Simpson studied at the University of Edinburgh from 1825 until 1832, becoming a licentiate of the Royal College of Surgeons of Edinburgh in 1830. In 1836 he gained a position at the City Lying-in Hospital in Edinburgh and he began practicing midwifery. By 1839 Simpson held the chair of midwifery at the University of Edinburgh and his practice grew rapidly, catering for both obstetrics and general medicine. Simpson experimented with chloroform, first on himself along with two assistants, before starting to utilise it on his patients. He was criticised for his use of anaesthetics in cases of normal, uncomplicated labour, with contemporaries from both within and outside of the clergy arguing that the pain was healthy or divinely sanctioned. Nonetheless, the use of anaesthesia, particularly chloroform, became standardised obstetric practice and Simpson gained international fame.