This section is from the "A Practical Treatise On Materia Medica And Therapeutics" book, by Roberts Bartholow. Also available from Amazon: A Practical Treatise On Materia Medica And Therapeutics
Obtained from the seeds of Theobroma Cacao; cocoa, Fr.; Kakao, Ger.
The active principle is theobromine, a substance which resembles the alkaloids of coffee and tea, except that it contains more nitrogen than theine and caffeine. Another important difference between cacao and coffee and tea is the large amount of a peculiar fat (cacao-butter) contained in cocoa. There is also present a minute quantity of a volatile oil, on which depends in part the characteristic aroma.
The use of coffee and tea, or of a corresponding beverage, is almost universal among civilized nations. This fact is supposed to indicate that a need exists in the human constitution which these beverages supply. Such a view is hardly tenable, the highest physical and mental activity not being incompatible with entire abstinence from them. Under some circumstances, however, they are peculiarly grateful; for example, to remove the sense of fatigue and hunger, and to allay the mental unrest produced by fatigue and anxiety.
Coffee has a somewhat laxative action on most persons; on the other hand, tea has astringent properties — especially that variety known as green tea. It has been affirmed and denied that coffee and tea lessen the rate of tissue metamorphosis, and consequently the excretion of urea. If these beverages check waste, they may be considered as indirect nutrients. If used to excess as beverages, they derange the organs of digestion and excite functional disturbances of the nervous system—on the part of the digestive organs: acidity, flatulence, pyrosis, eructations, etc.; on the part of the nervous system: headache, vertigo, tinnitus aurium, and confusion of mind. The evil results of habitual excess are best seen in sewing-women addicted to tea-tippling. It is not uncommon for these women to live upon tea and bread for long periods, resulting in their becoming excessively nervous and dyspeptic. The mucus of the stomach plays the part of a ferment; the bread undergoes the acetic fermentation, and this process is facilitated by the presence of a quantity of a weak astringent solution. Disorders of digestion due to this cause can be removed by withdrawal of the offending beverage. It is not less true that the after-dinner cup of coffee not infrequently assists the digestion of a too elaborate dinner. Those accustomed to the morning cup of coffee are apt to suffer from headache if deprived of their usual beverage, partly because it hastens the intestinal movements and assists the morning evacuation, and partly because it favors the stomach digestion if not taken in excess.
A cup of strong coffee taken in the early morning is held to be prophylactic against malarial infection. Coffee produces wakefulness, and opposes opium narcosis; hence strong black coffee is one of the means resorted to in the treatment of opium-poisoning.
Cocoa, as already set forth, is more directly nutritious than coffee or tea, and, as it is rich in fatty matters, is much more difficult of digestion, so that many dyspeptics can not use it at all. Cocoa is the most useful beverage in those conditions of the system requiring nutritious aliment, especially in phthisis and similar wasting diseases, and should constitute a part of the diet in these maladies unless it disagrees.
Caffeine as a remedy will be considered in its appropriate place.