Lister, Joseph, 1st Baron Lister (1827-1912), British surgeon, whose discovery of antiseptics in 1865 greatly reduced the number of deaths due to operating-room infections. Born in Upton, Essex, and educated at the universities of London and Edinburgh, Lister began to study the coagulation of blood and the inflammation that followed injuries and surgical wounds. In 1861 he was appointed surgeon of the Glasgow Royal Infirmary in a new surgery unit designed to reduce gangrene and other infections, then thought to be caused by bad air. Despite his efforts to keep surgical instruments and rooms clean, the mortality rate remained close to 50 percent.
Believing infection to be caused by airborne dust particles, Lister sprayed the air with carbolic acid, a chemical that was then being used to treat foul-smelling sewers. In 1865 he came upon the germ theory of the French bacteriologist Louis Pasteur, whose experiments revealed that fermentation and putrefaction were caused by microorganisms brought in contact with organic material. By applying carbolic acid to instruments and directly to wounds and dressings, Lister reduced surgical mortality to 15 percent by 1869.
Lister’s discoveries in antisepsis met initial resistance, but by the 1880s they had become widely accepted. In 1897 he was made baron by Queen Victoria, who had been his patient.