CACAO.

Theobroma Cacao, Linn.

Nat. order , Sterculiaceæ.

Tribe , Buettnerieæ.

Common name , Cocoa (chocolate in part).

Preparation , Trituration of the seeds (crude).

Authority.

Marvaud, Aliments d'épargne.

In order to ascertain the effect of the active principles (aromatic essences and theobromin) contained in Cacao upon the nervous system and its dependencies, it was necessary to separate those principles, as far as possible, from the fatty substances (Butter of Cacao) of which the beans are so largely composed.

With this view, we prepared a decoction of powdered Cacao in boiling water, and conducted our experiments with this liquid.

By placing ourselves under the influence of a decoction highly charged with aromatic principles, and made from powdered Cacao well roasted, we ascertained that this beverage produces an excitement of the nervous system similar to that caused by a strong infusion of black coffee; since these effects are insignificant if a decoction of the raw bean is employed, it is natural to attribute them to the aromatic essences which are developed in the Cacao by the process of roasting.

A still wider difference is observed when we compare the effects on the circulation respectively produced by a decoction of powdered Cacao roasted, and one of the same substance in a crude state. In the former case, the sphygmographic tracing indicates an excited state of the circulation, as shown by an accelerated pulse, with increased fulness and diminished arterial tension.

When, on the other hand, an infusion of the raw bean is made use of, the action of the theobromin predominates, and an entirely different character of pulse is the result, as may be placed beyond doubt by examining the following traces, obtained from a single individual.

In explaining the nutritive value of Cacao, we must take into account the presence in this substance of a special alkaloid, theobromin, whose physiological effects are identical with those of caffeine and thein (as we have proved by numerous experiments), and which, retarding the organic waste in the same way as the active principles of coffee and tea, place Cacao high up among "les aliments d'épargne ou antidéperditeurs" (the conservative substances, or those which check tissue-waste).

Normal pulse.

Pulse five minutes after a decoction of the roasted bean. (Action of the aromatic essences.)

Pulse fifteen minutes after a decoction of the crude bean. (Action of Theobromin.)