The letter from Huxley has not been found. CD was nominated for the Royal Society of London’s Copley Medal in 1862 and 1863 but his candidature was not successful (Royal Society, Council minutes, vol. 3 (1870), pp. 124, 160). CD was nominated again in 1864 and awarded the medal in November of that year (see Correspondence vol. 12, letter from Edward Sabine, 3 November 1864).