794 CHOCOLATE 



of lime havo been dissolved) by the number of grains of solution delivered 

 from the burette. Thus, suppose 437 grains have been used, 437 divisions: 

 as 437 : 1 :: 10,000 : 22-89 per cent, of chlorine in the sample in question. If iron 

 wire bo taken, 6-308 grains, or, allowing 0-3 per cent, for impurities, 6-327 grains 

 may be weighed, dissolved in dilute sulphuric acid, made up to 2,000 grains measure, 

 uucl the solution thus obtained employed instead of that of the crystallized proto- 

 sulphate. W.J.W. 



CHLOROFORM. When a mixture of chlorine and gaseous chloride of methyl 

 is exposed to the sun's rays, chloroform is produced. It is prepared usually by dis- 

 tilling alcohol with chloride of lime. It is used to produce insensibility. See Watts's 

 ' Dictionary of Chemistry.' 



CHliOROPHANE. A name given to some of the varieties of fluor spar, which 

 emit a phosphorescent light when heated. See FLTJOB SPAB. 



CHLOROPHYLL. The green colouring matter of leaves and other herbaceous 

 parts of plants. 



CHOCOLATE. (Eng. and Ger. ; flhocolat, Fr.) This is an alimentary prepara- 

 tion of very ancient use in Mexico, from which country it was introduced into 

 Europe by the Spaniards in the year 1520, and by them long kept a secret from the 

 rest of the world. Linnaeus was so fond of it, that he gave the specific name, 

 Theobroma, ' food of the gods,' to the cacao tree which produced it. The cacao-beans 

 lie in a fruit somewhat like a cucumber, about 5 inches long and 3<| thick, which 

 contains from 20 to 30 beans, arranged in 5 regular rows with partitions between, 

 and which are surrounded with a rose-coloured spongy substance, like that of water 

 melons. There are fruits, however, so large as to contain from 40 to 50 beans. 

 Those grown in the West India islands, Berbice, and Demerara, are much 

 smaller, and have only from 6 to 15 beans ; their development being less perfect than 

 in South America. After the maturation of the fruit, when their green colour 

 has changed to a dark yellow, they are plucked, opened, their beans cleared of 

 the marrowy substance, and spread out to dry in the air. Like almonds, they 

 are covered with a thin skin or husk. In the West Indies they are immediately 

 packed up for the market when they are dried ; but in the Caraccas they are sub- 

 jected to a species of slight fermentation, by piitting them into tubs or chests, covering 

 them with boards or stones, and turning them over every morning, to equalise the 

 operation. They emit a good deal of moisture, lose the natural bitterness and acri- 

 mony of their taste by this process, as well as some of their weight. Instead of 

 wooden tubs, pits or trenches dug in the ground are sometimes had recourse to for 

 curing the beans ; an operation called earthing (terrer). They are lastly exposed to 

 the sun and dried. The latter kind are reckoned the best, being larger, rougher, of 

 a darker brown colour, and when roasted, throw off their husk readily, and split into 

 several irregular fragments ; they havo an agreeable mild bitterish taste, without 

 acrimony. The Guiana and West India sorts are smaller, flatter, smoother skinned, 

 lighter coloured, more sharp and bitter to the taste. They answer best for the ex- 

 traction of the butter of cacao, but afford a less aromatic and agreeable chocolate. 

 According to Lampadius, the kernels of the West India cacao-beans contain, in 100 

 parts, besides water, 53'1 of fat or oil, 167 of an albuminous brown matter, which 

 contains all the aroma of the bean, 10-91 of starch, 775 of gum or mucilage, - 9 of lig- 

 nine, and 2'01 of a reddish dye stuff, somewhat akin to the pigment of cochineal. 

 The husks form 12 per cent, of the weight of the beans ; they contain no fat, but, 

 besides lignine, or woody fibre, which constitutes half their weight, they yield a light 

 brown mucilaginous extract by boiling in water. The fatty matter is of the con- 

 sistence of tallow, white, of a mild agreeable taste, called butter of cacao, and not apt 

 to turn rancid by keeping. It melts only at 122 F., and should, therefore, make 

 tolerable candles. It is soluble in boiling alcohol, but precipitates in the cold. It is 

 obtained by exposing the beans to strong pressure in canvas bags, after they have 

 been steamed or soaked in boiling water for some time. From 5 to 6 ounces of butter 

 may be thus obtained from a pound of cacao. It has a reddish tinge when first 

 expressed, but it becomes white by boiling with water. 



The beans, being freed from all spoiled and mouldy portions, are to be gently 

 roasted over a fire in an iron cylinder, with holes in its ends for allowing the vapours 

 to escape ; the apparatus being similar to a coffee-roaster. When the aroma begins 

 to be well developed, the roasting is known to bo finished ; and the beans must bo 

 turned out, cooled, and freed by fanning and sifting from their husks. The kernels 

 are then to be converted into a paste by trituration in a mortar heated to 130 F., 

 or by the following ingenious and powerful machine. The chocolate paste has 

 usually in Franco a little vanilla incorporated with it, and a considerable quantity of 

 sugar, which varies from one-third of its weight to equal parts. For 1 Ib. of cacao 

 one pod of vanilla is sufficient. The roasted beans soon lose their flavour by exposure 

 to the air. 



