792 NUTRITION AND HEAT REGULATION. 



proteids of food may be replaced by gelatin. In his experiments 

 a dog was brought into a condition of nitrogenous equilibrium upon 

 a diet of meat, rice, and lard, containing 9.73 gms. of nitrogen. 

 During the period this diet was continued the animal, whose weight 

 was 16.5 kgms., was oxidizing in its body 3.7 gms. of proteid daily 

 for each kilogram of weight. In a second period lasting four days 

 the quantities of rice and lard were the same as before, but the pro- 

 teid in the diet was reduced to 8.2 gms., or 1.3 gms. of nitrogen; the 

 balance of the necessary nitrogen was supplied in the form of gela- 

 tin, so that in round numbers only one-seventh of the required daily 

 amount of nitrogen was given as proteid. The result was that the 

 animal maintained its nitrogen equilibrium for the short period 

 stated. It was found that the experiments could not be continued 

 longer than four days, owing to the growing dislike of the animal 

 for the gelatin food. During the second period the animal was 

 receiving in its food and burning in its body only 0.5 gm. of pro- 

 teid daily for each kilogram of weight, as against 3.7 gms. upon 

 a normal diet. 



