1915] Frederic G. Goodridge and Max Kahn 119 



Salkowski and Kojo (5), in a preliminary communication, re- 

 cently suggested several methods for the determination of colloidal 

 nitrogen in the urine. A year later, Kojo (6) published the results 

 of a comparative study of the various procedures suggested in this 

 connection. Kahn and Rosenbloom (7) studied the zinc-sulfate- 

 precipitable, colloidal, nitrogenous material from the urine of nor- 

 mal subjects, as well as of carcinomatous patients, and concluded 

 that the amount of colloidal nitrogen was invariably increased in 

 Carcinoma. They also found that diseases like myocarditis, diabetes, 

 leukemia, and anemia, likewise gave a high coUoidal-nitrogen index. 

 They concluded that this quantitative test was not specific for 

 Cancer. Kahn and Rosenbloom (8) studied the amount of col- 

 loidal nitrogen in the urine of a dog suffering from a malignant 

 neoplasm. In this case they used dialysis as a part of the method, 

 and found that the quantity of colloidal nitrogen was much greater 

 in the urine of the diseased dog than the amount present in the urine 

 of normal dogs. 



Volpe (9) found that the colloidal-nitrogen index is of special 

 value in Cancer diagnosis. Mancini (10), using the Salkowski 

 method, found that there were increased ehminations of colloidal 

 nitrogen in the urines of patients afflicted with Cancer, but this in- 

 crease also occurred in pneumonia and pleurisy. Semionov (11) 

 reported that the colloidal nitrogen Output is low in normal in- 

 dividuals and is increased in Cancer patients. He concluded that 

 although the normal index excliides the possibility of a malignant 

 growth, the increased amount of colloidal nitrogen in the urine is not 

 specific for Carcinoma. Konikov (12) found that the average 

 amount of colloidal nitrogen in the urine, as determined by the Sal- 

 kowski-Kojo method, was 1.68 percent of the total nitrogen in 

 normal cases, and 2.47 percent in carcinomatous individuals. Of 73 

 cases of Cancer investigated by him, only 9 showed a higher coeffi- 

 cient than 2.5 percent. 



According to Marcel, Labbe, Dauphin (13) and others, on the 

 other hand, increase in the urinary colloidal nitrogen is an index of 

 a derangement of nitrogenous metabolism; and while it may serve 

 to detect functional insufficiency in the liver, it is not at all specific 

 for cancerous states. Carforio (14), also, concluded that the col- 

 loidal nitrogen index is not pathognomonic of Cancer. 



