Peckham — Nitrogen Content of California Bitumen. 253 



ents of the petroleum an emulsion, from which the aqueous 

 acicl solution of the basic oils is separated with much difficulty. 

 "With many of the distillates, and particularly those of highest 

 specific gravity, the acid radical or its hydrate does not dissolve 

 in the oil, and the acid solution of the bases, the acid hydrate, 

 and the oil not acted on by the dilute acid, form three distinct 

 layers in the containing vessel. In consequence of this differ- 

 ence in specific gravity and solubility, the solution of the basic 

 oils and the tar may be easily separated from the oils that origi- 

 nally held the salt of the basic oils in solution. 



After ascertaining these facts in the laboratory, I suggested 

 to Dr. Salathe, who then had charge of the refinery of the 

 Union Oil Co., that the presence of these compound ethers in 

 the California petroleums was no doubt the cause of the diffi- 

 culty which had been experienced in refining them. 



Steps were immediately taken to test the correctness of this 

 judgment with the most gratifying results; but it is only very 

 recently and under my own direction that the complete removal 

 of both the basic and acid radicals of these ethers has been car- 

 ried out on the large scale, in such a manner as fully to demon- 

 strate the great importance of this discovery to the technology 

 of this class of bitumens. 



No complete analysis of any of the hydrocarbons that make 

 up California petroleum has yet been made to my knowledge ; 

 but it has been assumed on other grounds that they belong to 

 the benzole and not to the paraffine or olefine series. The 

 basic oils also are allied to the benzoles. They form with the 

 dilute acid solutions that may be used to wash them from the 

 oils in which they may be dissolved, a reddish brown liquid. 

 From this liquid they may be precipitated as cream colored 

 flakes, which are hydrates of the basic radicals. If filtered off 

 the precipitate soon changes color on the filter to a dark brown 

 and on drying becomes nearly black. The acid tars also appear 

 as hydrates. The acid hydrates are dark green, brown or black 

 semi-solids, possessing extraordinary viscosity. The basic 

 hydrates when deprived of their water yield brown or cherry- 

 red oils which are very transparent and brilliant and which 

 with the acid hydrates are much, heavier than water. The 

 entire series of basic radicals has not yet been isolated with 

 certainty as to the higher members. It appears probable that 

 the series commences with pyridin and embraces a large num- 

 ber of pyridins and chinolins, rising to compounds so dense 

 that when left as a residue resembling coke, from distillation 

 at a temperature near the red heat, they are still soluble in 

 hydrochloric acid from which they may again be precipitated 

 as hydrates in cream-colored flakes. 



