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Nitrous Oxide

Nitrous oxide

Nitrous oxide was first identified by Joseph Priestley in 1772. Years later in the late 1790s, British chemist Humphry Davy (1778-1829) began experimenting with the effects of inhaling nitrous oxide. He noted its exhilarating effects, especially the way it made him want to laugh. This fact helped give the gas its popular nickname, "laughing gas." Davy published his findings in 1800, remarking that "As nitrous oxide appears capable of destroying pain, it may probably be used with advantage during surgical operations."

Nitrous Oxide and Dentistry

Little attention was paid to Davy's observations or to those of Henry Hill Hickman (1800-1830). Hickman was a general practitioner from Shropshire, England, who in 1824 explored methods of painless surgery on animals using both carbon dioxide and nitrous oxide gas. Davy repeatedly demonstrated the gas's exhilarating effects to gatherings of his friends, and inhalation parties became quite popular. Use spread to the United States as traveling lecturers spread knowledge about the new chemistry to the general public. These lectures usually including a demonstration of the effects of nitrous oxide inhalation on audience volunteers.

A New Anesthetic

One of these public lectures was given in Hartford, Connecticut, in 1844 by Gardner Quincy Colton (1814-1898). It was attended by local dentist Dr. Horace Wells (1815-1848). Wells observed that a volunteer, Samuel Cooley, obviously hurt himself while under the influence of nitrous oxide but didn't notice the pain. Wells immediately thought of using the gas to banish pain during tooth extraction. The next day he took some of Colton's gas while a fellow dentist removed one of Wells's teeth. As he had expected, Wells felt no pain.

After confirming the anesthetic effect of nitrous oxide on other patients, Wells arranged through his former dental partner, William T. G. Morton (1819-1868), to demonstrate his discovery to a group of Morton's Harvard Medical School classmates in January 1845. Unfortunately, the nitrous oxide was applied incorrectly, and the patient yelped with pain when his tooth was pulled, embarrassing Wells before the group.

After Morton used ether successfully as an anesthetic in 1846, Wells pressed his claims for primacy as the discoverer of anesthesia. Frustrated in these attempts, Wells began to abuse chloroform (a clear, colorless, heavy liquid used in refrigerants, propellants, resins, and as an anesthetic). He committed suicide in 1848 being arrested for throwing acid at two women in New York City.

A Practical Anesthesia

Nitrous oxide was finally made a practical anesthetic by Colton in 1863. Edmund Andrews (1824-1904), a Chicago surgeon, began to use nitrous oxide in combination with oxygen in 1868. As this method gained popularity, nitrous oxide became a staple in surgical as well as dental practice.

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nitrous oxide

nitrous oxide (N2O), commonly called ‘laughing gas’, was discovered in 1776 by Priestley. He inhaled the gas and noted that it caused confusion and analgesia. Later, in 1799, Humphry Davy suggested its use in surgical operations. However for the next forty-five years nitrous oxide was used only for entertainment, in which respectable persons were shown to lose their usual demeanour, breaking into laughter, often accompanied by singing and dancing or aggressive behaviour. Unwary persons were encouraged to volunteer for these exhibitions, particularly at fairgrounds. In 1844, Horace Wells, an American dentist, used the gas for tooth extraction, and two years later an American surgeon, William Morton, carried out major surgery under its influence. Nitrous oxide is not a very potent anaesthetic; it was sometimes used at 100% for rapid induction of anaesthesia, with subsequent addition of oxygen to avoid hypoxia.

Nitrous oxide continues to be widely used along with oxygen as a ‘carrier gas’ accompanying other inhalational anaesthetic agents. Its main advantage is that it has an analgesic (pain-relieving) effect, so that less of the main anaesthetic drug needs to be given. As ‘entonox’ it is also used, mixed with air, as an analgesic during labour. The common earlier use for dental extractions has diminished, with new regulations restricting the use of general anaesthesia for this purpose to special centres.

Alan W. Cuthbert


See also anaesthesia, general; analgesia; dentistry; labour.

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"nitrous oxide." The Oxford Companion to the Body. . Encyclopedia.com. 21 Aug. 2017 <http://www.encyclopedia.com>.

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nitrous oxide

nitrous oxide or nitrogen (I) oxide, chemical compound, N2O, a colorless gas with a sweetish taste and odor. Its density is 1.977 grams per liter at STP. It is soluble in water, alcohol, ether, and other solvents. Although it does not burn, it supports combustion since it decomposes into oxygen and nitrogen when heated. The gas is prepared commercially by the thermal decomposition of ammonium nitrate, NH4NO3, at about 240°C to produce nitrous oxide and water; the reaction must be carefully controlled to prevent explosive decomposition of the nitrous oxide. The gas is purified, liquified by compressing and cooling it, and stored in metal cylinders. A major use of nitrous oxide is in anesthesia, e.g., in dentistry. It is commonly called laughing gas since it produces euphoria and mirth when inhaled in small amounts. It is also used in making certain canned pressurized foods, e.g., instant whipped cream. Nitrous oxide was discovered (1772) by Joseph Priestley, who called it "diminished nitrous air" ; he prepared it from "nitrous air" (nitric oxide, NO) by treatment with iron powder or a mixture of iron and sulfur powders. Its properties were further studied (1799) by Sir Humphry Davy.

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nitrous oxide

nitrous oxide (ny-trŭs) n. a colourless gas used as an anaesthetic with good analgesic properties, administered by inhalation during surgery in combination with oxygen and other agents for the maintenance of anaesthesia. A mixture of nitrous oxide and oxygen (Entonox, Equanox) is administered for some dental procedures and in childbirth. Because it tends to excite the patient when used alone, nitrous oxide was formerly known popularly as laughing gas. Formula: N2O.

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"nitrous oxide." A Dictionary of Nursing. . Encyclopedia.com. 21 Aug. 2017 <http://www.encyclopedia.com>.

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nitrous oxide

nitrous oxide (dinitrogen oxide) Colourless gas (N2O) that is used as an anaesthetic or analgesic during surgical or dental operations. It is known as ‘laughing gas’ since it produces exhilaration. It is also used in making pressurized foods. It is also used in making pressurized foods. It was first prepared in 1772 by English chemist Joseph Priestley.

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"nitrous oxide." World Encyclopedia. . Encyclopedia.com. 21 Aug. 2017 <http://www.encyclopedia.com>.

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nitrous oxide

ni·trous ox·ide • n. Chem. a colorless gas, N2O, with a sweetish odor, prepared by heating ammonium nitrate. It produces exhilaration or anesthesia when inhaled and is used as an anesthetic and as an aerosol propellant. Also called laughing gas.

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"nitrous oxide." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 21 Aug. 2017 <http://www.encyclopedia.com>.

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"nitrous oxide." The Oxford Pocket Dictionary of Current English. . Retrieved August 21, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/nitrous-oxide

nitrous oxide

nitrous oxide A gas used as a propellant in pressurized containers, e.g. to eject cream or salad dressing from containers.

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"nitrous oxide." A Dictionary of Food and Nutrition. . Retrieved August 21, 2017 from Encyclopedia.com: http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/nitrous-oxide