1 92 Mr. Faraday ow sovie nexo Products 



other in volatility, as always happened in the earlier distilla- 

 tions. Though'conscious that these were mixtiu'es, perhaps 

 of unknown bodies, and certainly in unknown proportions, 

 yet experiments were made on their composition by passing 

 them over oxide of copper, in hopes of results which might 

 assist in suggesting correct views of their nature. They all 

 appeared to be binary compounds of carbon and hydrogen, 

 and the following table exhibits the proportions obtained : the 

 first column expressing the boiling temperature at which the 

 products were distilled, as before mentioned ; the second the 

 hydrogen, made a constant quantity ; and the third the carbon. 



These substances generally possess the properties before 

 described, as belonging to the bi-carburet of hydrogen. They 

 all resist the action of alkali, even that which requires a tem- 

 perature above 250° for its ebullition ; and in that point are 

 strongly distinguished from the oils from which they are pro- 

 duced. Sulphuric acid acts upon them instantly with phteno- 

 mena already briefly referred to. 



Dr. Henry, whilst detailing the results of his numerous and 

 exact experiments in papers laid before the Royal Society, 

 mentions in that read February 22, 1821 *, the discovery made 

 by Mr. Dalton, of a vapour in oil gas of greater specific gra- 

 vity than olefiant gas, requiring much more oxygen for its 

 combustion, but yet condensable by chlorine. Mr. Dalton 

 appears to consider all that was condensable by chlorine as a 

 new and constant compound of carbon and hydrogen ; but 

 Dr. Henry, who had observed that the proportion of oxygen 

 required for its combustion varied from 4*5 to 5 volumes, and 

 the quantity of carbonic acid produced, fro'm 2*5 to 3 volumes, 

 was inclined to consider it as a mixture of the vapour of a 

 highly volatile oil with the olefiant and other combustible 

 gases : and he further mentions, that naphtha in contact with 

 hydrogen gas will send up such a vapour ; and that he has 

 been informed, that when oil gas' was condensed in Gordon's 

 lamp, it deposited a portion of highly volatile oil. 



# Phil. Trans, for 1821, part i. See Phil. Mag. vol. Ivii. p. ;503. 



A writer 



