819 
Because, as it appears from (5), (6), and (7), the singular curves 
(M) 
(A) (c) 
E | (D) (£) 
C (Mm) 
Fig. 3. Fig. 4 
(A) and (B) are situated on different sides of each of the three curves 
(C), (D) and (F), it follows again that the (M)-curve is bidirec- 
tionable. With the aid of (1) and (6) we find a type of P,T-diagram 
as in fig. 4. We see that this diagram is also in accordance with 
(5) and (7). 
c) The five phases form a type of concentratidndiagram as in fig. 5. 
From the position of the phases with respect to one another 
follows: 
CA CBCE A CC) CDN ie zer Se even) 
Ee RT OVSINCG BY 39 Bree eae nore wea (0) 
CANE BRON ee ea a LD 
Hence it appears that the singular curves (A) and (5) are situated 
on the same side of the three curves (©), (D) and (/); the (J/)-curve 
is, therefore, monodirectionable and the three singular curves (MM), (A) 
and (B; coincide, therefore, in the same direction. We draw, therefore, 
in a P,T-diagram those three curves as in fig. 6. When we draw 
(M) 
