We can carry out this construction for different gross compositions 
and then put down the composition of the solutions saturated at f, 
after heating at 7, as function of the original composition. We then 
find the line PA in Fig. 20. 
When we determine the solubility line at a higher temperature ¢,, the 
line QC is found. If we heat at a higher temperature 7’, and again 
determine the solubility at ¢, and ¢,, the lines PB and QD are found. 
We see that these lines, at 100 at. °/,S of the original compo- 
sition, approach to a certain limitation value which is different for 
different temperatures of heating and of solubility. This limitation 
value can give a larger as well as.a smaller sulphur content than 
corresponds with the composition of the compound. 
The first is the case when the compound is but little dissociated 
and the solubility of the sulphur is great, the latter when the disso- 
ciation is great and the solubility small. 
Quite different becomes the course of these solubility lines when 
a new modification of sulphur is formed. In this case, the compo- 
sition of a ternary system is given by a point in a triangle the 
apices of which indicate S, Cl,,5, and the new sulphur modification. 
We then obtain the gross composition (for instance D, in Fig. 3a) 
Fig. 3a. 
by drawing a line // QR through D which indicates the real com- 
position. The line indicating the inner equiliorium between S) and 
38 
Proceedings Royal Acad. Amsterdam. Vol. XV. 
