PROFESSOR KELLAND, ON MOLECULAR EQUILIBRIUM. 41 



. M „ dD P (dU dU dV\ 

 hence the equation, , = — I —j— + -7 -j— 1 



ClX C \ ClX (I X ClX / 



gives 2^ (e~' R + aRe~ aR ) + 2 ^ («-««' + aRe~* R ') 



c 2, lR 3 + B' 3 a* \R> + R> AKe +aUe 



- A'(e-° R ' + aRe-° R )\~\ , 



hence M + M' = — — ^-= . 



2 



a 



The expression for the attraction of a particle of the first substance 

 on one of the same kind, whose mutual distance is a, is 



„ _ IttMPA f (l +al)e- al (1 +aa)e- aa \ M* 



a 8 I a 2 a' ~)~ IF 



and a similar expression, only accenting the letters, is true for the 

 mutual attractions of the other similar particles; call it S' : also, since 

 M attracts M', if T be the attraction of M' in virtue of M, we shall 

 have 



rr _^rPM'A i<J+al)e-"' (l+aa)e- aa \ MM' 



1 ^ \ J " a* ) + ~aT 



_ 2*hA e _ aa | ^Vyal + 1 j g _ ae _ &c J f 

 T - *" PMA ' f (l+qf)g— r (l+aa)g-'"' l 3fJT 



V \ a* a* J +_ ^~ 



2ttA^' „ ifa + l + aal V 

 e — 



a* 

 Vol. VII. Pa»t I. 



~{F^*a-'-<4 



