206 



Allen. Crenshaw, Johnston, and Lar sen- 



Inversion in ferrous sulphide. — Le Chatelier and Ziegler* 

 discovered a transformation in commercial ferrous sulphide at 

 about 130°. This has been confirmed by Treitschke and 

 Tammannf and by Kinne and Boeke.J The last named 



Fig. 12. 



authors were unable to find any heat absorption in approxi- 

 mately pure ferrous sulphide, though the addition of iron (or 

 carbon), which they believe goes into solid solution, makes the 

 heat change manifest. The dissolved iron is supposed by 



* Bull. Soc. d'Encouragement de l'Industrie, Sept. 1902, 368. 



f Loc. cit. 



jZs. anorg. Chem., liii, 338, 1907. 



