CATALASE REACTION OF MILK. 331 
(3) 
HCN = M/100,000 HCN = M/10,000 
t a-—w# TG t a—x K 
0 14:0 a 0 14:15 
20 13°1 "0026 10 14:00 "0011 
40 V2°7 0024 20 13:0 “0009 
70 11:6 -0026 40 12:9 "0023 
1080 T°4 ae 70 12-4 "0019 
1080 is 
Mean ‘0025 Mean -0015 
In (3) of the above tables the HCN was formed in the 
catalase solution by the addition of the requisite amount 
of HCl to the KCN. It will be noticed that the values for 
K decrease with the increasing concentration of potassium 
cyanide, and on comparing the values for hydrogen cyanide 
with those for potassium cyanide, that solutions of a 
strength M/100,000 and M/10,000 of hydrogen cyanide give 
approximately the same figures for X as solutions M/10,000 
and M/1,000 of potassium cyanide. From this it would 
appear that hydrogen cyanide has ten times the effect of 
potassium cyanide. 
It was at first thought that by calculating the values for 
the rate of destruction of the enzyme, figures would be 
obtained somewhat similar to those given in Tables IX and 
X for the effect of hydrogen peroxide and temperature, but 
this does not seem to be the case, as will be seen from the 
following table. 
Table XITI. 
| Amount of hydrogen 
eee |. e108 fe Kx peroxide 
; | decomposed. 
M/x been 38 76 275 6-4 
M/100,000 | 29 66 232 6°6 
M/10,000 26 57 192 UA, 
M/1,000 14 22 57 8:1 
