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Typo: A Monthly Newspaper and Literary Review, Volume 5

[Improved Method of Etching]

Improved Method of Etching.—According to the Papier Zeitung, of Berlin, a discovery has recently been made which bids fair to revolutionize the process of etching, especially in photo-gravure. The drawing is traced, as usual, on a plate of zinc, either by hand or by photography, with any suitable ground. The plate, backed with asphaltum, is laid in a bath of dilute acid. It is then put in circuit with a dynamo, the other pole being merely placed in the acid. When the current is allowed to pass, the acid attacks the metal with great rapidity, and a few minutes will suffice to bite the plate, and the depth of the etching can be easily controlled. The process is said to be far preferable to the old method in that the etching can be regulated with mathematical accuracy, while, after the old fashion, the surface becomes covered with a film of hydrogen or with a number of minute bubbles, which prevent an effect unless the plate be incessantly rocked or brushed. According to the inventor, whose name is withheld, the action of the acid in electric etching is due to a depolarization of the metal surface.