90 PROCEEDINGS OP THE AMERICAN ACADEMY. 



As usual, a dark red oil separated above the solution, but it lacked the 

 heavy sulphurous odor characteristics of sludge as it is ordinarily sepa- 

 rated from sulphur petroleum. The odor of this oil resembled that of 

 sludge after the sulphur compounds have been removed, and it showed 

 still greater similarity in its behavior toward bromine, with which it 

 readily united with the evolution of heat, and the formation of an addi- 

 tion product heavier than water precisely similar to the behavior of sludge 

 products. The precipitate with mercuric chloride resembled in all re- 

 spects the characteristic products which are so useful in separating the 

 sulphur compounds. 



As further evidence of the presence of unsaturated hydrocarbons in 

 this oil, a portion of the oil precipitated from sulphuric acid was heated 

 with concentrated hydrobromic acid to 100°, and the product fractioned 

 in vacuo to collect in a smaller limit the bromine addition product. It 

 was not intended to prepare an individual bromine derivative sufficient for 

 analysis, since this would have been impossible with the small amount to 

 be obtained in this manner, but only to be sure that an addition product 

 with hydrobromic acid could be formed. The higher vacuum distillate 

 gave an abundant reaction for bromine after heating with lime, showing 

 that addition of the acid had taken place. The results of these experi- 

 ments are described in full, that there ma}' be no misapprehension con- 

 cerning the source of the sulphur compounds and unsaturated hydrocarbons 

 which will be described in this paper. They confirm the results of simi- 

 lar experiments described in the former paper. 



In continuing the distillation of the 225 liters of crude sulphur oil with 

 the aid of the apparatus elsewhere described (These Proceedings, 13, 10), 

 the distillates were carried through entire up to 250° under 50mm., at 

 first within 5°, during four distillations. The lower fractions were then 

 continued within single degree fractions until the lower portions could be 

 distilled under atmosphere-pressure. It was not possible to accomplish 

 in this manner more than a general separation, since all the distillates 

 were mixtures, yet the value of the great amount of tedious labor was 

 shown after the separation of the individual constituents, of which the 

 greater portion distilled at approximately the same temperatures as the 

 original distillates. And although it seemed a great expenditure of effort 

 to distil such a large volume of oil in quantities of ten liters, the capacity 

 of the porcelain still employed, and to continue the distillation of the en- 

 tire quantity, this seemed to be the only available method for the separa- 

 tion of these peculiar bodies from the crude oil. When first collected, all 

 the fractions were nearly colorless, but on standing they turned dark red, 



