121 



distribution of tlic velocities of rotation over the molecules is taken 

 into account. 



Resuming we may conclude, that the observations by Perriek and 

 Kamerli>gh OniNEs concerning the susceptibility of liquid mixtures 

 of oxygen and nitrogen, although they do not furnish an experimenium 

 crucis between the theory of the negative ujolecular tield and the 

 application of the quantum-theory on paramagnetism, nevertheless 

 tit without any constraint ^) into the whole scheme which can be 

 built up on the basis of this application. 



§ 6. The results of the former § concerning the dependence of 

 <9„ on the density lead to ihe following inference regarding the 

 intltience of the rotatory motion on the external pressure. For those 

 densities at which u, is determined by the equations (4) and (5), 

 and at which ^^ ^ q''k the energy u, and also the entropy óv for 

 the rotatory motion are represented by the same functions (only 

 with another value of 0^) as the corresponding quantities for the 

 translatory motion in an ideal gas. 



In that case the rotatory motion gives a contribution to the external 

 pressure similar to that of the translatory motion. The ratio of this 

 contribution, for one degree of freedom, to that which in an ideal 

 gas is due to the translatory motion, approaches to 1 at increasing 

 temperature^). 



At small densities, however, viz. in the region in which 6^^ does 

 not depend on o, the rotatory motion does not give a contribution 

 to the external pressure. This agrees with what has always been 



of radiation tnergy supplied ffom outside only occurs when the representative point 

 lias arrived at one ot the limiting curves mentioned above (for instance in conse- 

 quence of the probability of emission on reaching a limiting curve, cf. Plakck, 

 Theorie der Warmestralung, 2te Aufl., § lot, being changed by the presence of 

 the radiation from outside) The observations by E. v. Bahr, Verb d. D. physik. 

 Ges. 1913, p. 1150, concerning hydrochloric acid seem to be more favourable to 

 this view than to a distribution, in which, in the plane mentioned above, only the 



enersv curves { n-\- ] — are covered with points, which is the assumption 



1 \ hv 



— are 

 2j 2 



alluded to in the note quoted p. 112, note 1. 



1) The views advanced in this § aboiU the coming into the foregrond of the 

 frequencies of rotation of the individual molecules are in fact, as will appear again 

 in § 0, a necessary complement for small densities to the theory of Suppl. N". 32a. 



~) I find that A. Wohl, ZS. physik. Gliem. 87 (11)14). p. 9, by quite different 

 considerations was also led to the suggestion that at large densities the molecular 

 rotatory motion may give a contribution to the external pressure. (Note added in 

 the trauslalionj. 



