TALBOT4638

S^t Leonard’s College
Nov^r 2^d 1842

Dear Sir,

I have searched in vain all the Edin^r Libraries for the Royal Institution Journal containing Mr Wedgewoods Paper; ¹ but I have found it reprinted in my own Copy of Nicholson’s Journal ² 8^vo vol. 3 p. 167 with a note of Sir H Davy’s ³ signed D.

If this Paper is identical, as I think it must be with it that in the Institute’s Journal, then it is clear that you, M. Arago & M^r Hunt ⁴ have all made a mistake in ascribing any part of the Paper to Sir H. Davy, or in supposing that he made any experiments whatever upon the subject. Arago directly ascribes to Davy the Exp^ts mentioned in the paper, with the images in the Solar Microscope! All this is most unjust to Davy & also to Wedgewood, if I am right. I have referred to the subject in my Article, ⁵ & shall expect to hear from you on the subject as it is very important in the history of the Matter. If Nicholson has copied correctly, then Davy did no more than mention in the note, signed D, the experiments of Scheele, ⁶ Senebier, ⁷ Ritter ⁸ & Wollaston. ⁹

D^r Adamson ¹⁰ was here today with his little book of Calotype Gems ¹¹ for you, but he still requires to get a good positive of one of me before he can send it. What is the strength of your iodine solution [in] parts of the saturated salt. We use 8 of water to 1 of Saturated solution. Do you dip the paper in the solution, or wash it? and do you dry it in blotting paper, & is this blotting paper always new? Be so good as to answer these Questions. My Son ¹² writes me that he never fails in taking positives, by dipping in the solution.

I am Dear Sir Ever Most Truly y^rs
D Brewster