324 PROCEEDINGS OF THE AMERICAN ACADEMY. 



flian crude oils, the series of hydrocarbons in Ohio oil should'explain the 

 difference in properties of commercial products obtained from it. 



In resuming the study of Ohio Trenton limestone oil in I'JOl, a barrel 

 of the crude oil was obtained at Welker, Ohio, which gave as its specific 

 gravity at 20", 0.83G7. A combustion gave the roUovving percentages 

 of carbon, hydrogen, and sulphur: — carlion, 85.4G ; hydrogen, 13.91; 

 sulphur, 0.48. 



This crude oil is not so heavy as some specimens from Lima and 

 Indiana, and the percentage of sulphur is not so high as specimens from 

 some other fields, but it was believed to re[iresent an average composi- 

 tion of Trenton limestone oil with reference to the principal series of 

 hydrocarbons. 



From 8 liters of the crude oil the portions distilling below 200°, 

 equivalent to 1.8 liters, were removed under atmospheric pressure, and 

 the residue was distilled in vacuo under a tension of 30 mm., at first 

 within limits of 10°, which left a residue above 280° of 2000 grams. 

 Subsequent distillation under the same tension brought the distillates 

 together in larger quantities within certain well defined limits of tem- 

 perature, indicating a greater proportion of individual hydrocarbons. 

 After ten distillations, greater amounts collected within the following 

 limits, and were found to represent definite hydrocarbons : 1 11°-113° ; 

 129°-130°; 138°-140° ; 152°-154° ; 164°-168 ; 177°-179°; 187°- 

 190°; 198°-202° ; 213°-216° ; 224°-227° ; 237°-240° ; 2o3°-255° ; 

 263°-265° ; 275°-278°. While it cannot be assumed that in a limited 

 number of distillations the individual hydrocarbons can be separated 

 completely, analysis and molecular weight determinations indicate that 

 the separation is sufficiently complete to admit of identification, not only 

 of members of the same series but of rather sudden changes from one 

 series to the next poorer in hydrogen. 



None of the fractions siiowed evidence of decomposition. The lower 

 fractions were liquid, but the distillate 213°-217° was nearly solid at 

 ordinary temperatures. The higher distillates were completely solid 

 from paraffine, which formed a large part of these fractions. Since the 

 solid hydrocarbons in Pennsylvania petroleum were identified as mem- 

 bers of the series C„H2„+2, and the solid hydrocarbons in Ohio petroleum 

 are without doubt composed of the same bodies, it was not thought 

 worth while to examine these solids from Ohio oil. For their removal 

 the oil was cooled to 0°, filtered, then cooled to — 10°, and again filtered 

 under pressure at the same temperature. In the higher distillates the 

 solid hydrocarbons formed one-third or one-half of the total distillate. 



