206 



Chalmers Watson, 



Two of the rats were on ox-flesh (with watei* ad libitum) which 

 had been their exclusive diet for four months previously; one was on 

 the standard diet (bread soaked with skim milk). The figures repre- 

 sent the intake and output for a period of four days. The weight 

 of the animal, and the total weight of food which it consumed are 

 also given. 



Ox-flesh 



Bread and Milk 

 C 



Weight of animal 

 Food consumed . 

 Intake of N . . 



Faeces 

 Output of N 



Urine . 

 Total . 



Difference 



290 gms 

 77 „ 

 2,286 

 0,129 

 2,101 

 2,230 

 + 0,056 



150 gms 

 37 „ 

 1,099 

 0,069 

 1,090 

 1,159 

 — 0,060 



170 gms 

 141 „ 

 1,297 

 0,173 

 1,079 

 1,252 

 J- 0,045 



It appears from this table 



1. That all the animals were practically in nitrogenous equi- 

 librium; 



2. That the quantity of food taken was such as to render the 

 amount of nitrogen metabolism per unit of body weight the same, 

 quite irrespective of the nature of the diet provided. Thus, taking 

 the average of intake and output to represent the nitrogen meta- 

 bolised, we get for each kilogram of body weight the following figures 

 (for 4 days). 



A 7,786 grnis. 



B 7,527 „ 



C 7,500 „ 



The result of this behaviour is that in the case (C) of bread 

 and milk, which contains much less proteid, 141 grms. of food had 

 to be consumed, as against 37 grms. by a flesh-fed animal {B) of 

 nearly the same weight. 



3. The distribution of excreted N between urine and faeces is, 

 however, materially affected by difference in the diet. On a diet of 



