6 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Tegernsee, Pennsylvania, Galicia, and Baku contain members of the 

 series C„H2„4.2 and C„H2,„ both unsaturated hydrocarbons and naph- 

 tenes. Engler asserts that all petroleums have the same composition, 

 differing only in the proportions of their constituents. Markownikoff 

 and Oglobliu * suggest the presence of unsaturated aromatic hydrocar- 

 bons in the oil from Baku. 



Most analyses of crude petroleum have fallen short of 100 per cent, 

 and the deficiency has been attributed to the presence of oxygen. In 

 ascertaining the composition of oils from different districts, St. Claire 

 Devillef showed that the percentage of oxygen varies between 2.1 per 

 cent in the Canadian petroleum and 5.6 per cent in the oil from Zante. 

 In 1874 Hell and Medinger t attempted to separate acids from crude 

 petroleum by agitating it with a solution of sodic hydrate and precipi- 

 tating with sulphuric acid. The oil which separated was distilled and 

 converted into a methyl ether. By saponification of this ether an acid 

 was obtained to which was assigned provisionally the formula 

 C11H20O2. From the sodic hydrate solution used in the refining of 

 Baku oil, by the addition of sulphuric acid, Aschan § separated a mix- 

 ture of acids, and, taking advantage of a difference in solubility of 

 their salts, he obtained one acid, C8H14O0, distilling at 237°-239°, and 

 another, CgHieOg, that distilled at 251° -253°. The first acid, called 

 by Aschan octonaphtenecarboxylic acid, by distillation with hydri- 

 odic acid, was converted into hexahydroisoxylol. 



The oxygen compounds in petroleum were considered by Zalo- 

 ziecki || to be lacto-alcohols which are oxidized to acids by contact 

 with air. By the same method which was followed by Heil and 

 Medinger, and Aschan, Zaloziecki obtained an acid, CioHigOa, to which 

 he gave the formula, 



CHo. /CHo. 



CH-(CHo)4-CH ^CHOH, 



CHs-^ \ O / 



and to the hydrocarbon obtained by distillation with hydriodic acid he 

 gave the formula, 



C[I-(CH.,)4-CH II 



* Ber. der deutsdi. cliem. Gesellsch., 1883, p. 1873. 

 t Comptes Rerulus. LXVI. 442 ; LXVIII. 485. 

 } Ber. der deutsch. chem. Gesellsch., 1874, p. 1216. 

 § Ibid., 1890, p. 867 ; 1891, pp. 1864,2710; 1892, p. 3661. 

 II Ibid., 1891, pp. 796, 1808. 



