1175 
Chemistry. — “In, mono- and divariant equilibria’. VL By 
Prof. F. A. H. SCHREINEMAKERS. 
(Communicated in the meeting of January 29, 1916). 
10. Relation between concentration- and P,T-diagrams. 
We have seen in our previous contemplations in what way can 
be deduced the types of the P,7-diagram which may occur in a 
system of -components and in what way the concentration-diagram 
belonging to each of those can be found. Now we shall consider 
more in detail the correspondence between the two diagrams. 
Instead of 2 reactions, each between + 1 phases, we consider 
2 reactions between the „+ 2 phases of the invariant point. We 
write these reactions: 
a,P, Hal, + + ante Hito ONE tp (1) 
and 
BRR gle, ie Papp. et + 2) 
We take a, and 5, always positive, so that in each of these 
reactions one of the other coefficients at least must be negative. 
Further we suppose that we have written the phases /, /,... in 
(1) and (2) in such order of succession, that: 
a Ne, EN (3) 
a, ds as Ana 
These ratios may all be positive; when one of the ratios e. g. 
h,: a, is negative, then in (8) going from left to right also all 
following ratios are negative. When we multiply (1) with 2 and 
when we subtract (2) from it, then we may write: 
b ; b. L 
a, k —- ) F+ ‚(7 — ‘) F+ „(> — ) Ve == Oe 0(4) 
a, a, : a, 
Hence we may deduce „+2  reaction-equations, each between 
n+1 phases. When we put >= b,:a, then the coefficient of 7, 
becomes zero; it is apparent from (4) that the coefficients /’,, /,... 
have the same sign as a,,a,... We represent this by the series: 
OP eas Eb eis SEG Ee 0) 
When we equate 42=%,:a, then the coefficient of /’, has the 
opposite sign of «@,, those of F,, /,... obtain the same sign as 
a,,a,... We represent this by the series: 
— a, 0 Ja, Hagen Hante . - - - » (6) 
For 4=6,:a, we obtain the series: 
OEE ae ee ut its. cou Ae) 
and at last for 4= b,42: Ante 
Proceedings Royal Acad. Amsterdam. Vol. XVIII. 
