q 6 Mr. Faraday on two new compounds 
is converted into vapour, which, rising through the acid, 
condenses in the upper part of the tube. 
It is not acted upon by oxygen at temperatures under a red 
heat. A mixture of oxygen and the vapour of the substance 
would not inflame by a strong electric spark, though the 
temperature was raised by a spirit-lamp to about 400°. When 
oxygen mixed with the vapour of the substance is passed 
through a red-hot tube, there is decomposition, and mixtures 
of chlorine, carbonic oxide, carbonic acid, and phosgene gases 
are produced. A portion of the chloride was heated with per- 
oxide of mercury in a glass tube over mercury ; as soon as 
the oxide had given off oxygen, and the heat had risen so 
high as to soften the glass considerably, the vapour suddenly 
detonated with the oxygen with bright inflammation. The 
substances remaining were oxygen, carbonic acid, and calo- 
mel ; and I believe there was no decomposition or action, 
until so much mercury had risen in vapour as to aid the 
oxygen by a kind of double affinity in decomposing the 
chloride of carbon. 
Chlorine produces no change on the substance, either by 
exposure to light or heat. 
When iodine is heated with it at low temperatures, the two 
substances melt and unite, and there is no farther action. 
When heated more strongly in vapour, the iodine separates 
chlorine, reducing the perchloride to the fluid protochloride 
of carbon, and chloriodine is produced. This dissolves, and 
if no excess of iodine be present, the whole remains fluid at 
common temperatures. When water is added, it generally 
liberates a little iodine ; and on heating the solution, so as to 
