334 
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 (19) have also employed the power on the 
part of galactase to accelerate oxidations 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 w T e 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 prepared 
from separator slime is not a pure enzyme, but a mixture of enzymes. 
Thus Wender (21) points out that the galactase of Babcock and 
Russell consists of milk trypsin or galactase proper, milk catalase, 
and milk peroxidase. According to AVender, the trypsin of milk 
becomes inactive at 76° C. 
The use of V. Storch’s tests (see p. 333), 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. 
[ + =color reaction; X=doubtful reaction; — =no color reaction.] 
Temperature (°C.). 
Time. 
Alkaline. 
Neutral 
to litmus. 
Acid 
N/10. 
N/10. 
N/25. 
| 10 1 
+ 
+ 
+ 
'+ 
65 
l 30 
+ 
+ 
+ 
+ 
1 60 
+ 
+ 
+ 
X 
1 10 
4- 
+ 
+ 
+ 
70 . - 
] 30 
+ 
+ 
+ 
X 
| 60 
+ 
+ 
+ 
1 10 
+ 
+ 
+ 
X 
75 
l 30 
+ 
-p 
+ 
- 
I 60 
+ 
+ 
+ 
- 
( 10 
+ 
+ 
+ 
' - 
80 
) 30 
+ 
+ 
X 

1 60 
X 
- 
Babcock and Russell (19) 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 
acids than the latter ferment. The heat boundary of its activity is 
