1346 
coexistence of liquid (L'L) and vapour (G'G), of S,-mixed crystals 
(Sor So) and liquid (L"L’) and of Ss-mixed erystals (Ss, 53,) and 
liquid (AL). The unary figure does not call for any further ex- 
planation. 
The higher the temperature is chosen, at the higher pressure the 
transition point of course occurs; in order to reduce the dimensions 
of the figure, however, I have not been able to observe this; the 
figures are, therefore, very schematical. 
The P,X-sections Fig, 7 and Fig. 8 (p. 1345) hold for the tem- 
peratures t, and t,, which lie slightly below, resp. above the stable 
unary melting point D. 
Now these figures differ in this that in Fig. 7 the line for the 
internal equilibria in the vapour meets the vapour line bG of the 
pseudo binary system, i.e. the line relating to the vapours coexisting 
with the g-mixed crystals, whereas the line for the internal vapour 
equilibria in Fig. 8 meets the pseudo binary P,X-figure in a point 
of the vapour line indicating the vapour phases which eoexist with 
a series of liquids. 
At an intermediate temperature, viz. the temperature of the stable 
unary melting point, the said meeting takes place exactly in the 
point G, which indicates the vapour coexisting with the liquid L 
By SC that at this temperature these 
three phases coexist also in the unary system, from which follows 
and the mixed erystal phase 5 
that this temperature is the stable unary melting point. 
4. P,T-projection of the P,T,X-spacial representation for 
the case that B is a polymer of a. 
When we again suppose that the unary system presents a point 
of transition under the vapour pressure, then the P,T-projection is 
as indicated by Fig. 9. (See following page). 
With regard to the direction of the lines of internal equilibrium 
in the P,X-sections it may be observed that as & is now supposed 
to be a polymer of a, it is beyond doubt that the internal equili- 
brium in the gasphase shifts towards the side of the polymer on 
increase of pressure according to the equation: 
dink Av 
im ue 
The direction of the lines for the internal equilibrium in the 
liquid and also in the solid phase will depend on this whether the 
total molecular volume increases or decreases on splitting up of the 
