On November 4, 1847, the Edinburgh doctor James Young Simpson and two friends inhaled chloroform in his dining room to see whether the sweet-smelling vapor could put a person to sleep, and the small test opened a new way to spare patients the worst of surgical pain.
Simpson had been hunting for something better than ether, which stung the throat and caught fire too easily near lamps, and he tried the new compound after reading that it had once been made as a cleaner and a fluid for easing chest illness.
The room went quiet. They woke with no memory. The test worked.
Chloroform acted fast and smelled less sharp, and Simpson soon used it on a woman in labor, a step that drew anger from some clergy who held that pain in childbirth was meant to stay, while other doctors feared the dose could stop the heart if a hand slipped with the cloth.
The practice spread through Britain and beyond within a year, and reports reached Queen Victoria, who accepted chloroform when her eighth child was born in 1853, a public choice that did more than any paper to quiet the critics who had warned against the drug.
Before this, surgery meant speed and a stick to bite, and the deep sleep that Simpson's vapor brought let operators work with care instead of haste, cutting the shock that killed many who might have lived had the knife not been rushed to beat the waking patient.
Scotland led the change. Other hospitals followed, and the dining-room test of 1847 turned a cleaning fluid into one of the most used tools in the history of medicine, though later years showed the dose had to be watched with care.