70 Prof. Thomson, On the Distribution of Electric Force, etc. 



On the Distribution of Electric Force along the Striated Dis- 

 charge. By Sir J. J. Thomson, M.A., F.R.S., Cavendish Professor 

 of Experimental Physics. 



[Read 9 November 1908.] 



A Wehnelt hot lime cathode was used to produce the discharge 

 as it was found that at low pressures the striations produced in 

 this way were remarkably steady and bright and in consequence 

 made accurate measurements of the distribution of electric force 

 much easier than with the ordinary discharge. It was found that 

 just in front of the bright surface of a striation towards the 

 cathode there was a reversal of the electric force. This reversal 

 causes a great accumulation of ions in the part of the striation 

 nearest the cathode, the recombination of the ions in this region 

 will therefore be much greater than elsewhere and it is shown 

 that a very simple explanation of the formation and behaviour of 

 striations was given by the hypothesis that the recombination of 

 the ions was the source of the luminosity in the striations. 



