The commonest salts of nickel are the nitrate, chloride, sulphate and oxide. The nitrate is obtained by dissolving the metal in warm diluted nitric acid, and evaporating the mixture by a gentle heat until the residue solidifies upon cooling. The oxide is made by adding to a solution of the nitrate, or other common salt of nickel, a solution of potash or caustic soda, un¬til it no longer forms a precipitate. There is no danger of adding too much of either potash or soda, as the oxide it forms is not soluble in a solution of either of them ; the precipitate which is oxide of nickel, should be collected by means of a filter and dried. It is a black pow¬der, insoluble in water, but dissolves readily in nitric, muriatic or sulphunc acid. The sulphate is obtained by dissolving either the nitrate, chloride or oxide in a quantity of diluted sulphuric acid, and evaporating the mixture nearly to dryness, when it will solidify upon cooling. A solution of the nitrate of nickel may be obtained by passing a tolerably strong current of electricity through a very dilute solution of nitric acid, by means of two plates of nickel, or by using a dilute solution of muriatic acid, the chloride may be obtained, and with a dilute solution of sulphuric acid, a solu¬tion of the sulphate is produced. Nickel is too highly electro positive a metal to be readily deposited upon other metals, unless they are more electro positive than itself. This consti¬tutes one of the greatest difficulties in the way of successful nickel plating, but one which we think may be "overcome by a careful observance of the directions given.
Thoroughly cleaned articles of copper, brass, and German silver, and articles of iron, steel, pewter, type metal etc., that have pre¬viously received a deposit of copper by the battery process, may be coated with nickel very readily in the following solution : Add to a boiling solution of pure tin tarter, a small quan¬tity of nickel oxide heated to redness, which will impart a greenish tint to the liquid. Use the solution hot, and stir the articles about in it with a brass rod until they have acquired a good deposit, then take them out, wash and dry them, and if necessary, polish them with finely powdered chalk This solution should yield a very brilliant deposit and is comparatively easy to manage, but the immersion of the least par¬ticle of zinc or iron in it will greatly impair its action, and perhaps ruin it.
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