1001 
or in other words the line indicating the vapours which can coexist 
with the mixed crystal phases 555, 
In case of behaviour as a unary substance solid violet phosphorus 
S, will therefore deposit from the vapour at G,, and this conversion 
will continue on diminution of volunie till everything has been con- 
verted to solid violet phosphorus. 
If we now continue to compress, the internal equilibrium in the 
solid violet phosphorus moves along the line SS’, 
| 
' P : 
| 8 
4 ; 
a a 
t : 
‘ : ; 
atl 
Te Da) eee 
Fig. 3. Fig. 4. 
Let us now suppose the point P to correspond to a pressure of 
12000 kg. as in Dr. BripeManN’s experiment. This point is then 
reached on account of the liquid phase LZ’, being converted to P 
under the same pressure. Let us now suppose that the pressure is 
quickly diminished to 1 atmosphere, then it is clear that the internal 
equilibrium will not be able to change in accordance with the 
pressure, and we then get a fixation of a state which corresponded 
with an internal equilibrium at a higher pressure. It is, therefore, 
