Sir Alexander Fleming (6 August 1881 – 11 March 1955) was a Scottish doctor and scientist who studied tiny living things, such as bacteria. He shared the 1945 Nobel Prize in Physiology or Medicine with Howard Florey and Ernst Chain for discovering penicillin and showing how it could cure diseases caused by bacteria. This was the first antibiotic ever found.
Gerhard Johannes Paul Domagk (German pronunciation: [ˈɡeːɐ̯haʁt ˈdoːmak]; 30 October 1895 – 24 April 1964) was a German scientist who studied diseases and bacteria. He discovered a drug called sulfonamidochrysoidine (KL730), which works as an antibiotic. For this discovery, he was awarded the 1939 Nobel Prize in Physiology or Medicine.
Paul Ralph Ehrlich (May 29, 1932 – March 13, 2026) was an American biologist, author, and environmentalist who warned about the effects of population growth, such as food shortages and the loss of natural resources. He held the title of Bing Professor of Population Studies at Stanford University’s Department of Biology. Ehrlich began working at Jasper Ridge Biological Preserve in 1959.
Karl Landsteiner ForMemRS (German: [kaʁl ˈlantˌʃtaɪnɐ]; 14 June 1868 – 26 June 1943) was an Austrian-American biologist, physician, and immunologist. He moved with his family to New York in 1923 when he was 55 years old to find better job opportunities, and he worked at the Rockefeller Institute. In 1901, he discovered the main blood groups by identifying the presence of agglutinins in blood, which led to the modern system for classifying blood types.
Sir James Young Simpson, a Scottish doctor who lived from 1811 to 1870, was an important person in the history of medicine. He was the first doctor to show that chloroform could be used to stop pain during surgery in humans. He also helped make chloroform widely used in medical treatments.
William Thomas Green Morton (August 9, 1819 – July 15, 1868) was an American dentist. In 1846, he publicly showed how inhaled ether could be used as a surgical anesthetic. He helped doctors and medical professionals accept the use of anesthesia during surgery.
Crawford Williamson Long was born on November 1, 1815, and died on June 16, 1878. He was an American surgeon and pharmacist who is famous for being the first person to use inhaled sulfuric ether as an anesthetic.
Ignaz Philipp Semmelweis (German: [ˈɪɡnaːts ˈzɛml̩vaɪs]; Hungarian: Semmelweis Ignác Fülöp [ˈsɛmmɛlvɛjs ˈiɡnaːts ˈfyløp]; 1 July 1818 – 13 August 1865) was a Hungarian doctor and scientist of German heritage. He was an early leader in developing methods to prevent infections during medical care and was called the “saviour of mothers.” Postpartum infection, also known as puerperal fever or childbed fever, refers to any bacterial infection of the reproductive system after childbirth. In the 19th century, this condition was common and often deadly.
Heinrich Hermann Robert Koch (born December 11, 1843; died May 27, 1910) was a German doctor and scientist who studied tiny living things called microbes. He received the 1905 Nobel Prize in Physiology or Medicine for his research on tuberculosis, a serious disease that harms the lungs. Koch discovered the germs that cause dangerous diseases such as tuberculosis, cholera, and anthrax.
Joseph Lister was an English surgeon, scientist, and pioneer in antiseptic surgery and healthcare. He changed the way surgery was done by carefully observing the human body, much like John Hunter had done for surgery itself. Although Lister was not the most skilled surgeon technically, his research on germs and infections in wounds changed surgery worldwide.