HYGIENE OF DIGESTION 139 



through scientific experimentation, that, in dogs, fear, anger, and 

 rage interfered with proper digestion and altered the character of 

 the digestive juices. 



Food should be thoroughly chewed to be properly mixed with 

 the saliva. As much water as possible should be taken each day. 

 There is no objection to drinking water with the meals, providing 

 that it is not so cold that the organs might be chilled, and that the 

 food is thoroughly masticated and not washed down by the water. 



As the undigested part of the food passes through the colon, 

 it gradually loses its water through the process of absorption. 

 This waste becomes semisolid. It should be removed dailv at 

 a regular time. If this defecation does not take place because of 

 haste, or inconvenience, or some irregularity in the routine, the 

 water in the solid waste becomes absorbed and the waste be- 

 comes so compact that it is difficult and in some cases impossible 

 to eliminate. A cathartic or laxative must then be taken to stimu- 

 late the activitv of the intestinal movement. It is a well-known 

 fact that improper foods may cause constipation. This condi- 

 tion may be avoided by eating bulky foods which will stimulate 

 the work of the muscles of the canal. Such bulkv foods are 

 vegetables, salads, and fruits. Proper routine, including regu- 

 larity of meals and regular times for elimination of wastes, must, 

 also, be established. 



Laxatives are useful in removing an acute condition of constipa- 

 tion but should not be taken regularly. Some laxatives contain 

 drugs that stimulate the nerves controlling the muscles used in 

 defecation. Other laxatives called^ the salines contain the salts 

 of sodium, potassium, and magnesium. They cannot be absorbed 

 by the intestine. They hold a great deal of water in solution and 

 increase and soften the bulk of the material, favoring its move- 

 ment along the canal. Epsom salts, magnesium citrate, and so- 

 dium phosphate are examples of saline cathartics. A third type 

 of laxatives is heavy oil, mineral or castor oil. These line the food 



