829 



in the best solvents, sulphur chloride and sulphide of carbon, the 

 solubililj onlj amounts to 10 7o ^^ ^^^^ same temperature. 



The line of equilibrium S).'^S:z in sulphur chloride jnust, there- 

 fore, be drawn so that the solubility lines lun niore steeply at Z), 6r, 

 and K, and that the points F, J, and M get to lie farther apart. 



This is satisfied in tig ure 4. 



The situation of the solubility lines drawn here, is however not 

 probable either, for here the solubility of -S; in sulphur chloride 

 would be lessened by addition of not too large quantities of Sn- 



if, however, the homogeneous equilibrium line is given a form 

 as ABC in figure 5, we arrive at a plausible shape of the solu- 

 bility lines. It is therefore probable that in figure 3 the line of the 

 equilibrium S).'^St, lies too low, in figure 4 too high, and that 

 figure 5 gives about the true situation. We may, therefore, assume 

 the equilibrium >Sn'^S;. in sulphur chloride at 100° in a mixture 

 of 50 at. 7o of total sulphur to lie at about 257o S^. In toluene the 

 equilibrium mixture at 140° contains not quite 5 at. "/„ S-. Accord- 

 ingly sulphur chloride has a particularly specifically favourable 

 infiuence on the formation of Sn- That this is not exclusively caused 

 by the greater solubility of Sx in sulphur chloride, appears from 

 an observation recorded in the third communication. It was 

 found there that a solution in sulphide of carbon with 56 at 7o of 



59 



Proceedings Royal Acad. Amsterdam. Vol XX. 



