This section is from the book "Meals Medicinal", by W. T. Fernie. Also available from Amazon: Meals Medicinal: With "Herbal Simples" Curative Foods From the Cook in Place of Drugs From the Chemist.
(And see Chocolate).
The seeds of Theobroma cacao (a Mexican tree, as already described) contain a considerable quantity of nitrogen, but only from 20 to 30 per cent of animal nourishment (proteids), the remainder being "amides." The seeds are first allowed to ferment, and then roasted, their two halves coming out under pressure in a machine as "Cocoa nibs." When ground between hot rollers these nibs have their oil, or fat, melted, and they become reduced to a fluid condition, which is gradually dried, and then powdered as "soluble Cocoa." Dutch manufacturers add an alkali so as to saponify the fat. "Navy Cocoa" is a pure preparation free altogether from husk. Cocoa contains further some tannin, and is said (by Dr. Haig) to furnish when dry 59 per cent of uric acid, or xanthins, being therefore unsuitable for gouty persons. But the ash of Cocoa is strongly alkaline, consisting chiefly of potash, and phosphoric acid; and the general conclusion is that, whereas out of each hundred pounds of Cocoa no less than three and a half pounds consist of pure vegetable salts, mainly phosphates, of high nutritious value, particularly as alkalies, this article of diet is excellent for those persons who are given to the formation of uric acid as a gouty element.
The whole bean is highly sustaining, with its fat, gum, starch, and albumin, besides the theobromin, having all the stimulating effects of tea without any harmful reaction. Cocoa contains nearly one-fifth of its full bulk as pure albumin, and in a state of fine division for being digested. But the action of Cocoa on the nervous system is much less pronounced than that of tea, or coffee, owing to the comparatively small amount of thein, or caffein, which it contains. In St. James's Street, London, when Queen Anne reigned, there was a famous Chocolate house known as the "Cocoa Tree." Its frequenters were Tories of the strictest school. In the course of time it developed into a more general club. Dr. Garth whilst sitting there had his snuff-box, which was highly ornamented with diamonds, so repeatedly borrowed by the poet Rowe in order to gain notice, that at last he took out his pencil and wrote on the lid the Greek characters Ф (phi.): P (rho.) = "Fie, Rowe!"