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hydrocarbons in general. One of his pupils, E. Spanier, in his 

 doctorate dissertation gives a very comprehensive survey of the 

 whole question enriched by some instructive experiments carried 

 out, no doubt, under Engler's advice. Heating the saturated 

 hydrocarbon hexane with sulphur at high pressure and at 210°C, 

 Spanier got practically no action ; hexylene, the corresponding un- 

 saturated define, was on the contrary much affected, only 2 per 

 cent, unchanged hexylene being recovered, the rest being con- 

 verted into unpleasantly smelling high boiling oils which con- 

 stantly gave off H' 2 'S on distillation. Spanier noted that the 

 sulphur compounds thus formed cannot be removed from the oils 

 by ordinary refining methods. The continuation of Spanier' s work 

 is seen in three papers of W. Friedman. In numerous experiments 

 he obtained well defined bodies such as thiophenes and thiophthenes 

 as well as various large amounts of asphaltic polymerised high 

 molecular bodies. Even more interesting from our point of view 

 are other facts elucidated by Friedman. Considering the action of 

 sulphur upon the whole series of the paraffin hydrocarbons it is 

 found that sulphur has no action at about 200°C. on any hydro- 

 carbon as far as heptane or octane, but beyond this point the 

 higher the number of carbon atoms in the hydrocarbon molecule 

 the more pronounced is the action. With unsaturated defines, on 

 the other hand, the action begins at the lowest member of the 

 series, ethylene. 



In most cases sulphur has the tendency to build up chiefly a 

 5-membered thiophene ring, partially or wholly substituted. The 

 yield of thiophene obtained from normal octane was only 2 per 

 cent., but from octylene, the corresponding define, it was 20 per 

 cent. Friedman also refers to a paper by Bauman and Klatt, who 

 found that by the action of sulphur on stilbene (diphenylethylene) 

 a tetra-substituted phenyl thiophene, known as Thionessal, was 

 readily obtained with a yield of 70 per cent. It is very evident how 

 readily a thiophene ring is built up from larger unsaturated mole- 

 cules by the action of sulphur. So pronounced is this tendency of 

 sulphur that when H 2 S is used to interact with stilbene free 

 hydrogen is liberated and thionessal formed. In addition a most 

 interesting secondary action takes place. The liberated hydrogen* 

 being in the nascent state, bydrogenises part of the stilbene to 

 toluene (splitting the stilbene molecule into two), and more remark- 

 able still, hydrogenises the thionessal in good yield to tetraphenyl- 

 butane, with elimination of sulphur. This indeed is a remark- 

 able example of desulphurisation by hydrogenation. Other 

 workers have obtained similar results by the hydrogenation of thio- 

 nessal under different conditions. From and Achert in this con- 

 nection call attention to the fact that tetra substituted thiophenes 

 are very indifferent to chemical desulphurisers of the ordinary type* 

 such as copper oxide and sodium, while Friedman quotes that they 

 cannot be sulphonated, i.e., dissolved in sulphuric acid, and do not 

 show the typical Indophenin reaction. 



