The experiments described in this paper were begun with the intention of determining the effect of uranium nitrate on the excretion of creatinin by the kidney, and the effect of creatinin injections on the nephritis produced by uranium nitrate. Chlorids were estimated in the last three experiments to check up the results with creatinin. Uric acid estimations were added, as it was found that no work had been done on the subject. The work was begun in the winter of 1911, during the writer's second year at the Johns Hopkins Medical School, but was not successful at that time. The experiments described below were conducted in this laboratory during the two succeeding summers of 1911 and 1912.
A. Methods.—Dogs which had not previously been used for any experimentation were taken. They were kept in cages of the type described by Dr. Gies.1 The