The son of an affluent Plymouth merchant, Jackson studied medicine at Harvard Medical School and then geology in Paris. When he met Samuel Morse onboard ship in 1832, Jackson explained to Morse the principles of the telegraph, or so he later recalled. Back in Boston, Jackson set up a private medical practice. But he gave it up in 1836 to establish a private laboratory dedicated to analytic chemistry. In 1844, Jackson demonstrated before several of his chemistry classes that inhalation of sulphuric ether causes loss of consciousness. One of his students was William Morton, a dentist seeking to expand his medical knowledge.
After Horace Wells' demonstration of nitrous oxide anaesthesia failed through under-medication, Jackson was approached by his former student for advice. In the decades ahead, the nature of that request and Jackson's response were bitterly disputed by Jackson, Morton and their respective partisans. After Morton's public success in what is now the Ether Dome, Wells said he had inspired them both; and then Crawford Long belatedly announced in print that he had been using ether anaesthesia for several years. Whatever the full story, it seems that Jackson advised Morton to try using a stronger agent than nitrous oxide for surgery, namely diethyl ether, H5C2-O-C2H5.
Ether is a colourless, volatile liquid with a pungent smell and an irritant vapour. It is flammable, but ether inhalation is indeed more suitable for major operations than laughing gas.
Jackson later excoriated his former student Morton as a forger and swindler who had stolen all the credit for himself. Mark Twain remarks how credit for pioneering anaesthesia had been stolen from Dr Long by "a Northern slicker". There seems no reason to doubt that Long, Wells, Jackson and Morton each sincerely believed that they had independently discovered surgical general anaesthesia, or that a Berkshire Medical College student, William E. Clarke, preceded them. Japanese historians note they were all pre-empted by Seishu Hanaoka and his disciples earlier in the century.
Refs and Further Reading
Anaesthesia and Anaesthetics