4 PROCEEDINGS OF THE AMERICAN ACADEMY. 



In Pennsylvania petroleum, Beilstein and Kuibatoff* recognized 

 hexahydroisoxylol. In the fraction 95°-100° the same chemists de- 

 tected the presence of a body containing less hydrogen than is required 

 for the series C„H2„+2. Crude American heptane, when treated with 

 nitric acid, gave a nitro-product corresponding to the formula C7H15NO2. 

 Nearly coincident with the researches of Beilstein and Kurbatoff, 

 Schutzenberger and Jonine f identified, in the petroleum of Baku, 

 hexahydrobenzol and hexahydrotoluol. 



In their classic researches on the composition of the Caucasus 

 petroleum, Markownikoif and Ogloblin f showed the presence, in the 

 oil from Baku, of benzol, toluol, isoxylol, pseudocumol, mesitylene, 

 isodurol, durol, and higher hydrocarbons of the composition C11H14, 

 C12II14, C11H12, and C13H14, and others, possibly homologues of 

 styrol and phenylacetylene. Contrary to the experience of others, 

 Markownikoff and Ogloblin found the naphtha from the Balachani 

 plain on the Apscheron peninsula very rich in aromatic hydrocarbons ; 

 in the oil from the Central Caucasus, naphtenes were found to the 

 extent of 80 per cent, and the aromatic hydrocarbons C„H2„_6 to 

 the extent of 10 per cent. At first Markownikoff looked upon 

 the naphtenes as isomeric with the hexahydro compounds, but later 

 Markownikoff and Spady § appear to accept the identity of octonaph- 

 tene and hexahydroisoxylol. || As members of the naphtene series 

 C„H2„, Markownikoff and Ogloblin identified hexahydromesitylene 

 and the higher homologues between CgHig and C15H30. In petro- 

 leum from Boryslaw in Galicia, beside benzol, toluol, isoxylol, and 

 mesitylene, Lachowicz 1[ found of the hexahydro series only hexa- 

 hydroisoxylol. 



The presence of unsaturated hydrocarbons C,,!!,,, in American 

 petroleum was not mentioned in the early publications of Pelouze 

 and Cahours, nor were they referred to by Schorlemmer. Warren ** 

 separated from Pennsylvania petroleum, rutylene, C10H20, boiling 

 point 174°. 9, margarylene, C11H22, boiling point 195°. 8, and laurylene, 



* Eer. der deutsch. cliem. Gesellsch., 1880, p. 2028. 



t Comptes Rendus, XCI. 823. 



t Ann. Chim. Phys., [6 ], II. 372. 



§ Ber. der deutstch. chem. Gesellsch., 1887, p. 1850. 



II In the Berichte, No. 7, April, 1895, recently received, the synthesis of 1-3- 

 dimetliyl hexametliylen, CeHjo(CH3), is described by Zellnsky, and it is shown 

 to be identical with the octonaphtene of Markownikoff, or he.xahydroisoxylol. 



1 Ann. Chem Pharm., CCXX. 187. 

 ** These Proceedings, XXVII. 56. Communicated May 12, 1868. 



