1799 - Laughing Gas

English chemist Humphry Davy produced laughing gas (nitrous oxide), found it “absolutely intoxicating” when inhaled and suggested its use as an anaesthetic in minor surgery.

Davy inhaled sixteen (16) quarts of the laughing gas and found that it made him immune to pain.

Nitrous oxide was first synthesized by English natural philosopher and chemist Joseph Priestley in 1772, who called it phlogisticated nitrous air.  Priestley published his discovery in the book Experiments and Observations on Different Kinds of Air (1775), where he described how to produce the preparation of "nitrous air diminished", by heating iron filings dampened with nitric acid. 

The first important use of nitrous oxide was made possible by Thomas Beddoes and James Watt, who worked together to publish the book Considerations on the Medical Use and on the Production of Factitious Airs (1794). This book was important for two reasons. First, James Watt had invented a novel machine to produce "Factitious Airs" (i.e. nitrous oxide) and a novel "breathing apparatus" to inhale the gas. Second, the book also presented the new medical theories by Thomas Beddoes, that tuberculosis and other lung diseases could be treated by inhalation of "Factitious Airs".

The machine to produce "Factitious Airs" had three parts: A furnace to burn the needed material, a vessel with water where the produced gas passed through in a spiral pipe (for impurities to be "washed off"), and finally the gas cylinder with a gasometer where the gas produced, 'air,' could be tapped into portable air bags (made of airtight oily silk). The breathing apparatus consisted of one of the portable air bags connected with a tube to a mouthpiece. With this new equipment being engineered and produced by 1794, the way was paved for clinical trials, which began when Thomas Beddoes in 1798 established the "Pneumatic Institution for Relieving Diseases by Medical Airs" in Hotwells (Bristol). In the basement of the building, a large-scale machine was producing the gases under the supervision of a young Humphry Davy, who was encouraged to experiment with new gases for patients to inhale. The first important work of Davy was examination of the nitrous oxide, and the publication of his results in the book: Researches, Chemical and Philosophical (1800). In that publication, Davy notes the analgesic effect of nitrous oxide and its potential to be used for surgical operations. 

Despite Davy's discovery that inhalation of nitrous oxide could relieve a conscious person from pain, another 44 years elapsed before doctors attempted to use it for anesthesia. The use of nitrous oxide as a recreational drug at "laughing gas parties", primarily arranged for the British upper class, became an immediate success beginning in 1799. While the effects of the gas generally make the user appear stuporous, dreamy and sedated, some people also "get the giggles" in a state of euphoria, and frequently, erupt in laughter.