Chapter II: BLEACHING of =Linen=:--Linen may be bleached in a similar way to (15)

It was first obtained by the action of caustic alkali upon chloral, but it is more easily prepared by distilling alcohol or wood spirit with chloride of lime. It may also be procured from wood spirit, acetone, oil of turpentine, and several essential oils, as well as from amylic alcohol, acetic acid, tartaric acid, and phenol; when these different bodies are severally subjected to the action of chloride of lime. When chlorine is made to act on marsh gas, or when chloral is treated with an alkali, chloroform is also produced.

_Prep._ 1. Chloride of lime (in powder), 4 lbs.; water, 12 lbs.; mix in a capacious retort or still, add of rectified spirit, 12 fl. oz., and cautiously distil as long as a dense liquid, which sinks in the water it passes over with, is produced; separate this from the water, agitate it with a little sulphuric acid, and, lastly, rectify it from carbonate of barium.

2. Chloride of lime, 4 lbs.; water, 10 pints; rectified spirit, 1/2 pint; proceed as last, using a spacious retort that the mixture will only 1-3rd fill, and the heat of a sand bath. When ebullition commences remove the fire as quickly as possible, lest the retort be broken by the suddenly increased heat, and let the solution distil into a receiver as long as there is nothing which subsides, the heat being restored if it be at all needed. Add to the distilled liquid four times as much water, and shake the whole well together; next cautiously separate the heavier part as soon as it has subsided, and to this add chloride of calcium, broken into fragments, 1 dr.; and shake occasionally during an hour; finally, let the fluid again distil from a glass retort into a glass receiver.

3. Hydrate of lime, 1 part, is suspended in cold water, 24 parts, and chlorine passed through the mixture until nearly the whole of the lime is dissolved; hydrate of lime, q. s. just to restore the alkaline reaction of the liquid, is then added; and, afterwards, rectified spirit of wine or wood spirit, 1 part, is mixed in; the whole, after repose for 24 hours in a covered vessel, is cautiously distilled as before.

4. (B. P.) Take of chlorinated lime 10 _lbs._; rectified spirit, 30 fluid ounces; slaked lime, a sufficient quantity; water, 3 gallons; sulphuric acid, a sufficient quantity; chloride of calcium in small fragments 2 _oz._; distilled water, 10 fluid ounces. Place the water and the spirit in a capacious still, and raise the mixture to a temperature of 100° F. Add the chlorinated lime, and 5 _lbs._ of the slaked lime, mixing thoroughly. Connect the still with a condensing worm, encompassed by cold water, and terminating in a narrow-necked receiver; and apply heat so as to cause distillation, taking care to withdraw the fire the moment that the process is well established. When the distilled product measures 50 fluid ounces the receiver is to be withdrawn. Pour its contents into a gallon bottle, half filled with water; mix well by shaking, and set it at rest for a few minutes, when the mixture will separate into two strata of different densities. Let the lower stratum, which contains crude chloroform, be washed by agitating it in a bottle with 3 fluid ounces of the distilled water. Allow the chloroform to subside, withdraw the water, and repeat the washing with the rest of the distilled water, in successive quantities of 3 oz. at a time. Agitate the washed chloroform for five minutes in a bottle with equal volume of sulphuric acid, allow the mixture to settle, and transfer the upper stratum of liquid to a flask, containing the chloride of calcium, mixed with 1/2 oz. of slaked lime, which should be perfectly dry. Mix well by agitation. After the lapse of an hour connect the flask with a Liebig condenser, and distil over the pure chloroform by means of a water bath. Preserve the product in a cool place in a bottle furnished with an accurately ground stopper. The lighter liquid which floats on the crude chloroform after its agitation with water, and the washings with distilled water, should be preserved and employed in a subsequent operation. Sp. gr. 1·456.

_Prop., &c._ Liquid; transparent; colourless; odour fragrant, ethereal, and apple-like; taste ethereal, sweetish, but slightly acrid; soluble in 2000 parts of water; mixes in all proportions with alcohol and ether; dissolves (readily) bromine, camphor, caoutchouc, gutta percha, iodine, oils, resins, wax, and several other like substances; boils at 141·8° Fahr.; kindles with difficulty; burns, when strongly heated, with a greenish flame; and communicates a dull, smoky-yellow colour to the flame of alcohol. Sp. gr. 1·48 (1·497, Miller); density of vapour 4·2. The vapour has the remarkable property of rendering a person breathing it temporarily insensible to pain.

Chloroform is frequently adulterated with alcohol and ether; and owing to careless manipulation, is also sometimes contaminated with other substances, as chloral, hydrochloric acid, free chlorine, aldehyde and certain chlorinated oils. These latter compounds are not only the most objectionable and prejudicial of the impurities found in chloroform, but if present in it to any appreciable extent, they render its anæsthetic administration not only inefficient, but frequently absolutely dangerous. These deleterious chlorinated oily compounds may be removed by agitation with strong sulphuric acid, or by distillation from it. Chloroform made from wood spirit is said to be more impure than that from alcohol. When pure it is free from colour, and of a pleasant odour. It is not perfectly soluble in water; and does not turn the colour of litmus red. Rubbed on the skin it quickly evaporates, scarcely leaving any odour. Dropped into water, it falls to the bottom and remains bright and limpid; but if it contain alcohol the surface of the drop becomes opaline. If the same experiment be made with diluted sulphuric acid, sp. gr. 1·44, the drop of pure chloroform will fall to the bottom; but that which contains spirit, if not shaken, will float or remain suspended in the acid solution. When contaminated with heavy hydrocarbon oils, a drop evaporated from the palm of the hand leaves behind a strong smell. Hydrochloric acid and free chlorine are detected by the ordinary tests.

Mr Shuttleworth, writing to the 'Canadian Pharmaceutical Journal,' says:--"In regard to the restoration of chloroform which has become spoiled, I would recommend that the chloroform be well agitated with a dilute solution of hyposulphite of soda.

"It should then be separated by means of a glass funnel from the supernatant liquid, and again washed; this time with simple water. After being separated the chloroform should be passed through filtering paper to free it from traces of moisture, when it will be found much improved and comparatively sweet, good enough in any case for external use.

"There are, of course, certain other impurities of chloroform which the hyposulphite will not remove. These are of a more stable character, and as they possess a higher boiling point than chloroform, may be separated by distillation, or by treatment with sulphuric acid in the usual manner."

_Uses, Action, &c._ Chloroform is anodyne, antispasmodic, sedative, stimulant, and anæsthetic. In small doses (5 to 12 or 15 drops, in water, mixed with a little syrup or mucilage) it is employed in spasmodic disorders, and as a stimulant and diaphoretic. It is now chiefly used as an anæsthetic to produce insensibility to pain during surgical operations. The dose for inhalation is 1 fl. dr., which is repeated, in a few minutes, if no effect is produced, until 3 fl. dr. have been thus exhibited; the effects being carefully watched, and the source of the chloroform vapour removed as soon as a sufficient degree of anæsthesia is produced, or any unpleasant symptoms develop themselves.

Chloroform in large doses depresses the heart's action, and causes profound coma, and death. It is therefore dangerous in all cases complicated with diseases of the heart or brain, or any visceral affections of a congestive character.

The treatment of asphyxia from chloroform is--the horizontal position, cold affusion to the head and spine, artificial respiration, and, if possible, either the application of electricity, or the inhalation of protoxide of nitrogen or oxygen gas, largely diluted with atmospheric air.

_Concluding Remarks._ The preparation of chloroform is not unattended with danger, and frequently miscarries in careless or inexperienced hands. This arises chiefly from the violent reaction which immediately follows the application of the heat. The common plan is attended with danger of explosion, or of the liquid in the still being forced over into the receiver, owing to the extraordinary rapidity with which the vapours are eliminated, and the ingredients, in consequence, swell up. A method which is successfully adopted on the large scale is to employ a very broad and shallow capsule-shaped still, having a flat rim round it, with a head or capital furnished with a corresponding rim at its lower part. In use, a flat, endless band of vulcanised india rubber is placed between the two rims, which are then held air-tight together by means of small, iron clamps. The application of heat is also delayed for some time after the admixture of the spirit with the other ingredients, and the process is interrupted as soon as the first violence of the reaction has subsided, by which time the whole product of chloroform will have passed over into the receiver. If the distillation is continued beyond this point, the remaining product is water. On the small scale, a very capacious, flat-bottomed retort or cucurbit should be employed. A similar condenser may be used to that noticed under ether.

=CHLOROFORMIC ANODYNE= (George Harley) is said to be an alcoholic tincture of opium with prussic acid and chloroform.

=CHLOROHYPONITRIC GAS= (NOCl) and =CHLORONITROUS GAS= (N_{2}O_{2}Cl_{4} are two peculiar compounds, formed when nitric acid and hydrochloric acid are mixed.

=CHLOROMETER.= _Syn._ CHLORIM'ETER. An instrument or apparatus employed in chlorometry. The chlorometers in common use are graduated measures and tubes precisely similar to those used in ACIDIMETRY, ALKALIMETRY, &c.

=CHLOROMETRY.= _Syn._ CHLORIM'ETRY. The estimation of the available chlorine in the bleaching powder of commerce, which is valued and sold in this country by its per-centage of that element. The plans generally adopted are applicable to the so-called chlorides of soda and potassa, as well as to the ordinary bleaching powder, chloride of lime. Most of them depend on the oxidising effect of water when undergoing decomposition through the action of chlorine.

_Dalton's Process._ The test solution is prepared as follows:--Pure protosulphate of iron (previously dried by strong pressure between the folds of cloth or bibulous paper), 78 gr., are dissolved in distilled water, 2 oz., and a few drops of hydrochloric or sulphuric acid added. This quantity of protosulphate requires for complete peroxidation just the quantity of oxygen liberated by 10 gr. of chlorine; in other words, the solution exhibits the indirect effect produced by exactly 10 grains of the bleaching element.

Exactly 50 gr. of the sample of chloride of lime to be examined are next weighed, and well mixed in a glass or wedgwood mortar with tepid water, 2 oz.; and the mixture poured into a graduated tube or chlorometer. The tube is next filled up to 0, or zero, with the washings of the mortar, and the whole well mixed, by placing the thumb over the orifice and shaking it. The solution of chloride of lime, thus formed, is next gradually and cautiously added to the solution of sulphate of iron, previously noticed, until the latter is completely peroxidised, which may be known when it ceases to be affected by a solution of red prussiate of potash. When a drop of the latter test, placed upon a white plate, ceases to give a blue colour on being touched with the point of a glass stirrer or rod dipped in the liquor under examination, enough of the solution of the chloride has been added. The number of measures thus consumed must now be carefully read off from the graduated scale of the chlorometer, from which the richness of the sample may be estimated as follows:--As 100 of the chlorometer divisions contain exactly 50 gr. of the chloride under examination, each measure will contain only 1/2 gr., and, consequently, the number of measures consumed will represent half that number of grains of the chloride examined; and the weight of the chloride thus used will have contained 10 gr. of chlorine--the constant quantity of that substance required to peroxide the test solution of sulphate of iron. Thus:--If 80 measures of the liquor in the chlorometer have been consumed, this quantity will represent 40 gr. of chloride of lime, and 10 gr. of chlorine. By dividing 1000 by this number, the per-centage of chlorine will be obtained. In the present instance this would be--

1000
---- = 25%
40

_Crum's Process._ Equal weights of water and hydrochloric acid are mixed together, and cast-iron borings digested in the diluted acid until saturation is complete; a large excess of iron being purposely employed, and the liquid kept at the heat of boiling water for some time. One measure of the solution, marking 40° on Twaddell's scale (sp. gr. 1·200), is then mixed with an equal quantity of acetic acid (sp. gr. 1·048). This forms the test-liquid. When mixed with 6 or 8 parts of water it is quite colourless, but chloride of lime occasions the production of peracetate of iron, which gives it a red colour.

The above proof-solution is next poured into 12 two-oz. vials, of exactly equal diameters, to the amount of 1/9th of their capacity; these are filled up with bleaching liquid of various strengths; the first at 1/12th of a degree of Twaddell, the second 2/12ths, and so on up to 12/12ths of 1°. They are then well corked up, and, after agitation, arranged side by side on a tray, furnished with holes to receive them. (See _engr._) To ascertain the strength of an unknown sample of bleaching liquor, the proof-solution of iron is put into a phial, exactly similar to the 12 previously used, and in precisely the same proportion (1/9th). The phial is then filled up with the bleaching liquor, well shaken, and placed beside that one of the 12 already prepared which it most resembles in colour. The number on that phial expresses the strength of the sample under examination, in twelfths of a degree of Twaddell's hydrometer.

_Obs._ The preceding method is admirably suited for weak solutions, such as are employed for bleaching textile fabrics, and is well adapted (from its simplicity) to the purposes of practical men. Indeed, it is quite astonishing to see with what ease and accuracy it is applied by unlettered operatives. This gives it great practical value. It has been for some time in extensive use in the bleaching houses of Scotland.

TABLE _exhibiting the quantity of Bleaching Liquid, at 6° on_ TWADDELL'S _scale_ (_sp. gr._ 1·030), _required to be added to a weaker liquor, to raise it to the given strengths. Adapted from_ MR CRUM'S _table by_ MR COOLEY.

-----------------------------------------------
| | Proportions required.
Strength | Required |-----------------------
of Sample | Strength. | Given | Liquor
in 1/12°. | | Sample. | at 6°.
-----------+-----------+-----------+-----------
| | Parts. | Part.
Water. | 8/12° | 8 | 1
1 | " | 9-1/4 | 1
2 | " | 11 | 1
3 | " | 13-1/2 | 1
4 | " | 17 | 1
5 | " | 23 | 1
6 | " | 35 | 1
7 | " | 71 | 1
Water. | 6/12° | 11 | 1
1 | " | 13-1/2 | 1
2 | " | 17 | 1
3 | " | 23 | 1
4 | " | 35 | 1
5 | " | 71 | 1
Water. | 4/12° | 17 | 1
1 | " | 23 | 1
2 | " | 35 | 1
3 | " | 71 | 1
Water. | 3/12° | 23 | 1
1 | " | 35 | 1
2 | " | 71 | 1
------------------------------------------------

According to Mr Crum, the range of strength within which cotton is "safe" is very limited. A solution at 1° of Twaddell's scale (sp. gr. 1·005) is not more than safe, while one at 1/2° is scarcely sufficiently strong for the first operation on stout cloth, unless it is packed more loosely than usual.

_Gay-Lussac's Indigo Process._ One part of the best indigo is dissolved in 9 parts of strong sulphuric acid by the aid of a gentle heat; this solution is then mixed with distilled water, in such proportion that 1 volume of chlorine gas shall exactly decolour 10 volumes of this solution. Each measure so decoloured is called a degree, and each degree is divided into fifths. 5 gr. of the best chloride of lime, dissolved in 500 gr. measures of water, possess the above power, and indicate 10° or proof; or in other words, will decolour 10 times its volume of the indigo solution.

_Obs._ This method of chlorometry is objectionable, and liable to error, from the indigo solution altering by keeping. When, however, the proper precautions are used, it may be safely trusted for weak bleaching liquors.

_Arsenious Acid Process._ This depends on the conversion, by oxidation, of arsenious acid into arsenic acid, in the presence of chlorine and water.

To prepare the test-liquor, pure arsenious acid, 100 gr., are dissolved in about 4 fl. oz. of pure hydrochloric acid (free from sulphurous acid), and the solution diluted with water until, on being poured into a graduated 10,000 grains-measure-glass, it occupies the volume of 7000 grains measure marked on the scale. Each 1000 grains measure of this liquid now contains 14·29 gr. of arsenious acid; corresponding to 10 gr. of chlorine, or 1/10th gr. of chlorine for every division or degree of the scale of the chlorometer.

100 gr. of the chloride of lime to be examined are next dissolved in water as before, and poured into a tube graduated up to 2000 grains measure. The whole is now well shaken, in order to obtain a uniformly turbid solution, and half of it (1000-grains-measure) transferred to a graduated chlorometer, which is, therefore, thus filled up to 0°, or the zero of the scale, and contains exactly 50 gr. of the chloride of lime under examination; whilst each degree or division of the scale contains only 1/2 gr.

1000 grains measure of the arsenious acid test-liquor are now poured into a glass beaker, and a few drops of solution of sulphate of indigo added in order to impart a faint but distinct blue colour to it; the glass is then shaken so as to give a circular movement to the liquid, and whilst it is whirling round, the chloride-of-lime solution from the chlorometer is gradually and cautiously added, until the blue tinge given to the arsenious acid test-liquor is destroyed; care being taken to stir the mixture well during the whole process, and to stop as soon as the decolorisation is completed.

Let us suppose now that, in order to destroy the blue colour of the 1000 grains measure of the arsenious acid test-liquor, 90 divisions or degrees of the chloride-of-lime solution have been employed. These 90 divisions, therefore, contained the 10 gr. of chlorine required to destroy the colour of the test-solution; and since each division represents 1/2 gr. of chloride of lime, 45 gr. of chloride of lime (10 gr. of chlorine) were present in the 90 divisions so employed, from which the per-centage strength may be ascertained. For--

45 : 10 : : 100 : 22·22

The chloride of lime examined, therefore, contained 22-1/4 per cent, (nearly) of chlorine.

_Obs._ This method is extremely simple and trustworthy when properly employed; but to ensure accuracy, certain precautions must be adopted. Instead of pouring the test-liquor into the solution of the sample (as in alkalimetry), the solution of the sample must be poured into the test-liquor.

Vogel found that in a normal solution of arsenious acid that had been prepared for using in the above process, half the quantity of the arsenious acid became oxidised to arsenic acid in the course of about a year. He therefore recommends that the standard solution, if kept for some time, should be tested by a magnesium salt. The formation of a precipitate would show the solution had undergone such a change, as to render it unfit for volumetric estimations.

_Penot's Process._ This is a modification of the previous process. For the arsenious acid solution arsenite of soda is substituted, and for the indigo solution a colourless iodised paper, which is turned blue by the smallest quantity of free acid. The paper is prepared in the following manner:--1 gram of iodine, 7 grams of carbonate of soda, 3 grams of starch, and a quarter of a litre of water are mixed. When the solution becomes colourless it is diluted to half a litre; in this fluid, white paper is soaked. The arsenical fluid is prepared by dissolving 4·44 grams of arsenious acid, and 13 grams of crystallised carbonate of soda in 1 litre of water. This solution is added by means of a burette to the solution of chloride of lime intended to be tested (10 grams of the sample to 1 litre) the completion of the reaction being known by the paper remaining uncoloured.

Lunge says that the same piece of moist iodine test paper may be made use of repeatedly, since the spots produced by testing usually disappear after about twenty-four hours if exposed to the air. The paper must, however, be kept away from dust.

_Wagner's Process._ This method is based upon the fact that a solution of chloride of lime separates the iodine from a weak (1 to 10) and slightly acidified iodide-of-potassium solution, the iodine being quantitatively estimated by means of hyposulphite of soda:--

Iodine 21, } {Iodine of sodium, 2NaI,
Hyposulphite of } yield {Tetrathionate of sodium, Na_{2}S_{4}O_{6},
soda, 2Na_{1}SO_{3} } {Water, 5H_{2}O.
+5H_{2}O,

The test is performed as follows:--100 c. c. =1 gram of bleaching-powder solution, obtained by dissolving 10 grams of chloride of lime in 1 litre of water, are mixed with 25 c. c. of solution of iodide of potassium acidified with dilute hydrochloric acid. The resulting clear, deep brown-coloured solution is treated with hyposulphite of soda solution until quite colourless. The hyposulphite of soda solution is composed of 24·8 grams of that salt to 1 litre of water; 1 c. c. of this solution neutralises 0·0127 grams of iodine, and 0·00355 grams of chlorine.

_Otto's Process._ This method is based upon the following data. Two molecular weights of protosulphate of iron when brought into contact with chlorine, in presence of water, and free sulphuric acid, give one molecule of persulphate of iron, and two molecules of hydrochloric acid, the process consuming one molecule of chlorine. Two molecules of crystallised sulphate of iron = 556, correspond to 71·0 of chlorine, or in other terms 0·7839 grams of the crystallised sulphate correspond to 0·1 gram of chlorine.

_Bunsen's Process._ This consists in adding iodide of potassium to the bleaching-powder liquor, acidulating the mixture with hydrochloric acid, and running the solution of arsenite of soda into it till only a yellow tint shows itself. A little starch paste is now added, and the arsenite solution cautiously introduced drop by drop, till the blue colour just disappears. The solutions must all be standardised. To preserve the starch paste Mohr advises the addition to it of a little chloride of zinc.

_Mr Davies_ uses glycerin as a solvent for the arsenious acid. He prepares a standard solution as follows:--13·95 grains of arsenious acid in 40 c. c. of glycerin and fitted up to 1 litre. Every c. c. corresponds to 0·1 grain of chlorine. Indigo sulphate solution is used as an indicator, and the bleaching liquor is run into the glycerin solution until the blue colour of the latter is changed to a brownish yellow.

_Dr Ure's_ as follows:--Liquor of ammonia, of a known strength, tinged with litmus, is added to a solution of a given weight of the chloride under examination, until the whole of the chlorine is neutralised, which is known by the colour being destroyed. From the quantity of ammonia consumed the strength of the sample is estimated.

The value of bleaching powder is estimated in England, America, and Germany by degrees corresponding to the per-centage of available chlorine contained in a sample of chloride of lime by weight; but in France the degrees denote the number of litres of chlorine gas at 0° c. and 760° Mm. Bar., which 1 kilo of bleaching powder can evolve. In the following table the chlorometrical degrees of France and England are contrasted:--

French. English.
63 20·02
65 20·65
70 22·24
75 23·83
80 25·42
85 27·01
90 28·60
100 31·80
105 33·36
110 34·95
115 36·54
120 38·13
125 39·72
126 40·04

The per-centage may be calculated by multiplying the French degrees by the coefficient 0·318.

=CHLOROCARBONIC ACID.= (COCl_{2}). _Syn._ PHOSGENE GAS, CARBONIC OXYDICHLORIDE. This compound may be produced by the direct combination of equal volumes of carbonic oxide and chlorine gases under the influence of sunlight (whence its name of "phosgene gas"), when the mixture gradually becomes colourless, and contracts to half its original volume. Chlorocarbonic acid has a peculiar pungent smell, and fumes strongly when exposed to moist air, the moisture of which it decomposes, producing at the same time hydrochloric and carbonic acids.

It is sometimes employed in chemical research for the removal of hydrogen from organic compounds, and the substitution of carbonic oxide, or its elements for the hydrogen.

=CHLOROPHYLL.= The green colouring matter contained in the leaves, stalks, unripe fruit, and juices of most plants.

=CHLORO'SIS.= _Syn._ GREEN SICKNESS. A disease which principally affects young unmarried females.

_Symp._ Languor, listlessness, fatigue after the least exercise, palpitation of the heart, flatulency, indigestion, acidity of stomach and bowels, constipation (generally), appetite for unnatural food, general debility, &c. As the disease advances, the skin at first pale, assumes a peculiar greenish tint, the respiration becomes affected, the feet and legs swell, and various organic affections of the viscera ensue. During the early stages of this disease the catamenia are usually pale and scanty, and return at irregular intervals, and as it progresses they disappear altogether.

_Treat._ This should be tonic and restorative. That recommended under ANÆMIA may be adopted with advantage. See also APPETITE, ATROPHY.

=Chlorosis, Electuary for--Female Electuary.= A greenish-black thick syrup, consisting of sugar, bayberries, carbonate of iron, iron filings, and water. (Buchner.)

=Chlorosis Powder--Female Powder=--consists of a mixture of anise, sugar, and 14 per cent. of iron filings. (Wittstein.)

=Chlorosis Powder--Female Powder=, according to Schott and Strauss, is a mixture of violet root, gum Arabic, and a tasteless green powder with 33 per cent. of steel filings. According to Hager, it is composed of 2 parts ferri pulvis, with 3 parts powdered sweet-flag root.

=Chlorosis Powder--Female Powders.= Steel filings, starch powder, and knot grass, of each 1 part, Florentine orris root, 4 parts.

=Chlorosis Powder--Female Powders.= A mixture of 1 part steel filings and 2 parts of a vegetable powder composed of gum Arabic, Florentine orris, knot grass, &c. (Egb. Hoyer.)

=Chlorosis Water= (Dr Ewich) contains in 10,000 parts 11 of sodium carbonate, 9 of sodium chloride, 1-1/2 sodium sulphate, 7 calcium carbonate, and 1·2 iron carbonate with an excess of carbonic acid. (Hager.)

=CHLOROUS ACID.= HClO_{2}. _Syn._ ACIDUM CHLORO'SUM, L. _Prep._ From chlorate of potassium, 4 parts; arsenious anhydride, 3 parts; nitric acid, 12 parts; (diluted with) water, 4 parts; heated together in a glass flask, furnished with a bent tube, and placed in a water bath. It must be collected in the same way as chlorine, or passed into water, when it forms a solution of chlorous acid.

_Prop., &c._ Chlorous acid is a greenish-yellow gas, non-condensable by a freezing mixture of salt and ice, but liquefiable by extreme cold. The aqueous solution undergoes gradual decomposition, yielding chloric acid and chlorine. Chlorous acid possesses powerful oxidising and bleaching properties; with the bases it forms salts called CHLORITES. These are all soluble in water, and bleach like the acid. They may be recognised by the evolution of chlorous acid gas when acted on by an acid. The use of the arsenious acid is to deoxidise the nitric acid employed in the process. Tartaric acid, or other deodorising agent, may be substituted for it.

=CHOC'OLATE.= _Syn._ CHOCOLA'TA, L.; CHOCOLLATI, Mexican; CHOCOLAT, Fr. A beverage or paste made from the roasted seeds of the _Theobroma Cacao_, or COCOA. Strictly speaking, the term "chocolate" is applicable to all genuine preparations of cocoa, but it is now generally used to distinguish those which contain sugar, and, commonly, flavouring substances. Of late years great attention has been paid to the manufacture of chocolate in England; our principal makers now import the finest descriptions of cocoa, and produce varieties of the manufactured article which are scarcely inferior to those of their French rivals. The different kinds of cocoa, and the processes of roasting, sweating, &c., are described under COCOA, to which article we refer the reader also for particulars respecting the chemistry of chocolate.

_Prep._ The cocoa nibs[245] are ground in a mill consisting of stone or metal rollers, which are usually heated either by charcoal fires or by steam, so as to soften or melt the natural fat.[246] The warm, smooth paste which passes from the mill is then placed in a mixing mill, and incorporated with refined sugar, and usually vanilla or other flavouring substance. The trituration is continued until the whole paste is converted into an entirely homogeneous mass, which is finally shaped, by means of suitable moulds, into various forms, as blocks, loaves, tablets, lozenges, &c.

[Footnote 245: The bruised, roasted seeds, freed from husk and membrane.]

[Footnote 246: Cacao- or cocoa-butter.]

_Obs._ Chocolate, prepared as above, without the addition of aromatics, is known in the trade as PLAIN CHOCOLATE. The Spaniards flavour it with vanilla, cloves, and cinnamon, and frequently scent it with musk and ambergris. With these additions it is termed SPANISH CHOCOLATE. In general, they add too large a quantity of the last four articles. The Parisians, on the contrary, use little flavouring, and that principally vanilla. They employ the best kinds of cocoa, and add a considerable quantity of refined sugar. So prepared, it is called FRENCH CHOCOLATE.

_Proportions._ 1. FRENCH CHOCOLATE:--The proportions used for the best description are said to be--2 beans of vanilla, and 1 lb. of the best refined sugar, to every 3 lbs. of the choicest cacao nuts.

2. SPANISH CHOCOLATE:--The following forms are said to be commonly adopted:--

_a._ Caracas cocoa, 11 lbs.; sugar (white), 3 lbs.; vanilla, 1 oz.; cinnamon (cassia), 1/4 oz.; cloves, 1/2 dr.

_b._ Caracas cocoa, 10 lbs.; sweet almonds, 1 lb.; sugar, 3 lbs.; vanilla, 1-1/4 oz.

_c._ Caracas cocoa, 8 lbs.; island cocoa, 2 lbs.; white sugar, 10 lbs.; aromatics, as above.

_d._ Island cocoa, 7 lbs.; farina, q. s. to absorb the oil. Inferior.

3. VANILLA CHOCOLATE. _Syn._ CHOCOLAT À LA VANILLE, Fr. A variety of French or Spanish chocolate highly flavoured with vanilla. The following proportions have been recommended:--

_a._ Caracas cocoa, 7 lbs.; Mexican vanilla, 1 oz.; cinnamon, 1/2 oz.; cloves, 3 in no.

_b._ Best chocolate paste, 21 lbs.; vanilla, 4 oz.; cinnamon, 2 oz.; cloves, 1/2 dr.; musk, 10 gr.

_Obs._ The vanilla used in making chocolate is reduced to powder by rubbing it with a little sugar before adding it to the paste.

_Pur., &c._ The chocolate commonly sold in England is prepared from the cake left after the expression of the oil, and this is frequently mixed with the roasted seeds of ground peas, and maize or potato flour, to which a sufficient quantity of inferior brown sugar, or treacle and mutton suet, is added to make it adhere together. Inferior sweet almonds are also employed in the same way.

Since the above paragraph was written there has been a vast improvement in English chocolates, though the cheaper sorts of certain makers are still much adulterated. Genuine chocolate should dissolve in the mouth without grittiness, and should leave a peculiar sensation of freshness; after boiling it with water the emulsion should not form a jelly when cold, for if it does starch or flour is present. The presence of animal fat may generally be detected by a cheesy or rancid flavour. See COCOA.

_Qual., &c._ Chocolate is nutritive and wholesome if taken in moderation, but is sometimes apt to disagree with weak stomachs, especially those that are easily affected by oily substances or vegetable food. When this is the case, by adopting the simple plan recommended under BUTTER, chocolate may generally be taken with impunity, even by the dyspeptic. The quantity of aromatics mixed with the richer varieties of chocolate improve the flavour, but render them more stimulant and prone to produce nervous symptoms and head complaints.

Chocolate is taken in the solid form, or made into a beverage; or, combined with sugar, is made into various articles of confectionery.

CHOCOLATE FOR THE TABLE is prepared by slicing or scraping very finely the required quantity into a jug, and adding to it a small quantity of boiling water. This is worked into a thin, smooth paste, and the jug immediately filled up with boiling milk-and-water. A froth is produced by the same means that eggs are beaten up. The operation of "milling," performed by rapidly twirling a notched cylinder of wood in the emulsion, raises the froth very quickly. Sugar may be put in with the scraped chocolate, or added afterwards at pleasure.

Chocolate should never be made for the table before it is wanted, because beating it again injures the flavour, destroys the froth, and separates the body of the chocolate, the oil of the nut being observed, after a few minutes' boiling, or even standing long by the fire, to rise to the top. This is one of the principal reasons why chocolate offends the stomach.

Preparations of chocolate, intended either as nutritious articles of food for convalescents, or as vehicles for medicine, are common among the pharmacop[oe]ial and magistral formulæ of the Continent. The following are a few examples:--

=Chocolate, Aromat'ic.= _Prep._ (Weiglebt.) Cocoa beans and sugar, of each 16 oz.; cinnamon, 1/2 oz.; cloves, 2 dr.; cardamoms and vanilla, of each 1 dr.

=Chocolate, Car'rageen.= See CHOCOLATE, WHITE (Nos. 1 and 2).

=Chocolate, Chalyb'eate.= _Syn._ FERRUGIN'EOUS CHOCOLATE; CHOCOLA'TA CHALYBEA'TA, C. MAR'TIS, L. _Prep._ 1. (Trousseau.) Spanish chocolate, 16 oz.; carbonate of iron, 1/2 oz.; mix, and divide into 1-oz. cakes. One at a time; in anæmia, amenorrh[oe]a, chlorosis, &c.

2. (Pierquin.) Iodide of iron, 2 dr.; chocolate, 16 oz. For 1/2-oz. cakes; as above, and in scrofulous and glandular affections.

=Chocolate, Guarana'.= _Syn._ PAULLIN'IA CHOCOLATE; CHOCOLA'TA PAULIN'IÆ, C. GUARAN'Æ, L. _Prep._ From guarana and white sugar, of each 1 oz., triturated together, and afterwards thoroughly mixed with good plain chocolate, 18 oz. Recommended as a restorative in debility, chlorosis, and other diseases of debility, especially those of a nervous character.

=Chocolate, Ice'land Moss.= _Syn._ CHOCOLA'TA CETRAR'IÆ ISLAND'ICÆ, C. LICHEN'IS, L. _Prep._ 1. (P. C.) Simple chocolate (P. C.), 32 parts; sugar, 29 parts; dried jelly of Iceland moss, 11 parts; mix.

2. (Cadet.) Chocolate, 4 lbs.; sugar, 2 lbs.; Iceland moss (freed from its bitter, and powdered), 1-1/2 lb.; tragacanth and cinnamon, of each 4 oz.; water, q. s.; to be beaten in a warm mortar, or ground with a muller on a warm slab to a paste. Recommended in pulmonary affections, general debility, weakness of stomach, &c. See COCOA (Iceland Moss).

=Chocolate, Pur'gative.= _Syn._ CHOCOLA'TA PUR'GANS, C. CATHAR'TICA, L. _Prep._ 1. Jalap, 1 oz.; chocolate, 9 oz.; mix, and divide into 1-dr. cakes.--_Dose_, 1 to 2 cakes, as a purge.

2. Jalap, 2 oz.; calomel and sugar, of each 1 oz.; triturate together, then add chocolate, 20 oz.; for 1-dr. cakes.

3. Scammony, 2 dr.; chocolate, 3 oz.; for 1 dozen cakes. The last two are given in worms.--_Dose_ (for an adult), 1 cake, taken fasting.

=Chocolate, Sal'ep.= _Syn._ SAL'OOP CHOCOLATE; CHOCOLA'TA CUM SAL'EP, L. _Prep._ 1. (P. C.) Chocolate, 16 oz.; powdered salep, 1/2 oz.

2. (Cadet.) Cacao paste and sugar, of each 1 lb.; powdered salep, 1 oz. Arrowroot chocolate and tapioca chocolate are made in the same manner. (See _below_.)

=Chocolate, Sim'ple.= _Syn._ HYGIEN'IC C., HOM[OE]OPATH'IC C.; CHOCOLA'TA, C. SIM'PLEX, C. SALU'TIS, L.; CHOCOLAT DE SANTÉ, Fr. _Prep._ (P. C.) Caracas and Maragnan cocoa, of each 96 lbs.; sugar, 160 lbs.; cinnamon, 1 oz. (to 2 oz.); triturated together in the usual manner, and formed into cakes or powder.

=Chocolate, Vanil'la.= _Syn._ CHOCOLA'TA CUM VANIL'LA, L. _Prep._ 1. (P. C.) Chocolate (plain,--P. C.), 16 oz.; vanilla, 1/2 dr.

2. (Cotterau.) Cocoa paste, 6 lbs.; sugar, 10 lbs.; vanilla, 11 dr.

See forms previously given.

=Chocolate, Ver'mifuge.= _Syn._ CHOCOLA'TA VERMIFU'GA, L. See CHOCOLATE, PURGATIVE (Nos. 2 and 3, _above_).

=Chocolate, White.= _Syn._ WHITE COCOA, CAR'RAGEEN C.; CHOCOLA'TA CUM CHON'DRO, PAS'TA CACA'O CUM CHON'DRO, P. C. C. LICHEN'E CARRAGHEN'O, L. _Prep._ 1. As Iceland moss chocolate, but employing carrageen moss.

2. (Ph. Dan.) Roasted and decorticated cocoa seeds (reduced to a subtile mass in a warm iron mortar) and powdered white sugar, of each 2 lbs.; powdered carrageen (debitterised), 3 oz.

3. (Cottereau.) Sugar, 6 lbs.; rice flour, 1-3/4 lb.; potato starch and butter of cocoa, of each 1/2 lb.; gum Arabic 1/4 lb. (dissolved); tincture of vanilla, 1/2 fl. oz.; boiling water, q. s.; triturate to a stiff paste. The above are highly nutritious, and are recommended as articles of diet for convalescents and debilitated persons.

=CHOKE-DAMP.= _Syn._ AFT'ER-DAMP. The term applied by miners to carbonic anhydride (carbonic acid) and other irrespirable gases and vapours evolved in mines. See CARBONIC ACID, FIRE DAMP, VENTILATION, &c.

=CHOKING.= Threatened choking may occur either in the gullet or swallow--or in the windpipe. If in the gullet press down the tongue with the handle of a spoon, and pass the fingers down without any hesitation, when the substance may generally be dislodged or pulled up. When it is small, and has got out of reach, it may mostly be removed by filling the mouth with liquid and swallowing it at a gulp, or by swallowing a large piece of bread. Foreign bodies thus swallowed generally pass harmlessly through the bowels.

If the choking occur in the windpipe or trachea, it is usually dislodged by the paroxysm of coughing which accompanies the act. Should it fail to be so, and a sense of suffocation ensues, accompanied with blueness of countenance and difficulty of breathing, place the patient, and follow the directions given in the article "SUSPENDED ANIMATION," while a medical man is immediately sent for.

_Treatment for Horses or Cattle._--Remove any foreign body by hand, as directed above, or have recourse to the probang. It may perhaps be necessary to call in a veterinary surgeon, in case the above methods fail, to extract the obstruction by cutting into the gullet.

=CHOLAGOGUES.= Medicines which promote a flow of bile.

=CHOLALIC ACID.= C_{24}H_{40}O_{5}. _Syn._ CHOL'IC ACID. A non-nitrogenous acid existing in bile. It is best prepared by boiling the resinous mass precipitated by ether from an alcoholic solution of ox bile with a dilute solution of potassa, for 24 to 36 hours, till the amorphous potassa salt that has separated begins to crystallise. The dark-coloured soft mass is then removed from the alkaline liquid, dissolved in water, and hydrochloric acid added. A little ether will cause the deposition of the CHOLALIC ACID from this solution in crystals. With sulphuric acid and solution of sugar it strikes a purple-violet colour; this constitutes Pettenkofer's test for bile.

=CHOLE'IC ACID.= _Syn._ TAURO-CHOLALIC ACID. A peculiar conjugated compound of cholalic acid with a substance called taurine, which contains both nitrogen and sulphur. In combination with soda, choleic acid constitutes a principal ingredient in bile.

=CHOL'ERA.= This word, which, from its derivation, can be only applied correctly to a bilious affection of the stomach and bowels, has been of late years very loosely extended to a malignant disease, the most marked characteristic of which is a total suspension of the functions of the biliary organs.

=Cholera, En''glish.= _Syn._ COM'MON CHOLERA, BIL'IOUS C.; CHOL'ERA MOR'BUS, L. A disease characterised by bilious vomiting and purging, accompanied by more or less pain and debility. Diarrh[oe]a is the most common precursor of the disease, and ought to be attended to without delay, particularly if the weather be warm. Cholera most frequently occurs towards the end of the summer and early in the autumn, when the increased heat of the sun stimulates the liver to an inordinate secretion of bile, by which the whole system becomes overloaded with it. Among secondary and accidental causes are sudden changes of temperature, checked perspiration, and the use of indigestible food, and food and beverages in a state of incipient decomposition. It is usually accompanied by fever, thirst, and severe colic, and sometimes by cold sweats, extreme debility, feeble pulse, &c., under which the patient sinks in 24 hours.

_Treat._ In most cases this complaint is not dangerous, and yields to proper treatment in a few days. As soon after the commencement of the attack as possible, some mild aperient should be administered. Opiates may be employed, both topically and by the mouth. Jeremie's solution is stated to be very efficacious in the diarrh[oe]a which so generally precedes cholera. A teaspoonful or two of laudanum, rubbed over the region of the stomach and bowels, is a simple application which will generally allay the pain. 10 to 20 drops of laudanum, mixed with a table-spoonful of good brandy, or a few grains of cayenne pepper, may also be taken every hour if the pain is severe. Should the stomach reject the medicine, or the vomiting be apparently increased by drinking warm diluents, a few spoonfuls of ice-cold water, or of a mixture of lemon-juice and water, may be taken instead, until the sickness abates. Dr Copeland recommends spirit of turpentine in violent attacks, both internally and as an external application in the form of warm epithems. When the violence of the symptoms has abated, tonics and bitters (as calumba, gentian, orange-peel, &c.) may be advantageously had recourse to. Calumba, in the form of a weak infusion, conjoined, if necessary, with aromatics, is, perhaps, the most valuable agent we possess for the after-treatment of the disease. See DIARRH[OE]A.

=Cholera, Malig'nant.= _Syn._ ASIAT'IC CHOLERA, EPIDEM'IC C, BLUE C, PESTILEN'TIAL C, SPASMOD'IC C.; CHOL'ERA ASIAT'ICA, C. ASPHYX'IA, C. MALIG'NA, L. This fearful disease first became known in this country in the autumn of 1831. The attack usually begins with sickness and purging; this discharge, however, is not bilious, as in ordinary cholera, but a thin, colourless fluid, like rice-water; at the same time there is great prostration of strength, and cold, clammy sweats. In a short time dreadful cramps assail the extremities and afterwards the abdomen; the body becomes bent, the limbs twisted, the countenance cadaverous, the pulse almost imperceptible, and the eyes sunken; the patient sinks into a state of apathy, and unless a favorable change speedily takes place, soon expires from exhaustion. When there is a reaction the pulse gradually returns, the natural warmth of the body is restored, and the spasms and difficulty of breathing give way. Frequently, however, the reaction is accompanied by fever closely resembling typhus, and which often terminates fatally in from four to eight days. The symptoms of epidemic cholera are not always of this terrible character.

_Treat._ In giving a few of the many remedies that have been recommended for this terrible disease, we may preface the list, by urgently counselling the sufferer to lose no time in sending for a medical man, in case of being attacked by this appalling malady.

1. (American Remedy.) Equal parts of maple sugar and powdered fresh-burnt charcoal, made into a stiff paste with lard, and divided into pieces the size of a filbert.--_Dose._ One, occasionally, swallowed whole.

2. (Austrian Specific.) The proportions of the ingredients in the following formulæ are founded on Mr Herapath's analysis of this celebrated preparation, and are given in the nearest available whole numbers:--

_a._ Sulphuric acid (sp. gr. 1·845), 20 gr.; nitric acid (sp. gr. 1·500), 12 gr,; sugar and gum, of each 15 gr.; distilled or pure soft water, q. s. to make the whole weigh exactly 1 oz.

_b._ Sulphuric acid, 3 dr.; nitric acid, 2 dr.; simple syrup, 6 dr.; water, q. s. to make the whole weigh exactly 10 oz. A single drop of essential oil of lemon may be added.

_Doses, &c._ One table-spoonful is ordered to be taken in water, on the first appearance of premonitory symptoms, followed by the free use of very cold water. In half an hour a second dose is to be taken. This (as asserted) is generally sufficient to arrest the progress of the disease. A table-spoonful is then to be added to a pint of cold water, and drunk _ad libitum_. In more obstinate cases it is said that 4 or 5 doses are generally required to effect a cure. When collapse sets in, double doses are ordered to be given, and to be repeated after every attack of vomiting until the sickness and cramp abate. After the vomiting abates the doses are still to be repeated until 5 or 6 doses are retained by the stomach. Should quiet sleep or drowsiness come on, it is not to be interfered with. The free use of cold water or soured water is to be allowed until perspiration sets in and the warmth of the body returns. According to the report, the use of warm liquors, wines, spirits, &c., must be carefully avoided as so much poison.

_Obs._ A bottle of the above remedy was handed to the late Mr Wm. Herapath by the superintendent of the Birmingham police, who had received it from the head of the Austrian police, as being in general use in Austria, under the sanction of the medical department of the government, and being found to act almost as a specific in cholera. In 1831-2 it was first tried on some criminals with perfect success, and soon afterwards with similar results on thousands of the general public. In 1849 the Austrian government ordered its use in the public establishments of the empire, since which not a single case of failure had occurred in which it had been fairly tried.

3. (Mr Buxton's Remedy.) From dilute sulphuric acid (spirit of vitriol), 25 drops; water, 1 fl. oz. For a draught; as the last.

4. (College of Physicians and Board of Health; for Premonitory Diarrh[oe]a.) Chalk mixture, 1 oz.; aromatic confection, 10 to 15 gr.; tincture of opium, 5 to 15 drops; to be repeated every 3 or 4 hours, or oftener, if required, until the looseness is arrested.

5. (Dr Graves's Astringent Pills.) Acetate of lead, 20 gr.; opium, 1 gr.; conserve of roses, q. s.; for 12 pills.--_Dose._ One every 1/2 hour or hour, at first; then one every two hours.

6. (Hom[oe]opathic Preventive.) Camphor, 1 dr.; rectified spirit, 6 dr.; dissolve, and preserve it in a well-corked bottle.--_Dose._ 2 drops on a lump of sugar, sucked as a lozenge two or three times a day.

7. (Hom[oe]opathic Remedy.) As the last, repeating the dose every 10 or 15 minutes, followed by draughts of ice-cold water, until the symptoms abate.

8. (Mr Hope's Remedy.) (_a._) Red nitrous acid, 2 dr.; peppermint water or camphor julep, 1 oz.; tincture of opium, 40 drops; mix.--_Dose._ One to two teaspoonfuls in a cupful of thin gruel every 3 or 4 hours.

_b._ Spirit of wine, 1 oz.; spirit lavender, 1/4 oz.; oil of orizinanum, 1/4 oz.; compound tincture benzoin, 1/2 oz.; spirits camphor, 1/4 oz.--_Dose_, 20 drops on moist sugar. To be rubbed outwardly also.

9. (Liverpool Preventive Powders.) Bicarbonate of soda, 20 gr.; ginger, 10 gr.; for a dose. One to be taken in a glass of water after breakfast and supper daily.

These powders are said to have been used with good effect among the workmen in the mining and manufacturing districts during a former visitation of cholera.

10. (Police Remedy; Mr B. Child's Remedy.) Rectified sulphuric ether and tincture of opium, of each 30 drops; for a dose for an adult; especially during the earlier stages.

11. (Mr Ross's Astringent Pills.) Each pill contains 1 gr. of nitrate of silver, made up with crum of bread, q. s.--_Dose._ One pill, to be repeated after the interval of half an hour or an hour, should the symptoms continue unabated.

12. (Russian Remedy.) Sumbul, in the form of tincture, concentrated essence, in decoction, in cold infusion, and in powder in the form of pill.--_Doses._ Tincture, from 20 to 60 drops; essence, from 5 to 10 or 20 drops; in a little camphor julep or plain water. The physicians of Moscow and St. Petersburg ascribe to the virtues of this drug the saving of thousands of lives during the last epidemic. See SUMBUL.

13. (Dr Stevens' Saline Powders.) Bicarbonate of soda, 1/2 dr.; common salt, 20 gr.; chlorate of potassa, 7 gr.; for a dose.

14. (Sir M. Tierney's Remedy.) Cajeput oil, in doses of 20 to 30 drops, every two or three hours. The oil excites the nervous system and equalises the circulation. The late Sir M. Tierney and others prescribed it frequently, it is said, with considerable success.

15. (Common Remedies of the Shops.) These generally consist of chalk mixture, with a little laudanum, and some aromatic or carminative, as cassia, cinnamon, cardamoms, nutmeg, or peppermint. In a few, some astringent, as tincture of catechu, or extract of logwood, is added.

16. (Dr Beaven's Preventative and Remedy.) _The Preventative._--Sulphite of magnesia, 2 dr.; sulphurous acid, 2 oz.; water, 2 oz.; tincture of capsicum, 1/2 oz. Mix and dissolve, a teaspoonful night and morning.

_The Remedy._--Sulphite of magnesia, 2 dr., sulphurous acid, 2 oz.; water, 2 oz.; tincture of capsicum, 1/2 oz.; sulphate of morphia, 2 gr. Mix and dissolve; a teaspoonful every half hour until relieved.

=CHOLERA MEDICINE.= The expressed juice of dandelion and milfoil mixed with brandy spirit. (Dr Horn).

=CHOLES'TERIN.= C_{2}_{6}CH_{4}_{4}O.H_{2}O. This substance is found in the bile, brain, nerves, blood, &c., and forms the principal ingredient of biliary calculi (gall-stones).

_Note._--The remedies containing astringents are the most efficacious.

=CHOL'IC ACID.= _Syn._ GLYCO-CHOLAL'IC ACID. A peculiar acid, existing as cholate of sodium, and associated with choleic acid in the bile. It is a conjugate compound of cholalic acid with a nitrogenised substance called glycocin.

=CHON'DRIN.= Gelatin obtained from cartilage. It differs from ordinary gelatin in being precipitable by acetic acid, alum, and acetate of lead.

=CHOREA.= [_Syn._ _St. Vitus's Dance._] A spasmodic disease affecting children and young persons, especially girls, between eight and sixteen years of age. It is caused by a debilitated condition of the nervous system, as well as by brain disease, scrofula, imprudent diet and worms.

The treatment recommended is the regulation of the bowels by mild purgatives. If the disease can be traced to worms, these should be removed by the proper remedies. If worms are not the cause, recourse should be had to the cold, or shower-bath. The hot hip-bath will be found serviceable in some cases. Where there is paleness of the skin any of the iron preparations will prove of great use, the bowels being kept regular. The best preparations of iron are either the tincture of the perchloride, or nitrate, or the citrate of iron and quinine. Some practitioners recommend arsenic--five drops of the solution (for an adult) twice a day after meals; others valerianate of zinc.

_Treatment for the Horse and other Animals._--Similar to the above.

=CHRISTOFIA= is a stomachic brandy or wine made of 1500 parts white wine, 20 parts cinnamon, 10 parts cloves, 60 parts bitter almonds, digested several days; 300 parts of sugar and 500 of spirit are then added, and the whole filtered. (Hager).

=CHROMACOME.= For dyeing the hair black. This is said to be prepared from harmless vegetable materials, but really consists of pyrogallic acid and nitrate of silver.

=Chromacome.= This is a French preparation which "contains nothing injurious to health." This hair dye consists of two fluids. The first, "Le chrômacome, teinture supérieure de William W. A. T., No. 1, Bonn," weighing about 45 grammes, is tincture of galls. The other, No. 2, is a solution of acetate of iron with a little nitrate of silver. When grey hair is moistened first with No. 1, then with No. 2, it becomes blackish-brown or black.

=CHRO'MATE.= _Syn._ CHRO'MAS, L. A salt in which the hydrogen of (hypothetical) chromic acid, HCrO_{4}, is replaced by a metal or other basic radical.

=Chromates=:--

_Prep._ The insoluble chromates, as those of barium, zinc, lead, mercury, silver, &c., may be made by mixing a soluble salt of those bases with neutral chromate of potassium. The first three are yellow; the fourth brick-red; and the fifth reddish-brown, or ruby red when crystallised. The soluble chromates may all be made by direct solution of the base in the acid, or by double decomposition. The chromates of commerce are prepared from either chrome ore or chromate of potassium.

_Prop., Uses &c._ The chromates are characterised by their yellow or red colour, the latter predominating when the acid is in excess; and except those with the alkaline bases, they are, for the most part, insoluble in water. Both the chromate and the bichromate of potassium are extensively used in dyeing and calico-printing. The former is employed in conjunction with sulphuric acid in the laboratory as an oxidising agent and in the manufactory for bleaching sperm oil. The bichromate of ammonium and potassium are used in photography.

They are readily recognised by the following tests:--