In a previous report1 the bacteriology of the urine in a number of cases of nonsuppurative nephritis was described. In all of the cases examined the urine contained numbers of bacteria, mostly anaerobes. In one case2 the bacterial flora of the urine was the same as that of a focus of infection in another part of the body. The bacteria isolated from the urine readily produced experimental nephritis. These facts led us to believe that bacteria multiplying in foci of infection frequently gain entrance to the blood stream and are excreted in viable condition through the kidneys, and that the excretion of bacteria in this way by the kidneys may be a common cause of nephritis.
It seemed desirable to examine a number of patients with evident focal infections to learn how frequently bacteria found in the focus of infection can be isolated from the urine, in what