"The point requiring most skill and care in the administration of the vapour of ether is, undoubtedly, to determine when it has been carried far enough." --John Snow, On the Inhalation of the Vapour of Ether in Surgical Operations, 1847 English physician John Snow was one of the first physicians to study the use of ether and chloroform as surgical anesthetics. This enabled patients to undergo surgical procedures without the pain they would...