464 



his Paper in These Proc. of 25 .Ian. 1913 (published March IS'^M, 

 had then already been treafed very fully in a series of four papers, 

 written by me at Olarens 1911 — 1912 (On the variability of /> etc. ; 

 see These Proc. of 26 Oct., 22 Nov. 1911 ; 24 Jan., 22 Febr. 1912). 

 That a good deal may be attained in this way can sufficiently appear 

 from these Pa])ers. That difficulties present themselves of the same 

 nature as have been advanced by van der Waals on p. 1076attije 

 bottom (loc. cit.), has also appeared at the end of the 4^'' Paper 

 (p. 716 et seq.). 



In any case it is a kind of relief that according to all that proceeds 

 the assumption of quasi association does not seem absolutely necessary. 

 The change namely of h with c and 7' can very well be explained 

 by other influences. 



5. That b,, gradually decreases with the temperature, so that //,, 

 would coincide with b^ at jf'=0, and accordingly the variability of 

 b would have quite disappeared — in consequence of which we 

 approach more and more to the ideal equation of state with constant 

 b, on approaching the absolute zero — this points to the invalidity 

 of the kinetic assumption, that for very large volume (for b,, ordy 

 refers to large volumes) i. e. in ideal gas state, b^ would be = 4//^. 

 For according to the well known kinetic derivation, b, would then 

 still be = 4/^0 at the lowest temperatures, whereas it has clearly 

 appeared that b,, approaches more and more to b^ at low tempera- 

 tures. Compare particularly III p. 1051, formula (35) and the sub- 

 sequent eloquent table. 



6. Thus after all it would prove true what I wrote in I p. 809 

 (These Proc. of 26 March 1914), that namely in v — b the quantity 

 b always refers to the real volume of the molecules ni and is not 

 ::= 4771, as the kinetic theory would lead us to assume. And iji this 

 way the difficnlty, which I emphatically pointed out in II, p. 925 

 (^at the bottom) — 926, would have naturally vanished. 



So it is getting more and more probable that the so-called quasi 

 diminution of b does not exist, and that there remains only real 

 diminution, which is represented by a formula of the form (29), as 

 far as the dependence on v is concerned, and by a formula of the 

 form (36), as far as the dependence on T is concerned. 



Why the earlier kinetic assumption b,, = 4/?i is really a fiction, 

 and what circumstance has been overlooked then — this I shall 

 demonstrate in a separate Communication. 



It will then have become clear that only v — )n, and not /; — 4;/? 

 determines the thermic pressure - wliicii becomes already pj-obable 

 when the kinetic energy of the moving molecules is thought to be 



