and Toxic Agents on the Amylolytic Action of Saliva. 69 
Magnesium sulphate. 
With this salt we obtained the following results: 
Total amount Starch 
MgS044+7H20. Wt. Cu in 4%. reducing bodies. converted, 
0 071475 gram. 0°3004 gram. 27-03 per cent. 
0°025 per cent. 071597 0°3260 29°34 
0°500 00510 01056 9°50 
Here, there is a slight increase of diastatic action with the smallest 
percentage, while 0°5 per cent. of the salt greatly retards the action 
of the ferment. 
Pfeiffer* has likewise noticed the retarding effect of this salt on 
salivary digestion. 
Potassium cyanide. 
This salt, so powerful as a poison, was found to have a decided 
effect also on the salivary ferment, causing a rapid decrease in 
amylolytic action. 
Total amount Starch 
KCN. Wt. Cu in 4%. reducing bodies. converted. 
0 0°1245 gram. 0°2532 gram. 22°78 per cent. 
0-0005 per cent. 0:1080 0-2200 * 19-80 
0°0010 0°0896 0°1828 16°45 
00030 0°0330 0:0700 6°30 
With 1:0 per cent. and even with 5:0 per cent. of potassium 
cyanide, the starch solutions became clear on the addition of saliva, 
showing that the ferment was able to effect some change, although 
in neither case were any reducing bodies formed. 
It is our intention at some future time, to study the exact nature 
of the products formed under such conditions. The ferment appears 
to be peculiarly affected ; for while a very small percentage of a 
substance like potassium cyanide or borax will completely prevent 
the formation of reducing bodies, increasing the amount of substance 
added a hundred-fold, has no effect on the clearing up of the starch 
solution by the ferment. Some light may be thrown upon the nature 
of the ferment or its mode of action. 
Potassium ferrocyanide. 
A preliminary experiment showed that this salt was less active 
than the cyanide and therefore larger percentages were used, with the 
following results: 
Total amount 
Starch 
K,Fe(CN)§+3H20. Wt. Cu in 4. reducing bodies. converted. 
0 01417 gram. 0°2884 gram. 25°96 per cent. 
0-025 per cent. 0°1497 0°3052 27°46 
0°100 071375 0°2800 25°20 
0°2084 
0°250 0°1025 
18°80 
* Centralbl, Med. Wiss., 1885, p. 328, abstract. 
