Colt did the stuff no favors with his snake-oil mercantilism. Because of its circus origins, anyone who suggested that this magic gas could have actual medical value was laughed out of the room. That was until 1846, when a dentist named William Morton put a patient under using nitrous oxide at Massachusetts General Hospital and removed a tumor from the patient's neck. Up to that point, surgery patients had been put under with generous doses of alcohol or opium and on occasion were literally beaten unconscious. When the patient didn't howl in pain, Morton knew he was on to something. And so did everyone watching from the audience stands, because the carnival aspect of medicine didn't going away until much, much later.
Not pictured: The unicycle-riding bear who juggled the discarded tumor.
To wit, the operating theater at Massachusetts General Hospital wasn't even called "the operating theater at Massachusetts General Hospital." It was known as the Ether Dome. Curious onlookers (who were probably also high on ether) could come in and watch all sorts of surgeries being performed, including amputations done by Robert Liston, who was known for his ability to saw off limbs in under three minutes. This was a big draw, because television had not yet been invented, and everyone in the middle- to upper-class was getting high off of medical sedatives all the time.