270 Chittenden and Hutchinson—Influence of 
Relative 
Uranium salt. Undigested residue. Fibrin digested. proteolytic action. 
0 0°1652 gram. 83°48 per cent. 100-0 
0:025 per cent. 0-1982 80°18 96-0 
0-050 02192 78°08 93°5 
0-100. 0°2569 74°31 89-2 
0°300 0°3486 65:14 780 
Increasing the percentages of the oxychloride still further, either 
with this strength of pepsin or the preceding, and there is seen a 
gradual diminution in the action of the ferment. Compared, how- 
ever, with the action of the preceding salts, retardation is seen to 
be quite slow; thus even 2:0 per cent. causes a diminution of pro- 
teolytic action amounting to only 50 per cent. 
The following table of comparisons shows the relative acceleration 
and retardation of the various salts compared with their respective 
controls expressed as 100. 
TABLE SHOWING RELATIVE PROTEOLYTIC ACTION. 
Percentage of Salts_________ 0:025 | 0:05 | 0-1 0°3 0:5 1:0| 2.0 
Uranyl nitrate! ie fe Se: BBB OS STO) he O78 SB Shee 
Uranyl acetate _--..=.. 2-.% 98°5 95-1 | 92°9| _.._ | 29.2! 0 : 
Uranyl sulphate __...__.... 913) 80-7] 83:8]... | 479) 217) 
Ammonio uranous sulphate_, 87°4 | 83:9 76°6 | = S| PHOS 0 
Sodio uranic sulphate -___. | 99-4| 85°5| 75°6| ___. 26°7 | 1:5 
Ammonio uranic citrate. --- | 99:4 | 95°7 | OR) se sit ue 0) Pep 
Potassio uranic oxychlo- ) 1 108-0  113°5 | 107°6 | 105°9 | 92°5 | - a 
Pets ee Oe, ses J2 96-0 | 935 892] 78:0| 81-0, 66-2| 49-4 
In retarding proteolytic action, the uranium salts act in part by 
combining with the proteid matter to be digested, forming a uranium- 
albumin compound, which is indigestible. Further, in a solution at 
all concentrated, the uranium salt is liable to precipitate mechanic- 
ally a portion or all of the pepsin along with the albuminous matter. 
In addition to this, however, retardation is also due, as already ex- 
pressed, to liberation of the acid of the salt by the hydrochloric acid 
of the gastric juice and to the subsequent formation of a pepsin-acid 
only partially, or not at all, capable of digestive action, 
