641 



Further : 



{■2q 



[COS'^'I ff] = [i-OS'''l 2'f] = ^.-T . I 



1 



22? 





Tliese formulae give finally: 



(16 128 18176 262144 



P-..0-' j- i!,.f-^ ('-■)"+ ^485 ^'^y- 419265 ^''^^ + 



+ 0,2360 (/(o)'-0,1355 {hv)- + 0,1019 (Ar)" . . . , 



so that 



5=^|n.^.Tö'Sl -1.0667 (/a-)-' + 0.1741 (Ar)" — 0.4738 (/af + 

 + 0.6252 (/iu)* — 0.2860 (Ar)'' + 0.1355 (Ar)' — 0.1019 (Ar)» . . .| 



(17) 



.{U 



^ 3. For the lower temperatures, e. g. at the BoYLic-poiiit (the 

 temperature at which B = 0), this series con\ erges very slowly, so 

 that for them the terms given above are nol sufficient. 



At the inversion point of the Joule-Kelvin effect for small densities 

 the term with {hiif in (18j amounts to about '/soo of B^ (^ /;„.«.), 

 the value to which B would approach for T=:cc, if the equations 

 found here remained valid. Hence for the inversion point just 

 mentioned and for higher temperatures, the terms given above may 

 be considered to be sufficient, assuming that none of the following 

 terms is unexpectedly large. At 0.75 7'„„f^=o) the above mentioned 

 term amounts to Vso of Bj,, so that on the same assumption we 

 may reckon upon an accuracy of about 1°/„ (of B^,). 



I have not succeeded in deducing a series which is more suitable 

 for lower temperatures. 



Just as for the (splierical) molecules, which bear a doublet at 

 their centre, so also for the (juadruplets the term with T~' is absent 

 in the series for B. Whereas, however, for the doublets all odd 

 powers are absent, here the higher odd powers appear in the series, 

 although the coefficient of T"'^ is still relatively small '). 



Above 37',„,.(^=u) with an accuracy of Viooo ^"d ^bove 1.2 7',„,.(.— o) 

 with an accuracy of Vioo- t'le first two terms in (18) are sufficient. 

 The dependence of B on temperature then agrees with the suppo- 



1) The questions under what conditions in general the ternn with T-i, as also 

 the higher odd powers disappear from B will be dealt with in a following paper 

 (Suppl. No. 390). 



