BUSHONG.|] Chemical Composition of Petroleum. 305 
higher members of this series. Mabery has isolated solid 
paraffins from Pennsylvania petroleum that had not been sub- 
jected to distillation. It is, therefore, believed that the above- 
mentioned hydrocarbons exist naturally in the crude petroleum 
and are not products formed during the process of distillation. 
HYDROCARBONS OF THE SERIES CyHon. 
1. Naphthenes.24° Saturated Monocyclic Hydrocarbons. 
Some Russian oils contain as much as 80 to 90 per cent. of 
naphthenes. Young,*4* in examining American petroleum, iso- 
lated a number of members of this series, but found them only 
in relatively small quantities. Mabery has found compounds of 
the formula C»Hx» in petroleum from Ohio, Texas and Cali- 
fornia, and also from foreign fields, which are believed to be 
naphthenes. 
The following are some of the naphthenes that have been 
found in American petroleum: 
Name. Yormula. Boiling-point. Density. 
Rentamechyvlenenn wasicts cuts seen aa ee CsHiv 50° 0.700 
Eexameth yl em) yreve yoyo c cis) shale hes elec ers C.Hi2 80.6° 0.7722 
Methylpentamethylene .............. CoH. UE 0.7660 
Methylhexamethylene ............... C,H 102° 0.7964 
2. Hthylenes. Unsaturated Paraffin Derivatives of Formula CnHon. 
“In the earlier literature on petroleum it was generally as- 
sumed that the ethylene hydrocarbons, series C.H», formed a 
considerable proportion of the constituents, and even after the 
discovery of the cyclic series CxH»—the naphthenes, accord- 
ing to the earlier nomenclature of Markownikow—many wri- 
ters, with no foundation on facts, still insist on the presence of 
ethylene hydrocarbons. It is now safe to assert that these 
bodies are present in any petroleum at most in very small 
amounts. ’—Mabery.?4" 
“According to Lachowicz, ethylenes are not present in Ga- 
lician petroleum, and it is his opinion, shared also by Engler, 
that in those cases where they have been found they were pro- 
ducts formed during distillation.” —H6fer.?48 
HYDROCARBONS OF THE SERIES CrHon», NAPHTHYLENES. 
In Louisiana petroleum?*® a series of saturated hydrocar- 
245. Die Naphthene, Cyclische Polymethylene des Erdéls, R. A. Wischin. 
246. Jour. Chem. Soc. London, LXXIII, 905; 1898. 
247. Jour. Amer. Chem. Soec., XXVIII, 415; 1906. 
248. Das Erdol und seine Verwandten, 2te Aufl. Hans Hofer, p. 65. 
249. Coates, Jour. Amer. Chem. Soc. 28, 384; 1906. 
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