CAR

( 252 )

CAR

oxygenation as before electrization. It is notimprobable that the affinities of carbon and hy-drogen for oxygen are fo nearly equal that eitherfubftance is able partially to decompofe the com-pleat oxyd of the other. Thus we find (asmentioned in the laft article) that when hydro-gen and carbonic acid are together fubjected toeleCtricity , the carbonic acid is partially decom-pofed, and the product is carbonous oxyd andwater; and on the other hand when water isdecompofed by red-hot charcoal, a part of theproduCt is alfo the carbonous oxyd.

The above expanfion of carburetted hydrogenby electricity Mr. Henry has {hewn not to de-pend on any oxydation of the contiguousmetals, fince it takes place in a clofe-ftoppedglafs with conductors of gold, as well as withoxydable conductors, and over mercury.

All the hydrocarbonates are fatal to animallife, not merely (as appears) from its unfitnefsto fuppqrt life, but alfo from fomething pofi-tively noxious, fince animals immerfed in itdie fooner than they would from the mere in-terruption of refpiration.

This gas is fcarcely, if at all, abfo.rbed bywater, but by long {landing over it, it lofes aportion of its combuftible matter. This lafthowever only applies to the hydrocarbonats thatrequire at leaft their own bulk of oxygen to fa-turate them, and efpecially to that variety calledthe olefiant gas.

Simple carburetted hydrogen, when fet fire•to, burns at the furface in contaCt with the airwith a blue flame with red edges, but whenmixed with any of the olefiant gas the flamebecomes much more brilliant, and refemblingthat of oil. Applied to the purpofes of illumi-nation, the hydrocarbonat from coal, from lampoil, or from wax, conveyed through an Argand’slamp produces full as much light as when fup-plied with oil in the ufual way, f and thefe arealfo the gaffes that appear to contain olefiantgas, and an excels of carbonous matter relatively

to their hulk. The brightnefs of the flame ismuch diminifhed when thefe gaffes have beenlong kept over water, and hence for illumina-tion they Ihould be ufcd as foon as prepared.

The combuftion of carburetted hydrogen ismuch more brilliant in oxygen gas. If burntin a veffel of oxygen in the way that hydrogen isburnt for the production of water (defcriheiunder that article), the produCts may hp colleCted,and are found to be limply carbonic acid andwater.

If any of the hydrocarbonats is mixed withfufficient oxygen gas, and fired by the eleCttiSfpark, or any other method, an explofion takesplace more or lefs violent according to the quan-tity of carbonous matter .condenfed in the hy-drocarbonat; and the remaining gas confifts ofcarbonic acid, together with any unconfumedgas, or excefs of oxygen, whilft the water con-denfes in drops on the fides of the jar. A finglecubic inch of the mixed airs is generally asmuch as can be conveniently managed at afingle explofion; and when any quantity of ole-fiant gas is prefent, even this quantity willendanger very thick glafs jars. A very vividred flame appears at the moment of explofion,and a great enlargement takes place in an in-ftant, after which the bulk is fuddenly reducedto much lefs than the original quantity. Whenthe carbonic acid is absorbed, if the gaffes havebeen properly proportioned, no gafeous refidueis left, except accidental impurities.

The following table will {hew the relativequantities of pure oxygen required to faturateioo cubic inches of moft of the known hydro-carbonats, but (as was mentioned in the begin-ning of this article) though the quantity ofcarbon contained in each gas may be readilyeftimated, no information is given as to theHate of the carbon, that is, whether as fimplqcarbon or carbonous oxyd, and therefore theactual quantity of hydrogen is equally un*known.

f Henry, Phil. Jour.