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the crystalline form of j'^, whereas the line ah refers (o mixed (nystals 

 in whieh /? is forced I)}- a to crystallize in the crystalline form of «. 



These states wonld certainly be realisable when the psendo compo- 

 nents presented the phenomenon of isodimorphy, bnt then we should 

 have to assume that the pseudo components can occur in different 

 crystalline forms, merely in consequence of a different arrangement 

 in the "Raumgitter" of a same kind of molecules. 



Without the slightest doubt such a case is conceivable, but it is 

 by no means probable. We can hardly assume tliat when the pseudo- 

 components in the solid stable state are miscible to a limited extent, 

 the phenomenon of Isodimorphy always occnrs. Besides it is in mi/ 

 opinion highly probnhk that a difference in composition is the cause 

 of the difference in crystalline form. It is now the question whethei- 

 another view is possible, which obviates the difficulty mentioned here. 



It is clear that the stability of the "Raumgitter" of the pseudo 

 component a becomes smaller as there has been dissolved more of the 

 pseudo component ^, and thus it will be possible that at a certain 

 concentration the "Ranmgitter" has become so unstable that it can 



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