M. Buff on some Compounds of Ethylene. 377 



almost insoluble in alcohol, by means of which it may be precipitated 

 from its solution in water. 



On examining the appearance and deportment of this salt. Dr. 

 Hofmann, in whose laboratory I performed these experiments, at 

 ouce recognized the identity of this compound with the barium-salt 

 of disulphetholic acid which he and Mr. Bucktoir have lately 

 discovered . 



This view was fully confirmed by the analysis which I made. 



The composition of the barium-salt, dried at 160°, is represented 

 by the formvda 



C,(H,Ba,)S,0>,. 

 The potassium salt of this acid is readily soluble in water ; it crystal- 

 lizes easily, and is likewise precipitated by alcohol from its solution 

 in water. Dried at 100° C, it contains 



At 160° it suffers no decomposition ; when exposed to a higher tem- 

 perature, however, it blackens aiid intumesces, empyreumatic sub- 

 stances being evolved. 



It is obvious that this bibasic acid stands iu the same relation to 

 ethylene as the monobasic ethylsulphurous acid to ethyle. 



The origin of the two acids is perfectly analogous, the latter acid, 

 according to Mr. Muspratt, being obtainable also by the action of 

 nitric acid upon sulphocyanide of ethyle. 



Sulphocyanide of ethyle, C^ Hj Cy S.„ produces ethylosulphurous 

 acid, C4 H3, H, S^ Og. 



Sulphocyanide of ethylene, C4 H^ Cyj S4, produces ethylensulphu- 

 rous acid, C4H4, 2H, 283 Oo. 



This reaction appears to throw some light upon the constitution 

 of polybasic compounds. The compoimds of monatomic molecules 

 of the hydrogen-group with elements or compound radicals of the 

 oxygen-group, are all remarkable for the simplicity of their construc- 

 tion. The union of biatomic radicals of the hydrogen-group with 

 molectiles of the oxygen-group gives rise to combinations of a far 

 more complicated character. Whilst one molecule of water, II„ O^, 

 most conveniently may be considered as the type of many compounds 

 of the former class, the corresponding compounds of biatomic radicals 

 frequently correspond to a double molecule of water, 2H2O0. 



Sulphocyanide of potassium may be viewed as water, in which the 

 oxygen is replaced by sulphur, one of the hydrogen molecules by 

 cyanogen, the other by potassium. 



Water tt [• O2 Sulphocyanide of potassium t/ / Sa 



In the production of sulphocyanide of ethylene two equivalents of 

 chlorine in chloride of ethylene (C4 II4 CL) have to be eliminated by 

 two equivalents of jiotassium. Thus the very reaction of the two 

 factors, chloride of ethylene (C4 H4 CL), and two equivalents of sul- 

 phocyanide of potassium 2(K Cy S.,), joins 4 equivs. of sulphur and 

 2 equivs. of cyanogen with one molecule of ethylene. This reaction 

 may be expressed by the following equation, which will illustrate at 



