Abstract
1. Attempts were made by various treatments to reduce the retention of radiostrontium after a single injection in mice. Treatment was started 48 hours after injection to obtain a true elimination of the isotope instead of a prevention of its deposition. 2. Optimal results were obtained by feeding the mice a phosphorus-deficient diet. After six weeks on this diet the radiostrontium retention was reduced by 30 to 50 per cent in comparison with control mice.