CATALASE REACTION OF MILK. 327 
Temperature Coefficient. 
As the range of temperature between the different values 
of & is not, in all cases, equal to 10° C., a formula was used 
by which the temperature coefficient for 10° OC. can be 
calculated. This formula is as follows: 
log K, — log A, = A(T7,-—7,) 
The temperature coefficient for 10° C. is given by A¢+10/K, 
where Ay+10/K, = 10°. 
The value for the temperature coefficient for 10° CO. was 
calculated by the above formula from the values of A given 
in Table VII. 
Table VIII. 
Temperature °C. | Temperature Coefficient 10° C. 
0-15 1°47 
0 — 25 1°55 
15 — 25 1°68 
25 — 35 he 
25 — 50 °83 
35 — 50 87 
The value for the temperature coefficient for the range 
0° — 15° C. is 1°47 and agrees with that given by Senter,’ 
0° - 10° C. = 1°5, for blood catalase. 
Inactivation of Catalase. 
In the experiments on the efiect of varying the concen- 
tration of hydrogen peroxide and the temperature, for 
which the values of X are given in Tables VI and VII, the 
ratio a/a — x showed a decrease, indicating that both 
hydrogen peroxide and temperature have an inactivating 
effect on the enzyme. 
Assuming that this inactivation proceeds as a first order 
reaction, Tammann’ has derived a formula by which the 
' Zeit. fur Physik Chemie, xxiv, 1903, p. 257. 
* Zeit. fur Physik Chemie, xviir, 1895, p. 436. 
