Open House Weekend London: Open House Weekend London: Animals and animal parts used in the Old Operating Theatre of the Old St Thomas's Hospital 1821-1862. This was built for women patients from the adjoining surgical block now occupied by a post office. The only early 19th Century operating theatre remaining, pre-Listerian it witnessed the advent of anaesthesia in 1846 and the foundation of the Florence Nightingale School of Nursing in 1860.