Nitrous oxide, discovered by Joseph Priestly in 1772, was one of the first gases used as anesthesia. Ether was first used for surgical anesthesia in 1842. Local anesthesia was introduced in 1853, using morphine, followed by cocaine and Novocaine. New York surgeon Leonard Corning experimented with spinal anesthesia in 1885, injecting a cocaine solution into a patient's spine. Today, anesthetics continue to be refined.
Patients can now safely administer their own anesthesia in many cases.
In the future, pain may be relieved without anesthetics, as scientists pinpoint and interrupt the pathways in the brain that people to perceive the pain sensation. In 1895, German physicist Wilhelm Roentgen announced that he could see the inside of the body without a scalpel. Only in the 1920s did they become a routine part of medicine. A series of imaging milestones followed. These have greatly advanced the study of metabolism and the functions of enzymes and hormones.