865 



CHLOROFORM. 



CHOCOLATE AND COCOA. 



CHLOROFORM (C^HCl.,), a peculiar compound fluid, obtained 

 about the same time by Soubeiran and Liebig. To procure it, distil a 

 mixture of alcohol and a solution of chloride of lime ; separate the 

 product from the liquid distilled with it, shake it with five or six tunes 

 its volume of concentrated sulphuric acid ; pour it off, mix with a little 

 sulphuric acid, distil, and rectify from chloride of calcium. 



Chloroform is a limpid fluid ; its specific gravity is 1'480 ; it boils at 

 about 141 Fahr. ; does not readily burn, but when a glass rod 

 moistened with it is put into the flame of a spirit lamp, it burns with 

 a yellow sooty flame fringed with green. It is soluble in alcohol and 

 ether ; water precipitates it from them ; it dissolves iodine, phospho- 

 rus, and sulphur ; is not decomposed by potassium ; but when this 

 metal is heated in its vapour, combustion and explosion ensue, chloride 

 of potassium is formed, and charcoal is deposited. Heated with alcoholic 

 solution of potash, it yields formiate of potash. 



Pure chloroform, when dropped into water, falls to the bottom with- 

 out becoming milky. If chloroform contain alcohol it is coloured 

 green when mixed with bichromate of potash and sulphuric acid. 

 Chloroform is the best solvent for caoutchouc and gutta-percha ; on 

 the evaporation of these solutions, the gums are left with all their 

 properties unaltered. When gutta-percha ia thus treated it becomes 

 white, like ivory. 



A large amount of the chloroform now manufactured is made from 

 methylated tpirit, which if properly treated yields chloroform equal in 

 purity to that furnished by duty-paid alcohol. Chloroform is almost 

 exclusively employed in medicine as an ansesthetic. [METHYL ; 

 ANESTHETICS.] 



OHLOROGENIN. [MADDER, COLOURING MATTERS OF.] 



CHLOROGINIC ACID. [CAFFEINE.] 



CHLOROMELAL (C^H^Cl^O^?), a resinous body, produced by 

 the action of chlorine upon hydrate of myricyl. 



CHLOROMETHYLASE, bichlorinated etkyle>ie? (C,H 2 C1 2 ), an oily 

 product obtained by the action of chlorine upon acetate of methyl. 



CHLOROMETHYLSULPHUROUS ACID, Moromethylditkimif 

 acid (CjH^lS.jO,,), a chlorinated derivative of methylsulphurous acid. 



CHLORONICEIC ACID. This acid has recently been proved to be 

 identical with chlorobenzoic acid. 



CHLORONICINE. This product, derived from oxyphenic acid, and 

 to which the formula C^HuCLN., had been assigned, is, in all proba- 

 bility, either identical or isomeric with chloraniline (C^HjClN). 



CHLORONITRIC GAS. [NITHOHVDROOHLOHIC ACID.] 



CHLORONITROUS GAS. [NITROHYDROCHLORIC ACID.] 



CHLOROPHANE. [CALCIUM, fluoride of.] 



CHLOROPHENISIC ACID. ['CHLORINDOPTIC ACID.] 



CHLOROPHYLL, Ckromuk. The colouring matter of leaves has 

 been thus named by Pelletier and Caventou. It is obtained by 

 bruising, pressing, and then washing them with water, and after- 

 wards treating them with alcohol, which dissolves the green colour 

 and wax ; when water is added to this solution, and the alcohol dis- 

 tilled, the green substance, which contains wax, floats on the surface 

 of the water ; when this is heated with ether, the wax is dissolved, 

 and chlorophyll remains nearly pure. When exposed to light, or the 

 action of chlorine, it is bleached. Acids produce a similar effect, and 

 by the alkalies it is converted into soap. The red tint which leaves 

 assume in autumn appears to be owing to the formation and action of 

 an acid ; the green colour is restored by an alkali. Its composition is 

 not known. 



CHLOROPICRIN, chloride of 'perdilorinatednitromet!tyl[C. ! Cl 3 ($O t )], 

 a colourless, transparent oil, obtained by the action of chloride of lime 

 upon picric acid. 



CHLORORUBIN. [MADDER, COLOUHINO MATTERS OF.] 



CHLOROSAMIDE, U;idride of chloronitroialicyl (C, 2 H 1S C1 3 N 4 ). 

 A yellow crystalline product obtained by passing a current of dry 

 ammoniacal gas into hydride of chlorosalicyl. 



CHLOROSUCCIC ACID (C HCl 3 O t ?), a chlorinated derivative of 

 snccinic acid. [Succraic ACID.] 



CHLOROUS ACID. [CHLORINE.] 



CHLOROXETHIDE. [OXALIC ACID.] 



CHLOROXYNAPHTHALIC ACID. [MADDER, COLOUIUNU MAT- 

 TERS or.] 



CHOCOLATE AND COCOA. Much confusion arises from the 

 application of the name cocoa to two entirely different plants, having 

 no connection whatever with each other. This is the more absurd 

 because the name is not strictly applicable to either ; the one being 

 properly Cocos, and the other Cacao. Again, there is no general- appre- 

 ciation of the difference between cocoa and chocolate. Referring to the 

 NATURAL HISTORY DIVISION for an account of the botanical charac- 

 teristics of the respective plants, we shall here briefly notice the 

 commercial distinctions in their relation to manufactured products. 



Cocoi. One of the most valuable o tropical trees is the Cocos nuci- 

 fera, the nut-bearing cocos, or cocoa-nut tree. Scarcely any other tree 

 in applied to so many uses by the natives of the countries in which it 

 Bourishes. The roots are chewed in place of the areca-nut ; gutters, 

 drains, and the posts of huts are formed from the trunk ; the young 

 buds are a delicate vegetable. Shade is furnished by the leaves when 

 growing, and after separation from the tree their large size and hard 

 texture render them invaluable as thatch for cottages ; they are, more- 

 over, manufactured into baskets, buckets, lanterns, articles of head-drew!, 



ART3 AND SCI. DIV. VOL. II. 



and even books, upon which writing is traced with an iron stylus. Their 

 ashes yield potash in abundance ; their midrib forms oars ; and brushes 

 are formed by bruising the end of a leaf with a portion of the midrib 

 adhering to it. From the juice of the stem a kind of palm wine, and 

 subsequently an ardent spirit, are prepared ; the farinaceous matter 

 contained in the stem is a good substitute for sago ; and a coarse dark- 

 coloured sugar, called jagghery, is obtained by inspissating the sap. 

 This jagghery, mixed with lime, forms a powerful cement, which resists 

 moisture, endures great solar heat, and will take a fine polish. The 

 ripe fruit is a wholesome food, and the milk it contains yields a grateful 

 cooling beverage ; indeed, these together constitute the principal suste- 

 nance of the poorer natives in many tropical countries. The fibrous 

 bark is used to polish furniture, as brushes, and to form a valuable 

 elastic bark is cordage called coir ; the fibrous matter of the husk is also 

 employed to stuff mattresses ; and a manufacture of it into cordage, 

 mats, sacking, &c., has sprung up in Great Britain. The shell is made 

 into drinking-vessels and vessels of measure ; and, finally, the albumen, 

 or white solid matter contained within the shell, yields by pressure or 

 decoction an excellent oil. This oil is not only employed for burning 

 and for making candles, but in the manufacture of torches, and in the 

 composition of pharmaceutical preparations ; and. mixed with dammer 

 (the resin of Skorea robusta) it forms the substance used in India for 

 caulking the seams of boats and ships. Cocoa-nuts are brought to 

 Europe as wedges to set fast the casks and other round packages in the 

 cargo of vessels ; their freight therefore costs nothing. They consti- 

 tute the part of the plant best known in this country, chiefly for its 

 palatable fruit. In reference to manufactures, the nut is more largely 

 valuable, on account of the oil which it contains. In Ceylon, the 

 natives expose the ripe nuts on mats to the heat of the sun, and bring 

 them to a certain state of dryness ; they are sent in this state to 

 England, under the name of copperah. When the natives express the 

 oil themselves they call the refuse oil-cake by the name oipoonac; this 

 also finds a market in England. For home purposes the Cingalese do 

 not obtain the oil by pressure ; they simply boil the fresh pulp, and 

 skim off the oil as it rises. When they prepare the oil for exportation 

 to England, they expose the copperah to the action of a press worked 

 by bullocks, and obtain about two gallons and a half of oil from a hun- 

 dred average-sized nuts. Steam-power has lately been used to super- 

 sede the less effective labour of bullocks. The oil is largely used in 

 the manufacture of candles and soap. A kind of cocoa-nut butter is 

 obtained from another species of the tree, the Cocos ftisiformis, or great 

 macaw tree, in Trinidad, Jamaica, and South America. The nuts are 

 slightly washed, cleansed, and ground to paste in a mill, and then on a 

 stove ; the paste is next heated, and mixed with 30 per cent, of its 

 weight of boiling water. The mixture is put into a bag, and pressed 

 between two hot iron plates, by which it is made to yield 75 per cent, 

 of its weight of oil. This oil, when purified by filtration, somewhat 

 resembles butter in appearance, with a golden-yellow colour, an odour 

 of violets, and a sweetish taste. It enters largely into use for toilet 

 soaps. So far as concerns the true cocoa-nut oil, it is imported more 

 and more largely every few years : between the years 1845 and 1847, 

 the quantity ranged from 30,000 to 50,000 cwts. yearly ; between 1848 

 and 1852, from 60,000 to 100,000 cwts. ; and between 1853 and 1858, 

 from 130,000 to 250,000 cwts. The operations carried on by the 

 Price's Patent Candle Company, at Vauxhall and elsewhere, have 

 effected more than anything else in bringing this kind of oil into use in 

 this country. [CANDLE MANUFACTURE.] 



Cacao. We now come to the plant which really yields the so-called 

 cocoa of the breakfast-table, and its off-shoot cfiocolate. The nut, bean, 

 berry, seed, or kernel (for it has been called by all these names) of the 

 Theobroma cacao is the part of the plant employed for this purpose. 

 To prevent confounding this with the nut of the Cocos nucifera (just 

 described), we will call it a bean. The Mexicans call the tree chocolatl, 

 and hence the European name for one of the preparations derived 

 from it. If the beans and husks be roasted, and then ground, the 

 result is a pasty mass, which constitutes cocoa ; or sometimes the nuts 

 are pressed to obtain a certain portion of oil, and then the remaining 

 cake is ground up into paste. As if to increase the confusion above 

 adverted to, the name of cocoa-oil, or cocoa-nut oil, is often given to 

 this oil, as well as to that obtained from the fruity cocoa-nut ; but 

 sometimes the better, because more distinctive, name of butter of cacao 

 is given to it. To obtain this butter or oil, the beans are confined 

 in strong canvas bags, and pressed by hydraulic machines at a certain 

 temperature ; the oil which flows out is agitated or churned with 

 dilute sulphuric acid, then allowed to settle, then skimmed and 

 decanted, and lastly filtered. It is used as oil for lamps, and as a sub- 

 stitute for cod-liver oil in medicines. Cacao stcarine is produced from 

 the cake which remains when the oil has been pressed out by steaming, 

 dissolving, settling, and cooling ; it is combined with other fatty 

 matters in making soap and candles. 



The cocoa prepared as a beverage is, as we have said, made either 

 from the roasted and ground beans or from the oil-cake. A cheap and 

 common kind is made from the oil-cake of damaged beans, mixed with 

 flour, meal, suet, fat, &c. ; it can be sold as low as 4d. or 6rf. per Ib. 

 Flake cocoa consists of roasted and ground beans compressed into a hard 

 substance, and then sliced or flaked by a machine. Soluble cocoa consists 

 of the bean ground fine, and mixed with sugar and meal to render it 

 more soluble in water. In roasting the beans for converting the cacao 



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