62 SIXTH REPORT — 1836. 



When between 70° and 80°, nearly tM'o degrees less ; but tbe progres- 

 sions appear to go on regularly as before. Tlie thermometer also gives 

 pretty accurate results with wine or strong beer when applied as above. 

 The author does not however presume to give the above as accurate 

 results, but merely to state that the thermometer appears to indicate a 

 regular progression according to the strength of the spirits and the 

 temperatures at which the experiments may be made. He desires at 

 present to draw attention to the subject, in hopes that some mode 

 of application may be discovered which may render it available, and per- 

 haps accurate, in ascertaining the qualities of spirits or acids. 



Notice of a new Gaseovs Bicarburet of Hydrogen. By Edmund Davy, 

 F.R.S., M.R.I.A., S;c., Professor of Cheinistry to the Royal DuUin 

 Society. 



Early in the present year the author, in attempting to procure potas- 

 sium by strongly heating a mixture of calcined tartar and charcoal in 

 a large iron bottle, obtained a black substance, which readily decom- 

 posed water, and yielded a gas which on examination proved to be a 

 new compound of carbon and hydrogen. This gas is highly inflam- 

 mable, and when kindled in contact with air burus with a bright flame, 

 apparently denser and of greater splendour than even defiant gas. If 

 the supply of air is limited the combustion of the gas is accompanied 

 with a copious deposition of carbon. Wiien the new gas is brought in 

 contact with chlorine gas instant explosion takes place, accompanied 

 by a large red flame and the deposition of much carbon ; and these ef- 

 fects readily take place in the dark, and are of course quite independent 

 of the action of the sun's rays or of light. 



The new gas may be kept over mercury for an indefinite time -with- 

 out undergoing any apparent change, but it is slowly absorbed by 

 water. Distilled water recently boiled, when agitated in contact A^ath 

 the new gas, absorbs about its own volume of it ; but on heating the 

 aqueous solution the gas is evolved apparently unaltered. The new gas 

 is absorbed to a certain extent by, and blackens, sulphuric acid. It 

 detonates powerfully when mixed with oxygen gas, especially if the 

 latter forms three fourths or more of the mixture ; and the only pro- 

 ducts of its combustion with oxygen are carbonic acid gas and water. 



The new gas requires for its complete combustion two and half vo- 

 lumes of oxygen gas, wluch are converted into volumes of carbonic 

 acid gas and water. 



From the author's analysis of the new gas by diff'erent methods, it ap- 

 pears to be composed of one volume of hydrogen, and two volumes of 

 the vapour of carbon condensed into one volume. Hence the new gas 

 contains as much carbon, but only half the quantity of hydrogen, that 

 is in olefiant gas. The density of the former is therefore less than that 

 of the latter, by the weight of a volume of hydrogen equal to its own 

 bulk. The new gas is in fact a bicarburet of hydrogen, composed of 



