of the three elementary colours, red, yellow, and blue, in which the blue preponderates to a greater or less extent.

=GRAY DYE.= Syn. TEINTE GRISE. Gray is dyed with the same materials as black, but both the bath and mordaunt are used in a more diluted state. COTTON goods may be worked in sumach and then in copperas; this gives rather a bluish grey, which may be modified to any particular hue by the addition of suitable colouring matter. To make it yellowish, a small amount of fustic and alum are employed; to make it ‘fuller,’ peachwood and Lima-wood with alum are used. The methods of obtaining grey on SILK and WOOL are very numerous; they are similar in principle to the above, all depending on the blending of the three primary colours, or on the modification of weak blacks. See BLACK DYE.

=GREASE.= A general term applied to soft animal fats; as BEAR’S GREASE, GOOSE GREASE, &c.

=Grease.= An inflammatory affection of the heels of horses, which produces dryness, scurfiness and stiffness. The treatment consists of emollient poultices, accompanied with physic and diuretic balls, to subdue the inflammation, followed by mild astringent lotions or ointments.

=GREAVES.= Syn. GRAVES. The sediment of melted tallow, consisting chiefly of animal membranes mixed with fat, made up into cakes. Used as a coarse food for dogs.

=GRE′CIAN WATER.= See HAIR DYES.

=GREEN.= Syn. VIRIDIS, L.; VERT, Fr. Of the colour of the leaves of growing plants; subst. a green colour.

=GREEN DYE.= Syn. TEINTE VERTE, Fr. All the green dyes in use, with the practically unimportant exception of Chinese green and oxide of chromium green, are compounded of blue and yellow. The goods, in practice, are generally dyed blue first, observing to regulate the shade according to that of the intended green; they are then dried, rinsed, and passed through a yellow bath, with the like precautions, until the proper shade is obtained. See BLUE DYE, YELLOW DYE, &c.

=GREEN PIG′MENTS.= Several of the green pigments of commerce are obtained from copper. Oxide of chromium furnishes some which are very beautiful. Many are formed by the mere mechanical admixture of blue and yellow pigments. The bright blues and yellows, when mixed in this way, produce the liveliest greens; orange, or red and blue, and the yellowish browns and blue, the more dingy greens. In this way are produced all the extemporaneous greens of the artist. Nickel and titanium also furnish green colours, but these are not in common use. The following list embraces all the best-known and most useful green pigments:——

=Green Arsen′ical.= Arsenite and aceto-arsenite of copper. See GREEN, SCHEELE’S and SCHWEINFURT (below).

=Green, Barth’s.= From yellow lake, Prussian blue, and clay, ground together.

=Green, Bice.= Same as mountain green.

=Green, Bremen.= This is properly green verditer, but other preparations are frequently sold under the name.

=Green, Brighton.= A mixture of impure acetate of copper and chalk, prepared as follows:——

To sulphate of copper, 7 lbs., add sugar of lead, 3 lbs.; each separately dissolved in water, 5 pints; mix the solutions, stir in of whiting, 24 lbs., set the resulting paste on chalk stones, and when dry grind it to powder.

=Green, Brunswick.= This is probably a crude chloride of copper, but a mixture of carbonate of copper and alumina or chalk is now commonly sold under the name in the shops.

Prep. 1. A saturated solution of sal ammoniac, 3 parts, is poured over copper filings or shreds, 2 parts, contained in a vessel capable of being closed up, and the mixture is kept in a warm place for some weeks, when the newly formed green pigment is separated from the unoxidised copper, by washing the mixture on a sieve; it is then edulcorated with water, and slowly dried in the shade. Colour very deep and rich. The lighter shades are produced by the addition of sulphate of baryta.

2. A solution of crude carbonate of ammonia or bone spirit is added to a mixed solution of alum and blue vitriol, as long as it affects the liquor; in a short time the precipitate is collected, washed and dried. The various shades of green are produced by using different quantities of alum, which pales and cheapens it.

=Green, Chrome.= The superb green pigment used by enamellers under this name is the green oxide or sesquioxide of chromium. A hydrated oxide of chromium forms the emerald green of Pannetier; it is prepared by melting in a crucible equivalent quantities of anhydrous boracic acid and bichromate of potassium, and treating the fused mass with water. The hydrated oxide thus produced is washed and finely triturated.

The chrome green of the oil and colour shops is a mixture of chrome yellow and Prussian green.

=Green, Cop′per.= Green bice or mountain green, Brunswick green, emerald green, verditer, and several other well-known pigments, may be thus named.

=Green, Em′erald.= This term is commonly applied to the aceto-arsenite of copper, as prepared in England. It is the same compound, chemically speaking, as Schweinfurt green (which see).

Prep. A pulp is formed with verdigris, 1 part, and boiling water q. s., and after being passed through a sieve, to remove lumps, is added gradually to a boiling solution of arsenious acid, 1 part, in water, 10 parts, the mixture being constantly stirred until the precipitate becomes a heavy, granular powder, when it is collected on a calico filter, and dried on chalk stones.

=Green, Frise.= Syn. FRIEZLAND GREEN. This resembles Brunswick green.

=Green, Gellart’s.= A mixture of cobalt blue and flowers of zinc with some yellow pigment.

=Green, Impe′rial.= Schweinfurt green (see below).

=Green, Iris.= A pigment prepared by grinding the juice of the petals of the blue flag with quicklime. It is very fugitive.

=Green Lake.= See LAKE.

=Green, Min′eral.= This is the same as mountain green.

=Green, Mitis.= Another of the many synonyms of Schweinfurt green.

=Green, Mountain.= This pigment is properly the native green carbonate or bicarbonate of copper (malachite) ground to powder, either with or without the addition of a little orpiment or chrome yellow. That of the shops is commonly prepared by adding a solution of carbonate of soda, or of potassa, to a hot mixed solution of sulphate of copper and alum. Green verditer is commonly sold for this article. According to Watts, mountain green is the same as Neuwieder green.

=Green, Neuwieder.= Schweinfurt green mixed with gypsum or sulphate of baryta.

=Green, Prussian.= The sediment of the process of making Prussian blue from bullock’s blood or horns, before it has had the hydrochloric acid added to it. It is also prepared by pouring liquid chloride upon freshly precipitated Prussian blue. As now sold, this pigment is generally a mixture of Prussian blue and gamboge.

=Green, Rinman’s.= This resembles that of Gellert.

=Green, Sap.= A very fugitive pigment, prepared from the juice of buckthorn berries. The berries are allowed to ferment for a week or eight days in a wooden tub. The juice is then pressed out, strained, a little alum added, and the whole evaporated to a proper consistence; it is next run into pigs’ bladders, and hung up in a dry situation to harden. An inferior article is made from the juice of black alder, and of evergreen privet. It is a common practice to add 3/4 pint of lime water and 1/2 oz. of gum Arabic to every pint of either of the above juices.

=Green, Scheele’s.= This is arsenite of copper.

Prep. 1. White arsenic (in powder), 1 part; commercial potash, 2 parts; boiling water, 35 parts; dissolve, filter, and add the solution gradually, whilst still warm, to a filtered solution of sulphate of copper (cryst.), 2 parts, as long as a precipitate falls; lastly, wash the newly formed pigment with warm water, and dry it.

2. (Ure.) Powdered arsenious acid, 11 oz.; carbonate of potassa, 1-1/2 lb.; boiling water, 1 gall.; dissolve, filter, and add the solution, as before, to another solution of crystallised sulphate of copper, 2 lbs., in water, 3 galls. Prod. 1-1/2 lb. A very fine grass-green colour.

=Green, Schweinfurt.= This splendid green pigment is the aceto-arsenite of copper.

Prep. 1. Acetate of copper and arsenious acid, equal parts, are each dissolved separately in the least possible quantity of boiling water, and the solutions mixed whilst still as hot as possible; an olive-green precipitate falls, which, by being boiled in the liquor 5 or 6 minutes, changes to a dense granular powder of a superb green colour.

2. Instead of boiling the solution containing the precipitate, it is allowed to cool and stand for several hours, or until the powder assumes a granular and beautiful tint. Very rich.

3. (Kastner.) Arsenious acid, 8 lbs., is dissolved in water as before, and added to verdigris, 9 or 10 lbs., diffused through water q. s., at 120° Fahr., the pap of the other being first passed through a sieve; the mixed ingredients are then set aside till the mutual reaction produces the proper shade.

4. (Dr Ure.) Sulphate of copper, 50 lbs., and lime, 10 lbs., are dissolved in good vinegar, 20 galls., and a boiling hot solution of white arsenic, 50 lbs., is conveyed as quickly as possible into the liquor; the mixture is stirred several times, and then allowed to subside, after which it is collected on a filter, dried and powdered. The supernatant liquor is employed the next time for dissolving the arsenic.

5. See GREEN, EMERALD (above).

Obs. This is a very fine, permanent green pigment. “A great deal of needless alarm has been excited about its supposed deleterious effects. It is extensively employed for staining wall-papers, and persons inhabiting rooms thus papered are said to have had their health seriously deranged by the arsenical fumes evolved from it. Now, it is utterly impossible that arsenic could volatilise from such a compound at ordinary temperatures; it does not decompose at any temperature below redness.” (Watts.) [It is, however, probable that the air of such apartments is sometimes charged with the poisonous pigment through its becoming mechanically detached from the paper. To breathe an atmosphere so impregnated would be dangerous. The use of papers coloured with Scheele’s green, especially of the kind called ‘flock,’ should, therefore, be carefully avoided.——ED.]

=Verd′igris.= See COPPER (Acetates) and VERDIGRIS.

=Green, Verd′iter.= This is essentially a mixture of oxide and carbonate of copper in uncertain proportions, with chalk. Factitious green bice and mountain green have a like composition. See VERDITER.

=Green, Verona.= The mineral called green earth.

=Green, Vienna.= The same as Schweinfurt green.

=GREEN SICKNESS.= See CHLOROSIS.

=GREEK FIRE.= This compound, so much used in ancient warfare, is believed to have had naphtha for its chief ingredient. According to some authorities, it was a mixture of asphalt, nitre, and sulphur.

=GREGORY’S SALT.= The crude hydrochlorate of morphia, prepared by Gregory’s process. It is a double hydrochlorate of morphia and codeia.

=GRINDELIA ROBUSTA.= A perennial plant belonging to the natural order Compositæ; a native of California, in which state it is largely used against poisoning by the “poison oak” (the Rhus toxicodendron). Of late years it is said to have been in American medical practice used with excellent effect in asthma and kindred diseases. Dr Q. C. Smith, writing to the ‘Pacific Medical and Surgical Journal’ for April, 1875, states one patient to whom pills made of the solid extract were administered, had suffered from severe and frequent attacks of asthma since childhood, and had found no relief from various remedies. Dr Smith gave his patient the extract of the grindelia in pills of three grains each, one three times a day for two or three days, then a pill at bedtime only, for eight or ten days longer. Under this mode of treatment the attacks are said to have been much less severe, and less frequent; the patient not only gaining in strength and general health in the meantime, but having experienced an immunity from attack for four months. The parts of the plant used are the selected leaves and tops.

=GRIND′ING.= The operation of reducing substances to powder by attrition or friction. In the laboratory, the term is chiefly applied to powdering by means of a mill or by mechanical power, in opposition to simple pounding or trituration in a mortar or with a slab and muller. All the principal powders, paints, &c., sold by the druggist, drysalter, and colourman, are reduced in the drug or colour mill. Recently machinery has even been applied to the common mortar. An ingenious and very useful contrivance of this kind is the ‘mechanical mortar’ of Mr H. Goodhall, of Derby.

=GRIND′STONES. (Artificial).= Washed siliceous sand, 3 or 4 parts; shell-lac, 1 part; melt together, and form the mass into the proper shape whilst warm, with strong pressure. The fineness of the sand must depend on the work the stone is intended for. The same composition is formed upon pieces of wood, as corn rubbers, and for the purpose of sharpening knives, and cutting stones, shells, &c. See EMERY.

=GROATS.= Syn. GRITS; GRUTELLUM, AVENA DECORTICATA, AVENÆ SEMINA, AVENA (Ph. L.), L. Common oats, deprived of their exterior integuments or husks. This is generally effected in a mill, which, at the same time, cuts them into two or three pieces. When crushed flat, they are denominated EMBDEN GROATS.

=GROUT.= Mortar reduced to a thin paste with water, used to fill up the joints of masonry and brickwork. A finer kind is used to ‘finish off’ the best ceilings.

=GRUEL.= Syn. OATMEAL GRUEL, WATER G.; DECOCTUM AVENÆ, L. Oatmeal or groats boiled with water to a proper consistence, and strained. It is variously flavoured to suit the palate; but the addition of a little white sugar, and finely powdered Jamaica ginger, with or without a glass of wine, is the least likely to offend the stomach. Nutmegs, cinnamon, &c., frequently disagree with invalids. Sometimes milk or butter is added. Embden groats require less boiling than the common groats. Of oatmeal, the Scotch is commonly said to be the best.

The following directions for making gruel from oatmeal are given by Dr A. T. Thomson: “Oatmeal, 2 oz.; cold water, 1-1/2 pint; rub the meal in a basin, with the back of a spoon, in some of the water, pouring off the fluid after the grosser particles have subsided, but whilst the milkiness remains; repeat this with fresh water, unite the washings, and boil until a soft, thick mucilage is formed.”

=GUA′IACIN.= Syn. GUAIACIC ACID, PURE GUAIACUM RESIN. A substance having the nature of an acid, discovered by Trommsdorff in the wood and bark of Guaiacum officinale.

Prep. The tincture of guaiacum is treated with hydrate of lime, and the guaiacate of lime thus formed is decomposed with dilute sulphuric acid; it is purified by dissolving it in alcohol.

Prop., &c. Insoluble in water; soluble in alcohol and ether; it unites with the caustic alkalies, forming alkaline guaiacates (guaiacum soaps); air and light turn it green; gluten, mucilage of gum Arabic, &c., turn it blue; nitric acid and chlorine turn it successively green, blue, and brown; tincture of guaiacin, added to hydrocyanic acid and sulphate of copper, produces an intense blue colour. (Pagenstecher.) A delicate photographic paper may be formed by washing unsized paper with an alcoholic solution of guaiacum resin, and afterwards with one of neutral acetate of lead. (Johnston.)

=GUA′IACUM.= Syn. GUAIAC, GUM GUAIACUM, GUAIACUM RESIN; GUAIACUM (Ph. L.), (GUAIAC RESIN, GUAIACA RESINA, B. P.). The resin prepared by means of fire from the wood of Guaiacum officinale, by natural exudation, by incision, or by heat. (B. P.) This substance is often adulterated. When pure, its “fresh fracture is red, slowly passing to green; the tincture slowly strikes a lively blue colour on the inner surface of a thin paring of raw potato.” (B. P.) Adulteration with resin may be generally discovered by the odour evolved when the guaiacum is heated. An alcoholic tincture of guaiacum, rendered milky with water, recovers its transparency on the addition of caustic potassa in excess; but this is not the case when resin is present.

Guaiacum is stimulant, sudorific, and alterative.——Dose, 10 to 30 gr., either in powder or pills; in chronic rheumatism, gout, obstinate chronic skin disease, scrofula, syphilis, &c. It forms the active ingredient of the once celebrated ‘CHELSEA PENSIONER,’ and the ‘GOUT SPECIFIC’ of Mr Emerigon. The latter was made by digesting 2 oz. of guaiacum resin in 48 fl. oz. of rum, for seven or eight days. The dose of this was a table-spoonful every morning, fasting, for a twelvemonth. Its other properties are similar to those of GUAIACIN, but are less marked. Sp. gr. 1·20 to 1·22.

=Guaiacum Wood.= Syn. LIGNUM VITÆ, GUAIACI LIGNUM (Ph. L.), L. The wood of Guaiacum officinale. This is employed under the form of shavings, raspings, and sawdust, in decoctions only. See DECOCTION and BALSAM.

=GUA′NO.= Syn. HUANHO, Peruv. This substance, now so extensively used in agriculture, is the partially decomposed excrement of certain aquatic birds, chiefly the common penguin, which congregate in countless numbers on the barren and uninhabited islets and rocks on the western coasts of South America and the coasts of Africa. It abounds in ammonia and the phosphates, and is undoubtedly the richest natural manure known. Under judicious application the increase of the crops of grain, turnips, potatoes, and grass consequent upon its use is said to be about 33%. “Guano is peculiarly adapted to horticultural and floricultural improvement, by its relative cleanliness and facility of application.” (Ure.)

“According to Denham Smith,[339] South American guano, as imported, presents itself in three distinct states, the three varieties being not unfrequently mixed together in the same bag; the first variety is damp and pulverulent; the second exists as large concretions, presenting various aspects when broken; the third is heavy and crystalline, and is termed ‘stone’ by the labourers. These three varieties differ widely in composition, as the following comprehensive analysis, by Smith, will show:——

[Footnote 339: ‘Proceedings of the Chem. Soc.,’ vol. ii.]

+--------------------------------------------------------------+ | Soluble in Water. | +-----------------------------+------------+---------+---------+ | | I. | II. | III. | | |Pulverulent.|Concrete.| Saline. | | +------------+---------+---------+ |Water | 222·00 | 250·00 | 97·00 | |Chloride of ammonium | 25·50 | —— | 30·30 | |Sulphate of potash | 80·00 | —— | —— | | ” soda | traces | 258·44 | 191·77 | |Oxalate of ammonia | 74·00 | 93·90 | —— | | ” soda | —— | —— | 105·63 | |Phosphate of ammonia | 63·30 | 61·24 | —— | | ” potash | —— | 77·32 | 49·47 | | ” soda | 1·20 | —— | 3·60 | |Chloride of sodium | —— | 29·22 | 286·31 | | ” potassium | —— | —— | 41·63 | |Organic matter | 15·00 | 6·68 | 25·53 | |Urate of ammonia | 154·18 | —— | —— | |Uric acid | 25·16 | —— | —— | |Ammonia phosphate of magnesia| 5·64 | 7·84 | 1·33 | |Animal matter | 11·80 | 8·60 | 7·56 | | | | Insoluble in Water. | +-----------------------------+------------+---------+---------+ | | I. | II. | III. | | |Pulverulent.|Concrete.| Saline. | | +------------+---------+---------+ |Oxalate of lime | 25·60 | 109·58 | —— | |Phosphate of lime | 199·30 | 62·70 | 132·23 | | ” magnesia | 20·30 | 8·74 | 25·80 | |Oxide of iron | —— | —— | 1·56 | |Humus and organic matters | 60·92 | 8·00 | 18·36 | |Sand | 15·60 | 7·20 | 4·20 | |Loss | ·50 | 10·54 | 7·78 | | +------------+---------+---------+ | | 1000·00 | 1000·00 | 1000·00 | +-----------------------------+------------+---------+---------+

“Several of the South American guano beds are now exhausted, but new varieties are constantly being introduced; and although the qualities are continually varying, guanos, on the whole, may be divided into two classes, the one characterised by the abundance of ammonia, the other by that of phosphates, the Peruvian and Angamos being characteristic of the former, and the Saldanha Bay and Bolivian of the latter. In selecting a guano, the following points (Anderson) ought to be attended to by the farmer:——

“1st. The guano should be light coloured and dry, colouring very slightly when squeezed together, and not gritty.

“2nd. It should not have too powerful an ammoniacal smell, and should contain lumps which, when broken, appear of a paler colour than the powder.

“3rd. A bushel should not weigh more than from 56 to 60 pounds.

“These characters are, however, imitated with great skill, so that they cannot be implicitly relied upon, and they are applicable to Peruvian guano only.”[340]

[Footnote 340: The above particulars are from an elaborate paper by Dr H. M. Noad, in the ‘Chemist and Druggist,’ vol. ii.]

Purity, Adulteration. Guano, owing to its high price, is very commonly adulterated, or is in an advanced stage of decomposition when sold. Much of what is vended under the name is altogether a fictitious article. These artificial mixtures are made to look so like genuine guano, that the mere practical man, who goes only by their appearance, is very often deceived by them, and, owing to the failure of his crops in consequence, is led to distrust the efficacy of guano as a manure. A sample of pretended guano examined by Johnstone was found to contain, in the state in which it was sold, more than half its weight of gypsum, the rest being peat or coal ashes, with a little common salt, crude sulphate of ammonia, and either dried urine or the refuse of the glue manufactories, to give it a smell. “I could not satisfy myself that it contained a particle of real guano.”[341] Vessels which sail hence for the guano stations are now very commonly ballasted with rough gypsum or plaster of Paris. This substance is mixed with the guano as it is loaded, and enables the importers to deliver from the vessel a “nice-looking, light-coloured article.” Purchasers of guano are very desirous of having it delivered from the vessel, as they believe they thus obtain it pure. The favourite material for the adulteration of guano, at the present moment, is a variety of umber, which is brought from Anglesea in large quantities. The rate of admixture is said to be about 15 cwt. of umber to about 5 cwt. of Peruvian guano, from which an excellent-looking article is manufactured, which is sold under the name of ‘African guano.’

[Footnote 341: ‘Elem. of Agric. Chem.’]

Pure guano has a pale-brown colour, a more or less offensive odour, and the average sp. gr. of 1·63 to 1·64. If the sp. gr. exceed 1·75, it is either damaged or adulterated; and if it is less than 1·62, it contains an undue quantity of moisture. The best is neutral to test-paper, and sometimes has even an acid reaction; but that of commerce has generally an alkaline reaction, owing to the presence of free ammonia, and, in consequence, turns turmeric paper brown, and gives white fumes when a glass rod dipped in hydrochloric acid is held over it. Triturated with quicksilver or caustic potassa, good guano evolves a powerful odour of ammonia; digested in water, fully one half of it is dissolved; dried by the heat of boiling water, it does not lose more than from 7 to 9% in weight; and burned upon a red-hot shovel, it leaves a white ash, not a red or dark-coloured one. (See directions for selecting guano given above, also below.)

Analysis or assay. The quantitative analysis of guano, so as to exhibit the names and proportions of all its numerous component substances, is an extremely tedious and difficult matter in the hands of persons unaccustomed to chemical manipulations. As, however, its value to the agriculturist depends chiefly on its richness in ammonia, potassa, and phosphoric acid, the analysis of guano for practical purposes may be reduced to an assay for these articles. Indeed, the presence of ammonia (the most valuable of them), in the proper quantity, may be fairly taken as evidence of the presence of the rest. The following methods of testing guano are both simple and accurate, and are so arranged as to permit its per-centage richness in one or more of its leading constituents to be determined without much trouble or expense.

1. a. 100 gr. of the sample for examination (fairly selected) are crushed to a powder, and placed on a small, weighed, and perfectly dry paper filter, and then desiccated, by exposure for 2 or 3 hours to the heat of boiling water. The loss in weight, taken in grains, after deducting 9, indicates the quantity per cent. of water or moisture which the sample contains in excess of that present in good or pure guano.[342]

[Footnote 342: According to Dr Noad, the proportion of water in genuine guanos ranges from 7 to 20%.]

b. The paper filter, with its contents, is next suspended for some time over concentrated sulphuric acid (oil of vitriol) contained in a wide-mouthed bottle or jar, by means of a thread attached to the cork or stopper, care being taken to exclude the external air. The exposure in this way is continued until the guano ceases to diminish in weight, which is ascertained by weighing it at intervals after the first 3 or 4 hours. When this point is arrived at, the filter and its contents are very carefully weighed. The difference between its present weight and its original weight (before the desiccation in a), taken in grains, gives the gross quantity of water per cent.

c. The dried guano from b is next placed in a weighed, smooth crucible or capsule, and exposed to a low red heat until all the organic matter is completely destroyed, and the whole is reduced to a white ash, which is weighed as soon as it has become cold. This weight, in grains, gives the gross weight per cent. of non-volatile matter (fixed alkaline and earthy chlorides, phosphates, and sulphates); the total loss of weight by combustion denotes the gross per-centage of combustible and volatile matter (urea, uric acid, ammoniacal salts, and organic matter). The latter should not be less than 55 to 60%.

2. a. A second 100 gr. of the guano, selected as before, is distilled along with about 75 gr. of fresh-slaked quicklime, and a little water, in a small matrass connected with a tubular, triple bulb-condenser, containing cold distilled water, and immersed in a basin of ice-cold water. (See engr.) The condenser is charged by plunging one of its extremities into the water, and sucking at the other, until the liquid reaches the level indicated in the margin. A very gentle heat only, cautiously increased, need be employed. After the process is over, the strength of the solution of ammonia found in the condenser is tested, either by taking its density in a small specific-gravity bottle, or by determining its saturating power in the manner described under ALKALIMETRY. This furnishes the per-centage of ready formed ammonia sufficiently accurate for all ordinary purposes, provided proper care is taken.

When extreme accuracy is required, the condenser is charged with a weighed quantity of dilute hydrochloric acid of a known strength, instead of water, and after the process is over, this is tested as before. The quantity of ammoniacal test-liquor (see ALKALIMETRY) now taken to saturate it, deducted from what it would have taken before the exposure in the condenser, gives the per-centage sought.

Another method, giving very accurate results, is to use a rather strong hydrochloric acid (sp. gr. about 1·13) for the condenser; after the operation is over, the contents of the latter are poured into a glass or porcelain capsule, a solution of bichloride of platinum is added, in excess, and the whole is then gently evaporated to dryness; the residuum is rubbed to powder, and exhausted with a mixture of two measures of alcohol and one measure of ether; the undissolved portion is next dried at a heat not exceeding 212° Fahr., and weighed. The weight, in grains, of the ammonia chloride of platinum thus obtained, multiplied by ·0763, gives the per-centage of ready-formed ammonia, as before. When hydrochloric acid is used for the condenser, a simple U-tube and beaker glass may be employed, if a bulb-condenser is not at hand. (See engr.) The advantages resulting from the use of acid instead of water for the condenser is, that with the former no ammonia can possibly escape being absorbed, whilst little care is required to keep the condenser cool.

b. 25 gr. of the guano are next weighed, and after being slightly moistened with a little dilute hydrochloric acid, are thoroughly dried by the heat of boiling water; the dried sample is then mixed in a warm unglazed porcelain mortar with 10 times its weight of a mixture of 2 parts of quicklime to 1 part of hydrate of soda (both quite dry). This mixture is introduced into a combustion tube of hard Bohemian glass, about 16 or 18 inches long, and 3/4 of an inch in diameter (see engr.) The mortar is rubbed out with a little of the soda-lime mixture, which is also introduced into the tube with that already put there; a little plug of ignited asbestos is then loosely placed over the whole, and the tube is immediately connected with a tubular bulb-condenser, containing moderately strong hydrochloric acid, great care being taken that the joints are made air-tight, which may be determined by the operator sucking a few bubbles out of the apparatus. If, after suction, the liquid remains at a higher level in the furthest bulb (b), it is a sign that the connection is sound. This being done, heat is applied to the combustion-tube, by means of spirit-lamps; or, more conveniently, by means of the furnace now usually employed in organic analysis (see engr.) The tube is next gradually surrounded with red-hot charcoal, by shifting by degrees the screen (c), and adding more charcoal, so as to gradually expel the ammonia. The disengagement of gas should take place uninterruptedly, but not too rapidly, in order that the acid may not ascend into the combustion-tube and spoil the experiment. The non-condensable volatile matters which pass off furnish a key to the progress of the operation. The heat is at length increased to a full red. When gas ceases to be evolved, and the mixture in the tube has become quite white, the experiment is at an end. The point (a) of the combustion-tube is broken off, and the ammonia which remains in the tube is expelled by sucking gently at the extremity (b) of the bulb-condenser. The latter is then disconnected with the apparatus, and emptied into a glass or porcelain capsule, in order to be tested, as directed under 2, a. The quantity of ammonia, in grains, thus found, multiplied by 4, gives the WHOLE QUANTITY of AMMONIA per cent., both actual and potential, producible from the sample of guano examined.

c. The quantity of ready-formed ammonia (see 2, a) deducted from the quantity last found (see 2, b) gives the quantity of LATENT or POTENTIAL AMMONIA that will be slowly developed by the decomposition of the guano in the soil, and become available for the food of plants. This is the most valuable product of this substance as a manure, and can only be obtained in quantity from well-preserved, dry guano.

3. a. A third quantity of 100 gr. of the guano, selected as before, is triturated and digested for some time with 12 times its weight of hot distilled water, and the whole being thrown on a filter, the undissolved portion is washed with a little warm distilled water; the solution and ‘washings’ are then mixed together, and acidulated with nitric acid; a solution of pernitrate of iron is next added, and afterwards solution of ammonia, in excess; the liquid is next heated for a short time, and the bulky reddish-brown precipitate is collected, washed with hot water, dried, ignited, and weighed. The weight, in grains, less the weight of the peroxide of iron in the pernitrate consumed, gives the weight of PHOSPHORIC ACID present in the soluble phosphates contained in the sample. The pernitrate of iron is made by direct solution in hot strong nitric acid, of twice as much pure iron wire as there is phosphoric acid suspected to be present in the liquid. A slight excess will not alter the result. The number of grains of metallic iron used to form the solution, multiplied by 1·4286, gives the weight of the peroxide of iron which is to be deducted from the gross weight of the precipitate.

b. The filtrate and ‘washings’ left from 3 a are mixed, and treated with a little oxalate of ammonia to throw down any lime, and then carefully evaporated to dryness and ignited; the residuum of the ignition, when cold, after being carefully weighed, is treated with the smallest portion of water that will dissolve it; the solution is acidified with hydrochloric acid, and a solution of bichloride of platinum added, in excess; some strong alcohol is next poured in, the precipitate carefully collected on a filter, washed with rectified spirit, dried at 212° Fahr., and weighed. The weight, in grains, multiplied by ·1940, gives the per-centage of POTASSA sought.

c. The weight of the potassa multiplied by 1·852, and deducted from the weight of the ignited residuum in 3 b already found (see above), gives the quantity of CHLORIDE OF SODIUM or COMMON SALT (nearly).

4. a. The insoluble residuum from 3 a, dried, and ignited, or the ash from 1 c, is digested for 10 or 12 hours in 600 times its weight of water (to which a little common salt or sal-ammoniac may be added), after which the whole is thrown upon a filter; a solution of chloride of barium is then added to the filtrate as long as a precipitate (if any) forms; the latter is collected, washed, dried, ignited, and weighed. The weight, in grains, multiplied by ·5843, denotes the quantity of GYPSUM or SULPHATE OF LIME which has been used to adulterate the sample.

b. The insoluble residuum last left on the filter is digested for some time in warm dilute hydrochloric acid; the whole is then thrown upon a filter, and the undissolved portion (SILICA or SAND, with, perhaps, a trace of ALUMINA) is washed, dried, ignited, and weighed. It should not weigh more than 3 to 3-1/2 gr. (3 to 3-1/2%).

c. The filtrate and ‘washings’ from b are next mixed together; the mixed liquid is acidified with dilute sulphuric acid and heated until all the hydrochloric acid is expelled, and the whole reduced to a soft pasty mass; rectified spirit is now poured in, and after active stirring for some time, the mixture is thrown on a filter, and the solid portion washed with a little more rectified spirit; it is then dried, ignited, and weighed. The weight, in grains, multiplied by ·7650, gives the quantity of PHOSPHATE OF LIME per cent. required.

d. The filtrate from c is diluted with water, and after being boiled for a few minutes, ammonia is added in slight excess, followed by a solution of sulphate of magnesia (previously mixed with as much sal-ammoniac as will prevent ammonia producing a precipitate in it), slowly dropped in as long as it disturbs the liquor; the whole is now allowed to rest for 10 or 12 hours, when the precipitate is collected on a filter, and washed with water alkalised with ammonia, as long as the filtering liquid is rendered turbid by chloride of barium; it is next dried, submitted to intense ignition for some time in a covered platinum crucible, and, when cold, carefully weighed. The weight, in grains, multiplied by ·6429, indicates the per-centage of PHOSPHORIC ACID in the insoluble phosphates (phosphates of lime, magnesia, &c.) in the sample examined.

5. A fourth 100 gr, of guano is weighed, and exhausted by trituration and digestion with hot water (see 3 a); the solution is evaporated to dryness by a gentle heat, and the residuum of the evaporation, after being weighed, is powdered and enclosed in a stout phial with 8 times its volume of alcohol, sp. gr. ·825 (63 o. p.); the plant is next securely corked and guarded, and exposed for some time, with agitation, to the heat of 212° Fahr., the whole is then allowed to cool, the contents of the phial filtered, the undissolved portion washed with hot alcohol, and both the filtrate and the ‘washings’ gently evaporated to dryness, and weighed. This gives the richness of the sample in UREA, one of the most valuable constituents of the best guano. Its presence is “a certain proof of its entire soundness.” (Ure.)

6. a. Another 100 gr. of the guano is taken, and, after being exhausted with water, is dried at 212° Fahr., and weighed; it is then digested with heat in 20 times its weight of borax-water (containing 1% of borax), or in a solution of caustic potassa, and after a time the whole is thrown on a weighed filter, washed with a little cold distilled water, dried by a heat not higher than that of boiling water, and again carefully weighed. The loss, in grains, indicates the proportion per cent. of URIC ACID.

The accuracy of the result may be verified by adding dilute hydrochloric acid, in slight excess, to the filtrate, collecting the bulky, crystalline precipitate of uric acid which forms, washing it carefully with a little rectified spirit, drying it, and weighing it, as before. This weight, which in general is a very little under that denoted above, is the more accurate of the two. The precipitate is shown to be uric acid by its assuming a rich crimson colour when treated with a little nitric acid, which turns to a rich purple (murexide) when it is moistened with ammonia water.

b. The quantity of uric acid last obtained, multiplied by 1·1012, gives the per-centage of URATE OF AMMONIA.

Obs. Amongst the numerous constituents of guano, none are so valuable in an agricultural point of view as the three substances referred to in the last two sections. Indeed, almost all the ammonia furnished by this substance to the soil, after the latter, manured with it, has been exposed to the air and rain, is derived from the slow decomposition of urea, or urate of ammonia. It is these substances from which the store of latent, or, as Dr Ure terms it, potential ammonia, is derived. The ammonia existing in the guano under the form of carbonate, or of soluble salts (ready formed ammonia), is either soon dissipated in air or is washed away by heavy rains, and, therefore, forms the least valuable and durable portion of this manure. It may be even added artificially, a matter almost impossible with the former. An assay, therefore, for the latent ammonia, or the urea, or the urate of ammonia, any one of them singly, at once furnishes us, as we have already hinted, with evidence of the quality of the guano examined, without the expense and trouble of a complete analysis of this substance. Urea and uric acid are only to be found in the very best samples of guano, and their presence is a positive proof of entire soundness and superior quality. The other valuable portions of guano are potassa and phosphoric acid (phosphate of lime chiefly); the rest are of little importance. (See 2 c, above.)

=GUARANA= (Grimault & Co., Paris). 12 migrain powders, each weighing 1·75 grammes, consisting of guarana, but perhaps also containing an admixture of cocoa seeds, neither prepared nor roasted. (Hager.)

=GUARANA′.= Syn. PAULLINIA, BRAZILIAN COCOA. An alimentary and medicinal substance prepared from the seeds of Paullinia sorbilis, a Brazilian tree. The dried seeds, deprived of their aril, are pounded and kneaded into a mass, which is afterwards made into oblong or rounded cakes (GUARANA BREAD). These cakes are used as we use chocolate——mixed with water and sugar, and drank as a beverage. In Brazil this beverage is largely consumed, both on account of its nutritive qualities, and for its stomachic, febrifugal, and aphrodisiac effects. See CHOCOLATE, &c., also below.

=GUARANINE′.= A crystalline substance discovered by M. Martius in guarana. It appears to be identical with caffeine, the active principle of coffee and tea.

=GUD′GEON.= The Cyprinus gobeo (Linn.), a small fresh-water fish, common almost everywhere. The white is considered the best. It was formerly used in medicine.

=GUM.= Syn. GUMMI, L. The general term for an important class of vegetable products. Gums are more or less soluble in cold water, but insoluble in alcohol, ether, and oils. They are obtained from certain plants in amorphous masses; most of them exude spontaneously, or on puncturing the bark. The most perfect type of this class is the substance called GUM ARABIC, or GUM ACACIA. The gums are employed as demulcents in medicines, and are used as cements, and for giving stiffness and gloss to textile fabrics. Among the vulgar the term is often incorrectly applied to the resins and gum resins.

=Gum Acacia.= Syn. GUM ARABIC; ACACIÆ GUMMI (B. P.); G. ARABICUM, G. ACACIA, ACACIA (Ph. L.), L. “From various species” (of Acacia) “yielding gum” (Ph. L. & E.), chiefly Acacia arabica and A. vera. “Whitish or yellowish, transparent or cracked on the surface, and opaque; brittle; it dissolves freely in water.” (Ph. L.) It is scentless, and may be bleached by exposure to the sun and air, at the temperature of boiling water. Sp. gr. 1·355. (Ure.) The pure soluble principle of gum Arabic is termed ARABIN (which see). BARBARY or MOROCCO GUM, GUM SENEGAL, and EAST INDIA GUM, are inferior commercial varieties of the same substance from other species of Acacia (see below).

Powdered gum Arabic (PULVIS ACACIÆ) is frequently adulterated with flour or farina, or with Senegal or other inferior gums. The first may be detected by agitating a little of the powder with cold water; the pure gum dissolves rapidly, whilst the starch or flour falls to the bottom of the vessel. Or, a little of the powder may be mixed with boiling water, and when cold, tested with tincture of iodine; if it contains starch or flour, the paste will assume a blue colour. If it contains cherry-tree gum or tragacanth, it will be only partly soluble in cold water, and the paste will be partly coloured, and more or less interspersed with gelatinous clots.

For the detection of dextrin in gum Arabic Hager finds that when some of the adulterated article is placed in a glass dish, with vertical sides, and a solution of ferric chloride, density 1·48, diluted with an equal volume of water, is poured over it until the grains are just covered, in the course of a minute or so that particles of gum Arabic will adhere to the bottom of the vessel, whilst the grains of dextrin do not.

Much of the white gum Arabic of the shops is formed by bleaching gum Senegal, by what is called ‘Picciotto’s process.’ The gum is dissolved in water, and sulphurous acid gas passed through the solution. The liquid is afterwards boiled to expel the sulphurous acid, a little of which, however, still remains behind. To obtain the gum in a still whiter state, carbonate of baryta is added, and after agitation the mixture is filtered; it is afterwards shaken with gelatinous alumina, again filtered, and evaporated. The product (BLEACHED GUM) is very white, but lacks the peculiar toughness and adhesiveness of the best gum acacia.

=Gum, Barbary.= Syn. MOROCCO GUM. An inferior product, consisting of a mixture of several Acacia gums. It is exported from Mogador.

=Gum, Bassora.= A solution of yellowish gum brought from the neighbourhood of Bassora. It differs from most gums in being nearly insoluble in water. The plant yielding it is believed to be a species of Mimosa. It contains the principle BASSORIN, which also exists in gum tragacanth.

=Gum, Bleached.= See GUM ARABIC (above).

=Gum, Brit′ish.= Syn. DEXTRIN, STARCH GUM. Starch converted by the action of acids, diastase, or heat, into a soluble substance resembling gum.

Prep. 1. Malt (crushed small), 1 lb.; warm water, 2 galls.; mix, heat the whole to 145° Fahr., add of potato starch 5 lbs., raise the heat to 160° or 165° Fahr., and mash for about 25 minutes, or until the liquid becomes thin and clear; it must then be instantly run off, and raised to the boiling point to prevent the formation of sugar; after boiling for 3 or 4 minutes the whole must be filtered, and evaporated to dryness by a steam heat.

2. By exposing dry potato starch, in a stove, to a heat of about 400° Fahr. Yellow and inferior.

3. (M. Payen.) Dry starch, 1 ton, is moistened uniformly with concentrated nitric acid, 4-1/2 lbs. (diluted with), water, q. s., and the paste or dough is made up into small bricks or loaves, and dried in a stove; it is next reduced to coarse powder, and exposed in a stove-room for some time to a current of air at 160° to 165° Fahr.; it is next ground, sifted, and exposed, as before, to a heat of about 228° Fahr.; it is, lastly, ground, and passed through the ‘bolting machine.’ Very white and superior. This process has been patented in France by M. Henzé.

4. (Pinel.) Water, 100 galls., nitric acid, 1/2 gall., and hydrochloric acid, 1/2 pint, are mixed together, and so much potato starch is mixed as will form a thin paste; in two hours the liquid is drained off, and the solid matter is made up into lumps, which are dried by a gentle heat in a stove-room; they are next coarsely pulverised, and the powder is exposed on three successive days to the respective temperatures of 100°, 150°, and 190° Fahr.; the whole is then sifted, and, lastly, exposed to a heat ranging from 300° to 350° Fahr. Darker coloured than the last. To give it the appearance of gum Arabic, it is made into a paste with water containing 1% of nitric acid, and after being spread on copper plates in layers 3/4 to 1 inch thick, it is exposed to a stove heat ranging from 240° to 300° Fahr.

Prop., &c. White; insipid; transparent; friable; soluble in cold water, and in dilute spirit; insoluble in alcohol and ether; its solution yields a precipitate with acetate of lead. Iodine commonly turns commercial dextrin blue, but does not affect the colour of pure dextrin. It is distinguished from ordinary gum by its right-handed polarization of light, and by yielding oxalic but not mucic acid, when treated with nitric acid.

Dextrin is nutritive, emollient, and agglutinant. In France it is largely employed by the pastry-cooks and confectioners, and in medicine as a substitute for gum. The French surgeons also commonly employ it as a ‘stiffening’ for the splints used for fractured limbs. In this country it is chiefly used as a fine dressing for muslins, silk, and other textile fabrics, and in calico printing. Recently it has been made up into tear-like masses, and sold for gum Arabic, to which, however, it is vastly inferior as an agglutinant. See DEXTRIN.

=Gum, Cherry-tree.= Syn. FRUIT-TREE GUM, PLUM-TREE G.; GUMMI CERASI, G. PRUNI, L. An exudation from the stems of cherry, plum, and some other of the Rosaceæ. It is only partly soluble in water. It contains CERASIN (which see).

=Gum, East India.= This product, which consists of inferior kinds of gum acacia, is chiefly exported from Bombay, having been previously conveyed there from the coast of Arabia. It varies greatly in quality. Some samples are quite unfitted for making gum-water.

=Gum, Insoluble.= See BASSORA GUM, CHERRY-TREE GUM, and GUM TRAGACANTH.

=Gum, Seed.= Syn. GUMMI SEMINUM, L. A species of soluble gum extracted from the seed of the flax (linseed), quince, &c.

=Gum, Senegal.= This product, which is largely exported from Portendie, Sierra Leone, and the French settlements on the Senegal, ranks next in quality to gum acacia, and for many purposes, as calico-printing for instance, it answers equally well. The transparent and light-coloured pieces are frequently picked out and sold as gum Arabic.

=Gum Trag′acanth.= Syn. TRAGACANTH, GUM DRAGON; GUMMI TRAGACANTHA, G. DRACONIS, TRAGACANTHA (Ph. L.), L. The gummy exudation of the Astragalus verus, hardened by the air. When digested in water, it swells considerably, a portion is dissolved, and the whole combines to form a thick mucilage. It is totally soluble in boiling water, when some change is supposed to take place in it; a great portion, however, afterwards separates. Sp. gr. 1·384. It is chiefly employed in calico-printing, and by shoemakers and lozenge-makers; by the latter to give toughness to the saccharine mass.

Powdered tragacanth is often adulterated with flour of starch, and not unfrequently with the commoner varieties of gum Arabic. According to M. Planche, a mixture of pulverised tragacanth and gum Arabic forms, with water, a thinner mucilage than the same quantity of either of these gums alone. This fraud may be detected as follows:——Make a mucilage of the suspected gum, and add thereto a few drops (2 or 3 to the dr.) of alcoholic tincture of guaiacum, taking care to stir it all the while. If the sample contains any gum Arabic, the mixture, in the course of a few minutes, assumes a fine blue colour, whilst it does not change colour if the gum tragacanth is pure, 5% of gum arabic can be thus detected. When the quantity is very small, one to four hours may elapse before the colour is developed. Starch and flour are detected in the manner noticed under GUM ARABIC.

=Gum, Turkey.= Various qualities of gum acacia are sold under this name.

=GUM RES′INS.= Syn. GUMMI RESINÆ, L. Vegetable products in which the properties of gum and resin are combined. They are partly soluble in water, and partly in alcohol. Many of them form a species of emulsion when triturated with the former fluid. The principal gum resins are AMMONIACUM, ASSAFŒTIDA, BDELLIUM, GALBANUM, GAMBOGE, MYRRH, OLIBANUM, OPOPONAX, SAGAPENUM, and SCAMMONY.

=GUN BAR′RELS.= See BROWNING.

=GUN COT′TON.= See PYROXYLIN.

=GUN MET′AL.= An alloy containing 90·5% of copper and 9·5% of tin, used for casting pieces of ordnance (erroneously termed ‘brass guns’), also those parts of machinery which are subjected to considerable friction. See ALLOYS, BRONZE, STEREO-METAL, &c.

=GUN′POWDER.= This substance is a mechanical mixture of saltpetre, charcoal, and sulphur. It is seldom prepared on the small scale.

Prep. The saltpetre having been trebly refined, by boiling, skimming, filtering, and crystallising, is melted into cakes, which are then brushed to remove any adhering grit or dirt, broken into pieces with a mallet, ground to a fine powder in a mill, and sifted through a fine bolting sieve of brass wire. The charcoal is that of the alder or willow, and is carefully burnt, as already described, and is then reduced to powder. The sulphur is refined by distillation, and ground to the same fineness as the charcoal and saltpetre. The ingredients are weighed out in the proper proportions, and mixed together in a machine consisting of a wooden drum, having a shaft passing through its centre, to which numerous ‘flyers’ in the shape of knife-blades are attached, the drum and flyers revolving in a contrary direction. When mixed, the charge is carried to the ‘incorporating mill,’ where it is ground under vertical iron ‘mill-stones,’ with a small quantity of distilled water, until the ingredients are thoroughly incorporated. The product of this operation is then pressed into a hard cake, which is next broken into pieces, granulated by means of sieves, and after being ‘glazed’ by friction, and the dust separated, is dried, with proper precautions, in a stove heated to about 130° by steam pipes.

The proportions of saltpetre, charcoal, and sulphur, used for different kinds of powder, differ very slightly. In ‘sporting powders’ the proportion of saltpetre is generally from 1 to 3% greater than in the Government powders. In ‘miners’ powders’ it is about 10% less, an excess of sulphur being used. The following are the proportions adopted by European powers:

Saltpetre. Charcoal. Sulphur. England 75 15 10 France 75 12·5 12·5 Austria 75 15 10 Prussia 75 13·5 11·5 Russia 73·78 13·59 12·63 Spain 76·47 10·78 12·75 Sweden 76 15 9 (Capt. Jervis-White Jervis.)

Obs. The quality of gunpowder is best estimated by actual trial of its power and cleanliness in use. It should be dry, hard, and free from dust; the grains should be of a uniform size, and glossy, and the colour a dark-grey or brownish-grey, not perfectly black. A very little placed on a piece of paper and fired should instantly explode with a flash, and neither leave an appreciable residue on the paper nor burn it. Dried by the heat of boiling water, or in vacuo, it should not lose more than 1/2 to 1% of its weight. Damp powder rapidly ‘fouls’ the gun. Gunpowder, containing more than 7% of water, does not recover its strength by simply drying it. The sp. gr. ranges between 1·795 and 1·800.

Karolyi succeeded in analysing the gases of gunpowder which had been fired in conditions closely resembling those which occur in artillery practice. For this purpose he enclosed a charge of powder in an iron cylinder of such strength that it just burst when the powder was fired by means of the electric spark. This charged cylinder was suspended in a hollow spherical bomb, from which the air was exhausted before firing.

After the explosion had been produced, the gases and the solid residue of the powder were submitted to analysis. The results obtained were the following:[343]

[Footnote 343: ‘Phil. Mag.,’ 1863.]

1. Composition of the Powder used.

Ordnance Powder. Small Arms Powder. Nitre 73·78 77·15 Sulphur 12·80 8·63 {Carbon 10·88 11·78 Charcoal. {Hydrogen 0·38 0·42 {Oxygen 1·82 1·79 {Ash 0·31 0·28 —————— —————— 99·97 100·05

2. Products of Combustion by Weight.

Ordnance Powder. Small Arms Powder. { Nitrogen 9·77 } { 10·06 } { Carbonic anhydride 17·39 } { 21·79 } Gaseous. { Carbonic oxide 2·64 } { 1·47 } { Hydrogen 0·11 } 30·58 { 0·14 } 34·18 { Sulph. hydrogen 0·27 } { 0·23 } { Marsh gas 0·40 } { 0·49 }

{ Ammonic sesquicarbonate 2·68 } { 2·66 } { Potassic sulphate 36·95 } { 36·17 } { ” carbonate 19·40 } { 20·78 } Solid. { ” hyposulphite 2·85 } 69·25 { 1·77 } 65·14 { ” sulphide 0·11 } { 0·00 } {Charcoal 2·57 } { 2·60 } {Sulphur 4·69 } { 1·16 } Loss. 0·17 0·68 —————— —————— 100·00 100·00

3. Products of Combustion by Volume in 100 of Gas.

Ordnance Powder. Small Arms Powder. Nitrogen 37·58 } { 35·33 } Carbonic anhydride 42·74 } { 48·90 } Carbonic oxide 10·19 } { 5·18 } Hydrogen 5·93 } 100 { 6·90 } 100 Sulphuretted hydrogen 0·86 } { 0·67 } Marsh gas 2·70 } { 3·02 }

It will be seen from the above figures that in addition to the generation of a considerable amount of carbonic anhydride (carbonic acid) by the combustion of gunpowder, there is liberated at the same time a large quantity of solid matter, in the form of sulphate and carbonate of potash, sulphide of potassium, sulphur, charcoal, &c. This will explain why the air of mines is so prejudicial to the health of the miner, particularly when he is engaged in blasting operations, these being carried on in a more or less confined space. See AIR, VITIATED.

=Gunpowder, Schultze.= The subjoined account of Schultze gunpowder is a transcription of a report communicated to the editor of the ‘Field’ newspaper by Mr F. Toms, A.I.C., F.C.S. After referring to a previous communication on the same subject Mr Toms proceeds as follows:——I have carried out some further experiments, with the aid (by Dr Frankland’s kind permission) of apparatus more suited to my requirements than that previously at my disposal; and I now proceed to lay before you the results of these experiments, and the conclusions to which they have led me, respecting the powders formerly received and the new Schultze powder, with a sample of which you have since favoured me.

The main constituent of the Schultze gunpowder, as you are aware, is wood fibre, which, having first been purified, is then subjected to the action of strong nitric acid (intensified by mixture with sulphuric acid), and thus is converted into a kind of nitro-cellulose or pyroxylin, the ordinary form of which is gun-cotton. The wood fibre undergoes no change in appearance by this treatment; but a change takes place in its chemical composition, which may thus be exemplified:

CELLULOSE NITRO-CELLULOSE (unconverted cotton or (cotton or wood fibre treated wood fibre). with nitric acid). Carbon 6 parts 6 parts. Oxygen 5 ” 5 ” Hydrogen 10 ” 7 ” or more. Nitroxyl (NO_{2}) none 3 ” or less.

It will thus be seen that the sole difference between gun-cotton or Schultze powder and ordinary cotton or wood fibre is, that some of the hydrogen is abstracted and has its place supplied by nitroxyl——a substance contained in nitric acid, and composed of one part of nitrogen united with two parts of oxygen. Under the most favorable circumstances, it is possible to replace three of the ten parts of hydrogen by three of the nitroxyl, when the substance produced is explosive, and is called from its composition tri-nitro-cellulose. This is the purest form of gun-cotton. If weaker acid is used, less hydrogen is displaced, and the product is called di-nitro-cellulose or mono-nitro-cellulose, according as it contains two or only one part of nitroxyl. These derivatives are either feebly explosive or not explosive at all. Such are the compounds known as photographic collodion and soluble gun cotton——the latter name distinguishing it from pure gun-cotton, which is not soluble in a mixture of ether and alcohol.

The Schultze powder contains both the explosive and the non-explosive varieties of nitro-cellulose.

If the wood fibre, after being carefully purified according to the method described in Schultze’s patent of 1864, were thoroughly desiccated and allowed to cool out of contact with air, and then dipped in acid of the strength mentioned in the specification, there seems no theoretical reason why an explosive powder containing at least 90% of true tri-nitro-cellulose should not be produced. As, however, I find on experiment that nothing like that per-centage is arrived at, I can only conclude that, in order to moderate the violence of the explosion, the Schultze Company secure the formation of a large per-centage of “soluble” or less explosive nitro-compounds by merely air-drying their wood.

If this supposition be generally true, it seems probable that the sample of Schultze powder supplied by Messrs Blissett may owe its extra explosive force to exceptional care being taken, during the interval between the drying and the dipping, to prevent the absorption of moisture——with the addition, perhaps, of an increased length of exposure to the action of the acid.

That some such variation of the ordinary procedure was carried out seems evident from the different proportions of soluble and insoluble gun-cotton in the specimens of Schuitze powder supplied by Messrs Blissett and Messrs Bland; for it was found that on the washed wood fibre from each being submitted to the action of a mixture of alcohol and ether, about one half of the former powder and two thirds of the latter were dissolved out. This shows that while the “Blissett” specimen contained about one half its weight of insoluble or explosive nitro-cellulose, the “Bland” contained only about one third——a difference which confirms the result obtained by analysis as stated below.

The soluble gun-cotton, ordinarily non-explosive, may, however, be rendered explosive by saturating it with bodies rich in oxygen, which promote the decomposition and complete the combustion of the fibre. Nitre is used for that purpose, because it parts with its oxygen readily; and nitrate of baryta is also used, because, being more stable than the nitre, it renders the combustion more gradual than would be the case if nitre were alone employed. When both are used, the nitre, I should think, would start, and the nitrate of baryta continue and finish the combustion of the powder. The amount used is, I suppose, the result of calculation and experiment; but a powder containing little true tri-nitro-cellulose should require more of these salts than one containing much tri-nitro-cellulose; and an excess of the salts would lower the rate of burning of the powder.

I will now give my analysis in full of the three powders, viz.——(1) the ordinary powder issued last season, being part of a supply obtained from Messrs Bland, gunmakers, of the Strand; (2) some powder furnished by Messrs Blissett, of Holborn, and alluded to in their letter in the ‘Field’ of Jan. 19th last, as having damaged a gun made by them; and (3) some of the new powder of 1878, as used at the ‘Field’ trial of explosives in May last.

1877 1878 Bland’s. Blissett’s. Trial or New.

Moisture, per cent. 2·18 2·39 2·97 {Nitrate of baryta, per cent. 21·50 16·59 22·32 Extracted { ” potash, per cent. 11·46 10·46 6·47 by water. {Yellow coloured organic {substance, trace of chlorides, {&c., undetermined

{The converted wood fibre } Insoluble { (nitro-cellulose) then } in water. { remaining contained the } 5·0 6·0 2·95 { following per-centage of } { mineral matter }

The converted wood fibre (after allowing for extraneous mineral matter) possessed the following per-centage composition. I place for comparison Professor Abel’s determination of the composition of tri-nitro-cellulose, and two of the impurities found along with it, in a parallel column.

Bland’s. Blissett’s. Trial or New. Tri-nitro- Impurities. Cellulose. Carbon 28·75 28·07 28·12 24·24 29·20 30·50 Hydrogen 3·49 3·65 3·54 2·36 —— 2·91 Nitrogen 10·80 15·60 11·66 14·14 11·85 —— Oxygen 56·06 52·68 56·68 59·26 —— ——

These powders exploded at a temperature of about 190° C. (374° F.), the different samples varying but slightly. Pure gun-cotton is stated by Professor Abel to explode at 150° C. (302° F.); and black powders are said, by different authorities, to explode at various temperatures between 500° and 600° F., according to the variation in their composition and manufacture.

In addition to the difference in chemical composition of these Schultze powders, I would point out that there is a difference in density——the Blissett being heaviest, the Bland next, and the New the lightest of the three. I think this fact also has some bearing on the violence of the explosion. In black powders, I believe, a dense powder, speaking generally, is stronger than a lighter one; and the Schultze patent states that hard woods make more explosive powders——not, I take it, because the composition is thereby altered, but because a denser powder is produced. It would appear to me, from the above analyses, that the new trial powder should contain rather more explosive force than the Bland variety, though considerably less than the Blissett. The result may, however, be modified by the difference in density of the powders; and your practical experiments will show how far this agrees with the results of the shooting.

I have hitherto only spoken of the explosive force of the powder; now I will touch on another point——its tendency to spontaneous decomposition. Knowing that, in the case of gun-cotton, its stability is injured by a small proportion of resin and other organic impurities, and by the presence of free mineral acids. I did not expect to find this powder (made from a less pure kind of cellulose, from which also it must be somewhat difficult to wash all traces of acid) equal in stability to gun-cotton; and on subjecting the three kinds of Schultze powder to the Government ‘heat test’ of 150° F. (with a minimum of 10 minutes’ duration), it was found that the

New or Trial (1878) Powder stood the test 12 m. ‘Bland’s’ sample ” 8 ” ‘Blissett’s’ sample ” 7 ”

This shows that the ‘new’ powder is very stable, as it stood the test for two minutes beyond the Government minimum, while the other two samples were a good way below it. The officials at Waltham Abbey would accept no gun-cotton which did not stand the test for ten minutes; and I have seen the best gun-cotton stand it for fifteen.

Whether the loose granulated condition of the Schultze powder, when stored, is sufficient to neutralise this inferiority in purity, and render a sample of Schultze, which only stands the test of seven minutes, as little liable to spontaneous combustion as gun-cotton which stands the test for ten minutes, there is at present no evidence to show.

To carry out this ‘heat test’ properly, some practice is required; so, in order to put the matter beyond doubt, I called in the assistance of my friend Mr Arthur Linnell, F.C.S., chemist to the Gun-Cotton Company, Stowmarket, a gentleman who uses the test daily, and who carried out the above three experiments strictly after the manner adopted by himself and by the Government officials.

In addition to Mr Linnell’s experiments, I noted that the aqueous extract of ‘Blissett’ was very faintly acid; that when heated in a chest at 195° F. moist blue litmus was very quickly reddened.

I think this serious defect (want of stability) is due to want of care in the washing; and I base this opinion on the following facts:

(1) The ‘Bland’ and ‘Blissett’ samples (the powders of least stability) are of a deeper tint than the ‘new’ (due to the soluble yellow impurity before mentioned). By continued washing in warm water they become pale, like the more carefully prepared new powder, and the yellow substance is dissolved away. Hence the lighter colour of the ‘new’ (and most stable) indicates it has less of this organic impurity.

(2) Sulphuric and nitric acids are used in the dipping of the powder, but should be entirely washed out, as they promote spontaneous decomposition. If left in, the sulphuric acid will, when the salts are added, decompose the nitrate of baryta, forming insoluble baric sulphate and free nitric acid.

On experiment I ascertained that the abnormally large quantity of mineral matter or ash (5 and 6 per cent.) found in the insoluble part of the ‘Bland’ and ‘Blissett’ powders is due to baric sulphate, and I think the acidity of the aqueous extract is due to the nitric acid thus set free.

Had this baric sulphate been present in the new powder, I should have thought it was purposely formed in all to prevent access of moisture; but, not finding this substance in this carefully prepared sample, I attribute its presence in the other cases to carelessness on the part of the workmen.

I should state that all these powders consisted of a granulated and consolidated pulp. This improvement must, I think, have considerable advantages over the sawdust form previously adopted by the Schultze Company in as much as it facilitates a more thorough purification being carried out, and produces a more homogeneous and equal powder. It is possible, too, that working with pulp may be of advantage, inasmuch as the company may now, by varying the pressure in forming the cake, obtain grains of any required density.

In conclusion, I may say that, in my opinion the most difficult task which the Schultze Company have had to encounter is that of obtaining uniformity of strength in their explosive; and the ‘Blisset’ sample of their powder may he looked upon as an experimental batch in which (by altering the mode of procedure in some such manner as I have indicated) they made a powder with a large per-centage of tri-nitro-cellulose, thus producing a more rapidly burning substance, and consequently a more violent explosion.

Taking all things into consideration, I think the Schultze Company, in manufacturing a nitro-explosive which gives the uniformity of shooting power shown in your recent experiments, have worked out a most troublesome problem with remarkable success. The difficulty of obtaining such results is evidenced by the fact that so many inventions of a somewhat similar character have been abandoned for sporting purposes from a deficiency in this respect.

But, however difficult it may be to manufacture a powder giving uniform shooting, it is evidently possible, with suitable care to produce (as the ‘new’ Schultze shows) a wood powder which is perfectly safe and stable, as far as spontaneous decomposition is concerned. The company, therefore, if they have not already done so, ought to take means to prevent powder of the low stability of the ‘Bland’ and ‘Blissett’ samples being again issued from their works.

P.S.——Since writing the above I have examined cursorily a sample of the ‘Dittmar’ wood powder, an American variety of ‘Schultze,’ used by Captain Bogardus in some of his recent shooting competitions. The powder is somewhat darker in tint, and of slightly larger grain, than the Schultze. In density it is intermediate between ‘Bland’s’ and the ‘new’ powder; and the charge in a twenty-bore cartridge was forty-two grains. This powder would seem to be made from solid cubes of wood (not a pulped mass like the present ‘granulated’ Schultze, or of sawdust splinters like the old so-called ‘cube’ Schultze). It contains no nitrate of baryta, but has a small quantity of nitrate of potash and soda. Possessing, as it would seem, therefore, a much smaller proportion of oxidizing salts than the English Schultze, it should contain, to make up for this loss of force, a larger proportion of explosive pyroxylin; but this is a point I have not experimentally determined. (‘Field,’ August 3rd, 1878, No. 1336, p. 143.)

=Gunpowder, White.= Syn. BLASTING POWDER. Prep. 1. See BLASTING POWDER, No. 3.

2. Yellow prussiate of potash and white sugar, of each 1 part; chlorate of potassa, 2 parts; powder each separately, and mix them well, but carefully, with a bone or wooden knife. It may be granulated like gunpowder, by making the powder into a paste with a little water, and pressing the mass through a parchment sieve.[344]

[Footnote 344: See the precautions noticed under BLASTING POWDER, page 230.]

=GUN′JAH.= See HEMP (Indian).

=GUT.= Syn. FISHING GUT, SILKWORM G. This is obtained from the Bombyx mori (Linn.) or silkworm caterpillar. Prep. The silkworms, when just ready to spin, are steeped in strong vinegar for 12 hours in warm weather, or 2 or 3 in cold weather, and are then broken in half, and stretched out as far as possible on a board, furnished with slits or pegs to hold them; in this state they are allowed to dry in the sun or a warm place.

Obs. Used by anglers. The worms may be known to be going to spin by refusing food, and by having a fine silken thread hanging from the mouth.

=GUT′TA PERCHA.= The concrete juice of the Isonandro Gutta, a tree growing only in the Malayan Archipelago, and of other species of the same genus. The stem of the gutta-percha tree grows to the diameter of 5 or 6 feet, and on being notched yields a milky juice, which, after exposure to the air for some time, solidifies, forming the gutta percha of commerce. It arrives in this country in irregular blocks of some pounds in weight, usually containing a large portion of impurities in the form of pieces of wood, stones, and earth. To prepare this crude product for manufacturing into useful articles, the blocks are first cut into slices, and then torn into shreds. These are softened by hot water, and kneaded in a ‘masticator,’ the stones, earth, and other impurities, being gradually washed away by water. After several hours the gutta percha is found to be kneaded into a perfectly homogeneous mass, which is rolled or drawn into sheets, bands, or tubes, as required.

Prop., &c. Gutta percha is a tough, inelastic substance, becoming soft and plastic at 212° Fahr., at which temperature two pieces may be firmly welded together. It is one of the best insulators of electricity, is impervious to moisture, and resists the action of acids and alkalies to a great extent. Its best solvents are benzol, chloroform, bisulphuret of carbon, rectified mineral naphtha, and rectified oil of turpentine. All these dissolve it readily. According to the analysis of Payen, the purified gutta percha of commerce consists of 75 to 828 of chemically pure gutta percha, which is insoluble in ether and alcohol, and a white and a yellow resin, soluble in boiling alcohol.

Uses. These are numerous and varied. No substance, perhaps, with the exception of caoutchouc, has been ‘tortured’ to so many different purposes. Its perfect plasticity when warm, and its capability of receiving the most delicate impressions, render it invaluable in many cases where india rubber would be useless. Beautiful mouldings, picture frames, and a number of ornamental articles, are made from it. To the chemist and photographer it is of great use as a material for making bottles, carboys, photographic baths, and voltaic battery cells. One of the most important uses to which it has been applied is for enclosing the metallic wires used for telegraphic purposes. Its indestructibility by water, its plasticity, and high insulating power, have rendered it particularly valuable for this purpose. At the International Exhibition of 1862 the Gutta Percha Company exhibited one mile of covered wire perfectly insulated, which was hardly thicker than common sewing cotton. Gutta percha may be rolled into thin transparent sheets, which, being perfectly impervious to moisture, are well adapted for surgical purposes. Again, a solution of gutta percha in chloroform forms an excellent dressing for incised wounds, and a protection for abraded surfaces, burns, &c. It is used in the same way as collodion.

=Gutta Percha, Purified.= Dr Cattell, of London, has succeeded in purifying gutta percha so perfectly from all extraneous matter, that it presents the appearance of ivory. The raw material is dissolved in a certain solvent, and the solution most carefully filtered until it leaves on evaporation the gutta percha in a pure milk-white condition.

=GYP′SUM.= This is native sulphate of lime. When baked, to deprive it of water, and ground, it forms PLASTER OF PARIS. Gypsum is an excellent manure for certain soils.

=HAARBALSAM, Vegetabilischer——Vegetable Hair Balsam= (Joh. Andr. Hauschild, Leipsic). A decoction of burdock root, containing a little spirit and coloured green with indigo. (König.) Hager analysed a turbid brownish fluid, which deposited a brown precipitate on standing, and when filtered consisted of a decoction of burdock root with 20 per cent. of spirit.

=Haarbalsam Mailandischer——Mailand’s Hairbalsam= (Kreller, Nuremberg). Beef marrow, 40 parts; cinchona extract, 5 parts; balsam of Peru, 1 part; storax, 1 part; oil of bergamot, 1 part; oil of lemons, 1/2 part. (Hager.)

=Haarbalsam Ostindischer——East Indian Hairbalsam= (Dr Ayer). Contains sugar of lead, sulphur, glycerin, oil of lavender, and water.

=Haarbalsam= (J. F. Sehwarzlose Söhne, Berlin). A brownish-yellow spirituous aromatic fluid, having nearly the composition of eau de Cologne, with liquid storax, carbonate of potash, and a fat——perhaps derived from cantharides. (Hager.)

=Haarbalsam= (A. Marquart, Leipsic). A mixture of 83 grammes water perfumed with eau de Cologne, with 12 grammes glycerin, 4·25 grammes milk of sulphur, and 1·2 gramme lead nitrate.

=HAD′DOCK.= A small sea-fish, allied to the cod, and esteemed an excellent article of food. It is the Gadus æglefinus of Linnæus. Split, smoked, and dried, it is common in the smaller shops of London.

=HÆMATEM′ESIS.= In pathology, vomiting of blood. See STOMACH AFFECTIONS.

=HÆM′ATITE.= Syn. HEMATITE. In mineralogy, one of the most important iron ores. Two kinds are distinguished, the red, which is an anhydrous peroxide of iron, and the brown, which is the hydrated peroxide.

=HÆMATOCRYS′TALLIN.= A crystalline substance obtained by the action of oxygen and afterwards carbonic acid on the ‘clot’ of blood.

=HÆMATOS′IN.= Syn. HÆMATIN, RED PIGMENT OF BLOOD. The red colouring principle of the blood. It is not known in a state of purity. It differs from the other animal principles in containing, as an essential ingredient, the sesquioxide of iron.

=HÆMATOX′YLIN.= A principle obtained by Chevreul from common logwood (Hæmatoxylon campechianum), and on which its colour appears to depend.

Prep. 1. Infuse logwood chips in water, at a temperature of about 130° Fahr., for 12 hours, filter, and evaporate to dryness in a water bath; digest the residuum in rectified spirit for 24 hours, again filter and evaporate; then add a little water; again gently evaporate and set aside the solution in a cold place that crystals may form; these must be washed in rectified spirit and dried.

2. Digest powdered hard extract of logwood in rectified spirit, and proceed as last.

3. Powdered logwood is mixed with sand and digested for several days in pure ether; the resulting liquid is filtered, evaporated to a syrup, and set aside to crystallise.

Prop., &c. Brilliant reddish-white or straw-yellow crystals, soluble in boiling water, forming an orange-red solution which turns yellow as it cools, but resumes its former colour on being heated. Alkalies in excess change its colour successively into purple, violet, and brown; acids brighten it; with the metallic oxides it forms compounds having a blue, purple, or violet colour.

=HÆMOP′TYSIS.= In pathology, spitting of blood. It generally arises from extreme fulness of the blood-vessels of the lungs, or the rupture of blood-vessels, as a consequence of ulceration; but sometimes it is induced by excessive exertion or external violence. Depletion, aperients, acidulous and astringent drinks, and nauseants, are the usual remedies. Acetate of lead, in small doses, has been recommended for this affection. When this substance is given, it should be accompanied with a sufficient quantity of free acetic acid, to prevent its being converted into the poisonous carbonate of lead in the system.

=HÆM′ORRHAGE.= Syn. HEMORRHAGE; HÆMORRHAGIA, L. A bleeding or flow of blood. Bleeding may be divided into active, passive, and accidental.——Active hæmorrhage is that arising from a full state of the vessels, or plethora.——Passive hæmorrhage, from general debility of the system, and of the blood-vessels in particular.——Accidental hæmorrhage, from external violence, as blows, wounds, &c. The first generally requires depletion, and the second the usual treatment to establish the general health and vigour of the body. The bleeding from wounds, if extensive, should be arrested by tying the ruptured blood-vessels; or where this cannot be done, and in less important cases, by the application of styptics, as creasote, sulphate of iron, infusion of galls, compound tincture of benzoin, &c.

=HAIR.= Syn. CAPILLUS, PILUS, L. The hair of the human head has continually formed a subject for the chisel of the sculptor, the pencil of the artist, and the lay of the poet. Nor is this surprising, since all the features of the face, as well as the head it covers, derive from it additional finish and unequalled grace. The hair is, indeed, one of the greatest auxiliaries of personal beauty, and imparts to it some of its principal charms. All nations, in all ages of the world, have been unanimous in their admiration of luxuriant and flowing or gracefully arranged hair.

Of all organic substances, hair is the one least liable to suffer spontaneous change. It is also less affected by aqueous liquids than most other substances. Hence its value in various branches of the useful arts.

The preservation of the hair of the head, independently of its connection with personal beauty, is a matter of the utmost importance in relation to hygiene. In other parts of this work, we have referred to its management under various conditions, but a few observations may be added here.

When the hair is in a weakly state, and either falls off or grows feebly, frequently cutting it will be found of the greatest service. “In the arrangement of the hairs, on the surface of the body, it might be inferred that little existed to excite attention; but this is not the fact, if we are to judge by the careful investigations to which the subject has given rise. The hair-tubes are not placed perpendicularly, but obliquely, in the skin; hence the direction of the hairs, after their escape from the tubes, is in the same sense inclined towards the surface; and the ‘set’ of the hair, from the root to the point, is governed by a law as precise as that which regulates any other of the secondary vital functions. Thus, on the head, the hair radiates from a single point, the crown, to every part of the circumference, making a gentle sweep, behind towards the left and in front to the right. The direction of this sweep is naturally indicated on the heads of children, and is that in which the hair is turned,” (Eras. Wilson.) The same occurs on the face and other parts of the body. In making our toilet, this natural arrangement of the hair should be interfered with as little as possible. Combing it or banding it in an opposite direction to that which it naturally assumes, is highly prejudicial to its healthy growth, and if long persevered in, leads to its premature and rapid decay. The practice now common among ladies, of throwing the hair from the forehead towards the back of the head, is of this reprehensible character.

In addition to our remarks elsewhere, we may here observe, that all the various systems proposed for strengthening or restoring the hair depend for their efficacy upon simple excitation or stimulation of the skin. Friction with the hair-brush, and the use of the ordinary hair-oils, pomades, and washes, are of this kind. The various advertised nostrums for reproducing or restoring the hair are either stimulants or rubefacients of more or less activity, or are emollients, which are directed to be applied by friction, in such a manner as to set up a considerable amount of irritation. When the affection depends on the languid circulation of blood in the part, this treatment often succeeds; but when the hair-bulbs are withered or decayed, or the scalp much attenuated, the restoration of the hair is an impossibility. See BALDNESS.

=HAIR COSMETICS.= Under this head are included all preparations which are used for beautifying, preserving, or restoring the hair. These are fully described in different parts of this work, and we shall here merely name the principal heads under which they will be found. The hard pomatums used for keeping the hair, moustache, and whiskers, in form, and sometimes to colour them at the same time, are noticed under COSMETIQUE; the mucillaginous preparations for stiffening the hair, under FIXATURE; the compounds for removing superfluous hairs, under DEPILATORY; the applications for the cure and prevention of baldness, under POMADES and WASHES; and those employed to cleanse or beautify the hair under the last two heads, and under HAIR DYES and OILS.

=HAIR DYES.= Syn. TINCTURA CAPPILLORUM, L. The practice of dyeing the hair is of great antiquity; and though not so common as formerly, it is still far from infrequent at the present day. The numerous preparations vended for this purpose have generally a basis of lead or silver. Bismuth, pyrogallic acid, and certain astringent vegetable juices, are also occasionally thus employed. The following list embraces all those of any value:

Prep. 1. Litharge, 1 part; fresh-slaked lime and starch, of each 2 parts; all in fine powder, and perfectly dry; mix, and keep the compound in well-corked bottles. This powder is to be made into a thin paste or cream with water (for black), or milk (for brown), and applied to the hair (previously freed from grease with soap and water, and dried), by means of a sponge or brush, or the fingers; observing to rub it well into the roots, and to pass a comb for some time through it, to ensure its coming in contact with every part. The whole must be then covered with a moist leaf of cotton wadding, or some brown paper several times doubled and well damped with hot water, and allowed to remain so for 3 or 4 hours, or even longer; or an oil-silk cap, or a bladder, may be worn, the object being simply to prevent the evaporation of the moisture. After a sufficient time has elapsed, the powder may be removed by rubbing it off with the fingers, and afterwards washing it out with warm soap-and-water. A little pomatum or hair-oil will restore the usual gloss to the hair. Another method of operating is to apply the cream or paste as before, and then to keep rubbing it about the hair with a brush as long as may be required, occasionally adding a few drops of hot water to preserve the whole moist. In this way the action of the dye is facilitated, and the process concluded in a much shorter time.

2. Lime (slaked in the air), 2 parts; carbonate of lead (pure white lead), 1 part; mixed and applied as the last.

3. (AQUA ORIENTALIS.) From grain silver, 2 dr.; steel filings, 4 dr.; nitric acid, 1 oz.; soft water, 1-1/2 fl. oz.; digested together, the solution being afterwards diluted with water, 3-1/2 fl. oz., and filtered. Applied by means of a fine-toothed comb, or a half-worn tooth-brush to the hair, previously well cleaned with soap and water, and dried.

4. (ARGENTAN TINCTURE.) From nitrate of silver, 1 dr.; eau de rose, 1 fl. oz.; nitrate of copper, 2 gr., or q. s. to impart a slight greenish tint. Used as the last.

5. (Dr Cattell.) Nitrate of silver, 11 dr.; nitric acid, 1 dr.; distilled water, 1 pint; sap green, 3 dr.; gum arabic, 1-1/4 dr.; digest together. Used as No. 3.

6. No. 1 Solution. Gallic acid, 7-1/2 gr.; acetic acid, 20 min.; distilled water, 1 fl. oz.

No. 2 Solution. Nitrate of silver, in crystals, 30-1/2 gr.; distilled water, 1 fl. oz.; ammonia sufficient to form the precipitate formed at first.

7. (CHESTNUT HAIR DYE.) “We have met with the following, but do not guarantee it:——Permanganate of potash gives the hair a beautiful chestnut-brown colour, varying according to the strength of the solution of the salt. A good formula is permanganate of potash, 1 dr.; powdered gum Arabic, 2 dr.; rose water, 3 oz.; mix. Apply carefully with a tooth brush so as to avoid staining the skin. (‘Chemist and Druggist.’)

8. (HAIR RESTORER.) This is in reality a dye. Sulphur, 45 gr.; acetate of lead, 20 gr.; glycerin, 1/2 oz.; water to make up 10 oz.

9. (GOLDEN HAIR DYE, AUREOLINE.) A solution of peroxide of hydrogen in water; containing from 3 to 6 per cent. of the peroxide.

10. (BROWN HAIR DYE.) Acetate of lead, 2 dr.; hyposulphate of soda, 1 dr.; rose water, 14 oz.; glycerin, 2 oz. Dissolve the acetate of lead and the hyposulphite in separate portions of the rose water; filter separately, mix the solutions, and add the glycerin.

11. (A HARMLESS HAIR DYE. Dr Hager.) Ten parts of subnitrate of bismuth, and 150 parts of glycerin are mixed in a glass vessel and heated in a water bath; solution of potash is then added in small portions, and with continued agitation, until a clear solution has been obtained, to which a concentrated solution of citric acid is added until merely a slight alkaline reaction is observed. Enough orange-flower water is added to make the whole liquid weigh 300 parts; the addition of a small quantity of a solution of an aniline colour completes the preparation.

12. (Chevallier.) Fresh-slaked lime, 5 dr.; water, 1-1/2 oz.; mix, strain through gauze, and pour the milk into a four-ounce bottle. Next dissolve sugar of lead, 5 dr., in water, 3 fl. oz.; add to this solution, dry slaked lime, 1 dr., stir well together, wash the precipitate with a little soft water, drain off the water, then add it to the milk of lime in the bottle, and shake the whole well together, and again before use. Applied as No. 1; but it acts much more quickly.

13. (Delcroix.) From acetate of lead, 2 oz.; prepared chalk, 3 oz.; quicklime, 4 oz.; each in an impalpable powder. Used as No. 1.

14. (EAU D’AFRIQUE——Hopekirk.)——a. Nitrate of silver (cryst.), 1-1/2 dr.; distilled water, 2 fl. oz.; dissolve, and pour the solution into the bottles labelled ‘Solution No. 1,’——b. Liquor of potassa, 3 dr.; sulphydrate of ammonium, 7 dr.; water, 1 fl. oz.; mix, and pour the liquid into the bottles labelled ‘Solution No. 2,’ For use, the hair is moistened by means of a small-toothed comb or tooth-brush, with the Solution No. 1, either alone or diluted with a little water; care being taken to avoid touching the skin, if possible. After the lapse of 8 or 10 minutes the Solution No. 2, diluted with at least 5 times its measure of water, is applied in the same manner, and any spots on the skin removed by rubbing them with the corner of a napkin wetted with the liquid. The skin is then sponged clean with a little warm water, and wiped dry, and the hair is arranged with the comb as usual. It is better to avoid rubbing it or washing it for a few hours. Sometimes the process is reversed, and the liquid No. 2 applied first. In this way the stains on the skin are more readily removed, but the dye is less permanent than when the other plan is adopted.

15. (EAU D’EGYPTE.) Resembles No. 4 (above).

16. (ESSENCE OF TYRE.) Resembles the last.

17. (GRECIAN WATER.) Resembles No. 3, or 4.

18. (Dr Hanmann.) Litharge, 275 gr. (say 1 part); quicklime, 1875 gr. (or 6-3/4 parts); hair powder (or starch), 930 gr. (or 3-1/2 parts): all in fine powder. Used as No. 1.

19. (Hewlet’s.) Resembles Spencer’s (No. 28).

20. (INSTANTANEOUS.) Moisten the hair first with a solution of nitrate of silver in water (1 to 7 or 8), and then with a weak solution of sulphydrate of ammonium. The colour of the hair, unaltered by the silver solution, instantly turns black when moistened with the sulphuret. See EAU D′AFRIQUE.

21. (La Forest’s.) See WASHES.

22. (Orfila’s.) From litharge, 3 parts; quicklime, 2 parts; starch, 1 part. The original form for this article is as follows:——Sulphate of lead, 4 parts; dry fresh-slaked lime, 5 parts; water, 30 parts; boil 1 hour, collect the paste on a piece of calico, and apply it in a similar manner to No. 1.

23. (POMADE DYE.)——a. Nitrate of silver, 1 part; nitric acid, 2 parts; iron filings, 2 parts; mix, and let them stand together for 4 or 5 hours, then pour them on oatmeal, 2 parts; next add, lard, 3 parts; and mix well together.

b. From nitrate of silver and cream of tartar, of each 1 dr.; liquor of ammonia, 2 dr.; dissolve, add of lard, 4 dr.; and mix well together.

24. (POUDRE D’ITALIE.) Resembles Orfila’s (No. 22.)

25. (PYROGALLIC STAIN.) A weak solution of crude pyrogallic acid. Another article sold under this name is prepared by distilling nutgalls (coarsely powdered) in a retort, dissolving the solid acid which sublimes in a little hot water, and after mixing this with the acid liquid which also passes over, adding a little rectified spirit. The floating oil is then separated and the solution filtered.

26. (Redwood.) Litharge, 2 oz.; slaked lime and powdered starch, of each 1 oz.; liquor of potassa, 2 dr.; water, q. s. to form a thick cream. Used as No. 1.

27. (Redwood.) Liquor of potassa and distilled water, of each 1 pint; mix, and pass sulphuretted hydrogen through the liquid until it is saturated. Of this solution take 20 oz.; liquor of potassa, 4 oz.; mix, and label it ‘Solution No. 1,’ Next dissolve nitrate of silver, 1 dr., in distilled water, 2 oz.; and label the liquid ‘Solution No. 2,’ Used in the same manner as No. 8 and 20.

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