Ignaz Semmelweis, Hungarian-Austrian physician and obstetrician (d. 1865)
Ignaz Philipp Semmelweis (German: [ˈɪɡnaːts ˈzɛml̩vaɪs]; Hungarian: Semmelweis Ignác Fülöp [ˈsɛmmɛlvɛjs ˈiɡnaːts ˈfyløp]; 1 July 1818–13 August 1865) was an ethnic German-Hungarian physician and scientist born in the Kingdom of Hungary, Austrian Empire, now known as an early pioneer of antiseptic procedures. Described as the "saviour of mothers", Semmelweis discovered that the incidence of puerperal fever (also known as "childbed fever") could be drastically cut by the use of hand disinfection in obstetrical clinics. Puerperal fever was common in mid-19th-century hospitals and often fatal. Semmelweis proposed the practice of washing hands with chlorinated lime solutions in 1847 while working in Vienna General Hospital's First Obstetrical Clinic, where doctors' wards had three times the mortality of midwives' wards. He published a book of his findings in Etiology, Concept and Prophylaxis of Childbed Fever.

Despite various publications of results where hand washing reduced mortality to below 1%, Semmelweis's observations conflicted with the established scientific and medical opinions of the time and his ideas were rejected by the medical community. He could offer no acceptable scientific explanation for his findings, and some doctors were offended at the suggestion that they should wash their hands and mocked him for it. In 1865, the increasingly outspoken Semmelweis supposedly suffered a nervous breakdown and was committed to an asylum by his colleagues. In the asylum he was beaten by the guards. He died 14 days later from a gangrenous wound on his right hand that may have been caused by the beating. Semmelweis's practice earned widespread acceptance only years after his death, when Louis Pasteur confirmed the germ theory, and Joseph Lister, acting on the French microbiologist's research, practised and operated using hygienic methods, with great success.