604 



where for domain 1 (he 3"', 5''', and 6''' terms between the brackets 

 must be omitted. Performing the calculation in the same way as for 

 C, we find : 



( T* t' 1 66 1 \ 



( o <1 a or T I 



a' Ö» 18 T 6 r ) 



r-+*7' + lF'"r-=i-7 



(26) 



while 



P J TT A*r» 



(27) 



(28) 



i t' 1 1 



SO that finally 



C,=^7i' . .T'Av](24/n2 - V^3) + - -j- 



( o- or t' 



3(T' 36 T 12 T 



-f- hi -; /7l 



Remarkable is that the radius t of the sphere of action does no 



longer occur in C\. Developing the logarithmic terms in (28) according 



,. a 



to ascending powers of — we obtain 



T 



C,=i n\zt^h\^ i !(24/n 2 - V^) _ ^ ^ • . -S • • (29) 



O' T 



SO that evidently the attractive forces excited by the molecules on 

 each other over mutual distances greater than a certain distance t, 

 furnish a contril)utioM to 6',, the ratio of which to the total term 

 is of the same order of magnitude as that in which the forces 

 decrease at an increase of the mutual distance from a to t. 



If now we put r = oo, we find, adding (20), (25) and (29) and 

 introducing the potential energy at contact 



<^'=A-^»'(l-'f(j')Ml-|(19-24/w2)Ar + ^(3840/«2 -2453) (Ar)^ .] 

 or 



C = ^n' (I -T a')' |1 — 1,418 /ir + 1,566 (Ar)* .. .| . . (30) 

 1 

 ^^ ''^=1 — 7fT, ^p being the well known constant of Planck, this 



gives us the first term in the development of C according to 

 ascending powers of T~^. 



