492 



DR EDMUND RONALDS ON THE MOST VOLATILE 



bung of the casks and inserting immediately a cork bung furnished with a tube, 

 for the delivery of the gas, and a long shanked funnel tube, through which liquid 

 petroleum was poured. 



Thus obtained the gas was of course a mixture of air and hydrocarbon ; it 

 was not affected by fuming oil of vitriol, nor was bromine water discoloured by 

 it. It was hence inferred that no perceptible quantities of the olefiant series were 

 present, and the temperature of collection is sufiScient guarantee for the absence 

 of any known members of the benzole series. 



The gas was treated over mercury, with solid potash and pyrogallate of 

 potash successively, when it yielded — 



1-27 per cent, of carbonic acid, and 

 6-58 „ „ oxygen. 



The residue, analysed eudiometrically, gave the following results : — 



Gas collected from the surface of Pennsylvanian Petroleum at a temperature of — 1°C., 

 freed from Carbonic Acid by Potash and from Oxygen by Pyrogallic Acid. 



Gas, 



Do. + air, 



Do. + do. + oxygen, . . . 

 After explosion, . . . . 

 After absorption of COj, . 

 After addition of hydrogen, 

 After explosion, . . . . 



Observed 

 Volume. 



133-1 



392-8 



465-6 



421-3 



383-4 



474-3 



346-5 



Pressure 

 m. 



0-3099 

 0-5666 

 0-6391 

 0-5940 

 0-5515 

 0-6395 

 0-5062 



Temperature 

 Cent. 



9°- 

 9- 

 8-2 

 10- 

 8- 

 3-8 

 4- 



Corrected vol. 



atO°C.+l m. 



pressure. 



39-934 

 215-47 

 288-92 

 245-09 

 205-23 

 299-15 

 172-86 



I 



Deducting the nitrogen, or 23-4 vols. = 54 per cent, of the original gas, we have 

 here a relation of hydro-carbon to condensation and carbonic acid, as — 



or, 



16-534 

 100 



43-83 

 265 



39-86 

 241. 



The oxygen consumed amounts to 67*16 vols., or 4*06 times the volume of 

 the hydrocarbon. The members of the olefiant and benzole series being absent, 

 it may fairly be inferred that the hydrocarbon resembles in constitution the 

 liquids with which it is associated ; and if this be the case, the gas must be a mix- 

 ture of the hydrides of ethyl and propyl, the former of which requires a relation 

 of hydrocarbon to condensation and carbonic acid, as — 



1:2-5:2 



while the hydride of propyl requires a relation of 1 : 3 : 3. By calculation 



