 He then went to Lyon to work on clinical medicine, surgery and also made a special study of the remains of the aqueducts of ancient Lugdunum (Lyon), also visiting medical schools in Italy and Sicily.In London, he studied at University College Hospital and in 1868 was appointed examiner for Honours Science at Oxford University.The following year he was appointed Professor of Hygiene and Public Health at University College, London, a position he held until his death.