THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JUNE 1900. 



L. On the Variation of the Electric Intensity and Con- 

 ductivity along the Electric Discliar ge in Rarefied Gases. 

 By Harold A. Wilson, B.A., B.Sc, Trinity College, 

 Cambridge*. 



1. The Electric Intensity. 



GRAHAM f has given a number of curves showing very 

 completely the variation of the electric intensity along 

 several continuous discharges in rarefied nitrogen. In the 

 following paper several similar curves are given obtained 

 under somewhat different conditions, and with other gases as 

 well as nitrogen. The results of some measurements of the 

 conductivity of the discharge, between small platinum elec- 

 trodes, along the whole length of the discharge are also 

 given. 



Skinner J has shown that very near the anode the electric 

 intensity is very small or zero when the positive column is 

 not striated. He also mentions that with a striated positive 

 column the potential-difference between the anode and an 

 exploring-wire near it was a minimum when the exploring- 

 wire was at a short distance from the anode, so that the 

 apparent electric intensity near the anode was negative. 

 These results are entirely confirmed by the observations 

 described below. 



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

 f W. P. Graham, Wied. Ann. lxiv. p. 69 (1898). 

 X Inaugural Dissertation, Berlin, 1899. " Ueber das Anodengefalle bei 

 der Glimmentladung," C. A. Skinner. 



Phil. Mag. S. 5. Vol. 49. No. 301. June 1900. 2 N 



