8 CAFFEIN IN ttEPHRECTOMIZED BABBITS. 



Bright's disease, stated that the amount of chlorin recovered exceeded 

 the total quantity ingested and eliminated in the urine, thus showing 

 undoubted compensatory elimination by the gastric epithelium. 

 They also observed that some of their patients vomited a fluid con- 

 taining chlorids when milk formed the exclusive diet. 



That other organs may behave in a manner similar to the stomach 

 and intestines appears from the following studies. Zezschwitz 80 

 examined the saliva of healthy people for urea, and found only traces 

 in some and no evidence of its presence in others. In cases of 

 nephritis, however, especially in chronic cases, he found appreciable 

 quantities of urea in the saliva. Powers 24 maintained many years 

 ago, on the basis of observations he made, that the elimination of total 

 nitrogen and urea by the skin was increased in cases of chronic 

 nephritis. 



The presence of a mechanism by which vicarious action or com- 

 pensatory elimination is brought about in the body has also received 

 support from experiments on animals. Claude Bernard 5 was proba- 

 bly the first to bring forward evidence of increased elimination, if not 

 of true vicarious action, by the gut, for he found that urea is elimi- 

 nated by the intestinal epithelium in dogs after the removal of both 

 kidneys from the circulation. He also demonstrated the presence 

 of potassium ferrocyanid in the saliva of dogs from which the kidneys 

 were removed or in which the ureters were tied. This substance 

 when injected into the circulation is not eliminated in the saliva of 

 normal dogs. Corroborative evidence of vicarious elimination was 

 furnished more recently by Achard and Loper. 1 After the adminis- 

 tration of potassium ferrocyanid to dogs whose kidneys were removed 

 they detected this substance in the lachrymal secretions, where in 

 the case of normal dogs it is not found. 



Kenewed interest in this subject has been shown within the last 

 few years. McCallum 15 endeavored to show that the intestine sup- 

 plements the eliminative function of the kidney. After infusing 

 large quantities of sodium chlorid into rabbits whose kidneys were 

 excluded from the circulation, he found large quantities of sugar in the 

 intestines and stomach. In one experiment in which the kidneys 

 were left intact the amount of glucose found in the small intestine 

 after the infusion of sodium chlorid was much less than that in the 

 animals in which the kidneys were deprived of their function. On 

 the basis of this evidence McCallum concluded that the intestine 

 assists the kidney in the function of elimination. 



This conclusion was disputed recently by Kleiner, 12 who carried 

 out a series of experiments on nephrectomized rabbits and on a large 

 number of controls which received solutions of dextrose intraven- 

 ously. He concluded that double nephrectomy increased the gastro- 

 intestinal elimination of dextrose, but the increase was too small to 



