1. A chronic nephritis was produced in the dog which involves all of the histological elements of the kidney by the use of one subcutaneous injection of 4 mg. of uranium nitrate per kilo. In such animals the sequence of the histological changes in the kidneys in correlation with their functional expression has been studied in dogs from the commencement of the; injury until the chronic nehritis has existed for 5 years and 2 months.
2. As early as the 2nd day following the development of an acute nephritis, the animals became polyuric with an albuminous urine containing granular casts. There was a marked reduction in the elimination of phenolsulphonephthalein, or it failed to appear in the urine in a 2 hour period. The reserve alkali of the blood was reduced to as low as 7.8 and a retention occurred in urea nitrogen, non-protein nitrogen and creatinine. At such periods of renal functional depression there was slight evidence of structural glomerular injury but marked evidence of proximal convoluted tubule degeneration and necrosis.