\ 
Uranium Salts on Ferment Action. 26 
cr 
(UO2)3(CgHs507)2+ Total amount Relative 
(NH,4)3C5H50;. reducing bodies. Starch converted. amylolytic action. 
0 0:4117 gram. 37:05 per cent. 100°0 
0-004 per cent. 02378 21°40 57:7 
0-005 0:2144 19-29 52°0 
0-006 0:2316 21°39 577 
0-007 0°1845 16°60 44:8 
0-008 0:1765 15°88 42°8 
0-010 trace 
The action of this salt is mainly a restraining one, but the action 
is pronounced only with the larger percentages. 
As to the way in which these uranium salts diminish the amylolytic 
action of the ferment, we cannot say detinitely. What has previously* 
been written regarding the action of other metallic salts, under like 
conditions, is doubtless true here. Loss of amylolytic power is due 
in part, no doubt, to partial direct destruction of the ferment, as 
well as to change in the reaction of the fluid. Coupled with this 
destructive action, however, there must be in addition something in 
the mere presence of these salts, dependent on chemical constitution, 
that controls the action of the ferment. 
The following table shows the relative acceleration and retardation 
of the. various salts, compared with their respective controls expressed 
as 100. 
2. Influence on the proteolytic action of pepsin-hydrochloric acid. 
The influence of uranium salts on the proteolytic action of pepsin- 
hydrochloric acid, was determined by ascertaining the amount of 
fibrin digested or dissolved in a given time, by a definite volume of 
a standard, artificial gastric juice, in the presence of varying amounts 
of the uranium salts. The gastric juice was made by dissolving 10 
c.c. of a glycerin extract of pepsin in one litre of 0-2 per cent. hydro- 
chloric acid. The volume of each digestive mixture was 50 @.c.; 
composed of 25 cc. of the above mentioned artificial gastric juice 
and 25 c.c. of 0°2 per cent. hydrochloric acid, containing the nece. 
sary amount of uranium salt. The proteid material consisted ot 
purified fibrin, coarsely powdered and dried at 100°C. One gram o’ 
fibrin was used in each experiment. The digestive mixtures were 
warmed at 40° C. for one hour and then the undissolved residue wa 
collected on weighed filters and finally dyied at 100-110° C. until of 
constant weight. The amount of fibrin dissolved is taken as a meas- 
ure of the proteolytic action. 
* See Studies from this Laboratory, vol. i, 1884-5, pp. 70-75. 
TRANS. Conn. AoApD., Vou, VII. 34 Noy., 1886 
