Letter, from William Henry Fitton to Sir John Herschel, dated at Bloomfield Lodge Autograph letter signed by sender, with diagrams. Is grateful for his paper on the solar spectrum. Hopes he will continue his experiments with light so that posterity may benefit, as would have been the case if Smithson Tennant had persisted with his efforts. Regarding some of the geological theories of the times. Hopes John Frederick William Herschel will come and stay with them. R. I. Murchison is on the continent. 10 June 1840