158 MR. J. S. TOWNSEND ON THE DIFFUSION OF IONS INTO GASES. 



it is produced. The mean square of the velocity of agitation of the ions will, on this 

 hypothesis, be equal to the mean square of the velocity of agitation of the molecules 

 of the gas. v[ and v\ will then be equal to 47 X 10* for the ions in oxygen. 



The number of negative ions that approach within a distance R of positive ions in 

 the time 8t will be 



Equating this number to the number that recombiue in the same time we obtain 



Theoretical ) 



R = 1 10~ 5 centim. 



At a distance ^10"* the charge on an ion would exert a force equal to a fall of Theoretical 

 potential of 16,200 volts, per centim. This force would make two oppositely-charged 

 ions move towards each other with a velocity of 2 X 10* centims. a second. ,m 



It would be premature to discuss any further the results which have been obtained, 

 as experiments are being carried out which may throw additional light upon the 

 subject. illator ' H 



In conclusion, I wish to state that I am greatly indebted to Professor THOMSON for 

 his advice and suggestions during the course of these investigations. ave Di . lgrP . 



' 



