the treatment of sewage with a chemical called carbolic acid reduced the incidence of disease among the people and cattle of a nearby small English town. Lister follows the lead and, in 1865, develops a successful method of applying carbolic acid to wounds to prevent infection. He continues to work along this line and establishes antisepsis as a basic principle of surgery. Thanks to his discoveries and innovations, amputations become less frequent, deaths due to infection plummet, and new surgeries previously considered impossible are being routinely