360 Mr. Biiggs on Distribution of Active Deposits of 



showed that the anode activity was due to the diffusion of 

 neutral deposit atoms : hence if c and d are the cathode and 



anode activities respectively, , would give the fraction 



v * ' c + d P 



of the RaA atoms positively charged, if, as assumed by 



Wellish, the recoil of JfaB from the electrodes is negligible. 



This assumption will be shown later to be incorrect. In 



c — d 



column A of Table I. are given the values of = cal- 



& c-fd 



culated from the anode and cathode activities for radium 



emanation mixed with air. No evidence is shown of a 



continual increase with voltage, the limiting value being 



practically reached at 60 volts per cm. The mean value 



89*6 is in good agreement with that found by Wellish when 



using a different type of testing vessel. 



Table I. 



C 





Air. 



c-d 

 c-t-a 



100. 



Pressure. 



Volts per cm. 



A. 



B. 



20 cm. 



60 



89-2 

 89-5 



89-4 



• 



Atmospheric. 



150 







jj 



1000 







>> 



2000 





... 



„ 



4000 





... 



,, 



6000 



90-7 





?> 



7000 



88-9 

 89-0 





» 



8000 



89-3 



88-7 





„ 



9000 





90-5 



j> 



,, 





906 



>» 



10,000 



90-6 



91-9 



,, 



12,000 



£9-4 



91-3 



•t 



14,000 



91-0 



91-8 



... 



89-8 





92-4 





92-8 





93"8 



94-7 





95-4 





95-6 



Mean ... 89- 



To determine the reason for the discrepancy in the results 

 obtained by the author and by Henderson, experiments 

 were made with an apparatus similar as far as possible 

 to that used by Henderson. The two results shown in 

 column C sufficed to show that his experimental results 



