MABERY AND QUAYLE. — CANADIAN PETROLEUM. 91 



especially those with higher boiling points. The fractions collected below 

 125°, tension 50mm., were found to be exceedingly unstable. On stand- 

 ing from six months to two years, some of these distillates deposited very 

 dark heavy oils, doubtless formed from unstable unsaturated hydrocarbons, 

 terpenes, or sulphur compounds by polymerization. 



In separating the constituents of the vacuum distillates, we followed 

 in general the method described in a former paper (Mabery and Smith, 

 These Proceedings, n. s. 17, 218). Three or four hundred grams of the 

 oil was shaken in a large flask with an excess of an alcoholic solution of 

 mercuric chloride, which gave a heavy precipitate, crystalline in the lower 

 fractions, a thick viscous mass in the less volatile, and a heavy oily de- 

 posit in the vacuum distillates above 160°. There invariably separated 

 above the alcohol a lighter oil, which contained no sulphur, or at most, 

 analysis showed less than one half of one per cent. Upon diluting the 

 alcohol more lighter oil collected, which doubtless has a different com- 

 position than the other, since, as will appear later, it showed essentially 

 different properties. 



In recovering the sulphur compounds from the mercuric chloride pre- 

 cipitates, after thoroughly washing with alcohol and very volatile gasoline, 

 the precipitate was decomposed by hydric sulphide in presence of a con- 

 siderable volume of alcohol, the mercuric sulphide separated by filtration, 

 washed with alcohol, and the alcohol largely diluted. For the most 

 part the lighter oil separated, some remaining in suspension, which col- 

 lected after standing a short time. With all possible care in washing 

 the mercuric chloride precipitate, a single precipitation was never suffi- 

 cient to remove all the sulphur-free oil. The percentages of sulphur in 

 the individual sulphur comp muds invariably came from one to three per 

 cent too low, however long they were fractioued, until they were a second 

 time converted into the mercuric chloride compound and again separated 

 by hydric sulphide. Upon diluting a second time, usually another portion 

 of the sulphur-free oil collected, or remained in suspension, and after 

 sufficient fractioning, the percentage of sulphur then corresponded to the 

 value theoretically required. 



It has already been explained that the vacuum fractions of the crude 

 sulphur oil, before the separation of its constituents, is a mixture of an 

 unsaturated hydrocarbon, a sulphur compound, and another hydrocarbon 

 of a series not determined. More attention will be given later to the 

 sulphur-free oils. All the portions selected for the separation of these 

 constituents had previously been fractioned from four to twenty times, for 

 the most part in vacuo, and since the sulphur oil from any particular 



