744 
Mr. S. Russ on the Electrical Charge, 
The amount of active deposit obtained on the plates decreased 
as their distance from the actinium was increased, but the rate 
of decrease was different for the two plates. 
Inspection of the figure shows that at first there is an 
increase in the ratio of negative to positive activity as at the 
lower pressure, which subsequently shows a decrease similar 
to that observed at the high pressure. 
Fig. 5. — 1*2 cms. pressure. 
o. 
5" so /y 20 2s- JO 
D/STA/VCE //V C/VS. 
It must be noted that in the region between 11 and 18 cms. 
from the actinium it was impossible to obtain concordant 
results, sometimes a high and sometimes a low value for the 
ratio resulting. 
It has been observed by Debierne in the paper already 
referred to, that there is a position of maximum activity in a 
vessel containing a preparation of actinium, but the writer 
does not know whether the experiments here described have 
any bearing on that point. 
The question arises as to whether the apparent loss of the 
positive charge of the particles can be explained by their 
diffusion to the sides of the vessel, but considering the re- 
latively small distance travelled necessary for the observed 
effects, it is difficult to see how loss by diffusion can account 
for them; moreover, it would not explain the marked increase 
in the activity of the positive plate in the experiments at 
atmospheric pressure. 
