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Knight's Mechanical Encyclopedia (ed. Knight), S. (search)
allic silver on the article to be coated. Nitrate of silver and alcoholic solution of tannin have been employed by Unger for silvering glass and porcelain. Cimeg's process consists in moistening the cleansed glass with a solution of 1 part Rochelle salts (tartrate of soda and potassa) in 200 parts of water, and afterward pouring on it a solution containing nitrate of silver 20, Rochelle salts 40 parts, which is allowed to flow uniformly over the glass; the plate is then kept in a horizontaRochelle salts 40 parts, which is allowed to flow uniformly over the glass; the plate is then kept in a horizontal position for one half-hour, when it is washed; when dry, the silver is coated with a varnish composed of gumdammar, 20 parts; asphaltum, 5; gutta-percha, 5; benzine, 75. R. Bottger's process is based on those of Petitjean and Cimeg. He dissolves one drachm of nitrate of silver in an ounce of distilled water and pours this slowly into a boiling solution of tartrate of soda and potassa; a second liquid is prepared by dissolving one drachm nitrate of silver in one ounce of distilled water. T