FOODOl" ANIMALS. 199 



time. Thus, although the albuminous principle is all that is required 

 to replace the fibrin of the blood consumed in the act of nutrition, 

 yet animals fed on white of egg alone, perish after a certain time 

 of starvation. For a still stronger reason, animals fed on pure 

 sugar, or gum, or starch, or oil alone, die of starvation, for these 

 substances contain no materials for repairing the waste of the tis- 

 sues. In the simplest kind of food, as that of carnivorous ani- 

 mals, there is a mixture of the albuminous principle with fat. In 

 the food of herbivorous animals there is a mixture of the albumi- 

 nous with the saccharine, and with a smillor portion of the oleagi- 

 nous principle. 



"But," says Prout, " it is in the artificial food of man that we 

 see this great principle of mixture most strongly exemplified. 

 He, dissatisfied with the productions spontaneously furnished by 

 aature, culls from every source, and by the power of his reason, or 

 rather of his instinct, frames in every possible manner, and under 

 n cry disguise, the same great alimentary compound. This, after 

 ill his cooking and art, however he may be inclined to disbelieve 

 t, is the whole object of his labor, and the more nearly his results 

 ipproach this, the more nearly they approach perfection. Thus, 

 rom the earliest times, instinct has taught him to add oil or butter 

 farinaceous substances, such as bread, which are naturally de- 

 ■ective in this principle. The same instinct has taught him to fat- 

 en animals with the view of procuring the oleaginous in conjunc- 

 ion with the albuminous principle, which compound he finally 

 onsumes, for the most part, in conjunction with saccharine prin- 

 iples, in the form of bread and vegetables. Even in the utmost 

 sfinements of his luxury, and in his choicest delicacies, the same 

 .reat principle is attended to ; and his sugar and flour, his eggs and 

 'utter, in all their various forms and combinations, are nothing 

 lore nor less than disguised imitations of the great alimentary pro- 

 j)type — milk — as presented to him by nature." 

 i From what precedes, it will be seen that there are three great 

 aminal principles of food : 



1st. The albuminous, which is destined to repair the loss of the 

 ssues in the act of nutrition ; that is, destined to be converted into 

 iganized tissues. 



2. The oleaginous principle, containing a large proportion (60 

 1 r cent) of carbon united with hydrogen and oxygen, but not in 



