67? 



pressure than thai of the internal equilibrium, and the phenomenon 

 discussed here will have to be attributed to this siipeiposilion. 



In conclusion it nmj be pointed out that other particularities may 

 still present themselves, when the internal equilibrium line of the 

 liquid phase under the vapour pressure lies so much on one side 

 that there exists no meta- 

 stable melting point under 

 this pressure. If we now 

 think that this case occurs, 

 and that the internal equili- 

 brium line for the liquid 

 phase under the vapour 

 pressure lies greatly on 

 one side towards the right, 

 and that this line moves 

 towards the left on increase 

 of pressure, we get what 

 follows : The phenomenon 

 of phase allotropy ') is wanting under the vapour pressure, monoti-opy 

 can however, occur at higher pressure. 



The metastable melting-point line will start at the absolute zero 

 e.g. in the case of tig. 10 of the preceding communication ^), and 

 run further as represented in fig. 7. 



If on the other hand we have to do with the case of fig. 12 of 



Fig. 7. 



Fig. 8. 



1) For the occurrence of a substance in two or more similar phases the word 

 phase allotropy might be used, while the occurrence of a substance in different 

 kinds of molecules, for which 1 before introduced the name homogeneous allotropy, 

 might be designated by molecular allotropy. 



2) loc. cit. 



