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Silvering Small Iron Articles

The small iron articles are suspended in dilute sulphuric acid until the iron shows a bright clean surface. After rinsing in pure water, they are placed in a bath of mixed solution of sulphate of zinc, sulphate of copper, and cyanide of potassium, and there remain until they receive a bright coating of brass. Lastly they are transferred to a bath of nitrate of silver, cyanide of potassium, and sulphate of soda, in which they quickly receive a coating of silver.

Silver Plating Without a Battery. 1. The process consists in exposing the article, which has previously been well cleansed with a potash solution and dilute hydrochloric acid, to the operation of a silver bath, which is prepared in the following manner: Form a solution of 32 grams (1 OZ., 13.8 grains) nitrate of silver, 20 grams silver (12 dwts., 20.6 grains) in 60 (1 OZ., 18 dwts., 13.9 grains) grams nitric acid. The silver is precipitated as silver oxide with a solution of 20 grams solid caustic potash in 50 grams (1 OZ., 12 dwts., 3.6 grains) distilled water, carefully washed, and the precipitate taken up by a solution of 100 grams (3 OZ., 4 dwts., 7.2 grains) cyanide of potassium in 500 grams distilled water. The fluid, distilled through paper, is finally diluted with distilled water to 2 liters (4 1/2 pints). The thus prepared silver bath is gently warmed in the water bath, and the article to be silver plated laid in it and kept in motion for a few minutes, and after taking out it is dried in sawdust, and then polished with Vienna chalk for giving luster. 2. For rapid silver plating, prepare a powder of 3 parts of chloride of silver, 20 parts carefully pulverized cream of tartar, and 15 parts pulverized cooking salt; mix it into a thin paste with water, and rub it upon the well cleaned metallic surface with blotting paper. After you are certain that all parts of the article have been touched alike, rub it with very fine chalk or dust upon wadding or other soft cloth. Wash with clean water and dry with a cloth. 3. Dissolve 1 OZ nitrate of silver, in crystals, in 12 OZS., soft water; then dissolve in the water 2 OZS. cyanide of potash, shake the whole together, and let it stand until it becomes clear. Have ready some half-ounce vials, and fill half full with Paris white, or fine whiting, and then fill up the bottles with the liquid, and it is ready for use. The whiting does not increase the coating power, it only helps to clean the article, and save the silver fluid. 4. Make a solution of 4 ounces lunar caustic (equal to a solution 2 1/2 ounces silver in 7 1/2 ounces nitric acid); the silver of this solution is precipitated as an oxide of silver by the addition of a solution of 2 1/2 ounces of caustic potash in 6 1/2 ounces distilled water; and the precipitate, after being washed, is added to a solution of 12 1/2 ounces of cyanide of potassium in one quart of water. This solution is then filtered and water added to bring it to 4 quarts. In this solution, which is heated on the water bath, the pieces to be silvered are left for a few minutes. Being agitated, they are taken out, and put to dry in fine sawdust and then polished. Steel-Blue on Brass. Dissolve 1 1/2 drachms of antimony sulphide and 2 ounces calcined soda in 3/4 pint of water. Add 2 3/4 drachms of kermes, filter, and mix this solution with another of 2 3/4 drachms of tartar, 5 1/2 drachms of sodium hyposulphite and 3/4 pint of water. Polished sheet brass placed in the warm mixture assumes a beautiful steel-blue.

To Give Copper a Durable Luster. Place the copper articles in a boiling solution of tartar and water for fifteen minutes. Remove, rinse off with cold water and dry.

ELLICOTT, JOHN. A celebrated London clockmaker. He was born in 1700, was elected a fellow of the Royal Society n 1738, and published a work on pendulums in 1751. He invented a compensation pendulum in 1753, in which the bob rested on the longer ends of two levers, of which the shorter ends are depressed by the superior expansion of a brass bar attached to the pendulum rod. The invention, however has not proved of any practical value. He died in 1772.