28 September 1928
Sir Alexander Fleming discovers penicillin
Born in Scotland in 1881, Sir Alexander Fleming devoted his life to medicine. In 1928, Fleming was working on the flu virus and studying a bacteria called staphylococcus. He was growing the bacteria in glass dishes. When he checked them, he noticed that mould had formed. Where there was mould, he found that the bacteria had been killed. He later realised that the mould was an antibiotic, which he later called penicillin. When the drug was introduced in the 1940s, it completely changed the way people were treated, and helped save millions of lives.