Carbolic acid spray, 19th century.

UNITED KINGDOM - JANUARY 04: A carbolic acid spray, said to have been used by Joseph Lister (1827-1912), the founder of antiseptic surgery, for sterilising operating environments. In 1860 Lister introduced the use of antiseptic conditions in operating areas in his hospital, greatly reducing the risk of the patient's death from infection and blood poisoning following surgery. The success of his methods led to their widespread introduction in Britain and gradually throughout the world. He discovered that carbolic acid (which was already used for drain cleaning) could also kill the germs that caused infection in the human body, and stressed the importance of cleanliness during surgery. (Photo by SSPL/Getty Images)