In the first Maternity Clinic of the Vienna General Hospital, one in eight women died after giving birth. They called it childbed fever, marked by days of fever and severe pain, and explained it as miasma, bad air, or God’s will. They called it anything except what it was. Ignaz Semmelweis noticed that doctors who moved between patients and performed autopsies — and walked straight from the corpses to the delivery room — without washing their hands. He introduced mandatory handwashing with chlorinated lime. The death rate collapsed immediately. The medical establishment dismissed him and attacked his methods, his tone,...