610 Mr. S. Russ on Distribution in Electric Fields of 
It will be seen that for S0 2 there is a much greater dif- 
ference in the activities of cathode and anode than is the 
case for air, while for hydrogen practically no difference in 
activity over the same range of pressure was obtained. 
Fiff. 5. 
> 
< 
1 
300 
S^ 
/ CcUAod& 
200 
/ ^^^kwr 
o ^^ 
+ 
100 
f\lA- * 
o 
•J 
Pressure in Mms 
We should expect that the curves for cathode and anode 
in the case of hydrogen would show a divergence at higher 
pressures, for if an encounter between the active deposit 
particle and a hydrogen molecule is not so effective in 
reducing the velocity of the former as a sulphur dioxide 
molecule, then we shall require a higher pressure with 
hydrogen to observe the same effects as with sulphur 
dioxide. 
