THE ACTION OF 1·2 : 5·6 DIBENZANTHRACENE ON THE METABOLISM OF RATS

1. Injection of 10 mg. followed by 15 mg. of 1·2 : 5·6 dibenzanthracene in adult rats did not alter the metabolic rate or the food consumption. 2. These injections, however, produced a prolonged loss of weight and death in 4 out of 8 rats. The deaths occurred 42 to 65 days after injection. 3. The inhibition of the growth of young rats by 1·2 : 5·6 dibenzanthracene was not affected by treating the rats with thyroid or insulin. 4. 1·2 : 5·6 dibenzanthracene in large doses did not affect normal cestrus in rats. This work was made possible by a grant from the Medical Research Council for the maintenance of animals and laboratory expenses, and by a personal grant from the Cancer Control Organisation for South‐East Scotland. Thanks are also due to Dr. C. M. Scott for advice and assistance.