54 Chittenden and Cummins—Amylolytic Action 
The amylolytic action of 4 and 5 was tested directly by warming 
the mixtures at 40° C, for 30 minutes and then determining the 
amount of reducing bodies. No. 1 (the control) was warmed at 40° 
C. for 30 minutes, while No. 2 was warmed at the same temperature 
for 15 minutes and No. 3 for 30 minutes. Neutralizing and equaliz- 
ing mixtures were added as follows: 
Z 2. 3. 
01 per cent. Na,COs_-_ 0 3°5 @. @. 3°5¢0¢c. 
(021 percent. AICI i222 24¢.¢. 0 0 
lol per cent. Na2CO3_-- aay 0 0 
All three were then mixed with one gram of starch and made up 
to 100 ¢.¢. in order to determine amylolytic action; each solution 
was neutral and contained the same quantity of sodium chloride as 
well as the same amount of ferment and starch. Following are the 
results of all five: 
Total amount 
No. Wt. Cuin ¥. reducing bodies. Starch converted. 
1 0:1630 gram. 0°3332 gram. 29°98 per cent. 
~ 2 071253 072554 © 22°98 
3 071195 0°2434 21:90 
§ 4 0°1628 0°3322 29°89 
O50. 071749 0°3578 32-19 
It is thus seen that with this amount of ferment, 0°0024 per cent. 
combined acid causes an acceleration in amylolytic action (Nos. 4 
and 5) amounting to over 2 per cent. in the quantity of starch con- 
verted, while warming the same amount of ferment with the same 
amount of acid, but under a less degree of dilution, causes a destruc- 
tion of the ferment amounting to 7 per cent. in the conversion of the 
starch; 15 minutes longer at 40° C. causes only a slightly increased 
destruction. 
. 
Influence of acid-peptone. 
By increasing the amount of proteid matter, larger percentages of 
hydrochloric acid can be added to a malt extract without retarding 
the action of the ferment or even interfering with the accelerating 
action of the smaller percentages. As previously stated, Falk has 
shown that peptone prevents to a certain extent the retarding action 
of hydrochloric acid, but it does more than this, it causes accelera- 
tion in ferment action not only in neutral solution, as already shown, 
but in an acid solution likewise, provided there is an excess of pep- 
tone present, in which case the acid-peptone compound formed, causes 
greater acceleration than the same percentage of peptone alone 
would do if added to a neutral solution of the ferment, The follow- 
