MABERY.-— CONSTITUENTS OF PETROLEUM. 127 



Calculated for Found. 



C,oH,,. I. IT. 



4.92 5.21 5.16 



A portion of the same distillate was treated with fuming sul[)huric acid 

 with the aid of heat, and occasional agitation. When first added, a 

 slight rise in temperature was observed, doubtless caused by the forma- 

 tion of mesitylene sulphonic acid. The acid was diluted, neutralized 

 witli baric carbonate, and the filtered solution evaporated nearly to dry- 

 ness. A barium salt separated in clusters of needles, sparingly soluble 

 in cold, more so in hot water. The quantity of this salt was too small 

 for analysis. Another portion of the same distillate, with a mixture of 

 nitric and sulphuric acids in the cold, formed an oily layer above the 

 acids, which became solid on standing, and after crystallization from hot 

 alcohol the needles that separated melted at 83°-84° ; melting point of 

 dinitromesitylene, 86°. When the dinitro product was warmed with 

 fuming nitric acid, it formed prisms sparingly soluble in alcohol, and 

 melting at 225° ; melting point of triuitromesitylene, 230°. In the treat- 

 ment with acids, 16 grams of the crude distillate gave 8 grams of the 

 purified oil, with a loss of 50 per cent. When treated with fuming sul- 

 [)huric acid, 16 grams of the crude product gave 9.5 grams pure oil, with 

 a loss of 40 per cent. Mesitylene formed, therefore, a considerable pro- 

 portion of the crude distillate. The purified oil had the faint odor 

 characteristic of the pure petroleum hydrocarbons. After the removal 

 of the hygroscopic moisture, the oil had no effect on bright metallic 

 sodium. It gave upon analysis values required for decane : — 



0.1644 gram of the oil gave 0.5084 gram COo, and 0.2284 gram HoO. 



The specific gravity of the purified oil at 20° was 0.7479, a value 

 somewhat lower, as mentioned above, than that found by Pelouze and 

 Cahours.* 



Its vapor density was determined by the Hofmann method : — 



0.1221 gram of the oil gave 68.5 c.c. of vapor at 182°, and under a 

 tension of 352.8 mm. 



Calculated for CjoHoj. Found. 



4.92 4.91 



* Ann. Chim. Phys., (4.), I. 62. 



