THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



APRIL 1897. 



XXXV. On the Electrification of Gases exposed to Rontgen 

 Rays, and the Absorption of Rontgen Radiation by Gases 

 and Vapours. By E. Rutherford, M.A., 1851 Exhibition 

 Science Scholar, University of New Zealand, Trinity Col- 

 lege, Cambridge* . 



IN a recent paper by Prof. J. J. Thomson and myself " On 

 the Passage of Electricity through Gases exposed, to 

 Rontgen Rays " (Phil. Mag. Nov. 1896) , a method of obtaining 

 electrified air by means of the Rontgen rays was very briefly 

 explained. 



The present paper deals with further experiments which 

 have been made to investigate more fully the way in which 

 electrified gases can be obtained by means of the Rontgen 

 rays, and also to examine the properties of the charged gas. 

 The opacity of gases for Rontgen radiation has also been 

 examined. 



A gas becomes a temporary conductor under the influence 

 of the Rontgen rays, and preserves its power of conducting 

 some short time after the rays have ceased to act; since the 

 conduction in the gas is probably due to the convection of 

 charged particles which travel through the gas with a velocity 

 of the order of 1 cm. a second for a potential gradient of one 

 volt per cm., it is not surprising that we can separate the 

 positive from the negative conducting particles before they 

 give up their charges to the electrodes. 



* Communicated by Prof. J. J. Thomson, F.E.S. 

 Phil. Mag. S. 5. Vol. 43. No. 263. April 1897. U 



