<Tr> <Td> </Td> <Td> </Td> </Tr> <P> Nitrous oxide, commonly known as laughing gas or nitrous, is a chemical compound, an oxide of nitrogen with the formula N O. At room temperature, it is a colorless non-flammable gas, with a slight metallic scent and taste . At elevated temperatures, nitrous oxide is a powerful oxidizer similar to molecular oxygen . </P> <P> Nitrous oxide has significant medical uses, especially in surgery and dentistry, for its anaesthetic and pain reducing effects . Its name "laughing gas", coined by Humphry Davy, is due to the euphoric effects upon inhaling it, a property that has led to its recreational use as a dissociative anaesthetic . It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system . It also is used as an oxidizer in rocket propellants, and in motor racing to increase the power output of engines . </P> <P> Nitrous oxide occurs in small amounts in the atmosphere, but recently has been found to be a major scavenger of stratospheric ozone, with an impact comparable to that of CFCs . It is estimated that 30% of the N O in the atmosphere is the result of human activity, chiefly agriculture . </P>

What is the use of nitrous oxide in surgery