Horticultural Society <1>
21, Regent Street. May 21 1853
My Dear Sir
I will see what can be done to replace your Tacsonia.
If you intend to apply yr discovery <2> to purposes of publication I dare say grains wd be as good subjects as you cd choose. But until surface, as well as outline can be rendered by the process I fear that any sun etching <3> will have very little scientific value: <4> for I do not see how you can shew any thing beyond form and ramification
Envelope:W. H. Fox Talbot Esq
1. Horticultural Society of London.
2. Photographic engraving, a process that Talbot had patented the previous year: WHFT, Improvements in Photographic Engraving, November 1852.
3. Talbot’s process involved two parts. In part 1, a steel plate is coated with a combination of gelatine and potassium bichromate, which hardens according to the degree to which it is exposed to light. A photographic exposure is made on to this coated plate. The mixture that has not reacted to light is then washed off, leaving a coating of hardened gelatine on the plate. In the second part, a suitable etchant is poured on to the plate, biting into the steel wherever this is not still coated with the gelatine. See Doc. No: 07253.