CHAPTER XVI 

 FOOD ACCESSORIES, DKUGS, ALCOHOL, AND TOBACCO 



1. Food accessories and drugs. Through the alimentary 

 and respiratory tracts there are received into the blood not 

 only substances such as proteins, gelatin, fats, carbohydrates, 

 salts, and water, which we have described as supplying the 

 material for power and for growth and repair, but also other 

 substances capable of modifying in one way or another the 

 course of events within the body. The flavors which con- 

 tribute to the enjoyment of foods play an important r61e in 

 the secretion of the gastric juice, and yet the substances 

 which cause these flavors are negligible as sources of power. 

 Salt belongs under the same head, for we use in cooking 

 more salt than is needed to make good the daily loss from 

 the body, and we do this to develop an agreeable flavor in 

 our food. Substances of this kind are spoken of as food 

 accessories, and among them must be included coffee and tea, 

 for their effect is not chiefly a matter of nutrition ; certain 

 constituents of tea and coffee absorbed into the blood affect 

 the nervous system, and it is largely for this reason that we 

 use them. 



We may pass in this way from the necessary food acces- 

 sories through those, like coffee and tea, which, while not 

 essential, may still be regarded as part of the food of a large 

 portion of mankind, to the great number of chemical com- 

 pounds known as drugs, which also act by changing the 

 course of events within the body ; and it is difficult to draw 

 any sharp line of distinction between those which occasionally 

 serve as medicine or " stimulants " and those of which daily 

 use is made as food accessories. 



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