THE CHEMICAL GAZETTE. No. CCCXCI.—February 1, 1859. SCIENTIFIC AND MEDICINAL CHEMISTRY. On Platinocyctnide of JEthyle. By Karl von Thann. The author first endeavoured to prepare this body by the action of iodide of sethyle upon platinocyanide of silver. Even at the ordinary temperature the yellow colour of iodide of silver made its appearance after the mixture had stood for several days; to com plete the process, the tube was heated in the water-bath, when the fluid disappeared almost entirely in a few hours; the substance was treated with strong alcohol; the filtrate, when evaporated in vacuo, only left a very small quantity of a yellowish, dichroitic (yellow and violet) residue, so that the aether could not be isolated in this way. Probably the platinocyanide of sethyle formed is contained in the yellow substance which is insoluble in alcohol, combined with the iodide of silver to an insoluble compound. This yellow residue was suspended in alcohol and decomposed by sulphuretted hydrogen gas. The fluid filtered from the sulphuret of silver thus produced was evaporated in the water-bath, when it left a brick-red amorphous residue, which was very soluble in water and in alcohol, deliquescent in the air, and possessed an extremely unpleasant taste and odour (like mercaptan). With nitrate of silver the aqueous solution gave a reddish-brown precipitate, like hydrated peroxide of iron, and with nitrate of mercury a dark blue, caseous precipitate, which acquired a bright red colour in spots by exposure to the air. This brick-red substance is probably a sulphoplatino- cyanide of sethyle. When ignited, it left 26'9 per cent, of platinum. As the aether could not be obtained in this way, its preparation was attempted by the treatment of the alcoholic solution of platino- hydrocyanic acid with muriatic acid. For this purpose perfectly pure platinocyanide of barium was dissolved in water, and preci pitated by nitrate of silver; the precipitate was then thoroughly washed by decantation with hot water, suspended in water, and decomposed by sulphuretted hydrogen, the filtered fluid evaporated to dryness in the water-bath, the residue of platinohydrocyanic acid Chein. Gaz. 1859. d