Cocoa is derived from the seed of a plant called the theobroma cacao. The name was given by the botanist Linnseus, who expressed his high opinion of cocoa by the name "theobroma," which means "food for the gods". The seeds are embedded in a pulpy fruit; when ripe they are separated, sun-dried, and roasted. Cocoa nibs consist of the crushed kernels of these seeds; but cocoa such as we generally use has undergone a long and elaborate process of preparation. The following analysis (Payen) of cocoa will show in what way it differs from tea and coffee:-

It is thus seen that cocoa is rich in fat, that tannin is absent, and that it contains an alkaloid, theobromine. This alkaloid is almost identical with theine and caffeine, and has probably the same stimulating and inhibitory action; but as it is present in diluted cocoa in very small amount, cocoa is a less stimulating drink than tea and coffee. Its constitution shows, however, that it is highly nourishing. In the various prepared cocoas, the excess of fat has been extracted, and sugar, and sometimes starch, added. There are three ways of making cocoa according to the mode in which the cocoa has been prepared. Stewing: The cocoa nibs are slowly boiled or stewed for several hours, and the subnatant fluid is poured off. A more stimulating, but less nourishing, drink is thus obtained than from prepared cocoas. Infusing: In cocoas prepared without the admixture of starch, such as Van Houten's and Schweitze's, it is necessary only to mix a certain amount with hot water to make a soluble infusion. These cocoas are particularly suitable to those persons who must avoid starch in their diet. Boiling: Most of the prepared cocoas contain a large amount of added starch; it is therefore necessary to boil them before drinking. They form a highly nutritious and fattening food, especially when taken, as is usual, with milk.

Chocolate is prepared from cacao seeds by grinding, and by the addition of a large amount of sugar and various flavouring matters. It forms a luxurious and highly nutritious food, and is very rich in all the necessary constituents of diet, viz., hydro-carbons, carbo-hydrates, and albuminates. A small amount of solid chocolate will be found a valuable preventive against hunger when circumstances oblige one to go long without food. I have frequently found that a penny slot of chocolate at a railway station will enable me, after being eight or nine hours without food, to continue my avocations without being tormented with the sense of hunger.