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LXXT. The Recombination of Ions in Carbon Dioxide and 

 Hydrogen at Different Temperatures. By Henry A. 

 Erikson, Assistant Professor of Physics, University of 

 Minnesota *. 



IN a previous paper f it was shown that the rate of recom- 

 bination o£ ions in air at constant density increases ns 

 the temperature of the gas is lowered. Results showing this 

 were also obtained, in the case of air, by Phillips J. 



In this paper are given the results the writer obtained some 

 time ago for carbon dioxide and hydrogen. 



The arrangement of the apparatus used was practically the 

 same as described in the previous paper. The method con- 

 sisted in measuring Q, the number of ions produced by the 

 rays per second, and N, the number of ions of the same sign 

 in the gas after the condition has been reached where as many 

 ions are recombining per second as are being produced by the 

 rays. The coefficient of recombination (a) was calculated 



from the relation a = K ~, where K is a constant depending 



upon the dimensions of the ionization-chamber. 



Carbon Dioxide. 



The C0 2 used in the experiment was obtained from a com- 

 mercial cylinder of the liquid, and was dried by passage 

 through a coil imbedded in C0 2 snow. 



In this gas also the coefficient of recombination of the ions 

 was found to increase as the temperature was lowered from 

 + 100° C. to —61° 0. The following are the average values 

 obtained for N and a in arbitrary units : — 



Temp. 



N. 



a. 



100° C. 



1046 



2'6 



68 



9-36 



31 



52 



8-82 



3-67 



23 



7-67 



4-65 







7-06 



5-48 



-64 



6-95 



5-89 



* Communicated by Prof. Sir J. J. Thomson, F.R.S. 



t Erikson, Phil. Mag-, vol. xviii. p. 328 ( 1909). 



J Phillips, Roy. Soc. Proc. Ser, A. lxxxiii. p. 246 (1910). 



