Preparation of Cadmium Oxalate.
A weighed piece of cadmium was dissolved in nitric acid and the excess of acid evaporated off. The nitrite was then dissolved in a large quantity of water and an equivalent amount of oxalic acid in solution added. The oxalate separated in a few moments as a crystalline precipitate. It was collected on a porcelain filter and washed thoroughly to remove nitric acid and ammonium nitrate. A considerable amount of ammonium nitrate was formed during the solution of the cadmium in nitric acid. The oxalate was finally dried in an air-bath for fifty hours, at 150°C.