Joseph Lister (April 5,1827 - February 10, 1912) was an English surgeon and a pioneer of antiseptic surgery. Until Lister's studies of surgery most people believed that chemical damage from exposures to bad air (miasma) was responsible for infections in wounds. He found that carbolic acid solution swabbed on wounds remarkably reduced the incidence of gangrene. Lister tested the results of spraying instruments, the surgical incisions, and dressings with a solution of it. He instructed surgeons under his responsibility to wear clean gloves and wash their hands before and after operations with 5% carbolic acid solutions. Instruments were also washed in the same solution and assistants sprayed the solution in the operating theater. As the germ theory of disease became more widely accepted, it was realized that infection could be better avoided by preventing bacteria from getting into wounds in the first place. Lister died in 1912 at the age of 84.