Two Ions produced in Gases hy Runhjen Radiation, 121 



§ ±. Manipulation and results. 



§ 5. Difference of velocity shown by blowing along a 



charged wire. 

 § 6. Difference of velocity shown by using an alternating 

 E.M.F. 



§ 7. Metals and air oppositely charged when exposed to 

 Rontgen rays. 



§ 8. Air charged negatively discharges faster to a surface 

 than when charged positively. 



§ 9. Distribution of electrification between two plates. 

 § 10. Dependence of blowing methods upon the velocity of 

 the blast. 

 § 11. Potential gradient between two plates. 

 § 12. Remarks. 



The extension of the idea of ionization to the various types 

 of conduction through gases has enabled us to explain most of 

 the observed phenomena. 



While in many liquids some ionization occurs at ordinary 

 temperatures, in gases high temperatures are required, and 

 it is brought about, in addition, by the action of various 

 agents upon the cold gas. 



The charged carriers that exist in the gas due to any of 

 these causes, and take part in the conduction, are all called 

 ions, no matter whether in the various cases they may differ 

 in their structure or properties. 



It is known from the changes in concentration at the two 

 electrodes that in liquids the two ions do not move with the 

 same velocity; and this is attributed to a difference in size. 

 In gases a difference of velocity has not heretofore been 

 determined. 



A. Schuster (Proc. Roy. Soc. xlvii. p. 553) gives some 

 reasons for believing that the negative ions in gases move 

 faster than the positive ones; and J. J. Thomson (Phil. Mag. 

 Dec. 1895) explains some phenomena in electrodeless tubes 

 by assuming that the negative ion in oxygen and hydrogen 

 travels faster than the positive one. Rutherford (Phil. Mag. 

 Xov. 1897, p. 436), in determining separately the velocities 

 of the two ions in air for conduction under the influence of 

 Rontgen rays, did not observe any difference. 



The dependence of the quantitative values obtained in 

 certain determinations (§9 and § 10) upon the sign of the 

 electrification used led me to undertake the present investi- 

 gation, in which it is shown that a difference of velocity does 

 exist, and its amount is determined. 



While methods are not wanting for determining with more 

 or less accuracy the sum of the two velocities, a reliable method 



