Coffee and caffein are physiologically antagonistic to the common narcotics, nicotine, morphine, opium, alcohol, etc., and are frequently used as antidotes for these poisons. Binz found that dogs that have been stupified with alcohol could be awakened with coffee. It may thus be prescribed for hard drinkers to counteract the baleful excitability produced by alcohol; in fact, many topers taper off after a long debauch with coffee containing small amounts of alcoholic beverages. Considering its ability to counteract the slow intoxication of tobacco, it may be inferred that coffee is indispensable for hard smokers. In general, the medicinal value of coffee may be said to be directly attributable to its caffein content, although its antiseptic properties are dependent upon the volatile aromatic constituents. Its function is to raise and to sustain vitalities which have been lowered by disease or drugs. Although some of the cures attributed to it are probably purely traditional; still, it must be admitted, that by utilizing its stimulating qualities in many illnesses the patient may be carried past the danger point into convalescence. _Physiological Action of "Caffetannic Acid_" It has been demonstrated in chapter XVII that there is no definite compound "caffetannic acid," and that the heterogeneous material designated by this name does not possess the properties of tanning. Further substantiation of this contention, and more evidence of the innocuous character of the tannin-like compounds in coffee, are contained in the testimony of Sollmann.[247] "Tannins precipitate proteins, gelatine, and connective tissue, and thus act as astringents, styptics, and antiseptics. The different tannins are not equivalent in these respects. Some (which are perhaps misnamed) such as those of coffee and ipecac, are practically non-precipitant.... On the whole, one may say that the small quantities of tannin ordinarily taken with the food and drink are not injurious, but that large quantities (excessive tea drinking) are certainly deleterious. The tannin of coffee is scarcely astringent, and, therefore, lacks this action," which is proven by the fact that it does not precipitate proteins. "It has been claimed that 'caffetannic acid' injures the stomach walls, but there is no evidence that this is so."[248] Wiley,[249] in reporting some of his experiments, says: "Apparently the efforts to saddle the injurious effects of coffee-drinking upon caffetannic acid in any form in which it may exist in the coffee-extract are not supported by these recent data." The fact that tannins retard intestinal peristalsis, whereas coffee promotes this digestive action, lends further proof to the non-existence of tannin in coffee. These statements by eminent authorities may be consolidated into the verity that there is no tannin, in the true sense of the term, in coffee; and that the constituents of the coffee brew which have been so designated are physiologically harmless.