HISTORY OF ELECTRO-METALLURGY. 5 



Spencer's First Experiments. Mr. THOMAS SPENCER, of Liver- 

 pool, states that, in 1837, while experimenting with a modification 

 of a Daniell's battery, he used a penny piece instead of a plain piece 

 of copper, as a pole. Copper was deposited from the solution upon 

 it, and on removing the wire which attached the penny to the zinc 

 plate he also pulled off a portion of the deposited copper, which he 

 found to be an exact counterpart or mould of a part of the head and 

 letters of the coin as smooth and sharp as the original. But this did 

 not suggest to him any useful application, until some time after he 

 dropped, accidentally, a little varnish upon a slip of copper which he 

 was about to use in the same way as he had used the penny piece. 

 On finding that no deposit of copper took place on the parts where 

 the varnish had dropped, he then conceived the idea of applying this 

 principle to the arts, by coating a piece of copper with varnish or 

 wax, and cutting a design through the wax or varnish, leaving the 

 copper bare, and then depositing upon these parts, so that upon 

 removing the varnish the design would be left in relief. 



Jacobi's Experiments. While Mr. Spencer was following up 

 these ideas, the following paragraph appeared in the Athenaeum for 

 4th May, 1839 : 



" Galvanic Engraving in Relief. While M. Daguerre and Mr. Fox 

 Talbot have been dipping their pencils in the solar spectrum, and 

 astonishing us with their inventions, it appears that Professor JACOBI, 

 at St. Petersburgh, has also made a discovery which promises to be 

 of little less importance to the arts. He has found a method if we 

 understand our informant rightly of converting any line, however 

 fine, engraved on copper, into a relief, by galvanic process. The 

 Emperor of Russia has placed at the Professor's disposal, funds to 

 enable him to perfect his discovery." 



In consequence of this announcement, Mr. Spencer, on the 8th of 

 May, 1839, gave notice to the Liverpool Polytechnic Institution, that 

 he should make a communication to them of his process for effecting 

 results similar to those of Professor Jacobi. But Mr. Spencer ap- 

 pears to have changed his design of reading it to the above Institution, 

 in order to have it read at the meeting of the British Association, 

 which was to take place a short time after. So that the extent of 

 Mr. Spencer's knowledge of electro-metallurgy at this time is not 

 known. 1 



1 As he evidently did not then sufficiently appreciate the real value of his dis- 

 covery, and the knowledge he was in possession of, however, it is to be remembered 

 that, previous to this date, Mr. Spencer had not only shown medals and other 

 objects electrotyped, but had read a paper upon the subject to the Liverpool Poly- 

 technic Society, which, although not printed at the time, is, so far as priority in the 

 discovery of a fact is concerned, as much a publication as if it had been printed in 

 the Times or Athencewn a circumstance which must be borne in mind by the 

 reader, when forming his judgment upon the different claimants for the priority of 

 the discovery. 



