Autograph letter signed from Archibald Primrose, 5th Earl of Rosebery to Leonard Lyell, 1st Baron Lyell, and his wife Mary, from 38 Berkeley Square, [London], 8 & 18 May 1899: “Dear Lyell. I really cannot thank you enough. You could not have pleased me more than by giving me this book (of the very existence of which I was ignorant) about one whose memory I so truly revere [...]” (18 May 1899, to L. Lyell, who had sent him the Memoir of Leonard Horner). – In a secretarial hand: “I am much obliged for your letter, and am greatly interested to learn that there is a niece of Francis Horner still living. It was a great pleasure to recall your uncle’s memory at the City Liberal Club [...]” (8 May 1899, to Mary Lyell, signed “Rosebery”. Includes a handwritten copy of her letter to the Earl of Rosebery, 6 May 1899).