_Case IV_,—J. L., age 30, was admitted to Dr. Keyes’ service in Bellevue Hospital in May, 1912, with the simple, but all-important, history of hematuria and frequency of urination for one year. A physical examination of the lungs revealed probable tubercular lesions. Cystoscopy with catheterization of the ureters was performed at once, showing pus from the right ureter whose orifice was swollen, with deficient function of the right kidney. A microscopical examination of the urine from this kidney showed the presence of Gram negative cocci (which could not be grown, however,) and later a culture of the bladder urine showed Gram negative cocci which were positively identified as gonococci. Finally, T. B. Bacilli were found in the bladder urine. Suspecting the right kidney of being tuberculous, 25% argyrol was injected into the right renal pelvis, and the right loin X-rayed. An excellent radiograph showed small round shadows throughout the kidney, and a mouse-eaten appearance of some of the papillae, a typical tuberculous picture. This diagnosis was subsequently confirmed by the finding of T. B. bacilli in the urine from the right kidney. The right kidney was accordingly removed, and found to be rotten throughout. It was likewise full of argyrol. When last heard from (February, 1915), the patient had gained considerable weight despite his lung condition. The above case was selected mainly to show what was doubtless a gonococcus infection engrafted on to a tubercular kidney, as it is only reasonable to suppose that the Gram negative cocci obtained from the right ureter were the same as those in the bladder which was subsequently found to be gonococci. Aside from the readiness with which the diagnosis of tuberculosis of the right kidney was made (by virtue of the T. B. bacilli in the urine) the swollen right ureteral orifice, pus from the same, and deficient function of the right kidney by the phenolsulphonephthalein test, the case is of further interest because of the corroboration of this diagnosis by pyelography after the injection of an organic silver preparation.