Lecture on electro-metallurgy : delivered before the Bank of England Library and Literary Association, November 25th, 1851 / by Alfred Smee.

  • Alfred Smee
Date:
1851
Catalogue details

Licence: Public Domain Mark

Credit: Lecture on electro-metallurgy : delivered before the Bank of England Library and Literary Association, November 25th, 1851 / by Alfred Smee. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    n lb it others, by covering them with a fine layer of wax and phosphorus, which, as I have already told you, deposits metals from their solution, and pro- duces a metallic coating, which renders it a conductor for the metallic deposit to travel over. Electro Silver Plating.—In no department of electro-metallurgy does the benefit conferred by electricity more strikingly shine forth, than in the results which have been obtained by silver-plating. By it we obtain a surface of silver, which, to appearance, renders the object as valuable as though it were made entirely of silver. Formerly the plated articles used to be made of copper, with a thin layer of silver, and when struck the most prominent part being the most extended, had the least portion of silver to resist the greatest friction. At the present time a white metal is used, and Mr. Elkington has furnished me with a waiter silvered on one half its surface, whilst the other is in its natural state. Though you can now see a notable difference between the two halves, it is manifest, that if a portion of silver should, in process of time, wear off, nevertheless, it will not be an eye-sore, like the difference of colour which is afforded by the protrusion of copper. There is no difficulty in plating. The object to be coated is simply to be placed in the silver decomposition apparatus, which I before described, and you have only to be careful to deposit enough metal. In buying plated articles it is necessary to select a respectable vendor, for, as a thin layer of silver looks as good as a thick layer, you must trust to the character of the manufacturer as to the quality of your purchase. I need hardly call your attention to the manifest advantages which result from the power of replating articles, nor to the comparatively speaking economical manner in which articles of elaborate design may be manufactured, a fact which is wrell illustrated by the candelabra upon the table. The effects produced by the oxidized silver, and by partially plated articles, immediately show the value of these processes to the observer. Electro-Gilding.—The gilding of metallic surfaces is almost exclu- sively conducted by the electro process. Formerly a very pernicious mode of proceeding w'as adopted for gilding, as a large quantity of mer- cury was employed, which made great havoc with the health of the work- people employed in this trade. At this late hour it would be almost im- possible to recount the extensive application of electro-gilding; suffice it to say, that no other process is now required for coating metallic surfaces with this precious metal. The operation is conducted in the manner which you have already seen, when the reduction of gold was under consideration. The effect of partial gilding and plating as a means of increasing artistic power, is beautifully demonstrated in some of the specimens which Mr. Elkington has sent. I have now, gentlemen, taken a rapid sketch of the leading principles
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