Professor Alexander Fleming, ‘Discoverer of Penicillin', 1943.

UNITED KINGDOM - NOVEMBER 28: Professor Alexander Fleming, ‘Discoverer of Penicillin', 1943. A photograph of Professor Alexander Fleming [1881-1955] at work in his laboratory, taken for the Daily Herald newspaper. The blue pencil marks indicate how the photograph was to be cropped for publication. Working as a doctor and researcher at St Mary's Hospital, Paddington, London, Fleming discovered the antibiotic penicillin in 1929. He successfully isolated the chemical from the mould Penicillium notatum, but could not purify the compound. During the Second World War two British scientists, Sir Howard Walter Florey [1898-1968] and Ernst Boris Chain [1906-1979], developed a means of producing penicillin on an industrial scale. Together with Alexander Fleming they shared the Nobel Prize in 1945. Their work on producing a 'wonder drug' saved millions of lives. (Photo by Daily Herald Archive/SSPL/Getty Images)