of Diastase of Malt, as modified by various conditions. 57 
tive action on the ferment; when half saturated, destructive action is 
more pronounced ; when wholly saturated it is, under the above con- 
ditions, complete. 
Frequently, such small percentages of combined acid as the above 
will have no retarding effect whatever on amylolytic action, though 
if the ferment be warmed for half an hour with the same percentage 
of peptone and combined acid, its subsequent amylolytic power will 
be much reduced, owing to a partial destruction of the ferment. 
This is well illustrated by the following series of experiments : 
A. B. 
SS SS SS ——_—— aaa SS 
if a. 3. 4. 5. 6. 
Malt extract -.---- arere OCA C Lorex laexe ISrexe: iby exc! 
0-1 per cent. HCi.- 0 l 2 0 2 sue: 
Peptone sol. 0°5%_- 10 10 10 20 20 20 
Ei Oe ea as 25 24 23 65* 63* 61* 
50 50 50 100 100 100 
Combined HCl.... 0 0-002% 00044 0 00024 0-004% 
Reptone =+=.=2==- 014 01 01 0-14 0-1 0-1 
Nos. 4, 5 and 6 were warmed directly, with the starch, for 30 min- 
utes at 40° C. and the reducing bodies determined. Nos. 1, 2 and 3 
were warmed at 40° C. also for 30 minutes, then neutralizing and 
equalizing mixtures were added, the solutions diluted to 100 ¢. c. and 
warmed with 1 gram of starch for 30 minutes at 40° C. The follow- 
ing results show the amylolytic power of the six solutions: 
Total amount Starch 
No Wt. Cuin 4. reducing bodies. converted. 
1 071482 gram. 0°3024 gram. 27.21 per cent. 
JN 1 2 0°1412 0°2876 25°88 
3 071351 072754 24°78 
( 4 0°1594 0°3256 29°30 
B. } 5 0°1628 0°3324 29°91 
6 0°1605 0°3282 29°52 
In series A, we see a gradual decrease in the amylolytic power of 
the solutions ; this can be due to nothing but the destructive action 
of the acid-peptone compound, for the solutions are in every respect 
alike, being in the same degree of dilution and containing the same 
amount of sodium chloride, etc. The destruction is not great, as 
the peptones are in considerable excess. In series B, where the fer- 
ment is exposed to the direct action, in the presence of the starch, of 
the same percentage of peptone and acid there is no retardation of 
* Containing 1 gram of starch. 
TRANS. Conn. AcaD., Vou. VII. 8 Oct., 1885, 
