R Institution | Decr. 28th
My dear Sir
I do not know any good of even commonly good process of the kind you want. Chlorine ie bleaching liquid has been used but it either does not remove the stain of the stain returns after a while[.]
Your query is not a new one to me[.] Chantr[e]y2 has often asked me the same question & a dealer in statuary marble tried to tempt me once by saying a perfect method would be worth four or five thousand pounds.
Ever Dear Sir | Yours Very Truly | M. Faraday
Endorsed: Professor Faraday. | 1828.
Please cite as “Faraday0383a,” in Ɛpsilon: The Michael Faraday Collection accessed on 27 April 2024, https://epsilon.ac.uk/view/faraday/letters/Faraday0383a