Sodium chlorid, though a true inorganic food and required to the amount of about 10 grams a day, is often used in excessive amounts as a relish. It has even been held accountable for cancer but without sufficient grounds. While it would seem that the formation of hydrochloric acid and the various osmotic processes in which salt takes part might be performed with the quantity ingested as a constituent part of an ordinary diet, almost all races of man and even quadrupeds have a natural craving for salt. Wild animals travel miles to salt licks and domestic animals allow themselves to be caught for the sake of a handful of salt. Whenever a high tax on salt has prevented its use, the health of the people has suffered, though it is only fair to consider that there has doubtless been a dearth of organic food also. Thus, the addition of reasonable amounts of salt to the diet seems justified on physiologic grounds, though the amount ingested altogether should not exceed 20 grams.

See discussion of hyper- and hypochlorhydria and dropsy.

Various spices, notably peppers, mustard, etc., are commonly used in preparing food and some persons use an excessive quantity. It is possible that even moderate amounts, long continued, may induce sclerosis of the liver, kidney, etc., while larger amounts undoubtedly cause gastro-enteritis of mild grade. It has been demonstrated that the normal and a fortiori, the hyperchlorhydric stomach is stimulated to secrete more hydrochloric acid by condiments. On the other hand, in hypochlorhydria, the intention for which these stimulants are given, usually fails. Hence, it is wise to use all such substances very moderately, although they are of occasional value to relieve nausea and to stimulate appetite and even the secretions, at least of the salivary glands and stomach. Nearly all of the spices are toxic in sufficient dose, myristica (nutmeg, including mace) especially so. Vanilla also produces anaemia and general depression in those engaged in its preparation.

Initiative mental and physical energy seems to depend largely on the presence of purins in the system. These will be considered elsewhere, but in this connection, may be mentioned the close relation of the active principles of a group of beverages to one of the chief excrementitious purins. Xanthin is found in human and other urines; Mono-methyl-xanthin in rabbit's urine; dimethyl-xanthin is theine or caffeine of tea and coffee; tri-methyl-xanthin is theobromine of chocolate. Mate, guarana and cola are practically equivalents of tea and coffee. Thus considerable portions of both continents are supplied with indigenous plants furnishing mild stimulant beverages. Betel nut and coca erythroxylon leaves are also chewed as stimulants.

Contrasting tea and coffee, the former is more apt to cause constipation and chronic gastro-enteritis of mild grade on account of its greater content of tannin, while the latter is more apt to produce cardiac palpitation and nervous disturbance on account of the relatively greater proportion of caffeine. Tea should be prepared by infusion with boiling water, not by boiling in water, whereas coffee should be prepared by boiling or, better by percolation or the use of a double celled tank, the upper holding the coffee, the lower the water, which rises by steam pressure as it boils, so as to percolate once or twice through the coffee.

The proportion of caffeine varies considerably in different samples and the beverage is, of course, of very different strengths, according to the amount of tea or coffee used and the time allowed for infusion or decoction. Thus, a cupful (about 200 c.c.) may contain anywhere from one to ten centigrams of caffeine, on the average two or three.

Cacao beans contain, both in the coats and the kernel, about 2% of theobromine. The best grades of bitter chocolate contain about the same amount, while the proportion in sweet chocolate, the mucilaginous cocoas, etc., varies according to the amount of sugar, meal, etc., used in making up the mass. Chocolate is best made by rubbing up the cake with water, to make a soft paste and stirring this evenly into hot milk or equal parts of hot milk and water. A cupful of chocolate or cocoa may contain anywhere up to 30 centigrams of theobromine. As compared with caffeine, theobromine is more diuretic and less powerful either as a primary cardiac stimulant or secondary cardiac depressant. For some reason, it is less likely to cause a pathologic habit, although the use of chocolate either as a beverage or in the form of the sweet or bitter cake or of the beans, and to a serious degree, is not rare and the effects are very much the same as from coffee but almost entirely limited to alkoloidal poisoning, there being relatively little tannin.

For various reasons, tea, coffee, and chocolate are used to stimulate intellectual and physical activity and to replace food. The most harmful effects are seen in poor working women who economize on food and keep a strong decoction (not infusion) of tea on the stove, consuming considerable quantities both of theine and tannin during the day.

The most justifiable use of these adjuvants to food is in some emergency, requiring physical exertion, exposure to extreme cold, or mental keenness. A shipwreck, a battle before which there is no time for preparing a hearty meal, a labor case - either for the patient or physician - , an examination, are examples. On account of portability and considerable organic food value, cakes of sweet chocolate, which are also convenient on account of allowing quite accurate estimation of theobromine content and caloric value, should not be forgotten in such emergencies. The medicinal use of these stimulants, mainly strong decoctions of coffee, in opium poisoning, shock, etc., need only be mentioned.

The principal danger of these stimulants is their habitual use to stimulate the fatigued brain and muscles in the morning, to continue such stimulation during the day and to postpone the natural feeling of drowsiness in the evening. Especially senseless, is the serving of coffee at the close of social functions, after the excuse for stimulation has ceased to exist and with the result of rendering the individual wakeful when he has a chance to sleep.