Nitrous oxide has been used for anaesthesia in dentistry since December 1844, where Horace Wells made the first 12–15 dental operations with the gas in Hartford. Its debut as a generally accepted method, however, came in 1863, when Gardner Quincy Colton introduced it more broadly at all the Colton Dental Association clinics, that he founded in New Haven and New York City. Hospitals administer nitrous oxide as one of the anaesthetic drugs delivered by anaesthetic machines. Nitrous oxide is a weak general anaesthetic, and so is generally not used alone in general anaesthesia. In general anaesthesia it is used as a carrier gas with oxygen for more powerful general anaesthetic drugs.Medium size empty blue coloured cylinder with rounded base and painted white neck once containing Nitrous Oxide. A large blue on white diamond shaped label is adhered onto the main cylinder body.Printed on manufacturer's label: 'CIG [logo] / [blank weights table] / DRY / NITROUS OXIDE / C.I.G. (Victoria) PTY. LTD. / 50 LA TROBE STREET, MELBOURNE C3 / Telephones: FJ 6681 / FJ 4164 / USE NO OIL / OR GREASE'nitrous oxide, dental anaesthesia, dental anesthesia, gardner quincy colton, colton dental association

This object dates back to 1925 and was sectioned by Dr Geoffrey Kaye in 1938. Flowmeters were attached to an anaesthetic machine to measure the flow rate of gas or liquid.Metal cylinder with glass inner chamber and gauge inside. The object has been sectioned for teaching purposes.Inscription on top screw valve. "K/38, Screw Lightly, Oxygen Fine." Inscription on back of top screw valve. "Direct Ox." Inscription on top of flowmeter tube. "G. Kaye fecit. 1938"flowmeter, water depression, gas, sectioned, slight feed, anaesthetic machine

Early cylinders were coloured as their maker saw fit, usually black, perhaps with a white top for oxygen. The Americans first achieved standardisation, but other countries do not follow American Standards. Australia follows the colour-scheme of the British Oxygen Corporation. The body is coloured individually for each gas, viz: compressed air, grey; carbon dioxide, brown; oxygen, black; nitrous oxygen, blue’ cyclopropane, primrose-yellow’ ethylene, mauve. Panels of other colours may appear on the body, but indicate technical points of cylinder-design and do not concern the anaesthetist. (Penn catalogue entry)Empty small pale green painted cylinder with rounded base and attached outflow valve with circular 'On-Off' knob.Handwritten in red paint across the main body of the cylinder: ST. VINCENTS 32510 Printed on manufacturer's label: 'KEEP CYLINDER COOL / CIG [logo] / MADE IN AUSTRALIA / MEDICAL AIR COMPRESSED / DO NOT ALLOW OIL OR GREASE ON VALVE / OPEN VALVE SLOWLY CLOSE AFTER USEcompressed air, cylinder, colour standardisation