62 KELLERMAN: EFFECTS OF CHEMICAL AGENTS 
increased energy of the enzyme in the presence of one-per-cent. 
peptone, and also in the presence of sodium chloride, while dibasic 
sodium phosphate is not favorable. Effront * divided the favorable 
salts into three groups: salts of aluminum, phosphates and various 
amides, as asparagin. 
From Tables III and V it may be seen that the diastase was 
much less sensitive to these salts and organic bodies than it was 
to acids. A normal solution was used as the maximum, instead 
of one tenth normal. The differences in their effects between 
sodium, potassium, calcium and magnesium salts of the same acid 
were greater than the different salts of any one of those bases, 
which seems here to indicate that the cation is more important 
than the anion. The calcium and magnesium salts seem more 
injurious than sodium and potassium, with the exception of the 
monobasic calcium phosphate, which gives practically no action 
at 2/10 concentration, and a marked acceleration at dilutions of 
n/too and 2/1,000. Potassium bichromate gave a slight check at 
njt28, and none at 2/256. Calcium sulphate and magnesium 
phosphate are so insoluble that they are given on Table III 
merely in terms of saturation, ‘“Zxcess’’ standing for a saturated 
solution at 43°, ‘‘Sa¢.” for a saturated solution at 23°. Sodium 
chloride, potassium nitrate and potassium phosphate gave the 
greatest acclerations. Malt diastase closely follows the action of 
the taka diastase and shows no especial point of variation from it 
in the presence of these chemical agents. 
A large number of investigators have tried peptone and aspar- 
agin, and all have noted a decided acceleration. Other organic 
compounds, however, seem to act more as do the salts of the min- 
eral acids ; thay have less marked effects, and are more irregular. 
As seen in Table V, sodium acetate and ammonium citrate are 
the most injurious of those used, giving a marked inhibition at a 
concentration of /2; their injurious action decreases rapidly to 
some intermediate point, and they accelerate starch conversion at 
dilutions of 2/100 and 2/1,000.. Sodium formate and sodium lac- 
tate act very slightly either to retard or accelerate transformation. 
Potassium tartrate and sodium acetate gave the most acceleration 
_ of the organic series. Formalin inhibits markedly ; even up to 
* Effront, Zc. a 
. 
