Sulphuric acid dissolves it, forming a deepred solution.
Iridium sesquichloride, IrC1 31 is obtained when one of the corresponding double chlorides is heated with concentrated sulphuric acid, the mixture being then thrown into water.
It decomposes steam at a red heat, and slowly dissolves in dilute hydrochloric and sulphuric acids, but more readily in nitric acid.
By heating a mixture of cobalt oxalate and sal-ammoniac in air, it is obtained in the form of minute hard octahedra, which are not magnetic, and are only soluble in concentrated sulphuric acid.
It is a black amorphous powder soluble in concentrated sulphuric and hydrochloric acids, and when in the moist state readily oxidizes on exposure.
