228 PROCEEDINGS OF THE AMERICAN ACADEMY 



sulphur determinations are somewhat higher than the percentage 

 required for pentyl sulphide. 



Hexyl Sulphide. 



From the fraction 160—170° (P=100 mm.) by precipitation 

 with mercuric chloride and decomposition with hydric sulphide a light 

 yellow oil was obtained that distilled with some decomposition at 

 225 — 235°, and it gave a percentage of sulphur required for hexyl 

 sulphide. 



0.3110 gr. of the oil gave 0.3531 gr. BaSO^. 



Calculated for (CeHi3)23. Found. 



S 15.84 15.59 



At least one third of the original oil distilled above the boiling point 

 of hexyl sulphide, but with considerable decomposition even under 

 diminished pressure. It consisted to a very large extent of sulphides, 

 but we have not attempted to separate them for identification. 



In order to satisfy any doubt as to whether these sulphides are 

 contained in the crude petroleum, we distilled several litres under 

 diminished pressure to avoid decomposition, and extracted portions of 

 various distillates with sulphuric acid, and other portions with aqueous 

 mercuric chloride. The oils, separated from the acid solution and 

 from the mercuric chloride addition product, resembled in all respects 

 the products previously described. From the distillate corresponding 

 to 150 — 300° atmospheric pressure, or to the best grades of burning 

 oil, by agitation with aqueous mercuric chloride, the characteristic 

 heavy precipitate was formed, aud the oil obtained from it contained 

 19.72% sulphur and gave all the reactions for sulphides. In sepa- 

 rating sulphides from oils extracted with sulphuric acid, we have 

 frequently obtained small quantities of a product with a penetrating 

 odor resembling that of turpentine ; and at other times, oils contain- 

 ing no sulphur with an odor characteristic of certain ethereal oils, 

 such as peppermint or pennyroyal. But we have not yet obtained 

 these oils in quantity sufficient for examination. 



The study of Ohio oils will be continued, and the investigation will 

 include an examination of oils from other localities for sulphur com- 

 pounds, and also the composition of other acid residues and by-products 

 obtained in refining petroleum oils. 



