Calcium Trithiocarbonate

By the action of carbon disulphide on calcium hydrosulphide only double compounds of calcium trithiocarbonate and calcium hydroxide can be obtained, and not the simple salt. From aqueous solutions reddish-yellow needles of the composition 3Ca(OH)₂.CaCS₃.9H₂O separate, and from alcoholic solutions similar needles corresponding with the formula Ca(OH)₂.CaCS₃.2H₂O. On acidifying a solution of either compound, one-third of the sulphur is evolved as sulphuretted hydrogen. Sulphur dissolves in the solution, forming a solution of perthiocarbonate.