Produced by Rontgen Rays. 53 



Conclusion. 



(1) The recombination of ions takes place approximately in 

 accordance with the law. 



dn „ 



w=- an 



provided that sufficient time has elapsed to enable an effectively 

 uniform distribution of the ions to be established in the gas. 



(2) When a is determined by considering a certain volume 

 of ionized gas as a whole without regard to the distribution of 

 the ions, a as given in the above expression is not a constant 

 but has an initial maximum valne and approaches its final con- 

 stant value at first rapidly and then more slowly. 



(3) An explanation of this effect is suggested based on the 

 ■assumption of a non-uniform distribution of the ionization pro- 

 duced by Rontgen rays, the final values of a corresponding to 

 an effectively uniform distribution. 



(4) The value of a is shown to fall off as the pressure of the 

 gas is reduced. 



I wish to express my gratitude to Asst. Prof. E. M. Wellisch 

 for suggesting these experiments, and for his very helpful 

 interest throughout the work. 



Sloane Laboratory, 



Yale University, 



August, 1912. 



