Faraday to William Francis Cowper   4 August 1860

[Royal Institution embossed letterhead] | 4 August 1860

Private

Dear Sir

When I was first called in to form some kind of judgment respecting the preservation of the stone work, I was to be guided by the appearance and state of the prepared specimens, and these alone. When I met M. Szerelmey at the Houses of Parliament¹, the engagement with him was already made; as Sir Chas. Barry, who was then present, told me:- but he was permitted to retain his secret. I tasted the liquid in one of his buckets, and have no doubt it was an alkaline silicate:- but I did not take any of it, nor ask him for it, as he would have then kept me to secrecy, and I did not chose to be in that position. I should not have thought it honest to take any of his preparation without his knowledge. I think you ought to have some security that he is dealing honorably & fairly with you;- but the permission was given long ago that he might retain his secret,- and unless he freely yields up the knowledge I do not know what you can do; except to decline upon principle dealing with a person who has a secret, and over whom, consequently, you can have no hold[.]

I hope you understand that, in my opinion, a process, whether secret or open, whether guided by most promising principles or altogether by rule of thumb, can only be judged of by the proof of times action[.]

I have the honor to be | Dear Sir | Your Very faithful Servant | M. Faraday

The Right Honorable | William Cowper M.P. | &c &c &c &c