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



muriatic acid gas, whilst the carbon of the bicarburet is liberated. Effects, which, 

 as is well known, are analogous to the action of hydrogen and chlorine on each 

 other, by electricity, or the solar rays. To notice a single experiment, — 



Experiment. 



^ cubic inch of chlorine, containing ^ impurity, being let up into a gra- 

 duated tube containing ^ cubic inches of bicarburet of hydrogen, instant 

 inflammation, and a copious deposition of carbon, took place; and ^ cubic 

 inches were condensed. Now ^^ of the gas + 7^ of chlorine = ^ muriatic acid 

 gas ; and it was found by experiment, that upwards of -^ of chlorine must have 

 been absorbed, in being let up through the column of water in the tube. These 

 results agree as nearly as can be expected, in experiments of this sort. 



Electricity occasions no expansion in the bicarburet of hydrogen ; for after 

 several hundred discharges of a Leyden phial were passed through it, and it was 

 resolved into carbon and Inflammable air, there was not the slightest increase of 

 volume; on the contrary, there was a diminution of bulk, amounting to about 

 one-tenth of the original gas, which I am inclined to refer to the admixture of a 

 little common air. 



From comparative experiments I made on the different hydrocarbonates, I 

 am satisfied that the bicarburet of hydrogen, is more readily decomposed by 

 electricity than olefiant gas, and this gas more easily than carburetted hydrogen.* 

 Thus, after passing a thousand discharges from a moderate sized Leyden phial, 

 through about one-tenth of a cubic inch of olefiant gas in a detonating tube, the 

 gas was only partially decomposed ; for there was merely a faint partial blush of 

 black carbonaceous matter on the surface of the tube, nearest to the wires, and 

 an expansion not exceeding one-half of the original volume. The same number 

 of discharges being passed through an equal bulk of carburetted hydrogen, pro- 

 duced on the tube, only a small quantity of a dark brownish carbonaceous 

 substance ; and an expansion not exceeding one-third of the original bulk. — . 



* In the able work of the late Dr. Turner, " Elements of Chemistry," fifth edition, it is said, 

 " light carburetted hydrogen is not decomposed by electricity ;" but this statement is opposed to 

 the experience of the late Sir H. Davy, and also to my own. 



