On the difference in the response of animals of different ages to a constant quantity of uranium nitrate. 1

The following report is based upon the difference in the response of forty-eight animals of different ages to a constant quantity of uranium nitrate.

Dogs have been employed in all of the experiments. The animals have varied in age from puppies of four months old, to animals of extreme old age, one of the animals having reached the age of twenty years.

All of the animals have received uranium nitrate in the dose of 6.7 mgs. per kilogram on two successive days. The uranium was given subcutaneously.

The animals were fed on raw meat and bread.

In a recent publication 2 it has been shown that when a constant quantity of uranium nitrate is given to young and full grown animals, that the age of the animal influences the total output of urine and also the composition of the urine. The total output of urine in a twenty-four hour period was greater in the adult animals. The percentage of glucose in the urine (Benedict determination) was greater in the adult animals than in the puppies.

In the urine of the puppies acetone was either absent or present in very small amount. The urine of the adult animals invariably contained acetone.

The present series of forty-eight animals shows the same differences in the total output of urine and in the composition of the urine as has been above referred to.

In addition, these animals of different ages show certain other characteristics which are apparently dependent upon the age of the animal.

1. Ten of the animals were puppies varying in age from four to eight and a half months. Only one of these animals developed a glycosuria within the first twenty-four hours following the initial injection of 6.7 mgs. of uranium. The percentage of glucose in the urine of this animal was 0.103 per cent.