The percentages of carbon and hydrogen required for the formula 

 C12H26 are, C 84.72, H 15.30; for the formula CisHog, C 84.78, 

 H 15.22. Evidently the dilFerences in percentage composition are not 

 sufficient to distinguish by analysis alone which of the two formulas is 

 the correct one. But the differences between either of these formulas 

 and the formula C12H24, C 85.71, H 14.29, should be readily shown by 

 analysis. 



Having at hand a portion of the purified distillate 214°-216° that had 

 been treated with chlorine and the part not chlorinated distilled, I con- 

 tinued the distillation until the chlorine derivatives were completely 

 removed, and the hydrocarbon was treated with fuming sulphuric acid 

 and distilled over sodium. It then gave as its specific gravity 0.7729, 

 substantially the same as before chlorination. Normal dihexyl prepared 

 by the action of zinc and hydrochloric acid on normal hexyl iodide boils 

 at 21 4°. 5 and apparently is identical with a hydrocarbon having the same 

 composition, obtained by electrolysis of potassium cenanthylate (Schor- 

 lemmer). The latter has the specific gravity 0.7738 at 17°. It is there- 

 fore probable that the hydrocarbon CioHoe, boiling at 214°-216°, from 

 American petroleum, has the same form. The purified hydrocarbon then 

 gave the following percentages of carbon and hydrogen : — 



I. 0.1599 gram of the oil gave 0.4978 gram CO2, and 0.2177 gram 

 H2O. 

 II. 0.1 617 gram of the oil gave 0.5021 gram COo, and 0.2270 gram H.O. 

 III. 0.1559 gram of the oil gave 0.2193 gram H2O. The CO2 was lost. 



Calculated for Found. 



CjoH,,;. I. II. III. 



C 84.72 84.89 84.69 



H 15.28 15.10 15.31 15.63 



These results indicate the absence of any impurity not readily acted 

 on by chlorine. 



As one of the results of this examination it can, I think, be safely 

 asserted that the constituents of Pennsylvania petroleum with boiling 

 points at 163°-164°, 173°-174°, 196°-197°, and at 215°-216°, constitute 



