Difference in Response to Uranium Nitrate. 161 



That the above differences in the response of puppies and adult 

 animals to a constant quantity of uranium are not dependent upon 

 the relative weight of the different animals and therefore associated 

 with the total amount of uranium received by the animal but are 

 associated with the difference in the age of the animals is clearly 

 shown by the following experiments: 



Experiment 18. — Puppy, aged 7 months. Weight 9.35 kilos. 

 The animal received 6.7 mg. of uranium nitrate per kilogram on 

 two successive days. The urine following the first injection con- 

 tained neither glucose nor acetone. Following the second injection 

 of uranium the urine contained 0.35 per cent, glucose and a trace of 

 acetone. 



Experiment 38. — Full-grown animal, old, weight 7 kilos. Fol- 

 lowing the first injection of 6.7 mg. of uranium nitrate per kilogram 

 the urine contained acetone and the animal developed a glycosuria. 

 Glucose was present in 1.21 per cent. Following the second in- 

 jection of uranium the amount of acetone was apparently greatly 

 increased. Glucose in the urine had increased to 2.84 per cent. 



The experiments were terminated by either shooting, or killing 

 the animals with chloroform or ether. 



In the account which is to follow of the fatty changes which are 

 induced in the liver and kidney of the animals of different ages, 

 none of the animals which were subjected to the effect of an anes- 

 thetic will be included. As has been previously shown the anes- 

 thetic very greatly increases these changes. 1 



Frozen sections were made at once and stained by Herxheimer's 

 Scharloch R method for fat. The sections were counter stained 

 by Mayer's Haemalum. It is important for both of these stains 

 to be fresh. 



The frozen sections have shown that the amount of fat in the 

 liver and in the kidney of puppies which have been given uranium 

 nitrate is very much less than in the adult animals. The fat in 

 the liver is found as dust-like particles which serve to outline the 

 bile capillaries while the epithelium of the interlobular bile ducts 

 contains larger quantities of fat in the form of coarse granules. 

 The cytoplasm of the liver cells contains numerous small fat 

 droplets, but the principal localization of the fat is either within the 



1 MacNider, Jour. Med. Research, XXVIII, III, 1913. 



