The myth

One miraculous day, mould spores drifted through an open window in the laboratory of Alexander Fleming, and settled on a petri dish of bacteria. The bacteria died; Fleming had accidentally discovered antibiotics. ��

The “truth”

Divine intervention, or at least the redundancy of scientific method, is clearly implied in this story’s popularity. Fleming was searching for a so-called “magic bullet” against infection. In 1922 he sneezed on to a culture dish, and subsequently noticed that bacteria didn’t form in the spots of his mucus. He’d discovered lysozyme, a kind of natural antiseptic.

In 1928, Fleming returned to work from a fortnight’s holiday to discover that bacteria he’d been culturing had died in contact with a fast-growing mould.