Chemistry. — "A Third Kind of Sulphur Molecule". (Fifth Com- 

 munication). By Dr. A. H. W. Atün. (Communicated by Prof. 



A. F. HOLLEMAN.) 



(Communicated in the meeting of Oct. 27, 1917). 



1. Introduction. 



In the first publication on this subject ') the solubility of rhombic 

 sulphur was treated in mixtures of sulphur chloride and sulphur, 

 which were heated to temperatures of 75° — 175°, and were then 

 quickly cooled down. It then appeared, that this heating greatly 

 enhanced the solubility of rhombic sulphur. This phenomenon is 

 explained in this way, that the rhombic sulphur, when heated with 

 sulphur chloride, is converted to another form of sulphur, S^ . 



Tiie question how sulphur behaves, when it is heated with other 

 solvents, has only been briefly treated in the preceding commu- 

 nications. 



What had appeared was, that the conversion of Sy into S^z takes 

 place at 100^ not only in sulphur chloride, but also in carbon 

 sulphide. To enable us to make a better comparison between sulphur 

 chloride and other liquids as solv-ent, the solubility of rhombic 

 sulphur was determined in mixtures of sulphur and toluene, which 

 had been heated to different temperatures. 



2. Increase of solubility of sulphur by heating in toluene-solution. 



The solubility of rhombic sulphur in toluene amounts to 0,927o 

 at 0°. When a solution of sulphur in toluene is heated at 150^ for 

 some hours, it is found that after cooling the solubility has become 

 greater at 0°, and the more so as the original solution contained more 

 sulphur. This is accompanied by a change of the colour of the 

 solution. A solution of *S', in toluene is almost colourless at 0°. After 

 being heated the same solution exhibits the yellow colour of Sn at 

 0°. From this follows that also in toluene S;. is partly converted into 



1) Zeitschr. f. physik. Chem. 81, 257 (1912). Following communications ibid 83. 

 442 (1913); 86, 1 (1913); 88, 312 (1914). 



