SIMON, SIR JOHN (1816–1904), English surgeon and sanitary reformer, was born in London on the 10th of October 1816. His father, Louis Michael Simon,was for many years a leading member of the London Stock Exchange. Both his grandfathers were French emigrants, who carried on business in London and Bath respectively. His father died at almost ninety-eight, and his mother at nearly ninety-five years of age. Simon was educated at a preparatory school in Pentonville, spent seven years at Dr Burney's school in Greenwich, and then ten months with a German Pfarrer in Rhenish Prussia. His father intended him for surgery, and he began the study of medicine on 1st October 1833, when he was a few days short of seventeen. He was an apprentice of Joseph Henry Green, the distinguished surgeon at St Thomas's, well known for his friendship for Samuel Taylor Coleridge, whose literary executor Green became. He became a demonstrator of anatomy, and was assistant surgeon to King's College Hospital for several years; and in the autumn of 1847 he was appointed surgeon and lecturer on pathology at his old school, St Thomas's, where, with progressive changes, he continued to remain an officer. His life was divided between two great pursuits—the career of a surgeon, and the mastery and solution of many of the great problems of sanitary science and reform. In the spring of 1844 he gained the first Astley Cooper prize by a physiological essay on the thymus gland, and the following year was elected a fellow of the Royal Society. In 1847 he gave his first lecture at St Thomas's Hospital, on the " Aims and Philosophic Method of Pathological Research," followed a little later by lectures on general pathology in relation to the principles of diagnosis, and the treatment of disease. These lectures were of great importance at the time, and of the utmost value in directing energy into new and profitable channels of work. Simon published many clinical surgical lectures of the greatest importance, and contributed a masterly article on " Inflammation " to Holmes's System of Surgery, which has become a classic of its kind. It was, however, on his appointment in 1848 as medical officer of health to the City of London, and afterwards to the government, that Simon's great abilities found scope for congenial exercise. He stimulated and guided the development of sanitary science, until it reached in England the highest degree of excellence, and gave an example to the civilized world. It is impossible to overestimate the value of Sir John Simon's work, or the importance of his influence in the furtherance of the public health and the prevention of disease, and in inculcating right methods of medical government. In 1878, after filling other offices in the Royal College of Surgeons, he became its president, and in 1887 was created K.C.B. It was largely due to his advocacy that the new St Thomas's Hospital was rebuilt on its present site after it was compelled to leave its old habitation near London Bridge. As a surgeon, Simon's work came second to his interest in sanitary science, but he claimed priority over Cock in the operation of perineal puncture of the urethra in cases of retention from stricture. He died on the 23rd of July 1904. (W. MacC.)