465 



= 1 - 

 7'*_1 





(20) 



*i-o 



with a given value of 0^ the value of T^ may then be derived; 

 finally T follows from 



G 



a a — 



T=T* . -—e n(i ,256). 



bha 



§ 4. 7%^^ spontaneous in(t(jnetlz(ition of magnetite and of nickel. 

 In Fig. 1 the data are represented for a comparison of the obser- 

 vations concerning the spontaneous magnetization of magnetite and 



of nickel with the relations (23) !o (26) of § 3. 1\ is the tempei'a- 

 turc of the Curie point. The curve marked "equipurtilioJi" has been 



30 

 Proceedings Koyal Acad. Amsteidam. Vol. X.V1. 



