( 259 ) 
melting-point of the compound has disappeared here., -that the liquid 
branch of the two-phase region coexisting with solid no longer cuts 
the line for ,c = V 3 in the ^’-projection; the vapour branch, 
however, meets the latter line in two points: the maximum-sublimation 
point M and a point e. If in this case we examine the behaviour 
of the compound itself, it appears that on the line EM (P-7 7 -pro- 
tion) the solid compound exists by the side of its own vapour, 
that on the line Mine the three phases may occur side by side, and 
that the region Mmel indicates the area where liquid and vapour 
stably coexist, while a line for solid-vapour touches the three-phase 
line in e, and runs towards higher temperature in the P-P-projection 
below eq. Jf the solid phase does not occur, the coexistence of L 
•and G is moreover possible in the region nMmeko, to which the stable 
region Mlem then immediately adjoins. 
Fig. 3. 
