CHAPTER XXXVII 

 .- Composition of Animal Bodies 



485. Water and Dry Matter. About half of the live 

 weight of an animal is water. In fat animals, the pro- 

 portion of water is less than in lean animals. The same 

 general classes of organic compounds present in plants, 

 as non-nitrogenous and nitrogenous, are also present in 

 animal bodies ; the animal forms, however, are usually 

 somewhat more complex than the plant forms. Animal 

 bodies are characterized by containing a high per cent, of 

 fat and proteid materials and a low per cent, of non- 

 nitrogenous compounds other than fat. 



486. Mineral Matter. The ash elements in the animal 

 body are the same as those found in plants, and are 

 nearly all furnished from vegetable sources. The body 

 of an animal, live weight basis, contains from 2 to 4 per 

 cent, of mineral matter, from a half to three-fourths of 

 which is present in the bones, while the remainder is pres- 

 ent both in solution in the various fluids, as the blood, 

 chyle, etc., and deposited and combined with the solid 

 and fleshy tissues of the body. Silicon in animal bodies 

 is found mainly in the hair, wool and feathers. Sodium 

 and chlorin, while unnecessary to plants, are absolutely 

 necessary to animals. A thousand parts of blood yield 

 about 4 parts of mineral matter, of which 1.2 are 

 sodium chlorid. In the blood, salt is necessary as a sol- 

 vent for the proteids. 



The per cent, of ash in the carcasses of different ani- 



