94 Chittenden and Allen—Influence of various Salts 
Magnesium sulphate. 
Pfeiffer * alone appears to have studied the influence of magnesium 
sulphate on gastric digestion. He found that retarding action com- 
menced in the presence of 0°24 per cent. of the salt and was very 
great in the presence of 4:0 per cent. Our results show decided 
retarding action, even in the presence of 0°005 per cent. of the crys- 
tallized salt. At the same time, it is to be remembered throughout, 
that probably differences in the strength of gastric juice, would cause 
some variation in the amount of retardation, produced by any given 
percentage. ' 
Undigested Fibrin Relative proteo- 
MgS04+7H20. residue. digested. lytic action. 
0 0°1081 gram. 89°19 per cent. 100°0 
0005 per cent. 01910 80°90 90°7 
0°010 0:2330 76°70 86°0 
0°050 0°3260 67:40 755 
0°100 0°4428 55712 62°3 
0 0°2605 73°95 100°0 
0°3 07551 24°49 33°1 
05 0-7886 21°14 28°5 
0°8 0°8250 17°50 23 T 
15 0°8891 11°09 15:0 
3°0 0°8894 11:06 14°9 
It is noticeable here, that while the retarding influence of the salt, 
becomes more and more pronounced as the percentage is increased, 
there comes a point (1°5 per cent.) when further addition does not 
materially influence the action of the ferment. 
Potassium permanganate. 
This salt, as with the amylolytic ferment of the saliva, shows very 
energetic action. Its influence is, without doubt, due to rapid oxida- 
tion and consequent destruction of the ferment ; indeed, the (at first) 
bright red color of the solution became almost immediately bleached 
out and the solution, at the same time, completely deprived of pro- 
teolytic power. The following results testify to its extreme activity. 
Undigested Fibrin Relative proteo- 
KoMnoOg. residue. digested. lytic action. 
0 0-1951 gram. 80°48 per cent. 100°0 
0°005 per cent. 08278 17°22 21°3 
0°010 0°9949 0°51 0°6 
It is thus more active in preventing proteolytic action, in gastric 
juice of the strength used, than in hindering the development of 
* Abstract in Centralbl. med. Wiss., 1885, p. 328. 
