BIOLOGY APPLIED TO HEALTHFUL LIVING 531 



with no more than the necessary amount of properly cooked 

 food the average individual can safely follow his natural 

 instincts as to the amount of mastication. There are those 

 who point to the rumination of cows and sheep for evidence 

 that naturally animals masticate food for a long time; but 

 this gives no rule for human guidance. In the first place, 

 a cow's natural food is uncooked and otherwise unprepared ; 

 second, her digestive organs are quite unlike the human; 

 and, third, dogs more closely resemble man in structure and 

 in foods and they never masticate. Obviously, it cannot be 

 concluded that man should chew his food long because cows 

 and sheep do. The only scientific conclusion must be based 

 upon individual human experience; and this indicates that 

 some people with weak digestion of starch need to give 

 special attention to mastication, but that most people may 

 safely forget their jaws while eating (i.e., masticate instinc- 

 tively) provided that they do not eat too rapidly or in excess. 

 However, it is well for each person to experiment upon him- 

 self, and thus determine how far special attention to masti- 

 cation is important for himself. 



One point in favor of thorough mastication deserves men- 

 tion, namely, that it tends to prevent overeating. When food 

 is rapidly swallowed, there may be an excess taken before the 

 gastric nerves give us warning of too much food. Prolonged 

 mastication tends to avoid this result, possibly because the 

 sugar obtained from the salivary digestion acts upon the 

 gastric nerves just as sweets before a meal " take away the 

 appetite " or reduce it. However, it is well never to eat until 

 hunger is completely satisfied, and this rule would avoid most 

 overeating. 



Stimulants. Should digestive stimulants be avoided, is 

 a much-discussed question, usually with regard to alcoholic 

 drinks. It also should apply to spices, condiments, coffee, 

 tea, cocoa, carbonated water, and even hot food ; for these 

 all have some stimulating effect upon the digestive organs. 



