This document discusses the history and methods of antisepsis in surgery. It begins by describing how the discovery of germ theory in the 1860s led surgeons to adopt practices like washing hands to reduce infection rates. It then outlines the four main types of antisepsis: mechanical, physical, chemical, and biological. The document focuses on mechanical and physical antisepsis, explaining techniques like debridement, drainage, dressings, heat, filtration, and radiation that remove or kill microbes. It provides details on how each method works and historical applications in surgery and food preservation.