On March 30, 1842, American surgeon and pharmacist Crawford Williamson Long for the very first time used inhaled diethyl ether as an anesthetic for surgery. Can you imagine a surgery without anesthetic? Standing the pain while a surgeon is cutting something somewhere in your body? I think better not to. But, anesthetics already have a long tradition, longer than you might think.
Already since antiquity, a variety of Solanum species containing potent tropane alkaloids were used for anesthesia throughout Europe, Asia, and the Americas. In 13th century Italy, Theodoric Borgognoni from the Salerno school of medicine used similar mixtures along with opiates to induce unconsciousness in the form of a “soporific sponge” (“sleep sponge”). In this anesthetic method, a sponge was soaked in a dissolved solution of opium, mandragora, hemlock juice, and other substances. The sponge was then dried and stored; just before surgery the sponge was moistened and then held under the patient’s nose. When all went well, the fumes rendered the patient unconscious. In 1275, Spanish physician Raymond Lullus, while experimenting with chemicals, made a volatile, flammable liquid he called sweet vitriol. Sweet vitriol, or sweet oil of vitriol, was the first inhalational anesthetic used for surgical anesthesia. It is no longer used often because of its flammability.
in 1772, English scientist Joseph Priestley discovered the gas nitrous oxide. Initially, people thought this gas to be lethal, even in small doses.  However, in 1799, British chemist and inventor Humphry Davy decided to find out by experimenting on himself. To his astonishment he found that nitrous oxide made him laugh, so he nicknamed it laughing gas. This is about the time, when Crawford Long came into play. Born in Danielsville, Madison County, Georgia on November 1, 1815, Long received his M.D. at the University of Pennsylvania in 1839. He noticed that his friends felt no pain when they injured themselves while staggering around under the influence of ether. Observing the same physiological effects with diethyl ether (“ether”) that Humphry Davy had originally described for nitrous oxide in 1800, he immediately thought of its potential in surgery. Conveniently, a participant in one of those “ether frolics”, a student named James Venable, had two small tumors he wanted excised. But fearing the pain of surgery, Venable kept putting the operation off. Hence, Long suggested that he have his operation while under the influence of ether. Long – who was by chance also a cousin of the western legend Doc Holliday – used ether for the first time on March 30, 1842 to remove the first tumor from the neck of James M. Venable, in Jefferson, Georgia. Subsequently, he removed a second tumor and furthermore used his ether as an anesthetic in amputations and childbirth. The results of these trials were published in 1849 in The Southern Medical and Surgical Journal.
But already on October 16, 1846, unaware of Long’s prior work with ether during surgery, William T. G. Morton administered ether anesthesia before a medical audience at the Massachusetts General Hospital in Boston, Massachusetts. Although Long had informed several surgical colleagues who had similarly administered ether in their practices, Morton is generally credited with the first public demonstration of ether anesthesia.
At yovisto academic video search, you can watch a TED talk given by Dr. Stuart Hameroff, a clinical anesthesiologist, who has studied how anesthetic gas molecules selectively erase consciousness via delicate quantum effects on protein dynamics. In his talk “Do we have a quantum Soul?“, Hameroff explored the theoretical implications for consciousness to exist independent of the body.
References and Further Reading
-  Boland, FK (2009). The first anesthetic: the story of Crawford Long. Athens, Georgia: University of Georgia Press
-  Crawford Long at answers.com
-  Joseph Priestley and the Discovery of Oxygen, SciHi Blog, February 6, 2015.
-  Humphry Davy and the Electrolysis, SciHi Bog, November 19, 2012.
-  Crawford Long at Wikidata