1913] HAWKINS—MALT DIASTASE 283 
positive ions (kations) and by hydroxyl ions.” He considers the 
effect of electrolytes on the rate of action to be compounded of two 
factors: (1) “the acceleration due to the anion; (2) the depression 
due to the kation.”” The work of this author showed that the 
addition of a small quantity of hydrochloric acid to a chloride in 
optimum concentration for diastatic hydrolysis did not result in an 
added acceleration, but in a decreased activity. This he accounted 
for by considering the acceleration produced by the chloride as 
due to the chlorine ions, these being already in optimum concentra- 
tion before the addition of the acid; hence when more chlorine 
ions were added with the acid there could be no further increase 
in diastatic activity. The observed decrease in enzyme efficiency, 
which accompanied the putting in of the acid, was explained as 
due to the increased concentration of retarding cations which 
must result from the presence of the acid and to the destruction of 
ferment by the hydrogen ions. The salt present in a molecular 
condition is not taken into consideration. 
This hypothesis appears to explain many of the phenomena of 
salt influence upon diastatic action as found in these studies. 
It does not, however, offer an explanation for the retardation of 
diastatic action by low concentrations of sodium and potassium 
chlorides. Coe suggests also that all cations seem to retard 
diastatic action alike, which would seem questionable from the 
standpoint of the results obtained in the present investigation. 
WouLGEMUTH, investigating the effects of certain salts on the 
hydrolysis of starch by pancreatic amylase, using a colorimetric 
method for determining the rate of hydrolysis, concludes that the 
acceleration caused by a chloride is due to the chlorineion. BANc,* 
working with dialyzed ptyalin and determining the amount of a 
reducing dextrin formed from soluble starch in a given time, as a 
measure of the rate of hydrolysis, agrees with WOHLGEMUTH in this. 
McGutean, working with malt diastase and using as a criterion 
for comparing the different salt effects the inhibition of the forma- 
tion of any reducing sugar in a certain time period, takes a view 
Opposite to that of Corr. He considers the acceleration of enzyme 
8 Banc, Ivar, Untersuchungen iiber Diastasen. Biochem. Zeitschr. 32:417-442. 
II 
