Th« Royal Society of London. 



15Q 



A hundred measures of the gas are 

 introduced into a graduated tube, and 

 the carbonic a-'id absorbed by a solution 

 of potassa ; the reuiaiiiiiii( gas is then 

 transferred (o thrice its volume of chlo- 

 rine of known purity, standing over 

 water in a tube of about half an inch 

 diameter, and exposed today-light, but 

 carefully excluded from the direct solar 

 rays; after twenty-four hours the car- 

 buret ted hydrogen and tlie excess of 

 chlorine will have been absorbed, and 

 the remaining gas, cousistiugof carbonic 

 oxide and hydrogen, may be analysed 

 t»y detonation with oxygen in excess; 

 the measure of carbonic acid formed 

 being the equivalent of that of the 

 original carbonic oxide. 



This proceeding depends upon the 

 iiou-formation of chloro-carbonic acid 

 in a mixture of carbonic oxide and 

 chlorine in the contact of water, and 

 out of the direct agency of the solar 

 rays. Such mixture I have kept seve- 

 ral days, occasionally renewing the 

 chlorine as it became absorbed by the 

 water, and have not observed any dimi- 

 nution in the bulk of the carbonic 

 oxide. In all these civses it is necessary 

 to ascertain the purity of the chlorine 

 by its absorption by water, and to be 

 aware of the evolution of common air 

 from water during that process. 



I repeated many of the above experi- 

 ments, substituting for coal-gas a mix- 

 ture of six volumes of hydrogen with 

 five of defiant gas. The specific gravity 

 of this mixture was ,4700; one hun- 

 dred cubical inches weighing 14,2 

 grains. The flame with which this 

 mixture burned was of the same colonr 

 and intensity as that of couuuon coal- 

 gas; its dilatation by heat was similar, 

 and it underwent an analogous increase 

 of bulk wlicn lieated with sulphur. 



The readiness with which carburetted 

 hydrogen is decomposed, when passed 

 through red hot tubes, appears to me to 

 offer a solid objection to a mode of 

 purifying coal-gas, which has been pro- 

 posed by Mr. G. H. Palmer, since it 

 would deposit carbon, and consequently 

 sustain great loss in its illuminating 

 power.The object in view was probably 

 to get rid of the sulphuretted hydrogen; 

 buit neither is this so to be attained. In 

 examining coal gas, I have often been 

 struck with the formation of sulphurous 

 acid during its combustion ; though, 

 when passed through solution of acetate 

 of lead, it occasioned no blackeninit, 

 a circumstance wliich led me to suspect 



[March 



the presence of some other sulphureouu 

 compound ; and I have ofcen thought, 

 in passing the open gas-pipes in the 

 streets, that I i)erceived the smell of 

 sulphuret of carbon. When sulphurous 

 iu-id or sulphuretted hydrogen arc passed 

 with carburetted hydrogen through a 

 red hot tube, a portion of carburet of 

 sulphur is always fcrmed, aud the va- 

 pour of that highly volatile compound 

 may well exist in the gas employed for 

 illumination, whicli is always hurried 

 through the condensers and gasometer. 



Most of the above experiments were 

 now repeated upon the gas obtained by 

 the decomposition of whale oil ; its spe- 

 cific gravity was ,7690; so that 100 

 cubical inches weighed rather more than 

 23 grains. Deducting the composition 

 of this gas, considered as a mixture of 

 liydrogen and olePant, from its specific 

 gravity, we should conclude that it is 

 composed of one volume of hydrogen 

 aud threeof olefiant, upon the presump- 

 tion that 100 cubical inches of hydro- 

 gen weigh 2,23 grains, and 100 of ole- 

 fiant 30,13. 



Such a mixture, when submitted to 

 the action of heat, of sulphur, and of 

 chlorine, and when detonated with 

 oxygen, afforded results similar to those 

 obtained by experiments upon the ori- 

 ginal oil gas, and it burned with the 

 same degree of brilliancy. 



1 have also submitted to similar ex- 

 periments the inflammable gases ob- 

 tained by the dccompasition of acetate 

 of potash, of alcohol, aud ether, and by 

 passing water over red hot charcoal. 

 All these contain a considerable portion 

 of carbonic acid,which,Mhen abstract- 

 ed by potassa, leaves a mixture of 

 carburetted hydrogen, aud carbonicr 

 oxide, in proportions liable to much 

 variation, according to tlie materials 

 employed, and to the circumstances 

 imder wliich their decouipositi(Ui has 

 been eft'ected, The specific gravity of 

 these products is of course liable to. 

 corresponding variations. 



The inference which, I think, may 

 be drawn from the preceding experi- 

 ments and observations, is, that there 

 exists no defiuite compound of carbon 

 and liydrogen, except that usually called 

 olejiaut gas ; that tlie vaiiuus inflam- 

 mable compounds employed for tho 

 purpose of illuminatioji, and produced 

 by the destructive distillation of coal,, 

 oil, &e. consist essentially of a mixture 

 of olefiant gas aud hydrogen ; that the 

 gas piocure<l from acetate of potash aud 



from 



