PROFESSOR KELLAND, ON MOLECULAR EQUILIBRIUM. 55 



Let the plane be divided into annuli of which the radius drawn 

 from the line of intersection with the axis of x is p, then 



2tto^p m + re „ -„ _. 



a^ijj-«-*(i + «jB) 



is the part of G for this annulus ; 



.-. part for plane = ?£ C P d P (,, + r e ) e «* i 1 t"-*? 



- -r / dB(r, + re) e~ aR i =;— '■ 



_ 27r(i; + re)<?- C+ re > 

 e tj + re 



— ~JL *-aln+re) 



Hence, G = -^<?- a "2 °V 



2tt <?-°» 



and F = - 



H 





6 2 (l-e" ae ) 



" dr, ~ 7(1^ e~ ae ) ' 

 so that the term in question is 



e £ (l-C"««) 



<r 



The other part of//, is iHJ^*-«'L+f^ 



a e* 



If, however, it were required to find the value of h for a particle 

 not far from the surface of the medium, it would be necessary that 



