112 Mr. Faraday on two new Compounds [Aug. 



gas was produced, but it was much too small to interfere with 

 the conclusions drawn respecting the binary nature of the com- 

 pound ; and was probably caused by air that had adhered to the 

 sides of the tube when the mercury was poured in. 



The most perfect demonstration that the body contains no 

 hydrogen, and indeed of its nature altogether, is obtained from 

 the circumstances which attend its formation. When the fluid 

 compound of chlorine and defiant gas is acted on by chlorine 

 and solar light in close vessels, although the whole of the chlo- 

 rine disappears, yet there is no change of volume, its place being 

 occupied by muriatic acid gas. Hence, as muriatic acid gas is 

 known to consist of equal volumes of chlorine and hydrogen, 

 combined without condensation, it is evident that half the chlo- 

 rine introduced into the vessel has combined with the elements 

 of the fluid, and liberated an equal volume of hydrogen ; and as, 

 when the chloride is perfectly formed, it condenses no muriatic 

 acid gas, a method, apparently free from all fallacy, is thus 

 afforded of ascertaining its nature. 



I have made many experiments on given volumes of chlorine 

 and defiant gases. A clean dry retort was fitted with a cap and 

 stop-cock. Its capacity was 25*25 cubic inches. Being ex- 

 hausted by the air-pump, it was filled with nitrogen (24*25 cubic 

 inches being required), and being again exhausted, 5 cubic 

 inches of defiant gas, and 10 cubic inches of chlorine, were 

 introduced. It was then set aside for half an hour, that the 

 fluid compound might form, and afterwards being placed again 

 over ajar of chlorine, 19*25 cubic inches entered ; so that the 

 condensation had been as nearly as possible 10 cubic inches, or 

 twice the volume of the defiant gas (barometer, 29*1 inches). 

 It was now placed for the day (Oct. 18) in the rays of the sun ; 

 but the weather was not very fine. In the evening the solid 

 crystalline substance had formed in abundance, and very little 

 fluid remained. When placed over chlorine, not the slightest 

 change in volume had been produced. The stop-cock was now 

 opened under mercury, and a small portion of the metal having 

 entered, it was agitated in the retort, to absorb the chlorine; the 

 neck of the retort was left open under the mercury all night, 

 and the whole agitated from time to time. Next morning 

 (barometer 29*6) the mercury which had entered, being passed 

 into the neck of the retort, stood at a certain mark six inches 

 above the level of the mercury in the trough, occupying 1*25 

 cubic inch, and leaving 24 cubic inches filled by the expanded 

 muriatic acid gas and nitrogen. These volumes corrected to 

 the pressure of 29*1 inches give 5*78 cubic inches for the chlo- 

 rine absorbed, and 19*47 cubic inches for the muriatic acid gas, 

 &e. These absorbed by water left 1*2 cubic inch of nitrogen; 

 so tliat the gases in the retort, after the action of solar light, 

 were : 



