912 



J Cl 



Fis. 8. 



1.Ï 



witli pure oxygen and for each decrease of temperature add tlie 

 necessary quantity of nitrogen '). 



§ 4. Theoretical conchis'tons. We must call attention to the fact 

 that every theoretical interpretation of our results must account for 

 two different facts: in the tirst place for the change of the magne- 

 tisation with the density, and in the second place the parallelism 



of the lines -=f{T). 



It is plain that hxyiGV.yi^'.s theuri/, onli/ supplemented by the hypothesis 

 of the neyatlve molecular jields, is sufjicient to give the explanation. 

 In fact if N represents the coefficient of tlie molecular field, it leads 

 to the law 



or 





X (T + A) = C, where L = CXq, 



(1) 



1) Experiments make it probable, that for gaseous oxygen x even at — 183oC. 

 does not deviate or at least (see the conclusion of § 4) deviates only very little 

 from Curie's law. In the application of the ascension method x ™ay therefore 

 not be supposed to be equal for the liquid and for the vapour, as was done in 

 formula (2) of Gomm. No. 116, but a correction must be applied, which, however, 

 in our case remains within the limits of experimental error. 



