MABERY. 



COMPOSITION OF PETROLEUM, 



303 



collected under atmospheric pressure were thoroughly treated with 

 fuminc sulphuric acid, washed, dried, and their molecular refractiou 

 determined : — 



HiREi Petroleum. 



A combustion of Hirei crude oil gave 82.28 per cent of carbon and 

 13.19 per cent of hydrogen. In the distillation of the Hirei oil, fractions 

 collected within the same limits of temperature as those from the other 

 crude oils. The distillate collecting in the vicinity of 98°, after treat- 

 ment with sulphuric acid, gave 0.7412 as its specific gravity. Its molec- 

 ular weight at the freezing point of benzol was 98 ; required for C7H14, 

 98. Its index of refraction was 1.4095, and its molecular refraction, 

 32.77; required for C^IIi4, 32.22. 



The fraction 118°-120° gave as its specific gravity 0.7523. Its mo- 

 lecular weight was 114 ; required for CgHie, 112. Its index of refraction 

 was 1.4151, and its molecular refraction, 37.34; required for CgHig, 

 36.82. 



The fraction at 135° gave as its specific gravity 0.7676. Its molecu- 

 lar weijrht was 128; required for CyHis, 126. Its index of refraction 

 was 1.4372, and its molecular refraction, 42.12; required for CgHig, 

 41.42. 



The fraction 162° gave for its specific gravity 0.7887. Its molecular 

 weight was found to be 137; required for CjoHjo, 140. Its index of 

 refraction was 1.4372, and its molecular refraction, 46.60 ; required for 

 C10H20, 46.03. 



The specific gravity of the fraction at 196° was 0.8192. Its index of 



