XVII.—InNFLUVENcE or Uranium SALTs ON THE AmyYLOLyTIC 
Action oF SALIVA AND THE ProtrEoLtytTic AcTION oF PEPSIN 
AND Trypstn. By R. H. Currrenpen anp M. T. Hutcn- 
INSON, Pu.B. 
Lirtie is known regarding the physiological, or even toxical action 
of the uranium salts. In 1825, Gmelin* reported upon the results of 
some experiments on the toxic action of uranic nitrate, but aside 
from the work done at that time, little is known regarding the action 
of uranium. It is our purpose, therefore, to carry out in this Lab- 
oratory, as opportunity offers, a series of experiments on the physio- 
logical and toxical action of uranium salts, and we have commenced 
the work by endeavoring to ascertain the influence of the above salts 
on the amylolytic and proteolytic action of the ferments occurring in 
the digestive fluids of the body. In this connection we wish to ex- 
press our obligations to Professor H. Carrington Bolton, of Trinity 
College, for his kindness in supplying us with an abundance of 
chemically pure uranium compounds. 
1. Influence on the amylolytic action of saliva. 
The method employed in determining the extent of amylolytic 
action was much the same as that previously+ used by one of us, 
except that the amounts of reducing substances formed under the 
different conditions of the experiments, were determined volumetri- 
cally by Fehling’s solution, instead of by Allihn’s gravimetric 
method. The experiments were made in series, in which one diges- 
tion of each series served as a control for comparison. 
The volume of each digestive mixture was 100 c. c. and contained 
1 gram of perfectly pure potato starch, previously boiled with a por- 
tion of the water, 10 ¢. c. of a diluted neutral saliva and a given per- 
centage of the uranium salt to be experimented with. The mixtures 
were then warmed at 40° C. for 30 minutes, at the end of which 
time, further ferment action was stopped by heating the solutions to 
boiling. The saliva employed in the experiments was human mixed 
saliva, freshly collected, filtered and made as neutral as possible with 
02 per cent. hydrochloric acid, then diluted with water in the pro- 
* Hdinb. Med. Surg. Gaz., xxvi., 136. 
{ Studies from this Laboratory, vol. i, 1884-5, p. 2 and 53. 
TRANS.. Conn. AcapD., Vou. VII. 33A Nov., 1886. 
