Faraday to James Tennant   16 October 1862

[Royal Institution embossed letterhead] | 16 Octr. 1862

My dear Sir

What is Smithsonite? a pale blue encrusting substance from Cumberland¹. Is it a silicate of copper? I cannot find it in the books. I suppose it is a new mineral. I only want to know in a very general way the nature of its constituents.

Ever Yours | M. Faraday

- Tennant Esq | &c &c &c.