29 Eaton Place <1>
2 Novr 1839
My dear Sir,
You have perhaps seen the last number of the Phil. Mag. in which Mr Towson speaks of Photogenic paper which gives the light and shade in their right places.<4> I was anxious to see these specimens. No. 1 is very good indeed.
I have examined my Camera furnished by Giroux with one of the same size & a rough lens.
The light seemed to me the same in both, but I think the lenses are so contrived that in Daguerre’s Camera the difference of focus for difference of distance is less in amount. The achromatism I [illegible] to be judge.
I have done some in the Camera on paper silvered as yet without decided success; but the weather has been very unfavorable.
Donné persists in engraving from Daguerre’s plates, though Daguerre said it was impossible.<5> Daguerre has done a portrait of himself, said to be excellent.
I saw Cooper at the Polytechnic taking a drawing with the Oxy hydrogen Microscope <6>.
Malaguti has made some very curious experiments upon the absorption of the chemical rays. It seems water impedes their passage less than air!<7>
Yours very faithfully
H. F. Talbot Esq
2. Letter not located.
3. François-Simon-Alphonse Giroux, of Alphonse Giroux et cie, stationers in Paris. Giroux was related to Louis Jacques Mandé Daguerre's wife and in August 1839 secured the exclusive contract to market daguerreotype cameras and outfits manufactured under Daguerre's supervision. With no optical experience, Giroux turned to Charles Chevalier to make the lenses.
4. ie, a direct positive. John Thomas Towson (1804–1881), scientific writer. "On the proper focus for the Daguerreotype," The London and Edinburgh Philosophical Magazine and Journal of Science, v. 15 no. 97, July-December 1839, pp. 381-385.
5. Alfred Donné (1801–1878), microscopist.
6. John Thomas Cooper Jr (1790–1854), chemist. As early as 15 February 1839 he "exhibited numerous figures of Mosses and Ferns produced by the Photogenic process of Mr. Talbot" before the Botanical Society of London; Annals of Natural History, or Magazine of Zoology, Botany and Geology, v. 4 no. 23, November 1839, p. 212. He began advertising pre-made photogenic drawing paper in the Athenæum in March 1839 and by October, as a licensee, began doing daily demonstrations of the Daguerreotype at the Polytechnic Institution on Regent Street in London. The oxy-hydrogen micrcoscope had been in use for a long time - the 'limelight' was an intensely brilliant flame created by passing hydrogen over a piece of lime (calcium oxide or calcium hydroxide).
7. Faustino Giovita Mariano Malaguti (1802–1878), chemist. He was exiled from Italy in 1831 and went to work in the Paris laboratry of Louis Joseph Gay-Lussac. His specialty was to become agricultural chemistry but earlier he was interested in the effect of light on chemicals. On 15 July 1839, he submitted his thesis to the Faculté des Science de Paris: “Premier Mémoire sur la Faculté qu’ont certains Liquides de Retarder le Effets Chimiques de Lumière diffuse.”