A manual of electro-metallurgy / By George Shaw.

  • Shaw, George
Date:
1844
Catalogue details

Licence: Public Domain Mark

Credit: A manual of electro-metallurgy / By George Shaw. Source: Wellcome Collection.

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    some analogy in principle with those of the Russian Professor, and may, probably, give me the right to claim priority in its discovery and application. These experiments were aban- doned from the want of that most important element in pursuits of this nature, time ; the writer’s share of the said element being occupied in a manner more imperative than pleasing. I regret, however, not having made it the subject of an earlier communication, as this would have placed my pretensions beyond doubt; but inasmuch as the nottce alluded to is given from memory, and is undescriptive, while I may be enabled to exhibit the modus operandi, my assertion may be at least partially substantiated. 16. ‘ It is well known to experimentalists on the chemical action of voltaic electricity, that solutions of several metallic salts are decomposed by its agency, and the metal procured in a free state. Such results are very conspicuous with copper salts, which metal may be obtained from its sulphate, (blue vitriol) by simply immersing the poles of a galvanic battery in its solution, the positive one becoming gradually coated with copper. The phenomenon of metallic reduction is an essen- tial feature in the action of sustaining batteries ; the effects, in this case, taking place on more extensive surfaces. But the form of voltaic apparatus which exhibits this result in the most interesting manner, and relates more immediately to the subject of the present communication, may be thus described : —lIt consists of a glass tube, closed at one extremity with a plug of plaster of Paris, and nearly filled with a solution of sulphate of copper; this tube and its contents are immersed in a solution of common salt. A plate of copper is placed in the first solution, and is connected, by means of a wire and solder, with a zine plate, which dips into the latter. A slow electric action is thus established through the pores of the plaster, which it is not necessary to mention here; the result of which is the precipitation of minutely-crystallized copper on the plate of that metal; in a state of greater or less
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