602 Mr. S. Russ on Distribution in Electric Fields of 
The rod which had served as cathode or anode was then 
made a neutral pole by connecting it to the containing vessel, 
and what may be called diffusion experiments, i. e. with no 
electric field existing in the gas, were then made. Observations 
showed that there was a marked decrease in the amount of 
active deposit that diffused on to the rod as the pressure was 
diminished. 
After a slight modification of the apparatus, a comparison 
of the activity obtained on a cathode and anode over a range 
of pressure extending from *1 mm. to 1 mm. was made 
with three gases having widely different densities, namely, 
hydrogen, air, and sulphur dioxide. 
The results in the case of air show that the activity of the 
cathode is considerably greater than that of the anode, but that 
they approach equality as the lower pressure is reached. 
This effect is more marked in sulphur dioxide, while for 
hydrogen no such difference in activity is observed, just as 
much active deposit being transmitted to the anode as to the 
cathode over this range of pressure. 
Methods of Experiment. 
A comparison was first made between the amounts of 
excited activity obtained on a wire maintained at 200 volts 
acting as cathode and then as anode over a range of pr essure 
extending from '01 mm. to 1*2 mm. 
Fig. 1. 
Radium Solution 
The apparatus used is represented in fig. 1. A brass wire 
IV 10 cms. long, '55 mm. diameter, on which the active 
