VOL. LXXXVII.] PHILOSOPHICAL TRANSACTIONS. 227 



were expanded to 5.1 6, the quantity of oxygen employed was 0.08 less than in the 

 former experiment; and it may therefore be presumed that a small quantity of in- 

 flammable air might escape unaltered, and might add apparently to the product of 

 azote. In the 8th experiment also, the portion of oxygenous gas that was more 

 than sufficient to saturate the carbonated hydrogen, would probably combine, in 

 part, with the remaining azote, as in the experiments of Dr. Higgins * and Dr. 

 Priestley -}~. But in the 9th, the quantity of oxygenous gas was hardly sufficient 

 to saturate both kinds of inflammable air after electrization, and could not there- 

 fore diminish the azotic gas. When the proportion of oxygen is duly increased, 

 and the inflammation of the electrified air is performed in small portions, there is 

 no augmentation, but on the contrary a decrease of the quantity of the azote, as 

 will appear on comparing the 1st and 2d of the experiments which I have related. 



Two circumstances were observed, in the experiments of Dr. Austin, which 

 have not been noticed in the preceding account of the repetition of them, viz. the 

 appearance of a deposit from the carbonated hydrogenous gas during its electriza- 

 tion, and the formation of ammonia by the same process. In some experiments, 

 which I made on the first portion of gas, both these facts were sufficiently apparent; 

 but neither of them occurred on electrifying the gas which was afterwards procured. 

 Suspecting that the cessation of them arose from the superior purity of the latter 

 portion from azotic gas, I passed the electric shock through a mixture of carbona- 

 ted hydrogen with about 4- its bulk of azote, and thus again produced the pre- 

 cipitate, which would have been of a white colour, if it had not been obscured by 

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

 plosion. An infusion of violets was tinged green when admitted to the electrified 

 gas ; but the change of colour did not occur instantly, as happens from the absorp- 

 tion of ammoniacal gas; and required for its production that the liquid should be 

 brought extensively into contact with the inner surface of the tube. From this 

 effect on a blue vegetable colour, we may infer that the precipitate was an alkaline 

 substance, and probably the carbonate of ammonia; but the quantity was much 

 too minute to be the subject of more decisive experiment. 



I shall conclude this memoir, with a brief summary of the facts that are esta- 

 blished by the preceding experiments^;. Those included under the first head are de- 

 ducible from the experiments of Dr. Austin. 1. Carbonated hydrogenous gas, in 

 its ordinary state, is permanently dilated by the electric shock to more than twice 

 its original volume ; and as light inflammable air is the only substance we are ac- 

 quainted with, that is capable of occasioning so great an expansion, and of ex- 

 hibiting the phenomena that appear on firing the electrified gas with oxygen, we 

 may ascribe the dilatation to the production of hydrogenous gas. 2. The hydro- 



* Experiments and Observations on acetous Acid, &c. p. 29 j.— f 79 Phil. Trans. 7. — f Since thig 

 paper was written I have extended the inquiry to phosphorated hydrogenous gas, which expands equally 

 with the carbonated hydrogen 3 loses its property of inflaming when brought into contact with oxygenous 

 gas ; and affords evident traces of a production of phosphorous or phosphoric acid. — Orig. 



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