SECRETION OF DIASTASE BY PENICILLIUM CAMEMBERTII 25 1 
with diastase formation. Neither would it appear that sulphur, 
chlorine, magnesium, and sodium are closely connected with diastase 
formation. The addition of traces of the salts containing these ele- 
ments produces no increase in the rate of digestion of starch. It is 
recognized, of course, that an abnormal condition is presented for 
the growth of the fungus when only a single salt is supplied, because 
the absence of other salts must be a limiting factor in the use of the 
one supplied. Nevertheless, if one of the nutrients mentioned above 
were specifically concerned in diastase formation, it might be expected 
that increased digestion w^ould occur in its presence. No such increase 
is noted. 
On the contrary, it has been found that the sulphates and the 
chlorides of potassium, sodium, calcium and magnesium in M/io,ooo 
and M/ioo,ooo concentrations decrease the rate of digestion. The 
cause of this inhibition is obscure. 
There seem to be two possibilities: either the decreased digestion 
is due to an inhibition of the activity of the secreted diastase by the 
salt, or the effect is physiological; one of decreased secretion. 
From a consideration of recent work on the effect of salts on the 
activity of diastase, the writer is led to believe that the effect is physi- 
ological. Recent work seems to show that if the salts at the concen- 
trations used here have any effect on the activity of diastase, it should 
be one of acceleration of action rather than retardation. Hawkins 
(1913), w^orking with malt diastase, determined the effect of NaCl 
and KCl, in concentrations varying from 2M to M/2,048; of CaCU, 
in concentrations varying from iM to M/4,096; and of MgClg, in 
concentrations varying from M/2 to M/8,192. NaCl and KCl pro- 
duced a retardation — 15 percent at M/128, and 5 percent and 7 percent, 
respectively, at M/512 — yet they had no effect at a concentration of 
M/2,048, and in all higher concentrations they produced a marked 
acceleration. CaCU, in all the concentrations used, accelerated the 
action of diastase; and MgClo, in all concentrations save M/8,192, 
which had no effect, also accelerated the digestion. 
VanLaer (191 3) states that in a medium of amphoteric reaction 
(a reaction amphotere), alkaline to methyl orange and acid to phenol- 
phthalein, small quantities of the neutral electrolytes are indispensable 
to the manifestation of the properties of diastase. 
In every determination of the reaction of the medium in this 
investigation where single salts were used, it was found that it was 
