66 Proceedings of Philosophical Societies. [Jan. 



of camphor. It is incombustible, except in the flame of a spirit- 

 lamp, and it then yields muriatic acid, with a bright yellow 

 flame. 



it remains fluid at 0° of Fahr. ; heated under water to about 

 1 66°, it is vaporized ; and while the temperature is continued, 

 remains so. When strongly heated by being passed over rock 

 crystal in a glass tube, a portion of it is decomposed ; and car- 

 bon is deposited in the tube ; but whether this decomposition is 

 to be attributed merely to the heat, or to action upon the glass, 

 is uncertain. Like the perchloride, it does not unite with water, 

 but it combinf»s with alcohol and ether ; the solutions burn 

 with a greenish flame, and muriatic acid fumes aid percep- 

 tibly evolved. The fixed and volatile oils also combine with it. 

 The metals act upon it nearly in the same way as upon the per- 

 chlorides ; potassium acts slowly upon it at common tempera- 

 tures, but when heated in the vapour of the protochloride, 

 brilliant combustion ensues, and carbon is deposited. Neither 

 nitric, muriatic, nor sulphuric acid, act upon it, and it does not 

 combine with alkahne solutions. Hydrogen passed through the 

 vapour of this chloride decomposes it at a high temperature, car- 

 bon is deposited, and muriatic acid formed. It appears to 

 consist of one atom of each of its constituents, or 33*5 chlorine 

 + 5*7 carbon. 



Mr. Faraday has also in this paper given an account of a triple 

 compound of iodine, carbon, and hydrogen. It was procured by 

 exposing iodine in olefiant gas to the solar rays. Crystals were 

 gradually formed ; no hydriodic acid appeared to exist in the 

 vessel ; and hence olefiant gas had not been decomposed, but 

 merely absorbed by the iodine. The triple compound of iodine, 

 carbon, and hydrogen, was purified by potash, which dis- 

 solved the uncombined iodine. It is a colourless, crystalline, 

 friable body ; its taste is sweetish, and its smell aromatic. It is 

 a non-conductor of electricity. By heat, it is first melted, and 

 then sublimes unchanged, and condenses into crystals which 

 are either tubular or pris,matic. At a high temperature it suffers 

 decomposition with the evolution of iodine. It burns in the 

 flame of a spirit-lamp, giving iodine and hydriodic acid. It is 

 soluble in ether and alcohol, but not in water, acid, or alkalinie 

 solutions. At between 300*^ and 400°, it is decomposed in sul- 

 phuric acid, but probably by the mere heat. Mr. Faraday con- 

 siders this substance as analogous to chloric ether. He proposes 

 to call it hydrocarburet of iodine. Mr. Faraday has not yet 

 procured an iodide of carbon ; but he entertains well-grounded 

 hopes of being able to succeed when the sun's rays are more 

 powerful than at this season of the year. 



On account of the extreme importance of the facts contained 

 in the paper of which I have now given an outline, I shall take 

 the earliest opportunity permitted by the Royal Society of laying 

 the whole of it before the reader. 



