38 Animal Heat. 



creature itself. In short, food possessing elements 

 exclusively of one kind, too rich in nitrogen, or 

 too rich in carbon, at once proves insufficient to 

 support life in a proper manner for any length of 

 time. The experiments of Majendie and others 

 who fed animals exclusively on one of the sub- 

 stances known as sugar, gum, starch, albumen, 

 fibrine, or caseine, set this matter at rest for 

 ever, and we are thereby taught that the animal 

 economy can live and thrive only upon food pro- 

 vided naturally, and which contains all the ele- 

 ments calculated to minister to the tissues and 

 functions of the body. 



The poor inhabitants of Ireland, as well as the 

 negroes of the Indies, also establish the truth of 

 the principle. The former, who consume potatoes 

 in large quantity, would exist in a poor degree 

 of capability for exertion, were they not to add to 

 this expensive and innutritious article of diet one 

 of the compounds very rich in nitrogen, viz., milk. 



The coolies, who eat impure sugar, receive with 

 it also nitrogenous compounds, gathered from the 

 vegetable kingdom, and all the eaters of maize 

 and rice resort to milk for the azotised principle, 

 caseine. 



Food, rich in mixed characters, supplies the 

 necessary elements without disturbing the balance 

 of the functions, which occurs when too much of 

 one kind is given indiscriminately. All vegetable 

 food is of a mixed character, but each kind 

 differs in the richness of its constituents. A 



