278 Raymond FH. Pond. 
Before titration, at the close of the incubation period, it was 
noted that in the unboiled preparations having the toxic agent present 
in concentration of above 1024 there was no sediment or precipitate 
in suspension. In 1024 there was no: sediment, but there was some 
precipitate in suspension. With increasing concentration of the 
agent the quantity both of sediment and of precipitate in suspension 
increased perceptibly to the eye. The sediment seems to bé identical 
with the precipitate in suspension. The final acidity of the unboiled 
is just double the initial acidity. The final and initial acidity of the 
boiled enzyme solutions is, however, identical. Boiling, therefore, 
stops autolysis. The enzyme solution used was the filtrate from I gm. 
of powder mixed with 200 c.c. of water. On heating this filtrate 
over the free flame there was-slight turbidity at about 45° C., floccu- 
lation at about 70°. Boiling was continued for only a moment. 
Several points of interest are to be noted here. The acidity of 
4 c.c. of the reagent in concentrations 8192-32768 inclusive is oO. 
The acidity of the boiled enzyme containing the toxic agent in those 
same concentrations is 0.15, or just exactly what it is if the toxic 
agent is not present. In the unboiled preparations corresponding to 
these concentrations, the autolysis, though very slightly checked, is 
almost the same as though the agent were not present. Comparison 
with other tables shows that the very same relations are sustained 
here as in those cases where the ethylbutyrate is present during the 
incubation, 
scuhitacanetan TABLE XV. 
COBALT. 
M. Reagent. Control. Enzyme. . Increase. 
8192 0.00 0.15 1.10 0.95 
4096 0.00 0.15 1.10 0.95 
2048 0.00 0.15 I.10 0.95 
1024 0.00 0.20 1.10 0.90 
512 0.00 0.30 1.10 0.80 
256 0.02 0.50 1.30 0.80 
128 0.05 1.40 1.80 co ee 
64 0.10 2.60 2.90 0.30 
32 0.20 3.20 3-20 0.00 
Water 0.15 1.10 0.95 
Enzyme, o.125 per cent. Incubation period, 4 hours. 40° C. 
The point of total inhibition is 32, just the same as for zinc. In 
the concentrations greater than 512 the end reaction on titration is 
. 
