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Document number: 4620
Dating: refers to 29 September 1842
Author: TALBOT William Henry Fox
Collection: British Library, London, Manuscripts - Fox Talbot Collection
Collection number historic: LA42-076
Last updated: 1st September 2003

The new improvements which I mentioned on 29th September 1842, are the following:

1. Preparing the surface of metal for being gilt or silvered, by first covering dipping it with in a very thin weak coating solution of mercury.

2. do by 1st causg it to give off hydrogen; wch is done by dippg it into water, adding coating a little mixed with a little acid of any kind, & causing a voltaic current to pass thro’ the metal & liquid: and repeating the same at intervals, & NB. That no solution this voltaic current battery is not usual in conjunction charged with any solution of gold or silver, but only contains acidulated water, as above mentioned.

3. Using two solns of silver alternately, viz. having silvered a piece of metal as far as possible by dipping it in a soln of silver, then obtaining a further coating of silver by the use of a difft solution, & afterwards reverting to the first & obtaining a fresh deposit from it. And so on alternately.

The like process in gilding.

4. When a piece of metal has been imperfectly gilt & looks dark dull it may be brightened by dipping it into a vy weak soln of mercury.

5. The old mode of gilding a piece of metal was to rub its surface with an amalgam of gold & mercury & then expel the mercury by heat. My improvement consists in removing the mercury by voltaic electricity; The amalgamated surface is plunged in weak nitric and or other acid, & a voltc current is made to pass so as to dissolve <illegible deletion> the mercury out of ye amalgam. –

NB Nos 4 & 5 relate to gilding only – The other Nos to both silvg & gildg.

Being in Town for some days it wd be no inconvce to me & I wd prefer with your permission to wait upon you personally, to receive your decision if you consider that < ye?> any of yeabove improvements are ye same interfere wth those brght frwd by Dr

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