As part of Fleming’s research into bacteria, he grew colonies of a certain bacteria on his petri dish plates. Legend says that Fleming only discovered Penicillin by accident. He went away on holiday and left his petri dishes as they were. Some suggest that he simply forgot to clean them and put them away. In any case, when he returned, he recorded what he saw and discovered on 28th September 1928. Mould grew in a ring around the bacteria in one of his petri dishes. No bacteria grew next to the mould. The mould was producing something that killed the bacteria. Alexander Fleming called that ‘something’ Penicillin after the mould itself, ‘Penicillium’. That something became the first recognised antibiotic.