1018 
Chemistry. — “Jn-, mono- and divariant equilibria’. IV. By Prof. 
F. A. H. SCHREINEMAKERS. 
(Communicated in the meeting of Noy. 27, 1915). 
7. Another representation of P,7-diagrams. 
In order not to extend unnecessarily the number of drawings of 
P,T-diagrams, we shall represent these diagrams in another way. 
We take e.g. the P,7-diagram in fig. 2 (IT)'); we shall represent 
this by the following figure, which we shall call a symbolical repre- 
sentation of this diagram. 
Stab. (1) (5) 4 (3) 7 (4) 
| | 
Metast. (3) (2) 1) (5) (4) 
In the P,7-diagram |fig. 2(II)] the stable parts of the curves 
succeed one another in the succession (1). (5), (4), (3), (2), (4), viz. 
starting from curve (1) in right-hand side direction; this succession 
is represented in the symbolical representation (1) by the upper line. 
In order to avoid errors this line is indicated by “stab.” 
The lower line, which is indicated by ‘metast.” relates to the 
metastable parts of the curves. Consequently it is apparent from 
the symbolical representation, in accordance with the P, 7-diagram 
(fig. 2(II)|, that between curves (1) and (5) the metastable part of 
curve (3) is situated; between (5) and (4) the metastable part of 
curve (2) ete. It is also apparent that curve (5) is situated between 
the metastable parts of the curves (2) and (3) etc. Curve (1) is 
situated between the metastable parts of the curves (3) and (4); 
this shows itself distinctly when we imagine the diagram (1) to be 
continued further towards the right. 
In order to see from the diagram, which curves are situated at 
the right and at the left of a definite curve, for instance of curve (1), 
we take into consideration that the limit between at the right and 
at the left of curve (J) is formed by the metastable part of this 
curve (1). Hence we see that (5) and (4) are situated at the right, 
(2) and (3) at the left of (1). It is also apparent that (4) and (3) 
are situated at the right, (1) and (2) at the left of curve (5). 
a / 
1) The Roman nnmerals I, II, or Ill between parentheses refer to communi- 
cation I, Il, or III. 
