Dt + a, =0 
(A= ) Y, ae A5 Ys dp Dr 000 OD =| dn Yn = 0 (10) 
ADE ae EZ dte th SE Aln Zn =S) 
etc. By this the 2—1 ratios between the coefficients 2, 2, .. . are defined. 
As 
Po (CEO == 25 OR ae Gn ae 6 oo oo SE Onan | 
NDL eee AE | GD 
the ratio B(aw): 2(2H) is also defined. Now it follows from (9) *): 
RT J (A) 
ON ne (4 
(2H) 
The value of dT’ in (12) depends on. 2(%z), consequently on the 
n increments 2, 2,...an. We may express them, however, in one 
of those increments e.g. in 2,. With the aid of (7) we obtain then: 
RT «, (Ap) 
Deis (wel 
(dT)p = (13) 
wherein : 
SAP) Att He Aas ee ees Eeen OL) 
When we take the equilibrium H— /,+ F,+...+F, of n 
components in 7 phases at constant temperature, then it is mono- 
variant (7Z’). In the same way as above we find now: 
RT Z (Az) RT a, = (Ap) 
adr =S == 15 
SS SA SOY) © 
Herein 2, 2,... have again the values, which are defined by (10) 
Z (Ae) has also the same value of (11) viz.: 
25 (2 x) == À, x, of A, Wai 005.0 4 + an En 
while Pe (l@) 
23 (2 Vi a VA + ds Ve San tes eerie dn Va | 
X(4u) has again the same value asin (14). 
In the previous considerations it is assumed that the quantity 
of the component X in the equilibrium H= F4 H+... + Fh 
of mn components in 2 phases is very small. When, however, this 
quantity becomes zero, then ME passes into an equilibrium of n—1 
components in ” phases. This is monovariant and is represented in 
the P,7-diagram by a curve. Under constant pressure it is inva- 
riant (P), at constant temperature invariant (7’). In this invariant 
(P or T) equilibrium between the phases F,... Fn may occur a 
1) For another deduction see F. A. H. Scurememaxkers, Die heterogenen Gleich- 
gewichte von H. W. Baxuuis Roozesoom. III. 289. 
