579 
pereeptible and how long the heating must be continued before the equi- 
librium is attained. It now appeared that a very perceptible conversion 
already occurs at 100°. Whereas, at 0° the solubility of S; in S,C1, with-_ 
out previous heating amounts to 36.1 at.°/, of S, this, after heating to 
100°, becomes 55.7 at. °/, of S for a 50 at. °/, mixture. The heating, 
therefore, causes a considerable increase in solubility. It also appeared 
that at 100° í'/, hour was required for the equilibrium to set in. 
This reaction, therefore, proceeds at 100° comparatively slowly and 
it may be expected that by rapid cooling the equilibrium can be 
fixed at 100°. Above 100° it is different. Because, as a rule, the 
velocity of a reaction for every 10° of rise in temperature becomes 
2—3 times greater, the setting in of the equilibrium will, at 140°, 
require about 5 minutes and at 170° less than one minute. Here 
we shall not be able to cool so rapidly that the equilibrium becomes 
fixed and hence we shall find, after heating to 170°, somewhat 
fluctuating values for the solubility. This explains why the deter- 
minations previously carried out at 170° agreed badly. At a lower 
BAB EEE 
Original Composition of the saturated “solution at 
composition 250 | 9° a — 60° 
at, ays | at%yS | at%)S 
0 53.5 36.1 11.6 
10.0 51.6 40.1 18.1 
28.7 62.0 47.4 31.9 
49.6 — Sad — 
49.9 66.6 56.0 42.9 
60.1 69.4 59.9 47.7 
69.1 12.8 — — 
79.4 | -- 72.0 65.2 
80.1 — 1.6 66.1 
89.9 82.1 — aa 
90.1 = 80.5 — 
94.6 87.7 — = 
97.4 91.0 — 5 
98.0 93.5 — = 
38* 
