To utilize the waste from nickel sand, which collects on the bottom of vats and also from cast nickel anodes, wash same often in clean hot water and then boil in dilute sulphuric acid, in which there is 1 part of acid and parts of water until the water, when poured upon waste, does not cloud same any more. At this stage pour off the liquid and submit the waste to treatment with concentrated nitric acid. Great care should be taken in doing this, a large earthen vessel being used to prevent the solution from running over. The solution will be of sufficient concentration when it contains but little free acid and should then be filtered and slowly evaporated, until dry. over the water bath. The name of the resultant product is nickel-nitrate. Proceed by the dissolution of this nickel-nitrate in hot water and precipitate same with gradual additions of caustic soda. Then filter and wash this precipitation of hydrated nickel oxide and submit it to treatment with dilute sulphuric acid with the assistance of heat until its solution. Concentrate this solution by evaporation and add an excess of concentrated solution of ammonium-sulphate. This precipitation is a double solution of nickel and ammonia and can be used for nickel-plating.