TALBOT6966

Sir J Herschel

Athenæum ¹
May 20/54

D^r Sir

Many thanks for your letter. I am very sorry to cause you so much trouble, more especially as your time is so fully and usefully occupied.

An affidavit in the Court of Chancery is a thing finished and done with, it leads to no further trouble – As there is no jury and no vivâ voce evidence, there is of course no cross examination – The affidavit speaks for itself and either produces an effect on the mind of the Vice Chancellor or none, as the case may be.

An affidavit is an expression of personal belief only. To put a parallel case: I could testify, if the occasion for it should arise, that I believe you to have been the discoverer of hyposulphuric acid, and of the solvent power of that acid, of the salts of silver – My testimony would not be to the fact, but to my belief of the fact. The fact itself might be quite otherwise, and yet [illegible deletion] the truth of my affidavit would be unshaken.

Of course we have proof, supporting the necessary affidavits, that the defendant in the present cause ² infringes my patent by selling portraits which are primâ facie the same as those produced by my patent process.

His defence is that he use a different process, viz. the Collodion process.

The reply is that the collodion process borrows from the Calotype process the essential part of the latter, viz. the development of a latent image by gallic acid. What we wished you if possible to testify was that (in your opinion) such development of a latent image
1. Was a leading feature of the Calotype process
2. Was new
3. Was of great importance to photography.

But since you feel scrupulous about making these assertions we will endeavour to dispense with the necessity of troubling you and I will not apply again unless my solicitor assures me that he feels himself in need of support from high scientific authority. We have Sir D. Brewster’s affidavit ³ to the above effect, though in other words.

Believe me yours ever truly
H. F. Talbot

I am glad you like my little attempt at etching the Pantheon. ⁴