-l&,pl^^ 



( 435 ) 



S ;/ ' ' ^ 1 



or, since we may replace %',j by 'W^^ and (j by (>q, 



— ~ V:t j Qo (S O!/ d '^ > 



which vanishes on account of (5). 



Hence, as far as regards the resultant force, we may put £ = g', 

 that is to say, we may take %' as the electric force, acting not 

 only on ions at rest, but also on moving ions. 



The equations will be somewhat simplified, if, instead of ?s', we 

 introduce the already mentioned difference §' — g'^. In order to do 

 this, we have only twice to write down the equations (Tc) — (IVe), 

 once for the vibrating system and a second time for the same system 

 in a state of rest ; and then to subtract the equations of the second 

 system from those of the first. In the resulting equations, 1 shall, for the 

 sake of brevity, write (V' instead of 5'— 5'o, so that henceforth a' will 

 denote not the total electric force, but only the part of it that is 

 due to the vibrations. At the same time we shall replace the valine 



We may do so, because we have supposed ii.f, a,;, ii^ to have the 

 same values all over an ion, and because (>„ is indc|ieii(l<'iit ol tiic 

 time, so that 



9 Co __ 9 Co 

 3 * 9 .r' 



Finally we have 



\ .*' • ,y s J 

 J^'v' S?' = , (TI,,) 



9 •?>'-- 9 •?>','/ . 9 ax 1 9 5V 

 17-3V='"^«-37 + F^ SV'^^'^- • • ("^'^) 



3 3'. 3 5'.v 34V:. ^ 



