On September 30, 1846, Morton performed a painless tooth extraction after administering ether to a patient. Upon reading a favourable newspaper account of this event, Boston surgeon Henry Jacob Bigelow arranged for a now-famous demonstration of ether on October 16, 1846 at the operating theatre of the Massachusetts General Hospital, or MGH. At this demonstration John Collins Warren painlessly removed a tumour from the neck of a Mr. Edward Gilbert Abbott. News of this use of ether spread rapidly around the world, and the first recorded use of ether outside the USA was in London, England, by the dentist James Robinson in a tooth extraction at the home of Francis Boote, an American doctor who had heard of Morton's and Bigelow's demonstrations. The MGH theatre came to be known as the Ether Dome and has been preserved as a monument to this historic event. Following the demonstration, Morton tried to hide the identity of the substance Abbott had inhaled, by referring to it as "Letheon", but it soon was found to be ether.