1062 ABSORPTION 



that the potassium sulphate, which is so abundant in vegetables in- 

 teracts with the sodium chlorid of the blood, forming potassium chlo- 

 rid and sodium sulphate. Both salts are then removed in the urine 

 and hence, it becomes imperative to renew the sodium chlorid content 

 of the blood repeatedly in order to keep it fairly constant. 



Accessory Factors. — Besides the digestibihty and nutritive value 

 of the diet, practical dietetics must also pay attention to its palata- 

 bility. This involves cooking and the addition to the food of flavors, 

 condiments and stimulants. The first factor is important first of all 

 from an economic standpoint, because it tends to render the cheaper 

 foods more available and to decrease the perfectly appalling waste of 

 all food. Secondly, it makes the food more appetizing and destroys 

 its indigestible envelopes so that the digestive juices are able to attack 

 the nutritive material directly. Thirdly, it destroys parasites and 

 microorganisms and those antibodies which might inhibit the action 

 of the digestive juices. Thus, it is a well-known fact that raw white 

 of egg is not digested in the stomach, because it contains an antibody 

 which hinders the action of the pepsin, while a finely divided boiled 

 egg is more rapidly acted upon by this enzyme. Lastly, cooking is 

 of importance because it renders the food more bulky and macerates 

 the cellulose material of green food so that it can be more advanta- 

 geously utilized as ballast for the feces. This in itself stimulates peri- 

 stalsis and liberates certain substances possessing a laxative action. 



The flavors and condiments have no especial food-value, but are 

 of importance because they make the food more 'appetizing. They 

 are divided into (a) aromatics, inclusive of such substances as cinna- 

 mon, vanilla and nutmeg, (6) pepper, (c) alliaceous substances, such 

 as garlic and mustard, {d) acid condiments, such as pickles, vinegar 

 and citron, (e) salty substances, such as the ordinary table salt, and 

 (/) sugar. 



The stimulants consist of wine, beer, tea, coffee, chocolate and 

 cocoa. While some of these contain considerable amounts of nutritive 

 material, their principal action is very similar to that of the condiments, 

 i.e., they render the food appetizing and stimulate the secretions. 

 However nourishing a food may be, it eventually produces an antago- 

 nistic effect unless mixed with these stimulants. Thus, the rind of the 

 bread, the skin of fruits, and extracts of meat are almost as important 

 as the foodstuffs contained in these articles of diet. Besides, such 

 articles as beer and cocoa possess a distinct nutritive value, although 

 they do not form an adequate food when ingested alone. Thus, 14 

 liters of beer would be required to yield 15 grm. of nitrogen, and 10 

 liters of it to furnish 250 grm. of carbon. In the case of cocoa, we obtain 

 as much as 50 per cent, of fat, 4 per cent, of starch and 13 per cent, of 

 proteins, but excessive quantities would have to be consumed in order 

 to satisfy our caloric needs. Its stimulating alkaloid is theobromine 

 or dimethyl xanthin (C7H8N4O2), which exerts a tonic action upon the 

 nervous and vascular system similar to that of caffeine. 



