328 
Hence so far as its power to digest gelatin is concerned the activity 
of galactase is destroyed in alkaline solution by ten minutes* expo- 
sure to temperatures of 65° C. in neutral solutions at 70° C. and in 
acid solutions at a temperature of 65° C. 
Babcock and Russell (18) have also employed the power on the 
part of galactase to accelerate oxidation by hydrogen peroxide as a 
test for the presence of the ferment, and have made use of this test 
as a means of determining the destruction temperature of galactase. 
This we now know is merely a test and measure of the peroxidase 
activity of the solution and not a test or measure of the activity 
of galactase at all. Indeed, as has been shown subsequently to the 
work of Babcock and Russell on this subject, galactase as pre- 
pared from separator slime is not a pure enzyme, but a mixture of 
enzymes. Thus IYender-(20) points out that galactase consists of 
milk trypsin or galactase proper, milk catalase, and milk peroxidase. 
According to TTender, the trypsin of milk becomes inactive at 
76° C. 
The use of Y. Storch’s tests (see p. 330), viz, with an iodide and 
starch or p-phenylene-diamine and a few drops of hydrogen peroxide 
as a means of determining the effect of high temperature on the 
activity of galactase, as employed by Babcock and Russell, is there- 
fore chiefly interesting as throwing light on the stability of milk 
peroxidase under the conditions employed in their work. Their 
results are given in Table III. 
TABLE III. 
[-f=eolor reaction; X= doubtful reaction; — =no color reaction.] 
Temperature (°C.). 
Alkaline. 
Time. 
N/10. N/25. 
Neutral 
to litmus. 
Acid 
N 10. 
Babcock and Russell (18) conclude therefore from their experi- 
ments that galactase is more stable in alkaline or neutral solution, and 
that it shows a close resemblance to trypsin, but is less sensitive to 
