The true history of the discovery of penicillin, with refutation of the misinformation in the literature.

In 1928, while investigating variant strains of Staphylococcus aureus, Alexander Fleming found that a fungus growing near the edge of a culture of S. aureus produced a substance which had diffused into the medium, lysed the nearest organisms and thus produced a clear area immediately surrounding the fungus. Further away was a zone of transparent, degenerate colonies, while those in the outer zone appeared healthy. This culture plate was one of several left on his laboratory bench at room temperature while he was away on holiday. On his return, he noticed the difference on this plate from the usual contaminated plate. He cultivated the fungus, Penicillium notatum, which he was initially informed was P. rubrum, and called the soluble extract penicillin. It cured local infections but, at the time, could not be purified to treat systemic infections. Many authors have criticized apparent failings in Fleming. This paper catalogs the criticisms and provides evidence to refute them.