THE 



LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



• >^ r ~' 



[SIXTH SERIES. 



MAY 1901 



XLVII. The Striated Electrical Discharge. By J. H. Jeans, 

 B.A., Scholar of Trinity College, and Isaac Newton Student 

 in the University of Cambridge *. 



[Continued from Ser. 5, vol. xlix. p. 262.] ^j 



Part II. 



§ 12. rFVEE first part of this paper contained an exami- 

 I nation of the differential equation which, upon 

 Prof. Thomson's theory o£ conduction by ions, is satisfied by 

 the intensity of electric force at any point of an electrical 

 discharge. With a view to simplifying the discussion of this 

 equation, the assumption has been made that the quantities g 

 and a. depend only upon the electric intensity at the point 

 at which they are measured. 



But a simple calculation will show that this electric in- 

 tensity is not, in itself, sufficiently strong to effect ionization f, 

 and the causes which seem most likely to account for ioni- 

 zation % are not such that q will satisfy the condition which 

 has been imposed upon it. We must, therefore, examine to 

 what extent the results which were obtained only upon this 

 assumption will remain valid if the assumption is not com- 

 plied with. 



At the outset it may be noticed that differential coefficients 

 of q do not occur in the equation for the intensity. Hence 



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

 t J. J. Thomson, ' Recent Researches/ § 213, p. 192. 

 X The causes of ionization have recently been discussed by Prof. 

 Thomson, Phil. Mag. 1. p. 278. 



Phil. Mag. S. 6. Vol. 1. No. 5. May 1901. 2 M 



