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LIII. Ionic Mobilities in Hydrogen and Nitrogen. By W. B. 

 Haines, J3.Sc, 1851 Scholar, University College, London*. 



IT has been recorded by Franck f that when nitrogen, 

 argon, and helium are carefully purified, there can exist 

 in them, even at atmospheric pressure, negatively electrified 

 particles having such high mobilities as leaves no doubt that 

 they are free elections. The values recorded are, 120 cm./sec. 

 for nitrogen, 206 cm./sec. for argon, and 500 cm./sec. for 

 helium, in unit field. These particles were found to be 

 extremely sensitive to any impurity in the gases. The 

 research which the present paper describes was undertaken 

 to investigate in greater detail the effect of impurities in 

 nitrogen, and the work has extended to some interesting 

 results for hydrogen as well. 



Method. 



The method adopted was the modification of Rutherford's 

 method described by Franckf, depending on the use of an 



Fig. 1. 



A 



jS 



alternating electric field. 



J^H^ T" 



ur 



1 is a diagram of the 



* Commuuicated bv the Author. 



t Franck, BericJit d. JDcut. Pfo/sik. Ges. 1909. 



\ Franck, Bericht. d. Dent. P/njsik. Ges. 1907. 



