published a number of collections of his lectures over the years. At his peak, he was the first President of the Royal Medical and Chirurgical Society (in 1833), a fellow of the Royal College of Physicians and the Royal Society, he had one of the largest private practices in London and, at his peak, was one of the pre-eminent physicians in the entire British Empire. Phrenology and Mesmerism He became interested in phrenology, and was founder and first President of the London Phrenological Society (in 1823). His interest in mesmerism had been aroused initially by the demonstrations conducted by Richard Chenevix in 1829, and re-awakened by Dupotet de Sennevoy's demonstrations in 1837. The Okey sisters This prompted Elliotson to begin experimenting with the Okey sisters, Elizabeth (17) and Jane (15), who had been admitted to his hospital, in April 1837, for treatment of their epilepsy. Their surname was often given as O'Key and it was and is widely assumed they were Irish but in fact they came from an old English family (Okey comes from the oak tree). Elliotson soon began using them as subjects – in 1837 he inserted "a large seton needle with a skein of silk into it", entirely painlessly, and without her even being aware that such a penetration had taken place, into the neck of Elizabeth Okey (the older sister) whilst she was mesmerized — within the confines of the hospital, in public demonstrations of the so-called 'higher states' of mesmerism: clairvoyance, transposition of the senses (seeing with the fingers, etc.), thought transmission, physical rapport or "community of sensation", psychical rapport, etc. Convinced that the elder sister, Elizabeth, had a talent for medical clairvoyance (able to see into the body, diagnose illness, prescribe treatment, and deliver a prognosis), Elliotson took her down into the wards in the dead of night and had her both diagnose and prescribe treatments. Thomas Wakley In August 1838, Thomas Wakley conducted a series of experiments on the sisters in front of several witnesses. His tests focussed on whether the girls could tell 'mesmerised' from 'unmesmerised' water. When they failed to do this consistently, he denounced them as frauds and proclaimed mesmerism a complete fallacy. In fact, the experiments did not prove the girls were faking nor did they show that mesmerism was false. By the end of 1838, however, Elliotson was forced to resign from the hospital. The Council of