238 
WILLIAM J. ROBBINS 
Influence of Quantity of Enzyme. — Fifty cubic centimeters of a 
2 percent (approximate) soluble starch solution was placed in each of 
seven 125 cc. Erlenmeyer flasks. The quantities of o.i percent Taka 
diastase solution used and of the water added in order to keep the 
concentrations of starch the same throughout are indicated in Table I. 
After approximately 30 minutes digestion at room temperature, 
20 cc. were removed from each Erlenmeyer flask and the undigested 
starch and dextrins were determined by the alcoholic precipitation 
method given above. The results follow in Table I : 
Table I 
50 Cc. of 2 
Per cent Soluble Starch Pius 
Undigested 
Starch (Mg. 
per 20 Cc.) 
Starch Digested 
(Mg. per 20 Cc.) 
Starch Digested 
per I Cc. of 
Diastase Solu- 
tion (Mg. per 
20 Cc.) 
0 CC. diastase 
+.32 CC. H,0 
208.0 
I cc. " 
+ 31 cc. " 
194.9 
I3-I 
I3-I 
2 CC. " 
+ 30 CC. " 
179-3 
28.7 
14-3 
4 cc. " 
+ 28 cc. " 
153-0 
55-0 
13-7 
8 cc. 
+ 24 cc. " 
114.8 
93-2 
11.6 
16 cc. " 
+ 16 cc. " 
101.7 
106.3 
6.6 
32 cc. " 
+ 0 cc. " 
47.8 
160.2 
5-0 
From these data it would appear that the proportionality between 
the amount of Taka diastase present and the amount of soluble starch 
digested, as measured by this method, holds to the point where 
approximately 25 percent of the original starch has been transformed 
into substances soluble in 73 percent acid alcohol. This is in fair 
agreement, considering the fact that the starch and enzyme prepara- 
tions employed were not purified, with the results obtained by Kjeldahl 
(1879), Henri (1903), and Ford (1904 B), who, working with different 
starch and enzyme preparations and under different temperature 
conditions, used the reducing power of the solution as .a measure of 
diastatic action. 
The results of the determinations summarized in Table I are pre- 
sented in the form of a curve in figure i. On the abscissse the amounts 
of Taka diastase solution used are given, and on the ordinates the 
amounts of digestion. The line parallel to the base represents the 
starch content per 20 cc. of the original solution. 
Influence of Time. — The Taka diastase used contained, according 
to digestion determinations, insufficient maltase to make certain 
