Nitrous oxide
Nitrous oxide, (N2O), laughing gas is used in surgery and dentistry for its anesthetic (pain-numbing) and analgesic (pain-relieving) properties. The gas gets its common name from the dreamy effect it creates and the giddy laughter it evokes, on inhalation.
A colourless, non-toxic and non-flammable gas at room temperature, nitrous oxide smells slightly sweet. It is emitted by bacteria, making it a natural part of the Earth’s atmosphere. Nitrogen fertilisers and animal waste cause bacteria to produce more nitrous oxide than usual. In terms of the concentration in the atmosphere, nitrous oxide comes fourth after water vapour, carbon dioxide and methane. It is a greenhouse gas, which means that it traps heat in the atmosphere, making the Earth warmer.
The gas was first synthesised by Joseph Priestly in 1772. However, the first medical experiments using the gas were conducted in 1794 by Thomas Beddoes and James Watt. Watt invented a device to produce the gas and another to inhale it while Beddoes suggested that inhaling the gas could help treat tuberculosis and other lung diseases. Humphry Davy was put in charge of monitoring experiments using the gas. It was Davy who first noted the gas' analgesic effects and published his findings in 1800. However, the world paid no heed. The gas was just popularly used to host 'laughing gas parties'. It was only in 1884, more than 40 years later, that Davy's findings were finally put to use and nitrous oxide was used as an anaesthetic.
