1825.] On new Compounds of Carbon and Hydrogen^ $<?. 155 



particularly two new compounds of carbon and hydrogen, and 

 generally, other products obtained during the decomposition of 

 oil by heat. My attention was first called to the substances 

 formed in oil at moderate and at high temperatures, in the 

 year 1820; and since then 1 have endeavoured to lay hold of 

 every opportunity for obtaining information on the subject. A 

 particularly favourable one has been afforded me lately through 

 the kindness of Mr. Gordon, who has furnished me with con- 

 siderable quantities of a fluid obtained during the compression 

 of oil-gas, of which I had some years since possessed small 

 portions, sufficient to excite great interest, but not to satisfy it. 



It is now generally known, that in the operations of the 

 Portable Gas Company, when the oil-gas used is compressed in 

 the vessels, a fluid is deposited, which may be drawn off and 

 preserved in the liquid state. The pressure applied amounts 

 to 30 atmospheres ; and in the operation, the gas previously 

 contained in a gasometer over water, first passes into a large 

 strong receiver, and from it, by pipes, into the portable vessels. 

 It is in the receiver that the condensation principally takes 

 place ; and it is from that vessel that the liquid I have worked 

 with has been taken. The fluid is drawn off at the bottom by 

 opening a conical valve : at first a portion of water generally 

 comes out, and then the liquid. It effervesces as it issues 

 forth ; and by the difference of refractive power it may be seen 

 that a dense transparent vapour is descending through the 

 air from the aperture. The effervescence immediately ceases ; 

 and the liquid may be readily retained in ordinary stoppered, 

 or even corked bottles, a thin phial being sufficiently strong to 

 confine it. I understand that 1000 cubical feet of good gas 

 yield nearly one gallon of the fluid. 



The substance appears as a thin light fluid ; sometimes trans- 

 parent and colourless, at others opalescent, being yellow or 

 brown by transmitted, and green by reflected light. It has the 

 odour of oil-gas. When the bottle containing it is opened, 

 evaporation takes place from the surface of the liquid ; and it 

 may be seen by the striae in the air that vapour is passing oft' 

 from it. Sometimes in such circumstances it will boil, if the 

 bottle and its contents have had their temperature raised a few 

 degrees. After a short time this abundant evolution of vapour 

 ceases, and the remaining portion is comparatively fixed* 



