A 1948 paper by Kety and Schmidt details the use of this compound to determine cerebral blood flow, 
A 1948 paper by Kety and Schmidt details the use of this compound to determine cerebral blood flow, while Linn and Doran assessed the effect of soil water content on its production in agricultural soils.  Goreau et al. measured its production by bacteria in (*) semi-anoxic conditions, and a 1998 paper detailed why its budget was the least constrained of any of the gases regulated by the Kyoto Protocol.  It has an atmospheric lifetime of 120 years and a global warming potential about 300 times that of carbon dioxide.  Humphrey Davy found that alkaline sulfites can help produce this gas, which he referred to as "dephlogisticated nitrous air," and Thomas Beddoes described the effects of its inhalation.  As additive E942, it is found in "whippits" and is abused by recreational users.  For 10 points, name this compound used by auto racers and formerly by dentists who used it as an analgesic.
A 1948 paper by Kety and Schmidt details the use of this compound to determine cerebral blood flow, while Linn and Doran assessed the effect of soil water content on its production in agricultural soils.  
{nitrous oxide} [or {N}{2}{O}; prompt on {laughing gas}; do not accept “nitric oxide”] (1) [RA]