46 MABERY—THE COMPOSITION OF PETROLEUM.  [April3, 
oil which distilled below 212°, and the same members were dis- 
covered that had been previously identified in Pennsylvania oil, 
although the proportion of these hydrocarbons was smaller than in 
Pennsylvania oil. The proportion of aromatic hydrocarbons is 
higher in Ohio than in Pennsylvania oil. The lower methylenes 
are also probably contained in larger proportion in the Ohio oil. 
An investigation just finished on the hydrocarbons contained in _ 
the limits between 112° and 280°, tension 30 mm., has identified 
thirteen hydrocarbons, with very satisfactory data on the propor- 
tions of carbon and hydrogen which establish the series, and the 
molecular weights and indices of refraction which identify the 
members of the series. The following hydrocarbons of the series 
C,H,, were found: C,H», CysHe., CAs; Cube Cy,Hy, Cy Hess 
Unfortunately the distillate that should yield the hydrocarbon 
C,,H,;, was lost, although its specific gravity was ascertained before 
filtration. 
Of the series C,H,, _,, the following hydrocarbons were identified : 
GCipHas; Cop Hs, Cas, 'CuHla; andof the series CJ 4, (Dean 
carbons: (Co bl4,, Cosel, optdue: 
The change in series is attended with a greater difference in 
specific gravity between adjacent hydrocarbons; for instance, the 
last change in series is very marked, as the following table shows: 
Distillate. Sp. Gr. Hydrocarbon. Difference in Sp. Gr. 
224-2270 -8614 Gea is Ws 
237-2409 -8639 CH .0025 
253-2550 -8842 Gokia. 0225 
263-2659 -8864 C, Hyg 0022 
The-distillates from which these hydrocarbons were separated 
above 150°, 30 mm., contained a large proportion of solid paraffine. 
The higher fractions were solid at ordinary temperatures, but no 
attention was given to the solid constituents, for without doubt 
they are identical with the solid hydrocarbons identified in Penn- 
sylvania oil. Much difficulty was met with in separating the liquid 
constituents. The distillate was first cooled to o° and filtered, 
and the filtrate then cooled to —10° and again filtered. 
In purifying these heavy oils they were first dissolved in gasoline, 
and after purification the gasoline was removed by distillation. 
The greater preponderance of the series poorer in hydrogen in 
Ohio oil over Pennsylvania oil explains the higher specific gravity 
