282 BOTANICAL GAZETTE [APRIL 
proportions 2:1) are similar to those which obtain for combinations 
of sodium chloride with the magnesium salt. It appears that the 
combination is here never more favorable for starch hydrolysis 
than the single salt treatments. 
In combinations of magnesium chloride with calcium chloride 
(molecular proportions 2:1) the efficiencies appear to follow those 
of the calcium salt, the magnesium in this combination seeming 
to have acquired as great efficiency for the acceleration of hydrolysis 
as that which characterizes the portion of the other salt which it 
replaces. - 
With combinations of copper chloride and ferric chloride 
(molecular proportions 1:1) the efficiencies’ generally lie between 
those for the single-salt treatments of the same concentration, as 
though the effectiveness of the combination were the mean influence 
of the two component partial treatments. No increased efficiency - 
is here brought out by replacing’ a portion of one of these salts 
with a molecularly equal portion of the other. 
While the considerations just presented appear to lead to the 
conclusion that certain concentrations of salt combinations may 
favor greater diastatic activity than do the same concentrations of 
either salt alone, yet it is obvious that sufficient information is not 
yet at hand to allow any attempt at generalization. The suggestion 
becomes patent that the study of properly balanced salt combina- 
tions, in their relation to enzymatic action, may add much not only 
to our knowledge of this persistently vague province of physiology, 
but also to our ability to control these important processes. 
THEORETICAL CONSIDERATION OF RESULTS 
In connection with the general problem of the nature of. the 
acceleration and retardation of diastatic action by electrolytes, 
the results of the investigations of Coxe deserve careful considera- 
tion. In a research carried on with dialyzed ptyalin, this author 
formulated a hypothesis to account for the influence of electrolytes 
on enzyme action, which to quote him directly is as follows (0?- 
cit. p. 211): “The hydrolysis of starch by ptyalin is accelerated by 
the presence in the solution of electronegative ions (anions) other 
than hydroxyl ions and depressed by the presence of electro-. 
