Lister’s work on the antiseptic principle in surgery. He believed that bacteria could enter wounds and cause suppuration and putrefaction and that it was necessary to kill the bacteria already in wounds and to apply dressings impregnated with some bactericidal substance. He finally hit on carbolic acid for this purpose. When this work was done it had not yet been proved that bacteria were the cause of disease. The above work is reprinted in Med. Classics, 1937, 2, 28-71.