44 Mr. Faraday on new Compounds [Jan. 



Article IX. 



On new Compounds of Carbon and Ht/drogen, and on certain 

 other Products obtained during the Decomposition of Oil by 

 Heat. By M. Faraday, F.R.S. Cor. Mem. Royal Academy 

 of Sciences of Paris, &c.* 



The object of the paper which I have the honour of sub- 

 ilaitting at this time to the attention of the Royal Society, is 

 to describe 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 tempe- 

 ratures, in the year 1820; and since then I have endeavoured 

 to lay hold of every opportunity for obtaining informaticn on 

 the subject. A particularly favourable one has been afforded 

 me lately through the kindness of Mr. Gordon, who has fur- 

 nished me with considerable 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 r-^tained in ordinary stoppered, 

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

 confine it. 1 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 ol' the liquid ; and it 

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

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



♦ Philosophical Transactions fox I8S5, Part II. 



