400 



ciation found by tliern actiiall}' refers to this three-phase equilibriuin, 

 we get the P, T figure (12). 



O 

 Oh 



O 



-5 



-10 





^^t 



-20 



-25 ' 



-30 ■ 



600 800 10GÖ 1200 



Fig. 12. 

 Of course these two last mentioned isotherms ai-e perfectly inadequate 

 to determine the direction of the three-phase line for Fe,Oj -|- Fe,0^ 

 -|- G with any certainty ; we will, therefoie, only point out that the 

 situation of this three-phase line, as it would follow from these 

 two data, with respect to other three-phase lines, would be in good 

 agreement with the expectation expressed schematically in fig. 10 

 or fig. 11. 



General and Anorganic Chemical 

 Lahoratory of the university. 



Amsterdam, June 28, 1918. 



