86 THE FORMATION OF FAT 



fat found in the bodies of these animals are formed 

 in their organism ; and when the full value of this 

 fact is recognized, it entitles us to conclude that a 

 certain quantity of oxygen, in some form or other, 

 separates from the constituents of their food ; for 

 without such a separation of oxygen, no fat could 

 possibly be formed from any one of these sub- 

 stances. 



The chemical analysis of the constituents of the 

 food of the graminivora shews in the clearest man- 

 ner that they contain carbon and oxygen in certain 

 proportions ; which, when reduced to equivalents, 

 yield the following series : 



In vegetable fibrine, albumen, and caseine, there are con- 

 tained, for 120 eq. carbon, 36 eq. oxygen 



In starch 120 100 



Incanesugar 120 110 



In gum 120 110 



In sugar of milk 120 120 



In grape sugar 120 140 



Now in aU fatty bodies there are contained, on an 

 average 



for 120 eq.carb. only 10 eq. oxygen. 



Since the carbon of the fatty constituents of the 

 animal body is derived from the food, seeing that 

 there is no other source whence it can be derived, 

 it is obvious, if we suppose fat to be formed from 

 albumen, fibrine, or caseine, that, for every 120 equi- 

 valents of carbon deposited as fat, 26 equivalents of 

 oxygen must be separated from the elements of these 

 substances ; and further, if we conceive fat to be 



