Faraday to Jöns Jacob Berzelius   2 November 1841

Royal Institution | 2 Nov 1841

Dear Sir

Though very unwilling to occupy the time or intrude on the attention of one whose exertions in the cause of science are so invaluable as your own yet I hope you will excuse my present letter both in kindness to myself & for its object to which I will come at once[.] One of our Noblemen the Earl of Ross[e] has been deeply & successfully engaged in casting & grinding specula for large reflecting telescopes and is now about to attempt one upon an enormous scale¹[.] He has been led to think that purity of copper may be of importance to him[.] I believe he intends by experiments to try the value of copper more or less pure but in the mean time is anxious to know the source of the purest in quantities amounting to perhaps a ton or two i.e from 1000 to 3000 or 4000 lbs. I have promised to ask you whether the commercial copper of Sweden is better or no (in your opinion) than English & whether it can be had. I thought I had heard that Russian copper was the best for alloying with silver but cannot recollect my authority. I should be ashamed to think of putting you to trouble but I thought (& hope) that a word from you would be sufficient for I have reason to know the range & accuracy of your knowledge. For myself I am not prepared to say that the small difference in the proportion of other metals in commercial copper would be important but it might & that point it will be better to test by experiment[.] The great object will be to obtain a speculum metal not readily tarnishing in the air[.]

With sincerest respect & the most earnest wishes for your health & happiness I am | My dear Sir | Your Obliged & Grateful Servant | M. Faraday

Baron Berzelius | &c &c &c &c