2 Chittenden and Lambert — Experiments on the 



ism. The results, already published,* show plainly that all of the 

 uranyl salts, with one or two exceptions, have a more or less marked 

 inhibitory influence on amylolytic and proteolytic action. With 

 the salivary ferment, even 0-010 per cent, of uranyl nitrate was suffi- 

 cient to completely stop all action, while with pepsin-hydrochloric 

 acid and with alkaline trypsin solutions, 0*5 per cent, of the same 

 salt was required to produce an equal effect. In this case the 

 inhibitory action of the uranium salt was, in part at least, due to the 

 formation of a more or less definite and indigestible compound of 

 uranium with the proteid matter to be digested.f 



On the excretion of carbonic acid, uranyl nitrate, by a later series 

 of experiments,! was also found to have a marked influence. With 

 rabbits, the hypodermic injection of this salt was followed by a slight 

 rise in body temperature and a decided increase in the elimination 

 of carbonic acid. The action of the salt was somewhat slow, but 

 repetition of the experiment always led to an increase of body 

 temperature and a decided increase in the amount of carbonic acid 

 excreted. 0*7 gram of the salt in divided doses was required to 

 produce the result stated, the rabbit not suffering any apparent ill 

 effects from this quantity. 



The object of the present series of experiments has been : 1st, to 

 ascertain the influence of uranium salts on proteid metabolism ; 2d, 

 to ascertain something regarding the toxic action of uranium salts ; 

 and 3d, whether uranium has any influence on the production of 

 glycosuria. 



Influence on proteid metabolism. 



In this experiment a mongrel bitch weighing 18*8 kilos was em- 

 ployed. The animal was confined in a convenient cage suitably 

 arranged for the collection of the excreta, and was fed during the 

 experiment upon a constant diet of known composition. A large 

 quantity of fresh, lean beef finely chopped, was dessicated at a low 

 temperature until it had lost about 75 per cent, of water. It then 

 contained 11 "88 per cent, of nitrogen, as determined by Kjeldahl's 

 method. A large quantity of ordinary soda crackers were obtained 

 and when sampled were found to contain 0*69 per cent, of nitrogen. 

 40 grams of this prepared beef and 25 grams of the crackers, with 



* Chittendea and Hutchinson. Studies from the Laboratory of Physiological 

 Chemistry, Yale University, vol. ii. 



f See Chittenden and Whitehouse. Studies, vol. ii, p. 111. 

 X Chittenden and Cummins. Studies, vol. ii. 



