and Toxic Agents on the Amylolytic Action of Saliva. 65 
ent in these experiments, stimulates the amylolytic action of the 
ferment ; a fact which might be expected, assuming that the acid 
combines with the proteids of the saliva, for as has been elsewhere* 
shown, acid-proteids when present in not too large an amount 
increase the amylolytic action of the salivary ferment. 
Schafer and Béhmf} state that arsenious acid has no influence 
whatever on the conversion of starch into sugar by a glycerine ex- 
tract of the pancreas. Possibly they sought only for retarding 
action, or it may be that the pancreatic ferment differs in this respect 
from the ferment of saliva. 
Arsenic acid. 
This substance being still more acid than the preceding, might 
naturally be expected to diminish amylolytic action, when present in 
quantities which in the preceding would increase the activity of the 
ferment ; and indeed there is to be seen in the results, a slight in- 
crease, followed by a rapid decrease of amylolytic action. 
H3AsOq4. Wt. Cu in ¥%. ean Wot eA eed. 
0 01755 gram. 0°3588 gram. 32°29 per cent. 
0°0005 per cent. 0°1765 0°3608 32°47 
0°0010 0°1635 073340 30°06 
0°0030 0°0310 0°0660 5°94 
0°0050 0 
With 0:005 per cent. of arsenic acid present in the fluid, no reduc- 
ing bodies were formed in the thirty minutes of the experiment, but 
the solution did become clear, showing the formation of soluble 
products. The same fact was observed in the presence of larger 
percentages of the acid; the starch solution becoming clear, after 
the addition of saliva, even in the presence of one per cent. of the 
acid, although, as before, no reducing bodies were formed. 
Ammonium ursenate. 
With this salt the following results were obtained: 
Total amount Starch 
(NH4)3 A804. Wt. Cu in 4. reducing bodies. converted. 
0 0°1527*gram. 0°3112 gram. 28°08 per cent. 
0:0005 per cent 0°1620 0°3308 29°17 
0:0010 0°1630 0°3340 30°06 
0:0050 071675 0°3420 30°78 
0°0150 071745 0°3568 ay AIL 
0°0250 0-1700 0°3476 31:28 
* Chittenden and Smith, Trans. Conn. Acad., vol. vi, p. 343. 
+ Abstract in Jahresbericht fir Thierchemie, 1872, p. 365. 
Trans. Conn. Acap., Vou. VII. 9 Oct., 1885. 
