1892.] Mr. J. Wilson Swan on Electro-Metallurgy. 625 



WEEKLY EVENING MEETING, 



Friday, May 20, 1892. 



David Edward Hughes, Esq. F.E.S. Vice-President, in the Chair. 



J. Wilson Swan, Esq. M.A. 



Electro-Metallurgy. 



This is not the first time a lecture has been delivered here on 

 electro-metallurgy. I find that so long ago as January 1841 there 

 was a lecture on the subject by Mr. Brand. 



At that time electro-metallurgy was very new and very small. It 

 consisted solely of electro-plating and electrotype. Electro-plating 

 had already begun to be practised as a regular industry, but it was 

 still a question whether the new kind of plating was good, and there 

 were not a few silversmiths who would not ofier electro-plate for sale 

 because of its supposed inferiority to plate of the old style. That 

 question has long been definitely settled by the fact that every week 

 more than a ton of silver is deposited in the form of electro-plate. 



Electrotype in 1841 was not so far advanced — it had not then 

 been taken hold of by the artisan and manufacturer — it was still in 

 the hands of the amateur. 



While the voltaic battery was the cheapest source of electric 

 current, electro-metallurgy was necessarily restricted to artistic 

 metal work, or to those applications where the fine quality of the 

 electrotype cast outweighed the consideration of its cost, or where 

 only a thin film of metal was required for the protection of a baser 

 metal from the action of the air. 



Within this limited field, the electro deposition of copper, of 

 gold, of silver, of iron, and of nickel, has been carried on commer- 

 cially with very great success and advantage for almost the whole 

 period of the existence of the art. But beyond these bounds, set 

 by the limitation of cost, it could not pass. 



Now, all this is changed — since engineer and electrician have 

 united their efforts to push to the utmost the practical effect of 

 Faraday's great discovery, of the principle of generating electric 

 currents by motive power. The outcome is the modern dynamo, 

 with its result — cheap electricity. The same cause that has led to 

 electric lighting, and to the electric transmission of power, has also 

 led to a very great development of electro-metallurgic industry, and 

 not only in the old directions but in new. It is no longer a matter of 

 depositing ounces or pounds of metal, but of tons and thousands of 

 tons. And it is no longer with metal deposition merely that electro- 

 metallurgy now deals, but also with the extraction of metals from their 



