

THE Ml TABOLISM OP PRd 62] 



in cases of pernicious vomiting of pregnancy, there was a relative in- 

 crease in the ammonia excretion. We have already seen that I 

 increase did qoI bear any relationship to the acid-absorbing power of 

 the blood plasma (see page 617). 



The importance of tin "kidneys in removing the urm from thi blood 

 is readily seen Erom the change in the percentage of urea in ihis Hui<l 

 after the partial or complete removal of the kidneys. Animals sur- 

 vive nephrectomy Eor aboul three days, and during this time urea rapidly 

 accumulates in the blood and begins to make its appearance in the 

 saliva and the intestinal secretions. In man also where the kidi. 

 are extensively diseased, a similar accumulation of urea occurs in tin- 

 blood, some of the excess being got rid of through the sweat and to a 

 certain extent through the intestine. The importance of encouraging 

 perspiration and a free movement of the bowels in eases of nephritis 

 thus indicated. It must not be concluded that the accumulation of 

 area in the organism is the direct cause of the symptoms. Urea its 

 is comparatively inert, and it is generally believed thai other metabolic 

 products with which the urea runs parallel in amount are the toxic 

 agents. Hewlett has found, however, that very large injections of o 

 do produce symptoms in animals. ' 



