152 The Feeding of Animals 



working, walking, breathing, the beating of the heart, 

 the movements of the stomach and intestines, as heat, 

 and as chemical energy necessary for carrying on di- 

 gestion and other metabolic changes. The animal body 

 is certainly the seat of greatly varied and complex 

 constructive and destructive activities, which are sus- 

 tained by the matter and potential energy of the food. 

 How this is done we do not fully understand, but we 

 know many facts which are of great scientific and prac- 

 tical importance and which the feeder must consciously 

 or unconsciously recognize if he would not come into 

 conflict with immutable laws. 



FUNCTIONS OF THE MINERAL COMPOUNDS OF 

 THE FOOD 



We have learned that mineral compounds are abun- 

 dant in the animal body. The tissues, the blood, di- 

 gestive fluids and especially the bony framework con- 

 tain a variety of these bodies, which are as essential 

 as any other substances to the building and mainte- 

 nance of the animal organism. Bone formation with- 

 out phosphoric acid and lime is not possible, and to 

 deprive the digestive juices of the chlorine and soda 

 which they contain would be to destroy their useful- 

 ness. Young animals fail to develop if given no 

 mineral food, and mature animals when entirely de- 

 prived of even one substance, common salt, become 

 weak, inactive and finally die. Not only must the 

 growing calf have the ash compounds for constructive 

 purposes, but the mature ox must be supplied with 



