DOMESTICATED ANIMALS. 85 



of starch, C 12 H 10 10 , we take 9 equivalents of oxy- 

 gen, there will remain in 100 parts 



C I3 79-4 



H 10 10-8 



O 9-8 



The empirical formula of fat which comes nearest 

 to this is C H H 10 0, which gives in 100 parts 



C u 78-9 



H 10 11-6 



O 9.5 



According to this formula, an equivalent of 

 starch, in order to be changed into fat, would lose 1 

 equivalent of carbonic acid, C0 2 , and 7 equivalents 

 of oxygen. 



Now the composition of all saponifiable fatty 

 bodies agrees very closely with one or other of 

 these two formulae. 



If from 3 equivalents of sugar of milk, 3C 12 H 12 12 

 = CggHggOgg , we take awRy foui equivalents of wa- 

 ter and 31 of oxygen, there will remain C 36 H 22 0, a 

 formula which accurately represents the composition 

 of cholesterine, the fat of bile. (18) 



Whatever views we may entertain regarding the 

 origin of the fatty constituents of the body, this 

 much at least is undeniable, that the herbs and roots 

 consumed by the cow contain no butter; that in 

 hay or the other fodder of oxen no beef suet exists ; 

 that no hog's lard can be found in the potato refuse 

 given to swine ; and that the food of geese or fowls 

 contains no goose fat or capon fat. The masses of 



