580 
temperature than 100°, the completion of the equilibrium takes a 
longer time and it can be fixed with still greater certainty. 
The method of investigation is very simple. A mixture of sulphur 
and sulphur chloride is heated for a sufficient time at the desired 
temperature. The liquid is then cooled rapidly, sulphur is added if 
the solution is not already saturated and the whole shaken at the 
temperature at which we want to know the solubility. When the 
solution is saturated a sample of the liquid is taken and its com- 
position determined. This determination is carried out by oxidation 
with aqua regia and bromine, evaporation of the volatile acids and 
titration of the residual sulphurie acid. 
In the first place, mixtures of varying composition were heated 
to 100° and the solubility determined at 25°, 0° and — 60°. 
The results are united in table I. (see p. 579). 
100 
ep) 
— 
cS 
— 
= 
Composition of the solut- 
ions saturated at 25°.0° 
and — 60°, after heating 
to 100° 
0 
bef j 
G 
7 
20 
ef Atom °/, S Composition of the 
1 original mixture. 
0 JORT IONA DENSO OT COR TOF VEO GORE LOO 
Fig. 4. 
If we represent graphically the relation between solubility and 
original composition we obtain the lines shown in Fig. 4. 
A comparison of these lines with those of Figs. 2? and 3° shows 
that they correspond with the lines of Fig. 3% which are drawn in 
case a new modification is present. The solubility line for 25°, in 
particular, proceeds very distinctly towards 100 at °/, of S. 
In the second place, mixtures of varying composition were heated 
Ed 
