“…Non-rebreathing also occurs in an rebreathing valves has been fully reported in the U.S.A. by Leigh and Kester (1948), Slater andStephen (1951, 1952), Adriani and Griggs (1953), Griggs, Adriani and Benson (1953), Smith (1953) and others. Its value in paediatric anaesthesia is established in the United States, owing to the small respiratory volumes in infants, and requires no further comment.…”