METABOLISM 



145 



4. The total amount of nitrogen eliminated by the rat during twenty- 

 four hours at different weights may be determined with a high degree of 

 accuracy by the formula (40) . 



For the nitrogen exchange in normal albino rats, the average 



values for three 3 day periods are given according to increasing 



body weight in table 100 (Cramer and Pringle, '10). 



TABLE 99 



Showing the average amount of urine, feces, and nitrogen -per day. Male rats alone 



were used. Average values for body weight groups 



These observations show that the nitrogen in the urine in- 

 creases with the increase in body w^eight, w^hile that in the feces 

 and that retained, diminish. 



The distribution of nitrogen in the urine has been studied by 

 Ordway and Morris ('13) in 3'oung rats — two males and one fe- 

 male — and their results are given in table 101. 



Folin and Morris ('13) have made similar studies in older rats 

 and their determinations are given in tables 193 and 150. 



