Solution Tension and Toxicity in Lipolysts. 279 
not sharp. The reagent itself, however, has a very sharp end reaction. 
In the higher dilutions of the plain reagent there is no precipitation, 
even at the neutral point. In greater concentrations of the plain 
reagent there is a precipitate at the neutral point. If the enzyme is 
present the precipitate appears long before the neutral point is reached, 
and as the alkali is added the precipitate takes up the purple for some 
time before the liquid shows alkalin. This accounts for the fact that 
the acidity of the control is so greatly in excess of the sum of the 
acidity of the enzyme and of the plain reagent. Compare with 
mercury in this particular: 
Cadmium, — 
LADL AT VE. 
CADMIUM. 
M. Reagent. Control. Enzyme. Increase. ~ 
8192 fore) 0.10 L:tO I 
4096 0.00 0.10 1.00 0-99 
2048 0.00 0.15 0.95 0.80 
1024 0.00 0.20 1.00 0.80 
512 0.00 0.25 0.95 0.79 
256 0.00 0.40 0.85 0-45 
128 0.05 0.70 1.20 0.50 
0.10 1.20 r25 0.05 
020 1.60 1.60 0.00 
oe 0.10 1.10 1.00 
Enzyme, 0.125 per cent. Incubation period, 4 hours. 40°C. 
The same remarks concerning the end reaction are applicable bere 
as in the case of cobalt, although I could not see that the precipitate 
turned purple before the liquid, as was the case with cobalt. The 
point of total inhibition is at 32, which is identical with cobalt and 
zinc. Since these tests were not contemporaneous, and, therefore, 
not strictly comparable, the following test is given : 
Cadmium, cobalt, and zinc in contemporaneous test. — 
TABLE XVII. 
CADMIUM. 
M. Control. Enzyme. Increase. 
32 1.40 1.40 0.00 
64 1.00 1.30 0.30 
CoBALT 
32 3-20 3-20 0.00 
