	He retired from practice, and devoted himself for the last thirty-five years of his life to the cultivation of his literary, classical, and scientific tastes. He retained his interest in medicine, however, and wrote to The Lancet in 1846 when he heard from his friend Jacob Bigelow about the use of ether as an anaesthetic in America. The first use of ether as an anaesthetic in Britain (for a dental procedure) was in his house at 24 Gower Street on 19 December 1846. This is commemorated by a plaque on the London School of Hygiene and Tropical Medicine which now stands on the site. A few days later a surgical operation under ether was carried out by Robert Liston at University College Hospital nearby.