MINERAL SUBSTANCES iS 



Mineral Substances. -— These occur in the plant in 

 various compounds of calcium, phosphorus, potassium, 

 sodium, and magnesium. In animals most of the mineral 

 matter is to be found in the bones, though phosphorus, as 

 has already been indicated, is essential to protein com- 

 pounds. 



Such feeds as bran, alfalfa, clover, and peas are high in 

 mineral matter, and for that reason are valuable for growing 

 animals which need the minerals for bone building. The 

 amount of mineral matter in feeds varies from .4 per 

 cent in wheat flour to 64.4 per cent in some samples of raw 

 ground bone. In animals, the mineral matter varies from 

 1.65 per cent in the fat pig to 4.66 per cent in the half 

 fat ox. 



Water. — ■ Water is found in varying amounts in all liv- 

 ing things. It is absolutely essential as a solvent of other 



WATER FAT EEOTEIiT 



Fig. 3. — Composition of the animal body. 



food materials ; it forms the basis of the circulating media 

 in the body ; and it regulates the temperature of the organ- 

 ism. In feeding stuffs, the amount of water varies from 

 about 6 per cent in weU-dried oat straw to over 90 per cent 

 in green clover crops. Growing plants contain relatively 

 more water than do mature ones. 



The bodies of young animals contain relatively more 

 water than do those of older ones. The fatter the animal 



