154 BIOLOGY AND HUMAN LIFE 



impossible a thorough mixing of sahva with the food and the 

 breaking up of food particles so that the gastric (stomach) juices 

 may reach the proteins properly. The time saved by eating too 

 rapidly is generally paid for later by indigestion. 



3. Water with meals. Many people have the notion that 

 water must not be taken with meals or with fish or with some 

 other particular kind of food. Experiments show, however, that 

 a person can take a quart of water at a meal without any harm- 

 ful results but, rather, with beneficial results. Probably none of 

 us ever drinks too much water. On the other hand, it is not 

 well to take water or any other fluid while there is solid food in 

 the mouth. Softening the food in this way hastens the swallow- 

 ing and prevents a thorough mixing of saliva with the food. 

 Water should never be a substitute for saliva to soften the food 

 or to aid in swallowing. Then the water should not be too cold. 

 Ice water as an introduction to a meal should especially be 

 avoided, since chilling the stomach is a decided handicap for the 

 work that is about to be placed upon it. 



4. Humanly speaking. Cattle and guinea pigs can be kept alive indefi- 

 nitely on a monotonous diet of ''essentials." When the same thing is 

 tried with human beings, they gradually lose those characters that dis- 

 tinguish them from the cattle or the guinea pigs ; one of the things that 

 drive men to drink and to drugs is the attempt to make them live like 

 cattle. The cheapest diet is commonly recommended to people who have 

 little of the pleasures of life and little time or training for enjoying the 

 more refined forms of pastime and recreation ; but the comparatively 

 simple pleasures of eating should not be denied to these people. 



131. Constipation, The digested foods are absorbed for the 

 most part by the villi of the small intestine (see section 115). 

 The refuse remaining by the time the mass has passed into the 

 large intestine is now subject to the decaying activities of bac- 

 teria, which are always present in the food tube. There are 

 thus produced substances which are poisonous if absorbed into 

 the blood and distributed to the living cells of the body. The 

 poisoning of the body by waste substances absorbed from the 

 large intestine is sometimes called autointoxication, or self- 



