e. 



Experiments on carionated Hydrogen Gas. 247 



both kinds of inflammable air after elcftrization, and could not therefore diminifli the 

 azotic gas. When the proportion of oxygen is duly increafed, and the inflammation of the 



ledtrified air is performed in fmall portions, there is no augmentation, but on the contrary a 

 decreafe of the quantity of the azote, as will appear on comparing the ift and 2d of the ex- 

 periments which I have related. 



Two circumftances were obferved in the experiments of Dr. Auftin, which have not been 

 noticed in the preceding account of the repetition of them, viz. the appearance of a depofit 

 from the carbonated hydrogenous gas during its eIe£lrization, and the formation of am- 

 rnoniac by the fame procefs. In fome experiments which I made on the firft portion of gas, 

 both thefe fads were fufficiently apparent; but neither of them occurred on eleflrifying the 

 gas which was afterwards procured. Sufpe£^ing that the cefTation of them arofe from the 

 fuperior purity of the latter portion from azotic gas, 1 pafled the eleftric fliock through a 

 mixture of carbonated hydrogen, with about one fourth of its bulk of azote, and thus again 

 produced the precipitate, which would have been of a white colour, if it had not been 

 obfcured by minute globules of mercury, that were driven upwards by the force of the ex- 

 plofion. An infufion of violets was tinged green, when admitted to the eleitrified gas ; but 

 the change of colour did not occur inftantly, as happens from the abforption of animoniacal 

 gas ; and required for its produ£tion, that the liquid fhould be brougnt extenfively into con- 

 ta6l with the inner furface of the tube. From this efFeit on a blue vegetable colour, we 

 may infer that the precipitate was an alkaline fubftance, and probably the carbonate of am- 

 moniar: ; but the quantity was much too minute to be the fubjedt of a more decifive experi- 

 ment. 



I fhall conclude this memoir with a brief fummary of the fa£l:s that are eftablifhed by the 

 preceding experiments *. Thofe included under the firfl head are deducible from the experi- 

 ments of Dr. Auftin. 



1. Carbonated hydrogenous gas, in its ordinary ftate, is permanently dilated by the efet^rie 

 fhock to more than twice its original volume ; and as light inflammable air is the only fub- 

 ftance we are acquainted with, that is capable of occafioning fo great an expanfion, and of 

 exhibiting the phenomena that appear on firing the eledtrified gas with oxygen, we may 

 afcribe the dilatation to the produ(Eiiin of hydrogenous gas. 



2. The hydrogenous gas, evolved by this procefs, does not arife from the decompofition of 

 charcoal ; becaufe the fame quantity of that fubftance is contained in the gas after as before 

 eleiSlrization. 



3. The hydrogenous gas proceeds from decompofed water; becaufe, when this fluid i-s ab- 

 fl:ra£led as far as poflTible from the carbonated hydrogenous gas, before fubmitting it to the 

 aflion of eleilricity, the dilatation cannot be extended beyond one-fixth its ufual amount. 



4. The decompf nent of the water is not a metallic fubftance, becaufe carbonated hydro- 

 genous gas is expanded when in contadl only with a glafs tube and gold, a metal which has 

 no power of fi par.iting water into its formative principles. 



5. The oxygen of the wa.ter (when the eledric fluid is pafletf through carbonated hydro- 

 genous gas, that holds this fubftance in folution) combines with the carbon, and forms car- 



* Since this paper was written, I have extended the inquiry to phofphorated hydrogenous gas, which ex- 

 pands eiiuall;^ with, the parboiiated hydrogen ; lofes its property of inflaming when brought into contadt with 

 •jtyjjeiieus gas, and affords eyident traces of a produilion of pbofphorous or phofphoric acid. 



benl< 



