MABERY. — SULPHUR PETROLEUMS. 23 



ronsiflerable gas always escapes in refinery distillation before a liquid 

 distillate appears, but we have not yet undertaken an examiuatioa of 

 its composition. Probably this is essentially the same as that of the 

 gis given off' in beginning a distillation of Pennsylvania oil together 

 with hydric sulpiiide, which is always evolved to a greater or less 

 extent in the distillation of sulphur petroleums. Sadtler* found that 

 (he gas from Pennsylvania wells consisted principally of methane, with 

 some ethane, nitrogen, and hydrogen. In the gas from Canada wells, at 

 Enniskillen, Fouque f found marsh gas, ethane, and small quantities of 

 carbonic dioxide. According to Ronalds, J the gas from Pennsylvania 

 petroleum contains 1.27 per cent of carbonic dioxide, 6.58 per cent of 

 oxygen, 54.00 per cent of nitrogen, and 38.15 per cent of ethane and 

 propane ; by exposing the escaping gas to a freezing mixture, butane 

 was condensed to a liquid. 



In an exhaustive study of natural gas from Pennsylvania wells, 

 Phillips § found that the principal constituents were hydrocarbons 

 C,jH2„_|_2i ^^'itb nitrogen in variable proportions and carbonic dioxide 

 in small quantity, but no hydrogen nor carbonic oxide. 



The crude distillate was subjected to fractional distillation in a 

 porcelain still, to which was attached a Warren condenser filled with 

 a mixture of salt and ice, with ice alone, or with water, according 

 to the fraction collected. Another ordinary condensing worm sur- 

 rounded with a freezing mixture was placed in front. Subsequent 

 distillations were conducted in glass stills, and the fractions rapidly 

 accumulated within limits of temperature which distinguish the hydro- 

 carbons C„H2„4.2' -A.t the beginning of the first and second distilla- 

 tions, a delivery tube was attached to the bottle receiving the distillate, 

 and extended so as to collect in a receiver inverted over water any 

 volatile constituents that might have escaped condensation. At first a 

 very little gas collected, which burned with a smoky flame, but none 

 afterwards. The following quantities were collected during the first 

 distillation : — 



—25° 25^-30= SOO-SS" 35°-i0=> 



Grams 525 400 450 400 



After the fourth distillation thirty-five grams collected between 0° 

 and 1°, distilling for the most part at 0°, barometer 740 mm. This was 

 evidently butane, boiling point 0°. Inasmuch as the boiling point of 



* Amer. Chemist, 1876, p. 97. t Journ. Chem. Soc, XVIII. 54. 



t Comptes Rendus, LXVII. 1045. § Amer. Chem. Journ., 1894, p. 406. 



