332 H. B. TAYLOR. 
The amounts of hydrogen peroxide decomposed are 
measured in ccs. of N/400 potassium permanganate solution. 
The figures for the values of A; show that, although the | 
activity of the enzyme is decreased, as shown by the values 
for A, the destruction of the enzyme proceeds at a slower 
rate. 
The addition of potassium cyanide and hydrogen cyanide, 
although they decrease the activity of the enzyme, have, 
therefore, the effect of causing the enzyme to decompose 
more hydrogen peroxide, (i.e.) increasing its stability. It 
might be said then that variations in the values for the 
velocity constants need not: necessarily be followed by. 
similar variations in the total amounts of hydrogen peroxide 
' decomposed, although for temperature and increase in 
enzyme concentration, the amount of hydrogen peroxide 
decomposed decreased in one case and increased in the 
other along with corresponding changes in the values for &,. 
From what has been said above there appears to be no 
doubt that the catalase of milk is analogous to the catalase 
obtained from blood. 
