Page:Popular Science Monthly Volume 20.djvu/377

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THE CHEMISTRY OF COFFEE AND TEA.
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it can be made (simply by action of nitrous acid) from guanine, which is abundant enough in guano. Guanine is found here and there in animal excrementitious material, is produced by spiders, and occurs in the pancreatic gland of the horse, and in organs of the salmon. The extensive group of bodies related to xanthine and theine have been found a very rich field of chemical research. Theine itself is a body of a very simply distinctive chemical structure, from which numerous derivatives are readily constructed. Hitherto, however, the chemical synthesis of theine from inorganic elements fails by lack of some short link whereby to form uric acid from any one of its own derivatives, nearly all which can be artificially formed. But the change of guanine into theine is easily accomplished. It is perfectly practicable to bring guano material to the laboratory, and send away the same atomic elements transformed into the snow-white, silky crystals of theine. Given only a sufficient demand for the pure stimulant principle of tea and coffee, and a market value high enough above the cost of its vegetable sources, and it might then safely be predicted that not many months would elapse before companies with thousands of capital stock would engage successfully in the chemical manufacture of theine from guano. Then, very likely, rival companies would establish the claim to manufacture a still purer article from certain of the waste substances of the world—articles more accessible than guano.

But it must not be forgotten that theobromine, just mentioned as an intermediate body in the chemical transmutation of guanine into theine, is itself an alkaloid of well-known vegetable origin. It has been found in only one plant (the Theobroma cacao), a beautiful evergreen tree of Mexican nativity, extensively cultivated in South America, growing twenty to thirty feet high, bearing small flowers in clusters on the large branches, and yielding fruit in a purple-yellow pod, seven or eight inches long, each holding twenty to forty seeds—the "cocoa beans" of commerce. From these are prepared all the forms of chocolate, "cocoa," and "soluble cocoa," now in use over the world as a beverage, a competitor for the favor accorded to the more nearly equal claims of coffee and tea. At the discovery of Mexico and Peru, the Spaniards found chocolate from time beyond record an habitual beverage, and the chocolate-tree in extensive cultivation, in both countries.

The chemist has yet to find, if he can, a plant on the globe containing the alkaloid theine, or its chemical associate, theobromine, that has not been, by some of the races of men in some of the ages of the world, brought into use as a refreshing beverage, or adjunct to food, prized for adding cheerfulness to nourishment, and giving solace to fatigue. However the peoples of the world—while wholly unconscious of the identities of chemical science—have been guided in their search over forest and field for a herb to infuse, in a beverage that should cheer but not inebriate, it is certain that no hint