NEW AMMONIO-CHROME COMPOUND. XXII.-Notice of a New Ammonio-Chrome Compound. BY3. MORLAND, F.C.S. WHENsulphocyanide of ammonium is fused and powdered bichrornate of potash added to it this salt dissolves quietly at first giving a purple coloration. After a short time however it very brisk reaction ensues ammonia and aqueous vapour are given off abundantly and %heresidue is of a beautiful crimson colour. This residue consists of sulphocy anide of ammonium sulphocyanide of potassium bichromate of potash sulphate of potash and the sulphocyanide of a new ammonio-chrome com- * Journal of Chemical Society xii 283. MORLAND ON AN AMMONIO-CHROME COMPOUND. 253 pound; this last salt is easily purified from the others by washing with cold water in which it is but sparingly soluble and after- wards by crystallization from alcohol which dissolves it freely or from ether in which it is moderately soluble.This new salt has the composition Cr Csy 2?JH,O. Analysis gave the fol- lowing figures :-Theory. Fomd. Cr 18.71 18-71 when the salt was dried at 120"C s 34.53 34.37 N 25.18 24.96 C 12.95 13.27 H 2-88 3-39 0 5*76 This is a perfectly neutral salt crystallizing in the cubical system. I obtained crystals by the spontaneous evaporation of an ethereal solution the form of which was the rhombic dodecahe- dron modified by the planes of the octahedron it has a strongly bitter taste especially at the back of the mouth. Heated in a closed tube it gives off ammoniacal vapours sulphuretted hydrogen and some compound of cyanogen with a garlicky odour ; the residue is sulphide of chromium which when heated in the air ignites gives off sulphurous acid and leaves sesquioxide of chromium.Neither acids nor alkalies decompose this salt in the cold but alkalies on boiling throw down oxide of chrome; and acids when concentrated decompose it by uniting with the ammonia. Heated on the water-bath with sulphuric acid it yields sulphate of ammonia and blue sulphate of chrome; oxalic acid gave violet oxalate of chrome and oxalate of ammonia Persalts of iron are not coloured by this salt but nitrate of silver immediately gives a precipitate of uncertain composition as much of this chrome salt is carried down. Other chromates as well as bichromate of potash also form this same salt with fused sulphocyanide of ammonium; chromate of potash and chromate of lead succeed pretty well but there are also other substances formed.I found the best proportion to be 5 of sulphocyanide to 2 of bichromate corresponding to 1 eq. bichromate to 5 of sulptrocyanide. FrB my's roseo-chrome salts have the composition (Cr,03.4NH3).3A GLADSTONE ON CIRCULAK POLARIZATION. which differs chiefly in the double quantity of ammonia. The cobalt-bases have according to FrBmy the following compo-sitions :-PO,~ 4 xrs3 5> Y.l 5 5J 6 fJ I have attempted to form other compounds by the reduction of chromates in the presence of ammonia-salts but at present without success.