Introducing historical perspectives.

Most of us have heard the story of the discovery of penicillin: how in 1928 the Scottish bacteriologist Alexander Fleming discovered a set of Petri dishes contaminated by spores of Penicillium mold that had seemingly destroyed the staphylococcal bacteria hewas studying. Less remembered is the fact that Fleming gave up on penicillin within a few months, finding it extremely difficult to extract and purify. His 1929 article went largely unnoticed for nearly 10 years until Howard Florey and his wartime research team, seeking effective treatments for battlefield wounds, found it in the library. Florey’s team deserves primary credit for developing penicillin into a practical antibiotic, yet it was the serendipitous nature of Fleming’s earlier discovery that captured the public imagination.1 What has been forgotten is that the story of penicillin involved a rediscovery—a great insight that was lost and then recovered thanks to a systematic historical literature search.