605 



^ 3. Development for rigid spheres with attraction proportional 

 luith r~^. Performing the calculation as in § 2, but now with 



(p{r)=- for T>r><j. . . . (31) 



r 



we find : 



C^ = — \n^ .n^hca \ 



[ 1 32 12 f 



16 2 ^ö' 8 40 T-Ö, 



The radius of the sphere of action neither occurs here in C,, 



while the development of 6', according to ascending powers of - 



r 



induces the same remark as was made in ^ 2 concerning the contri- 

 bution furnished by the attractive forces for greater mutual distances. 

 For T = 00 we obtain : 



C=jSn'{^:xoy\\ -f/a +(W4V-48/n2)(/nf .. \\ 



or [ . . (33) 



C=:^«^(-|jrö')'jl — 1,2/m? + 0,809(/mO' ■ • ■] ) 



§ 4. In order to represent the dependency of C on the tempe- 

 rature more in details and to compare this for the two laws of 

 force discussed in this paper, we shall introduce a temperature 

 characteristic of each gas as a reduction temperature ^). As the series 

 for B found Suppl. Leiden N°. 246 § 3 eq. (42) converges still 

 sufficiently i-apidiy at the BoYLR-poinf, this point suggests itself 

 as reduction temperature. 



For y (r) = cr ■♦ equation (42) Suppl. Leiden N". 246 becomes: 



B=^BJ,i~^hv~^{hvy-^^{hvY ...\ . . . (34) 



where B^ represents the value of B for A = 0, viz. for 7'= oo. 



From (34) we find for the BoYi,E-point for which B =z \ 



(Av)b = 0,3223. 



T ^ 



Writing now t(B) tor -^ -, wheie Tb is the Bovi-E-temperature, so 



that r(B; represents the reduced temperature with respect to the 

 BoYLE-point as reduction-temperature, we find for (34) 



B=B^\ 1—0,9669 t-/ — 0,0312 t^'J^ — 0,0019 t^^^ ... } . (35) 



1) Comp. H. Kamerlingh Onnes and VV. H. Keksom. Die Zustandsgleichung. 

 Leiden Suppl. N». 23 § 386. 



