It is well known that uranium nitrate given subcutaneously to laboratory animals will produce varying degrees of kidney injury. Large single doses cause an extremely acute necrosis of the cells lining the convoluted tubules, from which the animal may not recover. But when smaller doses are given over a long period of time, a marked chronic nephritis results. Dickson1 demonstrated this in guinea-pigs. Christian2 and his associates have produced it in rabbits. MacNider3 has obtained similar results in rabbits and dogs. The kidney pathology in experimental uranium nephritis has been described. The urinary changes during the uranium intoxication have also been followed. But since much of this work was done before the advent of blood chemistry, correlated studies of the chemical changes in the blood and urine, the renal functional tests and the pathology of the kidneys at various stages of the intoxication have not been frequently done. MacNider's researches