284 BOTANICAL GAZETTE [APRIL 
action brought about by a salt as due to the effect of the cation and 
the retardation as due to the anion. Although his results are not 
directly comparable to those of the present investigation, it may 
be noted that most of the salt effects here brought out may be 
explained by this theory about as satisfactorily as by that of COLE. 
It is manifestly impossible, however, from the evidence brought 
out in this investigation, to decide whether either theory is adequate 
to explain satisfactorily the phenomena of acceleration and retarda- 
tion of diastatic action by electrolytes. It is, of course, probable 
that diastatic action is, in some measure, affected by the presence 
of salts in a molecular condition, also that certain salts form 
compounds with the enzyme itself, or with other organic 
bodies which are present in the diastatic mixtures that have 
usually been used in experimentation of this sort. Likewise 
diastases of different origins may be influenced quite differently 
by the same electrolytes. Further and more careful experimenta- 
tion, with refinement of methods as suggested by Forp,?? SHERMAN, 
KENDALL and CLARK, FRANKEL and HAmBurG,* and others, are 
still much needed. 
Summary 
The present investigation deals with the effects of sodium, 
potassium, calcium, magnesium, cupric, and ferric chlorides, alone 
and in certain binary combinations, on the hydrolytic activity of 
Merck’s “‘diastase of malt absolute,” the enzymatic mixture acting 
on a boiled solution of washed maize starch, at 50° C. The dis- 
appearance of the ability of the starch to give a color reaction with 
lodine was taken as the end point of the reaction, and the reciprocal 
of the time period which elapsed before this end point was attained 
(considering the time period of the control without added salt as 
unity) was used as a measure of the intensity of enzyme action. 
A wide variation is clearly shown in the influence of the differ- 
ent, chlorides upon diastatic action, which is probably to be related 
to the properties of the various cations employed. More or less 
29 Forp, Joun S., Lintner’s soluble starch and the estimation of diastatic power. 
Jour. Soc. Chem. Ind. 23:414-422. 1 
39 FRANKEL and Hampurc, Uber Diastase. Beitr. Chem. Physiol. u. Path. 
8: 389-308. 1906. 
