﻿182 Mr. G. H. Livens on the 



and that 



2p% 

 Pi siD P l e- l ' l '"dl= 



we find that the contribution by the one electron to the total 

 sum is 



2rm 



i+«¥" 



The number of electrons per unit volume with initial velocities 

 in the limits between (f, tj, f) and (f + rff, 'n + drj, f+d?) is, 

 as before, 



K^K.e-* r2 d£d v d£ 



so that the contribution of these electrons to the total energy 

 dissipated is 



1+ 



and again integrating over all possible values of (f, ?/, f) we 

 find the total value of H in this case to be 



H= 



4tt N^UEJo 8 





?*■ 



Now the mean value of crE 2 is io-E g 2 , so that on com- 

 parison we find that 



8tt Ne 8 7 w /y 8 r rg^r^ 



3 m V 7tM 1: )V 



o i 27TC 



or put s = qr~ and ^? = -— : we get 



4 N* 2 L r q f °° e- s ds 



l,n / q J °° e s ds 



~ 3 m V 7tJ ±7r 2 c 2 l m 2 q 

 ■ \ 2 S 



" V 3?T 7??W wi J ^ 67rV/ w s 



2 * 



