80 



Drs. F. A. Bainbridge and A. P. Beddard. [Nov. 20, 





Total N intake. 



Daily average. 



Total N in 

 urine. 



Daily average. 



After first operation — 

 3 days' period 



grammes. 

 25-2 



23'4 



24-2 







grammes. 

 8-4 



3 9 



4-03 

 



grammes. 

 11 -3 



12-86 

 16-0 

 3-72 



grammes. 

 3-77 



2-14 



2-6 



0-93 



After second operation — 

 First 6 days 



Second 6 days 



Last 4 days 





The nitrogen intake for Cat III is not absolutely exact, since the meat and 

 milk were not analysed every day. 



The clinical condition of these cats was apparently identical with that of 

 Eose Bradford's dogs ; in both cases, the second operation was usually 

 followed by rapid wasting. In two of the three cats considerably more than 

 three-quarters of the total kidney weight was removed; in the third cat 

 rather less than three-quarters was removed, but since the animal died, one 

 may conclude that cats need rather more kidney than dogs in order to main- 

 tain life. In this connection it may be noted that in cats the average kidney 

 weight is 9*1 grammes per kilo., as compared with 6*7 grammes per kilo, 

 in dogs. 



There is no doubt, then, that the experimental conditions of Bradford's 

 dogs were strictly reproduced. Yet one of the cats showed no increased 

 output of nitrogen after the second operation ; in one cat the increase of 

 nitrogen first occurred five days after the operation, when the cat had lost 

 28 per cent, of its weight, and was almost moribund ; and in the other cat 

 the increase occurred four days after the operation, when the loss of 

 weight was 22*5 per cent. 



In none of the cats did the nitrogen output after the second operation ever 

 reach that observed after the first operation, and it never greatly exceeded 

 that found in normal fasting cats. The greatest daily output of urinary 

 nitrogen after the second operation, when the cats refused food, was 1*79 in 

 Cat II on the last day of life. For normal cats kept without food for 24 hours 

 the output of urinary nitrogen is about 1 gramme and the loss of weight 

 about 100 grammes. 



The protocols, moreover, show that the second operation has no appre- 

 ciable effect upon the percentage of urea, ammonia and creatinin relatively 

 to the total nitrogen. There is no increase in the output of creatinin (on 

 a milk diet) such as might be expected if muscular metabolism were 

 excessive. 



"We find, therefore, that the removal of three-quarters of the kidney weight 

 of cats has no influence upon their nitrogenous metabolism until the last 



