I am favoured with your letter of the 15th, but as I do not exactly understand what use you wish to make of my invention in your profession of Engraver, I will be obliged to you to mention it, and also to make your own proposition for the terms of a License which I will accede to, if I am able to do so.
You speak of your intention of trying to improve the collodion <1> & other photographic processes, I am of opinion that you will find them in their present state sufficiently perfect for your purpose.
I remain Yours very truly
W. Walker Esq.
1. The wet collodion on glass negative process was given freely to the public in 1851 by Frederick Scott Archer (1813-1857), a sculptor and photographer. He disclosed the operational details in an 18 February 1851 letter published in The Chemist, n.s. v. 2 no. 19, March 1851, pp. 257-258.