27 March 1839 <1>
My dear Sir,
I see in your Letter to Biot <2> you say that the Chloride of Silver is washed out. I do not think that the hyposulphite of Soda &c dissolves the chloride, or washes it out
I suspect that hyposulphite is added to chloride in water, it forms a soluble precipitate, of hyposulphite of Silver? (query) which is not acted upon light. At all counts it seems to me that if this mixture is put on paper & left to dry it does not discolour by light & it seems to me that if nitrate of silver is added a fresh precipitate of Chloride is formed.
May not Daguerre’s & Niepce’s <3> be done first on paper & then transferred from the paper on a metal plate
Yours very truly,
J W Lubbock
27 March 1839
Notes:
1. In WHFT’s hand.
2. This letter, Doc. No: 03827, was printed as ‘M. Biot communique l’extrait suivant d’une lettre que M. Talbot vient de lui adresser’ Comptes Rendus hebdomadaires des Séances de l’Académie des Sciences v. 8 no. 9, 1839, p. 341.
3. Substantial details of the process used by Louis Jacques Mandé Daguerre (1787–1851), French artist, showman & inventor and his former partner Joseph Nicéphore Niépce (1765–1833) were unknown at this time. The working process of the daguerreotype was not divulged until August 1839.