246 



ON THE EXCRETION OF 



Kynurenic acid excretion has also been investigated in 

 three dogs which were kept in nitrogenous equilibrium on a 

 fixed diet of meat, fat, and carbohydrates. The animals were 

 used in a research carried out in this laboratory on the in- 

 fluence of borax and boric acid on nutrition. Through the 

 kindness of Dr. Gies we have obtained equivalent portions of 

 each day's urine and have examined them for kynurenic acid, 

 the fractions of each period being united and analyzed col- 

 lectively. Further data are taken from the tables already 

 published.* 



FIRST EXPERIMENT. 



It will be observed from the tables that the only periods 

 during which kynurenic acid appeared hi the urine were those 

 in which administration of borax or boric acid gave rise to a 

 direct stimulation of proteid metabolism. This is particularly 

 brought out in the third experiment, during which a daily 



* Chittenden and Gies, Amer. Journ. Physiol., 1898, i, p. 1. 



