MABERY. — CONSTITUENTS OP PETUOLEUM. 145 



0.1512 gram of the oil gave 0.4677 gram COo, and 0.2088 gram HgO. 



Calculated for CioHjj- Found. 



C 84.51 84.35 



H 15.49 15.35 



For further assurance as to the composition of this hydrocarbon, an- 

 other portion of the crude distillate was first agitated in the cold with 

 fuming sulphuric acid, which produced no heat, and then heated with 

 the acid on the steam bath. As in most of the crude oils when treated 

 in this manner, the acid turned dark when heated, and evidently ex- 

 tracted a considerable proportion of the oil. After washing with sodic 

 hydrate and water, the remaining oil gave only the faint odor characteris- 

 tic of the petroleum hydrocarbons. In many of the analyses, it will be 

 seen that the percentage of hydrogen is somewhat lower than should be 

 expected in a pure substance. This deficiency is doubtless due to a very 

 small proportion of the hydrocarbon with less hydrogen, the last traces 

 of which it is somewhat difficult to remove. The fraction 160°-162'^, 

 after the last purification, contained the following percentages of carbon 

 and hydrogen : — 



0.1532 gram of the oil gave 0.4740 gram CO2, and 0.2113 gram H2O. 



Calculated for CjoHjj. Found. 



C 84.51 84.38 



H 15.49 15.33 



A determination of its specific gravity at 20° gave 0.7535, a value 

 slightly higher than the specific gravity of the corresponding fraction of 

 the Pennsylvania oil, doubtless due to the slight trace of impurity still 

 remaining. In determining the molecular weight of this decane by the 

 method of Beckmann, Mr. Hudson obtained 145; required for C10H22, 

 142. 



The boiling point of this hydrocarbon, so thoroughly purified that 

 neither fuming nitric acid nor fuming sulphuric acid produced further 

 change, was found to be nearly the same as that of 163° decane from 

 Pennsylvania petroleum. 50 c.c. distilled entirely between 162°. 5 and 

 163°. 5 under a barometric pressure of 757.5 mm. 



Since even a larger proportion of the crude distillate was removed in 

 combination with fuming sulphuric acid than from the Pennsylvania 

 distillate 163°, an attempt was made to ascertain the composition of the 

 barium salt, formed by neutralizing with baric carbonate and crystalliz- 

 ing the filtered solution, after boiling with bone black. A considerable 



VOL. XXXII. — 10 



