of Diastase of Malt, as modified by various conditions. 51 
Total amount | Starch 
Neutral peptone. Na»CO3. Wt. Cuin 4. reducing bodies. converted. 
1:0 per cent. 0 0:2078 gram. 04268 gram. 38°41 per cent. 
1:0 0-010 per cent. 0°1583 0°3234 29°10 
1:0 0°025 071529 0°3122 27:09 
10 0°050 071351 0°2754 24:78 
1:0 0°100 0:0086 0:0209 1:88 
2°0 0-100 071341 0°2730 24°57 
Here, as before, the retarding action of sodium carbonate is held 
in check by the peptone, although there is slight retardation due to 
the alkaline-proteid body formed. Finally, the percentage of sodium 
carbonate being increased beyond the necessary proportion of pep- 
tone, there is a sudden cessation of ferment action. Increasing the 
amount of peptone, however, prevents this retarding action; evi- 
dently the alkaline-proteid body is without much effect on the fer- 
ment, only slowly diminishing its amylolytic power. 
Influence of acid-proteids on the amylolytic action of diastase. 
Falk has noticed that peptone prevents to a certain extent, the 
retarding action of dilute acid on this ferment; no quantitative 
results, however, have been recorded, nor has any attempt been made 
to ascertain whether said action is due to simple retardation, or 
destruction of the ferment, or both. The action of acids, whether 
free or combined with proteid matter, on the diastase of malt is 
particularly important, in view of the rapid passage of the ferment 
into the stomach when taken in therapeutical preparations. Its 
ultimate fate must depend in great part upon the action of free and 
combined (proteid) hydrochloric acid upon it. It is, moreover, im- 
portant to compare the behavior of the ferment in this respect, with 
the amylolytic ferment of saliva. 
An aqueous extract of malt prepared as described, contains but 
little proteid matter; as a rule 2°0-2°5 c.c. of 0:1 per cent. hydro- 
chloric acid are required to completely saturate the proteid matter 
contained in 30 c¢.c. of the neutral malt extract. This point was 
ascertained by use of the tropaeolin test for free acid as recommended 
by Danilewsky.* Thus, by way of illustration, in one instance 30 e. c. 
of carefully neutralized malt extract required the addition of 3°3 
c. ¢. O11 per cent. HCl to give the tropaeolin reaction for free 
acid, and since nothing smaller than 0:003 per cent. free HCl can be 
detected by this method, it follows, making the proper deduction, 
that 2°3 ¢. c. of 01 per cent. HCl are required to completely saturate 
* Centralbl. Med. Wiss., 1880; also description in Trans. Conn. Acad., vol. vi, p. 360. 
