1820.] of Chlorine and Carbon, $c. 43 



the hydrogen. When potassium is heated in the vapour of the 

 substance, there is generally a small expansion of volume, and 

 inflammable gas produced ; but it is very difficult to cleanse 

 potassium both from naphtha and an adhering crust of moist 

 potash ; and either of these, though in extremely minute quan- 

 tities, would give fallacious results. 



A more unexceptionable experiment made with iron has 

 been already described ; and the inferences from it are against 

 the presence of hydrogen in the compound. 



Some of the substance in vapour was electrized over mercury 

 by having many hundred sparks passed through it. Calomel 

 was formed and carbon deposited. A very minute bubble of 

 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 olefiant 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 hydro- 

 gen, combined without condensation, it is evident that half the 

 chlorine introduced into the vessel has combined with the 

 elements of the fluid, and liberated an equal volume of hydro- 

 gen ; 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 olefiant gases. A clean dry retort was fitted with a cap 

 and stopcock. Its capacity was 25 '25 cubic inches. Being 

 exhausted by the aiivpump, it was filled with nitrogen (24'25 

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

 cubic inches of olefiant 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 a jar of chlorine, 19'25 cubic inches entered; so 

 that the condensation had been as nearly as possible 1Q cubic 



