Faraday to Samuel Parkes   22 June 1824

Royal Institution | June. 22. 1824

Dear Sir

The process I should propose for analysis would be the following but I have no doubt that during the progress of such an analysis incidental circumstances would make me introduce variations which might perhaps be essentially requisite for corroboration or correction[.]

Suppose the alloy to contain Copper, Zinc Tin Lead & Iron[.] Dissolve in Nitric acid and evaporate to dryness - then dissolve in water which will take up Copper Zinc Lead and a part of the Iron and leave Tin & a part of the Iron boil this residue in solution of potash the tin will be dissolved and leave the Iron of course as oxide precipitate the oxide of tin form the alkali by Nitric acid wash dry & weigh it: dissolve the oxide of iron in Muriatic acid throw down by ammonia wash dry & weigh.

To the solution containing copper zinc lead and iron add sulphate of soda to throw down sulphate of lead collect it &c &c. Then add potash in excess which will throw down the iron & Copper & dissolve the zinc saturate the separated solution carefully with acid & collect the oxide of zinc which after being washed dried weighed &c &c must be dissolved in acid and tested to prove that it retains none of the lead[.] The mixed precipitate of Copper & Iron must be dissolved in Muriatic acid & precipitated by ammonia which will give the iron as per oxide which when estimated is to be added to the former portion[.] The solution now only contains copper; add caustic potash in excess & boil; The ammonia will be dissipated & the oxide of copper be thrown down.

The oxide of Zinc when obtained should be also tested for Tin at that metal is rendered soluble in nitric acid to a certain extent (when per oxidized) by other metals[.]

All the results obtained require examination to be sure that they are pure and the analyses should be repeated that the results may be verified[.]

I am dear Sir | Yours in great haste | M. Faraday

S. Parkes Esq | &c &c