428 Mr. E. Rutherford on the Velocity and Rate 



Gas. 



T in seconds. 



Conductivity 

 compared with air=l. 





•65 



•3 



•35 



•51 



•45 



•18 



•5 

 1 

 11 

 1-2 



4 



18 



Air 











There seems to be no close connexion between the values 

 of T and the conductivities, although as a general rule it may 

 be taken that the value of T diminishes with increase of con- 

 ductivity. 



It was found, however, that the rate of recombination was 

 not always the same for the same gas with the same intensity 

 of radiation, but depended largely on the amount of dust 

 suspended in the gas as will be shown later in the paper. 



Effect of Intensity of Radiation on the value of T. 



The value of T for the same gas was found to depend 

 largely on the intensity of the radiation. This is to be ex- 

 pected from theoretical considerations, for 



and 

 therefore 



If then a is a constant for the same gas in the same state, 

 T varies inversely as s/q. This relation was found to hold 

 experimentally, for q is proportional to the intensity of the 

 radiation, which varies inversely as the square of the distance 

 from the bulb. 



For example, for a definite intensity of radiation the value 

 of T was *25 second. On placing a thick aluminium sheet 

 below the conducting vessel, which cut down the intensity of 



q = 



«N 2 , 



1 



«T, 



T = 



1 



\lqa. 



