The occurrence of indicanuria and its relation to putrefactive changes in the alimentary tract are well known. At one time there was considerable speculation in scientific circles regarding the origin of indican, some investigators being inclined to ascribe a part of the excreted product to abnormal changes in the tissues. The preponderance of evidence, however, points to indol, formed by bacterial decomposition of protein in the intestine, as the chief, if not the exclusive, precursor of urinary indican. The output of the latter appears to depend quite as much on the quantity and chemical character of the protein components of the diet as on the opportunities for bacterial changes in the alimentary tract.
One of the significant features of insufficiency of kidney function is the accumulation of catabolites in the blood. For example, the content of urea, uric acid and creatinin may be markedly augmented in the circulating medium of