Chapter II: BLEACHING of =Linen=:--Linen may be bleached in a similar way to (16)

On boiling a chromate in hydrochloric acid mixed with alcohol, chromic acid is first set free, and then decomposed, forming a green solution of chloride of chromium. Sulphuretted hydrogen and sulphurous acid effect similar changes. With acetate of lead the chromates give a yellow precipitate; with nitrate of silver, a reddish-brown; with nitrate of mercury, a red one.

=CHROME ALUM.= See ALUMS.

=CHROME GREEN.= See GREEN PIGMENTS.

=CHROME IRON.= See IRON.

=CHROME RED.= See RED PIGMENTS.

=CHROME YELLOW.= See LEAD, CHROMATE OF.

=CHROMIC ACID.= See CHROMIC ANHYDRIDE.

=CHRO'MIUM.= Cr. A metal discovered in native chromate of lead by Vauquelin in 1797. It is found in the state of oxide, combined with oxide of iron, in some abundance, in the Shetland Islands, and elsewhere; as chromate of lead it constitutes a very beautiful material.

Prepared in an impure condition as a white, very infusible, hard metal, by igniting the oxide with charcoal, at a white heat, in a lime crucible.

=Chromous Chloride.= CrCl_{2}. _Syn._ PROTOCHLORIDE. _Prep._ Ignite the chromic chloride in a current of dry hydrogen. A white, foliated mass, soluble in water (evolving much heat), and yielding a blue solution, which absorbs atmospheric oxygen with astonishing rapidity, acquiring a deep-green colour, and passing into the state of oxychloride of chromium. It is the most powerful reducing or deoxidising agent known.

=Chromic Chloride.= Cr_{2}Cl_{6}. _Syn._ SESQUICHLORIDE. _Prep._ Pass dry chlorine over a mixture of sesquioxide of chromium and charcoal, heated to redness, in a porcelain tube. The chloride collects as a sublimate, of a peach or violet colour, in the cool part of the tube.

Dissolve chromic oxide in hydrochloric acid and evaporate to dryness; the residue is chromic chloride. It forms a dark green mass, containing water, which is evolved by igniting at a temperature of 400°, turning a purplish red.

=Chromium Oxides=:--

=Chromous Oxide.= CrO. _Syn._ PROTOXIDE OF CHROMIUM. This oxide has not yet been obtained in a satisfactory manner, but the hydrate is prepared by the addition of potassium hydrate solution to a solution of chromous chloride or sulphate. A brownish-red powder, speedily passing to a deep foxy-red, with disengagement of hydrogen, and forming pale blue-coloured salts with the acids, which absorb oxygen with avidity, whilst the metal passes into a higher state of oxidation.

=Chromic Oxide.= CrO_{3}. _Syn._ SESQUIOXIDE. Prepared by igniting potassium bichromate at a red heat and well washing the residue, and as hydrate by cautiously adding equal parts of hydrochloric acid and alcohol or sugar to a boiling solution of chromate of potassa in water, in small portions at a time, until the red tint disappears, and the liquid assumes a green colour; pure ammonia, in excess, is next added, and the precipitate which subsides is collected and washed with water.

_Prop., &c._ The anhydrous oxide is a rich crystalline, green powder, insoluble in both water and acids; fused with borax and glass, it imparts a beautiful green colour.

The hydrate is soluble in the acids and in alkaline lyes; with the first it forms salts which have a green or purple colour. These compounds may be made by direct solution of the hydrate in the dilute acids. Chromic sulphate combines with the sulphates of potassium and ammonium, giving rise to salts (CHROME ALUMS) which crystallise in magnificent octahedrons of a deep claret colour. The finest crystals are obtained by spontaneous evaporation.

These salts of chromium are the most important, the chromous salts being seldom met with, and are best recognised by the following reactions:--Caustic alkalies precipitate the hydrate, easily soluble in excess of the precipitant. Ammonia the same, but the precipitate is nearly insoluble. The carbonates of potassium, sodium, and ammonium throw down a green precipitate of carbonate and hydrate, slightly soluble in a large excess. Sulphuretted hydrogen causes no change.--Sulphydrate of ammonium precipitates the hydrate of a bluish-green colour.

=Chromic Anhydride.= CrO_{3}. _Syn._ CHROMIC ACID, ANHYDROUS CHROMIC ACID, CHROMIC TRIOXIDE. _Prep._ By conducting gaseous fluoride of chromium into a silver or platinum vessel, the sides of which are just moistened with water, and the aperture covered with a piece of moist paper, the anhydride will be deposited under the form of red, acicular crystals, which will nearly fill the vessel. When the process is skilfully conducted, the product is of exquisite beauty and chemically pure. The fluoride referred to above is obtained from fluor spar, 3 parts; chromate of lead, 4 parts; fuming (or the strongest) sulphuric acid, 5 parts; mixed cautiously in a silver or leaden retort. A red-coloured gas is evolved, which acts rapidly on glass, forming fluosilicic acid gas, and upon water forming hydrofluoric acid and chromic anhydride. The moisture of the atmosphere is sufficient to effect the decomposition last referred to; the former substance escaping as gas, and the latter being deposited in small crystals.

It is also prepared nearly pure by adding a cold saturated solution of potassium bichromate to once and a half its bulk of pure strong sulphuric acid. As the liquor cools, the anhydrous chromic acid is deposited under the form of brilliant crimson-red prisms; the mother-liquor is then poured off, and the crystals, placed between two tiles of glass or porcelain, are submitted to strong pressure for some time, under a bell-glass or jar, when the anhydride will be found sufficiently dry. It may be deprived of a little adhering moisture by placing it over sulphuric acid for a short time _in vacuo_.

Commercially, it is prepared by one of the two following processes:--

To a saturated solution of chromate of potassium, 100 parts, add oil of vitriol (sp. gr. 1·845), 49 parts; and let the whole cool. This is the common process. The product contains sulphate of potassium, but this does not much interfere with its value as a bleaching agent.

From chromate of barium, decomposed by concentrated nitric acid. The anhydrous chromic acid is separated from the nitrate of barium by decantation, or, which is still better, by filtration through glass or asbestos. It is then evaporated to dryness, when the nitric acid is volatilised, and pure chromic anhydride left behind. The volatilised nitric acid may be condensed, and again used for the same purpose. The only precautions necessary to ensure the purity of the anhydrous chromic acid prepared by this plan are--to use a sufficient quantity of nitric acid and to take care that the nitric acid is sufficiently concentrated and pure.

_Prop., &c._ Forms ruby-red anhydrous prisms, very soluble in water, with formation of true chromic acid, and extensively manufactured for the purpose of oxidising and bleaching substances.

=CHROME IRON-STONE.= _Syn._ CHROME IRON-ORE. FeO.Cr_{2}O_{3}. This, which is the principal ore of chromium, corresponds in composition to brown oxide of chromium and to the magnetic oxide of iron; part of the iron, however, is generally displaced by the isomorphous metal magnesium, and part of the chromium by aluminium.

Chrome iron-stone is often met with in the form of octohedral crystals. Acids fail to dissolve it, and it cannot be fused in the furnace, but when heated it absorbs oxygen from the air. This oxidation may be effected very readily if the chrome ore reduced to very fine powder be mixed with a carbonate of one of the metals of the alkalies or alkaline earths, a chromate of the base being formed.

=CHRYSENE.= C_{18}H_{12}. A hydrocarbon found by Laurent in crude anthracene. It occurs in bright yellow, glistening scales. It may be obtained colourless by heating the yellow crystals with hydriodic acid and amorphous phosphorus to 240°. It cannot be sublimed without decomposition. Chrysene is very slightly soluble in cold alcohol, ether, benzene, and glacial acetic acid. In carbon disulphide it dissolves somewhat more readily. Its melting point is from 248° to 250°, and it boils at a temperature beyond that which can be registered by the mercurial thermometer.

=CHRYSOPHANIC ACID.= See RHEIN.

=CHYLE.= _Syn._ LYMPH. This is the name given to the nutritious milky fluid generated during digestion, and absorbed from the intestines by a set of vessels called the _lacteals_, which carry it to the thoracic duct, whence it is immediately conveyed into the circulation.

=CHYME.= The pulpy mass formed by the food in its first great change, in the process of digestion.

=CIDER.= _Syn._ CYDER; POMACEUM, L. Cider is the fermented juice of the apple, and is a very ancient beverage. Pliny calls cider and perry the "wine of apples and pears."

The attention of the cider farmer should be first directed to the culture of the apple tree. The situation most appropriate for an orchard is one on rising ground, rather dry than moist, and unexposed to sea air or high winds. The soil should be strong, but not too heavy, and should be rich in the alkaline and earthy bases, especially the phosphates. The selection of the proper varieties of the apple for grafting is also a point on which particular care should be taken. It is found that the juices of different kinds of apples vary in the quantity of saccharine matter which they contain, as well as in other particulars that influence the quality and flavour of the cider prepared from them. As a general rule, those varieties should be chosen that yield a juice rich in sugar, and contain no undue amount of acid, and which, after the period of active fermentation is past, furnishes a liquor which clarifies itself and keeps well. This quality of the juice may generally be determined from its specific gravity. The heaviest and clearest is the best, other points being equal. The specific gravity of the juice of the different varieties of apple varies from 1·060 to 1·100.

Cider apples are classed under three heads--bitter, sweet, and sour. The first are the best; their juice has the greatest specific gravity, is the richest in sugar, ferments the most freely, clarifies spontaneously the quickest, and keeps the best after fermentation. They contain a minute quantity of extractive matter which is not present in other apples. The juice of sweet apples ferments tumultuously, clears with difficulty, and the resulting cider does not keep so well as that produced from the first variety. The juice of sour apples contains less sugar and more acid than the other two, and consequently not only produces the weakest, but the worst cider; it, however, "fines" well, although it "stores" badly. Sour and "rough-tasted" apples are usually preferred by farmers for making cider. This preference, which is very decided in the West of England, may be readily accounted for. The sour and rough-tasted apples contain less sugar and more malic acid than some of the other varieties, and the presence of this acid impedes the conversion of the alcohol of the cider into vinegar; a change which their rude mode of operating renders otherwise inevitable. But cider made with such apples never equals in quality that prepared at a low temperature, from fruit abounding in sugar, provided equal skill is exercised in the manufacture as in the process of converting malt-worts into beer.

The process of making cider varies in different places, but in every case essentially consists of the collection of the fruit, the expression and fermentation of the juice, and the storing and management of the fermented liquor.

The collection of the fruit should not be commenced before it has become sufficiently mature, and should be performed with greater care than is commonly bestowed upon it. The apples, after being gathered, are usually left for 14 or 15 days in a barn or loft to mellow, during which time a considerable portion of the mucilage is decomposed, and alcohol and carbonic acid developed. If this "ripening" is allowed to go too far, loss arises, notwithstanding the vulgar prejudice in its favour. The spoiled apples are then separated from the sound ones, as they not only impart a bad flavour to the cider, but impede its spontaneous clarification.

The expression of the juice is the next step in the process of cider-making. The apples are crushed or ground in mills consisting of two fluted cylinders of hard wood or cast-iron, working against each other. The common practice is next to sprinkle the pulp with 1/6th to 1/4th of its weight of spring or river water, and then to allow it to remain in tubs or wooden cisterns for 12 or 14 hours, during which time incipient fermentation commences, and the breaking up of the cells of the membrane takes place, by which the subsequent separation of the juice is facilitated. This plan, though general among cider manufacturers, is prejudicial to the quality of the future liquor; as not only is a portion of the newly formed alcohol lost, but the skins and pips often impart to it a disagreeable flavour. By employing more efficient crushing machinery this system of vatting is rendered quite unnecessary. A machine furnished with a revolving circular rasp, similar to that used in making potato starch, is admirably adapted to this purpose.

The pulp of the crushed or ground apples is now placed on a kind of wicker frame, or in hair-cloth or coarse canvas bags, and after being allowed to drain into suitable tubs or receivers, is subjected to powerful pressure, gradually applied, in the cider press. The liquor which runs off first is the best, and is usually kept separately; whilst that which follows, especially the portion obtained by much pressure, tastes of the pips and skins.

The expressed juice or "must," obtained as above, is next put into clean casks with large bung-holes, and freely exposed to the air and the shade, where they are placed on "stillions," with flat tubs under them to catch the waste. They are now constantly attended to and kept quite full, in order that the yeast, as it forms, may froth over and be carried off from the surface of the liquor. After 2 or 3 days for weak cider, and 8 or 10 days for strong cider, or as soon as the sediment has subsided, the liquor is "racked off" into clean casks, which have been (according to the common practice) previously sulphured with a cooper's match. The casks containing the "racked cider" are then stored in a cellar, shaded barn, or other cool place, where a low and regular temperature can be ensured, and are left to mature or ripen. By the following spring the cider is commonly fit for use, and may be "re-racked" for sale.

The marc, or pressed pulp, is generally again sprinkled with 1/3 or 1/2 its weight of water, and re-pressed. The resulting liquor, when fermented, forms a weak kind of cider (cider moil, water moil), which is reserved for domestic use in the same way as table-beer. The refuse-pulp (apple-marc, pomace, pommage, apple cheese) is used as food for pigs and store cattle, and is very acceptable to them.

The storing and management of cider are matters of vast importance to the cider farmer, the factor, the wholesale dealer, and the bottler. The principles by which these should be directed are precisely similar to those which are explained under the heads BREWING, FERMENTATION, and MALT LIQUORS; and which, indeed, refer, with slight modifications, to all fermented liquors.

Preparatory to bottling cider it should be examined, to see whether it is clear and sparkling. If not so, it should be clarified in a similar way to beer, and left for a fortnight. The night before it is intended to put it into bottles the bung should be taken out of the cask, and left so until the next day, and the filled bottles should not be corked down until the day after; as, if this is done at once, many of the bottles will burst by keeping. The best corks should alone be used. Champagne bottles are the variety generally chosen for cider. It is usual to wire down the corks, and to cover them with tinfoil, after the manner of champagne. A few bottles at a time may be kept in a warm place to ripen. When the cider is wanted for immediate use, or for consumption during the cooler portion of the year, a small piece of lump sugar may be put into each bottle before corking it; or, what is the same thing in effect, the bottles may be corked within 2 or 3 hours after being filled. In summer, and for long keeping, this practice is, however, inadmissible. The bottled stock should be stored in a cool cellar, when the quality will be greatly improved by age. Cider for bottling should be of good quality, sound and piquant, and at least a twelvemonth old. When out of condition it is unfit for bottling.

_Qual., &c._ Cider, when of good quality, and in good condition, is doubtless a very wholesome liquor. Cider consumers, living in the cider districts, appear to enjoy almost an immunity from cholera, and often from other diseases which are common in other parts of the kingdom. At the same time, however, it is right to mention, that the dry colic or belly-ache (_colica pictonum_) is far from uncommon in these districts, but is wholly confined to those who drink early, hard, or inferior cider, made from harsh, unripe fruit. We believe that, in most cases, it may be referred to the acid of the common cider having acted on the lead, pewter, or copper of the articles or utensils with which it has come in contact, and of which it has dissolved a very minute portion. The best cider contains from 8% to 10% of absolute alcohol; ordinary cider from 4% to 6%.

_Concluding Remarks._ Much of the excellence of cider depends upon the temperature at which the fermentation is conducted; a point utterly overlooked by the manufacturers of this liquor. Instead of the apple-juice, as soon as it is expressed from the fruit, being placed in a cool situation, where the temperature should not exceed 50° or 52° Fahr., it is frequently left exposed to the full heat of autumn. In this way much of the alcohol formed by the decomposition of the sugar is converted into vinegar by the absorption of atmospheric oxygen, and thus the liquor acquires that peculiar and unwholesome acidity known in the cider districts by the name of "roughness." When, on the contrary, the fermentation is conducted at a low temperature, nearly the whole of the sugar is converted into alcohol, and this remains in the liquor, instead of undergoing the process of acetification. The acetous fermentation, by which alcohol is converted into vinegar, proceeds most rapidly at a temperature of about 90° Fahr., and at lower temperatures the action becomes gradually slower, until at 46° to 50° Fahr. no such change takes place. (Liebig.) It is therefore evident that if the saccharine juice of apples, or any other fruit, is made to undergo the vinous fermentation in a cool situation, less of the spirit resulting from the transformation of the sugar will be converted into acetic acid, and, consequently, more will be retained in an unaltered state in the liquor, to improve its quality, and by its conservative and chemical action to preserve it from future change. This is the principal cause, other circumstances being alike, of the difference in the quality of the cider made by persons living in the same district. The one has probably a cooler barn and cellar than the other to store his liquor in, and is more careful to keep the pulp and juice cool during the early part of the process. In Devonshire the pressing and fermentation are conducted in situations where the temperature varies little from that of the external air, and fluctuates with all its changes; the result is that Devonshire cider, of the best class, will rarely keep more than 4 or 5 years, and seldom improves after the second or third year; whilst the cider of Herefordshire and Worcestershire, where these operations are more carefully attended to, will keep for 20 or 30 years.

When the pressing the apples for the juice is deferred until late in the season, it sometimes happens that the fermentation is sluggish. Though the juice has been set on the old system, in November or December, the working hardly commences until March. At this time the cider is sweet; it now rapidly becomes pungent and vinous, and is soon ready to be racked for use. If the fermentation still continues, it is again racked into a clean cask that has been sulphured; or two or three cans of the cider are put into a cask, and a brimstone-match burned in it. The cask is then agitated, after which it is nearly filled with the cider. By this process the fermentation is checked, and the cider in a short time becomes fine. Great care must be taken that the sulphuring be not overdone, as it is apt to impart a slightly unpleasant flavour to the liquor. If, on the first operation, the fermentation is not checked, the process of 'racking' is repeated, until the liquor becomes clear, and is continued from time to time, till the cider is in a quiet state and fit for drinking.

A common practice in Devonshire is to add a stuff called 'stum,' sold by the wine-coopers, or an article called 'antiferment,' sold by the druggists, for the purpose of checking the fermentation, but a much better plan is that described above.

To improve the flavour of weak cider, or to render ordinary cider more vinous, various plans are followed by the cellarmen and bottlers. An excellent one is to add to each hogshead 1-1/2 gall. of good brandy or rum, with 2 oz. of powdered catechu (dissolved in water), 10 lbs. of good moist sugar or honey, 1/2 oz. each of bitter almonds and cloves, and 4 oz. of mustard seed (all in powder). These must be well 'rummaged' into the liquor, and the whole occasionally stirred up for a fortnight, after which it must be allowed to repose for 3 or 4 months, when it will usually be found perfectly 'bright,' and no bad substitute for foreign wine. Should this not be the case, the liquor must be 'fined' with a pint of isinglass finings, or a dozen eggs, and allowed to rest for a fortnight. If the cider is preferred pale, the catechu must be omitted, and instead of isinglass, a quart of skimmed milk is to be used as 'finings.' When desired of a pinkish tint, 1 oz. of cochineal (in powder) may be added instead of the catechu.

About 13 cwt. of November apples commonly yield one hogshead of cider. In Devonshire about 6 sacks or 24 bushels are the common quantity for the hogshead of 63 galls.

The best cider made at the present day is that of Normandy, Herefordshire, and New Jersey (U.S.), and next that of Devonshire and Somersetshire. See ANTIFERMENT, FERMENTATION, &c.

=Cider, Champagne.= This name is given in the United States of America to a fine, pale variety of cider, much used for bottling, which has a great resemblance to inferior champagne. The best variety comes from New Jersey. The name is also applied in this country in a similar manner. The following is a good form for a 'made' cider of this class:--

_Prep._ Good pale vinous cider, 1 hhd.; proof spirit (pale), 3 galls.; honey or sugar, 14 lbs.; mix well, and let them remain together in a temperate situation for 1 month; then add orange-flower water, 3 pints; and in a few days fine it down with skimmed milk, 1/2 gall. A similar article, bottled in champagne bottles, silvered, and labelled, is often sold to the ignorant for champagne.

=Cider, Made.= An article under this name is made in Devonshire, chiefly for the supply of the London market, it having been found that the ordinary cider will not stand a voyage to the metropolis without some preparation. The finest quality of 'made' cider is simply ordinary cider racked into clean and well-sulphured casks; but the mass of that which is sent to London is mixed with water, treacle, and alum. The cider sold in London under the name of Devonshire cider would be rejected even by the farmers' servants in that county.

=Cider, Raisin.= This is made in a similar way to raisin wine, but without employing sugar, and with only 2 lbs. of raisins to the gall., or even more, of water. It is usually fit for bottling in 10 days, and in a week longer is ready for use.

=CIDER SPIRIT.= See BRANDY.

=CIGAR.= _Syn._ SEGAR; CIGARRE, Fr.; CIGARRO, Span. A small roll of tobacco-leaf used for smoking. The leaf is stalked or stripped of its midrib, and damped before it passes into the hands of the cigar-roller. The envelope or skin is cut from a smooth, unbroken leaf, and is quickly rolled round sufficient tobacco to form the inside. To secure the loose end of the envelope a small quantity of paste, coloured brown with chicory, is generally used. Only those who have had great practice can make cigars of a good shape. A full account of the manufacture of cigars does not come within the scope of this work. Although cigars of British make cannot compete in point of flavour with those manufactured in tobacco-growing countries, they have obtained a high degree of favour from the excellent manner in which they are made, and from their comparative cheapness. For information respecting the adulteration of cigars, and the influence of their use upon health, see TOBACCO.

=CIGARS.= (In _pharmacy_.) _Syn._ MED'ICATED CIGARS, M. CIGARETTES'. The administration of medicinal agents in the form of cigars is of recent introduction, and as yet in only very limited use. The medicinal substance, if of a suitable description, as the leaves of plants, is made up into small rolls, like cheroots, and then smoked in the usual manner. In some cases, common cigars, or paper cigars (cigarettes), are medicated by moistening them in a preparation of the article to be administered. When the narcotic property of the tobacco would prove injurious, it is first exhausted by soaking and washing it in water.

=Cigars, Aromatic.= _Syn._ AROMATIC CIGARETTES; CIGARETTÆ AROMAT'ICÆ, L.; CIGARETTES AROMATIQUES, Fr. Aromatic spices, lavender flowers, &c., made into cigarettes. Smoked for their odour; and in tooth-ache, face-ache, &c. See CIGARS, SCENTED.

=Cigars, Arsenical.= _Syn._ CIGARR'Æ ARSENICALES, L. _Prep._ Dissolve arseniate of soda, 1 part, in water, 30 parts; dip white, unsized paper into the solution, and form it into small rolls, 3 or 4 inches long. Used in pulmonary consumption; 4 or 5 whiffs as many times a day.

=Cigars, Balsamic.= _Syn._ BALSAMIC CIGARETTES; CIGARRÆ BALSAMICÆ, CIGARETTÆ B., L. Thick, unsized paper is soaked in a solution of saltpetre and dried; after which it is brushed over first with tincture of cascarilla, and when again nearly dry, with compound tincture of benzoin; in about half an hour it is cut into pieces (1-1/2 × 4 inches), and rolled into cigarettes. Used in hoarseness, loss of voice, asthma, &c.

=Cigars, Belladonna.= _Syn._ BELLADONNA CIGARETTES; CIGARETTÆ BELLADONNÆ, L. _Prep._ 1. Belladonna leaves made into cigarettes of 1 dr. each.

2. (Compound--C. B. COMPOS'ITUM.) From belladonna leaves, 4 parts; moistened with tincture of opium (Ph. L.), 1 part; dried and made into 1 dr. cigarettes, as before.

Used as an anodyne and antispasmodic, in troublesome coughs, hooping-cough, toothache, sore throat, tic douloureux, &c.

=Cigars, Camphor= (Raspail, Paris). A remedy for various chest diseases, such as catarrh, hoarseness, loss of voice, coughs, spasms, hooping-cough, phthisis; also, if the saliva be swallowed, for heartburn, pains in the stomach, and gastritis. They consist either of a straw or quill filled with broken camphor, or of a bone or horn mouthpiece, furnished at the outer end with a little capsule for the camphor. (Wittstein.)

=Cigars, Cam'phor.= _Syn._ CAMPHOR CIGARETTES; CIGARETT'Æ CAMPHO'RÆ, L.; CIGARETTES DE CAMPHRE, Fr. _Prep._ 1. Bibulous paper, moistened with 2 or 3 drops of essence of camphor, and rolled into cigarettes. For use they are loosely placed in a tubular cigar-holder.

2. (Raspail.) These are made by loosely filling a quill or large straw with small fragments of camphor, closing the open end with a little cotton wool or bibulous paper, and piercing the closed end with a pin, to allow the passage of air.

_Obs._ Both the above are used unlighted by drawing the air through them into the mouth, which then becomes very slightly charged with the vapour of camphor. In cold weather the vaporisation is promoted by holding the cigarette for a few minutes in the warm hand. The hom[oe]opathists regard them as prophylactic of cholera, and the common people hold them to possess the same virtue in reference to contagious diseases generally, but especially typhus and scarlet fever. They should not be employed oftener than 3 or 4 times a day.

=Cigars, Hen'bane.= _Syn._ CIGARR'Æ HYOSCY'AMI, L. From henbane leaves, as directed under BELLADONNA CIGARS.

=Cigars, Indian Hemp.= The plant is made into cigarettes, which are used in asthma. They must be used with caution.

=Cigars, Mercu''rial.= _Syn._ CIGARR'Æ MERCURIA'LES, L. _Prep._ (Paul Bernard.) Ordinary cigars are deprived of their narcotic properties by soaking them in water, and are then wetted with a weak solution of corrosive sublimate, to which a little opium is generally added. The proportion may be, of corrosive sublimate, 1 gr.; rectified spirit, 20 drops; dissolve; add laudanum, 15 drops; with this solution 6 cigars are to be equally moistened to within about 1-1/2 inch of the mouth end, and then set aside to dry.

Used by persons afflicted with syphilitic affections of the throat and palate, as a convenient method of mercurial fumigation. For those accustomed to the use of tobacco, mild cigars, undeprived of their nicotine, may be employed for the purpose.

=Cigars, Scent'ed.= _Syn._ PERFU''MED CIGARS; CIGARR'Æ AROMAT'ICÆ, L. _Prep._ 1. By moistening ordinary cigars with a strong tincture of cascarilla, to which a little gum benzoin and storax may be added. Some persons add a small quantity of camphor, or of oil of cloves or cassia.

2. By soaking the tobacco, of which the cigars are to be made, or the cigars themselves, for a short time in a very strong infusion of cascarilla, and then allowing them to dry by a very gentle heat.

3. By simply inserting very small shreds of cascarilla bark between the leaves of the cigar or in small slits made for the purpose.

_Obs._ The above yield a very agreeable odour when smoked; but are said to intoxicate quicker than unprepared cigars of equal strength and quality. They lose much of their fragrance by age.

=Cigars, Stramo''nium.= _Syn._ DATU'RA CIGARS; CIGARRÆ STRAMO''NII, L. From the leaves of _Datura stramonium_, or preferably those of the eastern species, _Datura tatula_. See ASTHMA, DATURA.

=CINCHONA BARKS.= _Syn._ CINCHONÆ CORTEX; PERUVIAN BARK; JESUIT'S BARK. The native names are _quinquino_ and _quina_, _quina_. Of the nearly forty different known species of cinchona trees, the barks of about a third are employed, some either directly in medicine, but by far the larger number as sources of quinine and the other cinchona alkaloids. The original habitat of the genus _Cinchona_ is the Andes, where it is found at a height of between 3000 and 12,000 feet above the sea, growing mostly in patches, distributed amongst the palms, plantains, and other tropical trees that form the vast forests, for the most part clothing the eastern slopes of the Cordilleras, and extending from 10° north to about 19° south latitude. In this district there is always an abundance of moisture and a mean temperature of about 62°. In 1853 the Dutch government introduced the cinchona into Java, and in 1861 the East Indian government, following their example, introduced it into British India, where it is now acclimatised, large plantations of it growing on the Neilgherries and in the valleys of the Himalayas. The cinchona is now also successfully cultivated in Ceylon and Jamaica.

The method followed in the collection of the bark by the Peruvians is a very wasteful and destructive one, and consists either in stripping the bark from the trees when they have attained a sufficient age, or in felling the tree a little above the roots. If the latter method be adopted, the roots give out a growth of suckers, which yield a good bark. The bark is never removed during the rainy season.

Previous to being stripped off, the bark is sometimes cleaned with a brush, and then peeled off in pieces varying from 15 to 18 inches long, and from 4 or 5 in width. The thinnest pieces, which are derived from the branches or the trunks of small trees, are dried in the sun, and thus acquire the well-known quill-like form. The larger trunks yield the flat specimens, which are submitted to a kind of pressure as they are being dried. The inferior specimens being rejected, the dried barks (mostly of the same kind) are sewed in canvas, and thus conveyed to the nearest depôt, from whence, previous to being shipped, they are enclosed in another envelope of fresh hide, the package being then known under the name of a _seron_.

_Structure of Cinchona Barks._ A few general observations on the structure of the bark of cinchona will be appropriate here. The epidermis is only found on the youngest bark, before it has attained sufficient age for medicinal use; it is then replaced by the corky layer. In most species this cracks, and is easily separable, but in some it is firmly attached to the internal layers. These are composed of the middle layer of the bark or mesophlæum, formed of parenchyma, and the innermost layer endophlæum, or liber. The middle layer disappears in some barks, which are thus wholly composed of liber. This is a means of distinguishing them. The liber is traversed by medullary rays, which project into the mesophlæum. It is, therefore, composed of woody fibres (prosenchyma) and soft parenchyma.

The arrangement of the woody fibres, their colour, size, and shape, give a special character to the cinchona barks.

As compared with other barks, the fibres of the liber are shorter and more loosely arranged, being for the most part separate or united into very short bundles. The fibres, therefore, are easily isolated; they are spindle-shaped, sub-quadrangular, rarely exceeding 1-10th of an inch in length, usually straight, and are very brittle, the cavity of the cell of which each is composed being reduced by secondary deposits to a fine canaliculus. This short and loose fibrous structure is not found in other barks.

In some cinchona bark a system of lactiferous vessels is found between the liber and mesophlæum.[247]

[Footnote 247: Royle.]

The parenchyma of the barks abounds in starch and oxalate of lime, or else contains a soft brown deposit.

The 'British Pharmacop[oe]ia' divides the cinchona barks into the three classes of--

1. YELLOW CINCHONA BARK. _Syn._ CINCHONÆ FLAVÆ CORTEX. The _Cinchona Calisaya_ of Weddell.

2. PALE CINCHONA BARK. _Syn._ CINCHONÆ PALLIDÆ CORTEX. The bark of _Cinchona officinalis_; var. _Condaminea_ of Hooker. This bark is also known under the name of _Crown-bark_, from its having formerly been used by the royal family of Spain.

3. RED CINCHONA BARK. _Syn._ CINCHONÆ RUBRÆ CORTEX. The _Cinchona succirubra_ of Pavon.

The therapeutic properties of the cinchona barks are due to the following alkaloids:--

Quinia, or quinine, having the composition C_{20}H_{24}N_{2}O_{2}.

Quinidia, or quinidine, having the composition C_{20}H_{24}N_{2}O_{2}.

Cinchonia, or cinchonine, having the composition C_{20}H_{24}N_{2}O.

Cinchonidia, or cinchonidine, having the composition C_{20}H_{24}N_{2}O.

Quinamina, or quinamine, having the composition C_{20}H_{24}N_{2}O_{2}.

Besides the above, an alkaloid, which has been named _Paracina_, has been obtained from the bark of the _Cinchona succirubra_; whilst in those barks which contain only small portions of the more active constituents above named there have been found two alkaloids, named respectively _Aricia_ and _Cusconia_, which have lately been accurately investigated by Hesse, who has determined their chemical constitution (Liebig's 'Annalen und Berichte der Chemische Gesselschaft in Berlin').

_The following Prospectus of the principal Species of Cinchona is from_ FLÜCKIGER and HANBURY'S '_Pharmacographia_,'

--------------------------------------+---------------------+-------------+--------------------+-------------------------------------
Species (excluding Sub-species and | | Native | Where |
Varieties) according to Weddell. | Where figured. | Country. | cultivated. | Product - Cinchona Barks.
--------------------------------------+---------------------+-------------+--------------------+-------------------------------------
I. STIRPS CINCHONÆ OFFICINALIS-- | | | |
1. Cinchona officinalis, Hook. |'Bot. Mag.,' 5364 |Ecuador Loxe,|India, Ceylon, Java |Loxa, or Crown Bark, Pale Bark.
2. " macrocalyx, Pav. |Howard, 'N. Q.' |Peru | -- |Ashy Crown Bark. The sub-species
| | | | _C. Palton affords_ an
| | | | important sort called _Palton Bark_,
| | | | much used in the manufacture of
| | | | quinine.
3. " lucumæfolia, Pav. | " |Ecuador, Peru| -- |Carthagena Bark, confounded with
| | | | Palton Bark, but is not so good.
4. " lanciolata, R. and P. | " |Peru | -- } |Columbian Bark. Imported in immense
| | | } | quantities for manufacture of
5. " lancifolia, Mutis. |Karst., tab. 11, 12 |New Granada |India } | quinine. The soft Columbian Bark
| | | } | is produced by Howard's var.
| | | } | _oblonga_.
6. " amygdalifolia, Wedd. |Wedd., tab. 6 |Peru, Bolivia| -- |A poor bark, not now imported.
II. STIRPS CINCHONÆ RUGOSÆ-- | | | |
7. Cinchona Pityrensis, Wedd. |Karst., tab. 22 (G). |New Grenada, |India |Pitayo Bark. Very valuable; used by
| Triane | Popayan | | makers of quinine. It is the chief
| | | | source of quinidine.
8. " rugosa, Pav. |Howard, 'N. Q.' |Peru | -- |Bark unknown, probably valueless.
9. " Mutisii, Lamb. | " |Ecuador | -- |Bark, not in commerce, contains only
| | | | aricine.
10. " hirsuta, R. and P. |Wedd., tab. 21 |Peru | -- |
11. " Carabayensis, Wedd. |Wedd., tab. 19 |Peru, Bolivia| -- |Bark, not collected.
12. " panudiana, How. |Howard, 'N. Q.' |Peru |India, Java |A poor bark, yet of handsome
| | | | appearance; propagation of tree
| | | | discontinued.
13. " asperfolia, Wedd. |Wedd., tab. 20 |Bolivia | -- |Bark not collected.
14. " umbelluliferæ, Pav. |Howard, 'N. Q.' |Peru | -- |Bark not known as a distinct sort.
15. " glandulifera, R. and P. | " |Peru | -- | " "
16. " Humboldtiana, Lamb. | " |Peru | -- |False Loxa Bark, Jaen Bark. A very
| | | | bad bark.
III. STIRPS CINCHONÆ MICRANTHÆ-- | | | |
17. Cinchona Australis, Wedd. |Wedd., tab. 8 |South Bolivia| -- |An inferior bark, mixed with
| | | | Calisaya.
18. " scrobiculata, H. and B. | " |Peru | -- |Bark formerly known as _Red Cusco
| | | | Bark_ or _Santa Anna Bark_.
19. " Peruviana, How. |Howard, 'N. Q.' |Peru |India } |
20. " nitida, R. and P. | " |Peru |India } |Grey Bark, Huanuco, or Lima Bark.
21. " micrantha, R. and P. | " |Peru |India } | Chiefly consumed on the Continent.
IV. STIRPS CINCHONÆ CALISAYÆ-- | | | |
22. Cinchona Calisaya, Wedd. |Wedd., tab. 9 |Peru, Bolivia|India, Ceylon, Java,|Calisaya Bark, Bolivian Bark, Yellow
| | | Jamaica, Mexico | Bark. The tree exists under many
| | | | varieties; bark also very variable.
23. " elliptica, Wedd. | " |Peru, | -- |Carabaya Bark. Bark scarcely now
| | Carabaya | | imported. _C. cuneura_, Miq.
| | | | (flower and fruit unknown), may
| | | | perhaps be this species.
V. STIRPS CINCHONÆ OVATÆ-- | | | |
24. Cinchona purpurea, R. and P. |Howard, 'N. Q.' |Peru, | |Huamalies Bark, not now imported.
| | Huamalies | |
25. " rufinervis, Wedd. | " |Peru, Bolivia| -- |Bark a kind of light Calisaya.
26. " succirubra, Pav. | -- |Ecuador |India, Ceylon, Java,|Red Bark; largely cultivated in
| | | Jamaica | British India.
27. " ovata, R. and P. | " |Peru, Bolivia|India (?), Java (?).|Inferior brown and grey barks.
28. " cordifolia, Mutis. |Karst., tab. 8 |New Granada, | -- |Columbian Bark (in part). Tree exists
| | Peru | | under many varieties; bark of some
| | | | used in manufacture of quinine.
29. " Tucujensis, Karst. |Karst., tab. 9 |Venezuela | -- |Maracaibo Bark.
30. " pubescens, Vahl. |Wedd., tab. 16 |Ecuador, | -- |Areca Bark (Cusco Bark from var.
| |Peru, Bolivia| | _Pelletieriana_). Some of the
| | | | varieties contain aricine. _C.
| | | | caloptera_, Miq., is probably a
| | | | variety of the species.
31. " purpurascens, Wedd. |Wedd., tab. 18 |Bolivia | -- |Bark unknown in commerce.
--------------------------------------+---------------------+-------------+--------------------+-------------------------------------

The cinchona barks vary greatly in the amount of alkaloids they contain and in their proportion to each other, these being dependent upon the species or varieties, and many other circumstances. Of the alkaloids, quinia and cinchonia were till lately the most abundant, but since the introduction of cinchona cultivation into India, cinchonidia has been found in very large quantity. Royle says:--"Good Calisaya bark usually contains from 5 to 6 per cent. of quinia," but actually South American calisaya containing such an amount of quinia is rare in the market. Some barks, however, derived from cinchonas cultivated in India, such as _C. Calisaya_, var. _Ledgeriana_, and some varieties of _C. officinalis_, yield even a still higher per-centage of quinine.

The South American crown, or loxa bark, is very variable, and contains chiefly cinchonia.

Red bark also varies considerably, yielding from 3 to 10 per cent. of alkaloids, of which quinia forms only a small fraction, whilst generally cinchonidia is predominant. The development of the alkaloids is greatly influenced by cultivation, but particularly by the "renewing process," which, applied to the _C. succirubra_, trebles the amount of quinine in the bark.

In addition to the alkaloids already mentioned, the cinchona barks contain the following acid principles:--KINIC ACID, CINCHO-TANNIC ACID, and QUINOVIC or CHINOVIC ACID. The quinovic acid is accompanied by an amorphous bitter substance, named CHINOVIN or QUINOVIA, which is present in much greater proportion than the acid, of which generally there are only traces. A description of these bodies will be found by referring to them under their respective names. CINCHONA-RED is another amorphous substance which is the body to which the red hue of the cinchona barks is due. It is produced when cincho-tannic acid is boiled with dilute sulphuric acid, sugar being formed at the same time.

When fused with potash, proto-catechinic acid is formed. Cinchona red dissolves sparingly in alcohol, freely in alkaline solutions, but neither in water nor ether. Thick red bark contains it to the amount of more than 10 per cent.

Cinchona red is the product of the oxidation of cincho-tannic acid, and is contained largely in South American red bark, because this is the product of old trees; but sparingly in Indian red bark, because this is always collected from trees not more than fourteen years old.

_Medicinal Properties of the Cinchona Barks._ The therapeutic effects of the cinchona barks are doubtless due to the alkaloids they contain; but spite of their variability of composition in this respect, which has been shown to be very great, they are very extensively employed in medical practice in the forms of powder, decoction, tincture, and extract.

Dr de Vrij, the eminent quinologist, is of opinion that the therapeutic effects of bark are chiefly due in part to the alkaloids, and in part to the cincho-tannic acid they contain; and as red Indian bark is rich in both these constituents, he considers it the best suited for medical practice. See QUINETUM.

Garrod says:--"Given in small doses, bark causes an increase of appetite, especially in weak patients, and at the same time improves the condition of the muscular system; hence the improvement of the blood and general health. It may, therefore, be well designated a tonic.

Its power in bracing up the system is also seen in the check given to the colliquative sweating occurring in extreme debility. The pulse is not quickened by the use even of large doses of quinine, although it is frequently made stronger, nor does bark itself, in the majority of cases, increase the heart's action.

Bark also produces a peculiar influence upon the nervous system, which is exhibited in the extraordinary power it possesses of arresting the progress of certain diseases characterised by a periodical recurrence of their symptoms, as ague, the different forms of neuralgia, and certain inflammatory affections; how this effect is produced is at present unknown. Bark acts likewise as an astringent, and this property, combined with the tonic and antiperiodic powers, is often of much therapeutic value."

For the method of estimating the alkaloids in cinchona bark, see QUINOMETRY, QUININE, QUINIDINE, QUINOIDINE, QUINICONE, QUINAMINE, CINCHONINE; also the different pharmaceutical preparations of CINCHONA BARK.

=CINCHONIDINE.= _Syn._ CINCHONIDIA. C_{20}H_{24}N_{20}. This cinchona alkaloid is isomeric with cinchonine. It occurs in large, shining striated, rhombic prisms, which are anhydrous. It dissolves in ·76 parts of ether and 20 of spirit of wine. The solutions are fluorescent, but do not answer to the chlorine and ammonia tests.

"The great powers and activity of this alkaloid have only of late been appreciated. As a protoplasm-poison, and probably in every other physiological action, it comes next to quinine and quinidine, and decidedly above cinchonine."[248]

[Footnote 248: Dr C. D. Phillips.]

If it is chemically pure, cinchonidine belongs to the non-fluorescent alkaloids.

=CINCHONINE.= _Syn._ CINCHONIA. C_{20}H_{24}N_{2}O. This alkaloid abounds most in the paler varieties of the cinchona barks. It occurs in clear, colourless, four-sided prisms, which are soluble in 30 parts of water, and in about 400 parts of ether and 120 of spirits of wine. With acids it forms soluble salts, which do not fluoresce in solution, and are turned lightish brown-yellow by the chlorine and ammonia tests. Of its salts, the hydriodate is readily soluble in water, and still more so in alcohol, whether dilute or strong. Cinchonine may be prepared from its sulphate or disulphate in the same way as quinine.

=Cinchonine, Sulphate of.= _Syn._ CINCHONIÆ SULPHAS. (Ph. U. S.) Take of the mother-water remaining after the crystallisation of sulphate of quinia in the process for preparing that salt a convenient quantity, solution of soda, alcohol, diluted sulphuric acid, animal charcoal in fine powder, each a sufficient quantity. To the mother-water add gradually with constant stirring solution of soda, until the liquid becomes alkaline. Collect on a filter the precipitate formed, wash it with water, and dry it. Then wash it with successive small portions of alcohol to remove other alkaloids which may be present, mix the residue with 8 times its weight of water, and having heated the mixture, add gradually diluted sulphuric acid until it is neutralised and becomes clear. Then boil the liquid with animal charcoal, filter it while hot, and set it aside to crystallise. Lastly, drain the crystals and dry them on bibulous paper. By evaporating the mother-liquid more crystals may be obtained.

=CINCHO-TANNIC ACID.= This acid is precipitated from a decoction of bark by acetate of lead, after the decoction has been freed from cinchona red by means of magnesia.

If the cincho-tannate of lead thus formed be decomposed by sulphuretted hydrogen, and the solution carefully evaporated in vacuo, the acid may be obtained as an amorphous, hygroscopic substance, readily soluble in water. A ferric salt added to a solution of this acid imparts a greenish colour to it.

Cincho-tannic acid is very soluble in water, but not in acids. Therefore a concentrated watery infusion (1 to 4) of Indian bark gives a precipitate upon the addition of strong hydrochloric acid. By this means a rough estimation may be formed of the amount of cincho-tannic acid in a sample of bark.

=CINCHOVATINE.= The substance known under this name does not exist as an alkaloid, _sui generis_. It is nothing more than quinidine, or cinchonidine, or a mixture of both.

=CINNABAR.= _Syn._ NATIVE VERMILLION. This compound, which is one of the most abundant of the ores of mercury, is a product of considerable importance in the arts, and some portions of it are sometimes sufficiently pure in colour to be used after mere levigation. Generally, however, the factitious kind is employed. See VERMILION.

=CINNAMEIN.= C_{16}H_{14}O_{2}. _Syn._ OIL OF BALSAM OF PERU. A volatile oil existing in balsam of Peru.

=CINNAMIC ACID.= HC_{9}H_{7}O_{2}. A colourless, transparent, crystalline substance, obtained from oil of cinnamon, liquid storax, balsam of Peru, and balsam of tolu. It is freely dissolved by alcohol, but nearly insoluble in water. At 248° Fahr. it fuses, and at 560° Fahr. it sublimes unchanged. Distilled with dichromate of potassium and sulphuric acid it is converted into benzoic acid. Its salts are called cinnamates.

=CINNAMON.= _Syn._ CINNAMON BARK; CINNAMOMI CORTEX (B. P.), L. The inner bark of shoots from the truncated stock of the _Cinnamomum Zeylanicum_, imported from Ceylon, and distinguished in commerce as Ceylon cinnamon. The best is obtained from branches about three years old.

Used in _medicine_ as a carminative and astringent, chiefly as an adjuvant to other medicines, _e.g._ with chalk, in diarrh[oe]a.--_Dose_, 10 to 20 grains.

_Obs._ Owing to the high price of this drug it has become a general practice to substitute the bark of cassia (_Cassia_; _Cortex cinnamomi cassia_) for it, which so closely resembles it in flavour that the uninitiated regard them as the same. Cassia, however, is not only thicker and coarser than cinnamon, but its fracture is short and resinous, and its flavour is more biting and hot, whilst it lacks the peculiar sweetish taste of cinnamon. The thickness of cinnamon seldom exceeds that of good drawing paper.

=CISTERNS.= See TANKS.

=CITRATE.= A salt in which the hydrogen of citric acid is replaced by a metal or other basic radical.

=CIT'RIC ACID.= H_{3}C_{6}H_{5}O_{7},H_{2}O. _Syn._ ACID OF LEMONS, CONCRETE A. OF L.; AC'IDUM LIMO'NIS, ACIDUM CIT'RICUM (B. P.), L.; ACIDE CITRIQUE, Fr.; CITRONENSAÜRE, Ger. An acid peculiar to the vegetable kingdom. It is obtained in large quantity from the juice of lemons and other fruits of the genus CITRUS; it is also found in gooseberries, currants, cranberries, whortleberries, cherries, &c.; and Dr Wright has lately found it in great abundance in unripe mulberries, in conjunction with malic acid.

When currants or gooseberries are employed as a source of citric acid, they are first subjected to pressure, and the juice so obtained from them is then fermented. The fermented liquor is next submitted to distillation, and the alcohol collected.

The residue in the retort containing the citric acid is saturated with chalk, and the resulting citrate of lime is decomposed by means of sulphuric acid.

100 lbs. of the fruit are said to yield 10 lbs. of spirit and 1 lb. of acid.

_Prep._ The citric acid manufacture consists in separating it from the mucilage, sugar, and other foreign matter with which it is combined in the juice of lemons and limes.

1. (Ph. L. 1836,--Scheele's process.) Take of lemon juice 4 pints; prepared chalk, 4-1/2 oz.; diluted sulphuric acid, 27-1/2 fl. oz.; distilled water, 2 pints. Add the chalk by degrees to the lemon juice, made hot, and mix well; set by, that the powder may subside, and afterwards pour off the supernatant liquor. Wash the precipitated citrate of lime frequently with warm water; then pour upon it the diluted sulphuric acid, mixed with the distilled water, and boil the whole for 15 minutes in glass, stoneware, or lead; press the mixture strongly through a linen cloth, and filter it. Evaporate the filtered liquor with a gentle heat, and set it aside, that crystals may form. To obtain the crystals pure, dissolve them in water a second and a third time; filter each solution, evaporate, and set it apart to crystallise.

2. (Ph. L. 1851.) Merely placed in the materia medica.

3. (Ph. E. 1841.) Similar to that of Ph. L. 1836, except that the washed citrate of lime is ordered to be squeezed in a powerful press, and that the filtered solution of citric acid is ordered to be tested with nitrate of baryta, and if the precipitate is not nearly all soluble in nitric acid, to add a little citrate of lime to the whole liquor, till it stands this test.

4. (Ph. D. 1826.) Same as that of Ph. L. 1836.

5. (Ph. D. 1851.) Included in the materia medica.

6. (P. B. 1867.) Differs from the process of the Ph. L. 1836 in some unimportant detail only.

7. (Dr Price.) The crude juice is saturated with ammonia, potassa, or soda (carbonates), or with the ammoniacal product distilled from gas-liquor; chalk, 150 parts, or hydrate of lime, 90 parts, are then added for every 192 parts of citric acid contained in the liquor, and the whole stirred well together; heat is next applied, and the ammonia distilled into another quantity of lemon juice; the citrate of lime thus obtained is then decomposed with dilute sulphuric acid, and the whole process conducted as before. When potassa or soda is used the distillation is omitted, and the expressed liquor, after filtration, used to decompose fresh lemon juice.

8. (Ordinary manufacturing process.) To crude lemon or lime juice, mixed with water, is added ground chalk; the precipitate is washed to free it from the impurities dissolved in the water, and afterwards decomposed by sulphuric acid. If the citric acid is not sufficiently white, it is decolorised by digestion with animal black.