Chemist and entomologist. Studied at the Royal College of Chemistry, 1866–8. Assistant to the assayer of the Royal Mint, 1868–71. Worked in the coal-tar dye industry, 1871–3 and 1877–85. Took part in the Royal Society of London’s eclipse expedition to the Nicobar Islands, 1875. Professor of chemistry, Finsbury Technical College, from 1885. Interested in protective colouring and mimicry in moths; secretary of the Entomological Society of London, 1876–80. FRS 1886.