416 Mr. J. F. W. Johnston on Iodic Mther. 



tion becomes coloured, iodine is deposited and volatilized, and 

 olefiant gas is given off. If the experiment be made in a tu- 

 bulated retort, the iodine condensed in the beak and in the re- 

 ceiver is gradually converted, by the absorption of the olefiant 

 gas which comes over, into Faraday's iodide of carbo- hydro- 

 gen, which crystallizes in long white prisms of one or two 

 inches, or forms an entire massive coating in the interior of 

 the long beak. 



6. It dissolves largely in alcohol, either cold or hot, giving 

 a colourless solution, from which water precipitates a large 

 quantity of it, but of a brown colour. The alcoholic solution 

 when distilled gives a colourless neutral liquid not troubled 

 by water, but which, mixed with caustic potash and placed in 

 the light, becomes brown, showing that it contains iodine. In 

 the retort there remains the brown opake fluid. iEther mixes 

 with it in all proportions, and by agitation separates it from 

 the acid liquid in which it is formed. It might therefore be 

 employed with advantage in the preparation of the iodic aether, 

 were it not difficult again to separate the whole of it by water 

 without decomposition. Water dissolves it in small quantity. 

 When the yellow aether is washed with water it becomes less in 

 quantity, less fluid, and of a brown colour, which by further 

 washing gradually deepens to a dark brownish red. The 

 aqueous solution is colourless, and slightly acid, due, as ap- 

 pears from its reactions, to the presence of a small quantity 

 both of iodic and of hydriodic acid. 



7. Sulphuric acid in the cold decomposes it, rendering it 

 dark brown ; when heated it becomes dirty black, and vapours 

 of iodine are given off. A few minute prisms of a yellowish 

 colour also condense in the upper part of the tube, which are 

 probably iodide of carbo-hydrogen (iodide of aetherine). On 

 muriatic acid it floats unchanged, but as the lighter parts eva- 

 porate or are dissolved it becomes brown and dense, and 

 sinks to the bottom ; the acid at the same time becomes yellow. 

 Nitric acid in the cold does not act upon it. The acid solu- 

 tion in which it is formed retains it in solution only till it cools. 

 When once separated by cooling, it cannot be redissolved by 

 the application of heat. 



8. When chlorine is passed over it, muriatic acid is 

 formed, and the aether becomes red. This gas, however, does 

 not seem to be capable of decomposing it entirely; for when 

 gently heated after long exposure to an atmosphere of chlo- 

 rine, it gives off chlorine and muriatic acid vapour, and sinks 

 apparently unchanged, except in colour, when put into water. 

 9. When obtained by decantation from the acid liquid in 

 which it is formed, the aether reddens litmus; and from the 



