Mr. Davy on a new Gaseous Compound of Carbon and Hydrogen. 83 



Experiment. 



Thermometer 55° Fah. Barom. 30°. 



^ of a cubic inch of pure water (just deprived of air by air-pump) being 

 added to ^ of a cubic inch of the new gas, over mercury : after agitation for 

 some time, the gas diminished to ^, which, on examination, burned with a bright 

 flame, and spontaneously exploded in chlorine. The aqueous solution of the gas, 

 appeared to have no peculiar smell or taste, and did not affect litmus paper. On 

 heating it over mercury, the gas was again expelled apparently unaltered. — 

 Hence, I think I may venture to conclude, that pure water, recently deprived of 

 air by the air-pump, will, at the above temperature and pressure, absorb about 

 its own bulk of the gas, and that the gas may be again expelled, unaltered by 

 heat. 



The new gas is slowly absorbed by strong sulphuric acid, which, gradually 

 acquires a yellowish or brownish colour, like that of a mixture of alcohol and 

 sulphuric acid. 



I have not ascertained the density of the new gas by experiment, never 

 having had a quantity sufficient for that purpose at any one time; but from cal- 

 culations founded on experiments made on its composition, which are given in 

 the sequel ; I estimate its density, (the barometer being at 30°, and thermometer 

 at 60°,) as 0.917; atmospheric air being 1. 000; and 100 cubic inches should 

 weigh 28.4378 grains. 



The new gas is gradually decomposed, when a series of electrical sparks, or 

 discharges from a Leyden phial are passed through it ; and there is a copious 

 deposition of carbon, but no expansion, and scarcely any alteration of volume. 



COMPOSITION OF THE NEW GAS. 



Satisfactory evidences that the new gas is a compound of carbon and hydro- 

 gen, were gained, by firing a mixture of it with three or four times its volume of 

 pure oxygen gas, over dry mercury; when the only products were carbonic acid 

 gas and water. Also, by passing a series of electrical sparks, or discharges from 

 a Leyden phial, through the new gas; when there was a copious deposition of 



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