By repeated evaporation of the oxychloride with small quantities of water, a ‘metazirconium chloride’ is obtained, which dissolves in water to a colloidal solution, and on dialysis yields a colloidal solution of ‘metazirconic acid.’ The _bromide_, ZrBr₄, very closely resembles the chloride; when treated with water it forms the oxybromide, which separates from solution according to the conditions in various hydrated forms, of which the commonest is the octohydrate, ZrOBr₂,8H₂O. The _iodide_, ZrI₄, is a very reactive body, which closely resembles the preceding; it forms an oxyiodide, ZrOI₂,8H₂O. _Zirconyl chlorate_, ZrO(ClO₃)₂,6H₂O, is obtained from the sulphate by double decomposition with barium chlorate; it forms very soluble colourless needles. Alkali iodates or iodic acid throw down a voluminous _oxyiodate_, very sparingly soluble, like the corresponding ceric and thorium salts, in water and acids. _The Sulphates._--When zirconium dioxide is dissolved in concentrated sulphuric acid, and the excess of acid removed by heating to 400°, the ‘neutral’ sulphate, Zr(SO₄)₂, remains. The compound dissolves in dilute sulphuric acid to form solutions which contain various ‘complexes’ as shown by conductivity measurements, and the behaviour towards oxalic acid. Whilst solutions of the nitrate or chloride give immediate precipitates with this reagent, solutions of the ‘sulphate’ give no precipitate, or at most a very gradual one; moreover, addition of sulphuric acid or of alkali sulphates to other zirconium salts inhibits the oxalate precipitation. These facts are explained by regarding the ‘neutral’ sulphate, Zr(SO₄)₂,4H₂O, as zirconylsulphuric acid, ZrOSO₄,H₂SO₄,3H₂O, which in solution ionises to 2H^{.} and ZrOSO₄,SO₄´´. This conclusion is confirmed by the fact that whilst in solutions of the chloride in hydrochloric acid, zirconium goes on electrolysis to the cathode, on addition of sulphuric acid to the solution it travels to the anode. The anhydrous compound and the hydrate are extremely soluble in water, but much less readily soluble in dilute sulphuric acid. Probably in solution more complex salts are formed by further hydrolysis, for by addition of concentrated alkali sulphate solution in the cold, double salts of the formula Zr₂O₃(RSO₄)₂,8H₂O are obtained. When the solution is kept for some time at 39°-40°, a basic sulphate, 4ZrO₂,3SO₃,14H₂O, separates slowly. When concentrated solutions are boiled, a salt, 2ZrO₂,3SO₃,5H₂O, separates as a crystalline precipitate; in contact with water it slowly hydrates itself to the compound 2ZrO₂,3SO₃,14H₂O; when heated to 300°, it becomes anhydrous without further change. Various other basic, acid and complex salts have also been described.