of Diastase of Malt, as modified by various conditions, 
b. with 30 c. c. of the standard malt extract. 
Total amount 
4 
Na.Cos. Wt. Cu in 4. reducing bodies. Starch converted. 
0 0°1650 gram. 0°3372 gram. 30°34 per cent. 
0-001 per cent. 0°1578 0°3224 29°01 
0°003 071465 0°2986 26°87 
0:005 071147 0°2334 21°00 
0°010 00380 0-0796 7-16 
0-025 0:0238 0°0516 4°64 
0°050 0 
It is evident from these results that the amylolytic power of dias- 
tase, like that of ptyaline, is diminished in proportion as the percent- 
age of alkaline carbonate is increased. Moreover, it would appear 
by comparison with results previously obtained* that diastase is far 
more susceptible to the action of sodium carbonate than ptyaline, and 
also that dilution of the malt extract does not so materially affect 
the retarding action of the different percentages of alkaline car- 
bonate as in the case of saliva. Both of these results, however, may 
be due either to the presence of a larger amount of proteid matter in 
the saliva or to the presence of a larger proportion of ferment, or in 
fact, to both. - It is noticeable in both series of experiments that the 
amylolytic power of the ferment after gradually diminishing appears 
to receive a sudden check, which in the larger amount of malt ex- 
tract is produced by just double the percentage of carbonate requisite 
with the smaller amount of malt. In this way the effect of dilution 
is apparent and shows moreover that the exact influence of a given 
percentage of the alkaline carbonate can be designated only for a 
definite mixture. 
Destructive action of sodium carbonate on diastase. 
In order to ascertain how far the retarding action of sodium ear- 
bonate is due to destruction of the ferment, the following experiment 
was tried. Six mixtures were made as follows: 
1 2 3, 4 5 6 
Malt extract _._ 30c.c. at) (exe), 30 @e. 30 ce. 30 @.c. 30 ce. 
Wass SOL 2... ,0 Leese a asomers Ona aaa hate 0°5% 5 ‘ 05410 * 0°5% 
[S(O eee eels 20 iiesiorday Ce nya ee ies! fife Ome 
50 50 50 50 50 50 
Per cent. Na.Co; 0 0°0025 0°005 0:025 0°05 0°] 
These were warmed at 40° C. for 1 hour, then neutralizing and 
etjualizing mixtures were added as follows: 
* Chittenden and Smith. 
