Merbaphen (novasurol), an organic mercury compound, is at present being used as a diuretic in the treatment of certain patients with edema and ascites. It is well known that mercury readily damages the kidney. We1 have shown that merbaphen, though less toxic than certain other mercurials, in sufficient doses brings about degenerative changes in the renal epithelium of the rabbit identical with that produced by the other less complex mercury compounds in common use.
In this investigation, a further study of the action of merbaphen was made by carrying out combined functional and histologic observations in the dog. Five animals were employed. As shown by MacNider2 and Dayton,3 the dog is subject to spontaneous renal disease. To avoid confusion from this factor, the animals were subjected to functional tests and the urine examined before merbaphen was injected. The characteristic lesions of spontaneous nephritis as described by these authors were also