Peroxyhydrates of Calcium

By the action of concentrated hydrogen peroxide on calcium peroxide octahydrate at low temperatures, Riesenfeld and Nottebohm obtained a compound which they described as a diperoxyhydrate, CaO₂.2H₂O₂. By stopping the action after a shorter time a monoperoxyhydrate, CaO₂.H₂O₂, is obtained as a heavy, faintly yellow powder.