113 



N°. 32(7 ^). Tt is shown in § 2 that tlie answer is in the affirmative-, 

 in § 3 the same appears to be the case for the measurements con- 

 cerning the snsceptibilitv of liquid oxygen over a widei- range of 

 temperatures. § 4 contains the conclusion whicii follows from §§2 

 and 3. Finally in the following § § are treated the consequences 

 concerning the dependence of 6^ on the density, which follow from 

 the results of those measurements '^). 



^ 2. The susceptibility of the liquid mLvtures of oxygen and nitrogen 

 and the application of the quantum-theory to paramagnetism. As a 

 preliminary to the question whether the results of the measurements 

 by Perkier and Kamerlingh Onnes can be represented with the aid 

 of the relations of Suppl. N". 32(7, in so far as these are applicable 

 to paramagnetic substances, the spBcific susceptibility of the oxygen 

 in the mixtures (Table I, Comm. N^ lS9d) was compared witli the 

 specific susceptibility for pure oxygen in the gaseous state at the 

 same temperature, w^hich would follow from tlie measurements by 

 Weiss and Piccard if Curie-Langevin's law remained valid down to 

 that temperature (cf. tabie I, Comm. 'N\ 139^/). This value we will 

 call the equipartition value Xeq. 



On the assumption mentioned in § 1, that the presence of the 

 nitrogen molecules does not cause a change in the magnetic moment 

 of the oxygen molecules, the (paramagnetic) specific susceptibility of 

 the oxygen in the mixture is determined by Oosterhuis's relation : 



'/..O-i in mixture ^^^ o \ f 



In this relation n represents the number of oxygen molecules 

 in 1 gram of oxygen, ^ is the magnetic moment of an oxjgen 

 molecule, ?/, the mean rotatory energy (about two axes ± to the 

 magnetic one) of a molecule of oxygen in the mixture at the tem- 

 perature and density considered. According to Langevin 





Division gives 



1) For a detailed discussion of those measurements on the basis of the assump- 

 tion of a negative nioleculai- field, as well as a consideration of the other cir- 

 cumstances which may liave an influence, we refer to the paper by Perkier and 

 Kamerlingh Onnes quoted above. 



-) The principal results of this paper were already inserted in the translation 

 of Comm. No. 139d ; d. 915 note 2 



8 



Proceedings Royal Acad Amsterdam. Vol XVll 



