People have always used laughing gas, or nitrous oxide, recreationally. Whether they're casual whippet users or have access to a steady supply of the medical-grade stuff, people have enjoyed the drug since its discovery over 200 years ago. In fact, there was a time when doctors would have been horrified at the idea of using it in surgery. This wasn't medicine — it was a carnival attraction.
Nitrous oxide was invented by Joseph Priestley in the late 1700s. During that time, and for over a hundred years afterwards, people suffered agonies every time they had to have an operation while doctors found few ways to alleviate the pain. Why didn't they use laughing gas? Because that was for carnival demonstrations and wild nights out. For the first century and a half, laughing gas was for approved for only non-medical use.
Living near an early chemist would have been exciting, if slightly harrowing. At the time, chemistry consisted a great deal of sticking one chemical in another and seeing what happened. Joseph Priestley, in 1772, stuck iron filings in nitric acid. The combination gave off a gas which, being a chemist in the 1700s, he tested on himself. He noticed immediately a painless and giddy feeling. A few decades later, during his apprenticeship, chemist Humphry Davy noticed the same thing while he was testing the gas (on himself, natch) and supervising the construction of a machine that reliably produced large quantities of the stuff.
By 1800, two respected chemists had produced texts about the pain-relieving effects of the gas in a world desperate for safe anesthetics, so who was this machine for? Primarily, it was for demonstrations in fairs and marketplaces, and for widespread upper class "laughing gas" parties. N2O was a hit on the party scene, and in every small town. In the 1830s, Samuel Colt - later the inventor of the Colt 45 - toured the United States and Canada with phony medical credentials. He would stop in town squares and give people hits of nitrous oxide. He charged a quarter for adults and a dime for children. The people paid, and the crowd laughed at how they went loopy afterwards.
Which might be why those who advocated its medical use were so thoroughly laughed at. In 1844, a dentist named Horace Wells noticed someone who had been gassed stumble into a bench and badly hurt his leg without feeling even a twinge of pain. Dental procedures at the time were excruciating, and Wells saw a way of relieving the pain of dentistry. Wells began performing surgery with nitrous oxide almost at once, and after having great success he managed to get a chance to perform it in front of people at Harvard Medical School. This was not a particularly friendly crowd. Imagine, today, if a dentist decided to extract a tooth after a patient had had eight beers, or smoked a joint, or was hypnotized by a guy who generally did hypnosis on stage. The procedure worked in that the tooth came out and the patient felt a lot less pain than usual. However, the patient did feel some pain, and that was enough for the watching physicians. Wells was booed off the stage and his business was ruined. A few years later, he committed suicide.