58 Chittenden and Cummins—-Amylolytic Action 
amylolytic action whatever; presumably because of the rapid action 
of the ferment and the slow retarding action of the acid-peptone. 
Influence of free acid on the amylolytic action of diastase. 
As might be expected, free hydrochloric acid, even in very small 
quantity at once stops the amylolytic action of this ferment, quickly 
destroying it. It is interesting, however, to compare the action of 
very small percentages of free acid with results obtained in like 
manner with the salivary ferment. The first experiment gave the 
following results: the malt extract used, required per 30 c. ¢., 2°4 ¢. ¢. 
071 per cent. hydrochloric acid to saturate the proteid matter. 
Per cent. Per cent. Total amount Starch 
combined HCl. free HCl. Wt. Cuin 4. reducing bodies. converted. 
0 0 0°1378 gram. 0°2808 gram. 25°27 per cent. 
0°0024 0 071584 0°3236 29°12 
0°0024 ‘0001 071486 0°3032 27-29 
0°0024 0:003 0°0805 0°1642 14-77 
With another malt extract not so active, but containing the same 
percentage of acid-proteids, the following results were obtained: , 
Total amount 
Free HCl. Wt. Cu in ¥. reducing bodies. Starch converted. 
0 0°0780 gram. 071592 gram. 14°32 per cent. 
0:0003 per cent. 0:0719 01470 13°23 
0:0005 0:0631 071294 11°64 
0:0020 0:0380 0:0796 7-16 
0°0030 00091 0°0222 es)S) 
From these two series of results it is quite evident that a very small 
percentage of free hydrochloric acid will stop the amylolytic action © 
of this ferment. The main action of the acid is that of destruction, 
killing the ferment very quickly. The following is a sample of 
several experiments tried, to ascertain how far retardation is due to 
destruction of the ferment. 
af 2. 3. 4. 
Neutral malt extract -........--.=.- SUP CiCie eS NCC, sas OMIClCs ems O mica: 
0-1 per cent. HCl to saturate proteids 22 2 act 2°2 as D0 
0°1 per cent. HCl for free acid -._..- 0 05 “ 105s Lb i 
1G ©) ees Sie rere ae FRY bes 8 oy ISB 17-3 pe 16°8 ‘* Lé63e 
bO She BO 50-0 “ 50°0 ‘* 
Percent ineo EO wae sae oo eee 0 0-001 0°002 0:003 
These solutions were warmed at 40° C, for 30 minutes, then neu- 
tralizing and equalizing mixtures were added and the amylolytic 
power determined. No. 1 converted the usual amount of starch into 
sugar, but No. 2 showed only a trace of amylolytic power and Nos. 
3 and 4 none at all. Evidently then 0-001 per cent. of free acid had 
