Feby 26 – 1841
I am informed, by the kindness of Sir J. Herschel, <1> that you have much improved the sensibility of your Photographic processes. <2> As I am about to publish a Popular Treatise on the Art, <3> to form a Vol of Griffin’s Scientific Miscellany – you will possibly oblige me by stating the extent to which the sensitiveness has been increased by you –
I do not of course ask for any premature disclosure of your processes – At the same time any information you may be inclined to allow me to communicate, as the result of the experience of the Author of Photographic processes on paper, will be highly valued and most honorably acknowledged. –
I have within a few days received a communication from Daguerre <4> – in which he informs me his instantaneous process, is certain in his own hands – but not yet rendered sufficiently easy to make publication advisable – I may be allowed to add that I have obtained some very curious effects of colour on papers prepared with the Chromate of Silver, hitherto considered insensible to luminous influence
I am Sir with the greatest respect Your Obedient Servt
Royal Cornwall Polytechnic
1. Sir John Frederick William Herschel (1792–1871), astronomer & scientist.
2. This was WHFT's calotype process, which used a developer to bring out a latent image, much reducing exposure times in the camera. Its manipulatory details had not yet been made public.
3. Robert Hunt, Popular Treatise on the Art of Photography, including Daguerréotype, and All the New Methods of Producing Pictures by the Agency of Light (Glasgow: Richard Griffin and Co, 1841).
4. Louis Jacques Mandé Daguerre (1787–1851), French artist, showman & inventor.