In 1928, Alexander Fleming accidentally discovered penicillin when he noticed that bacterial growth was inhibited around the mold he was growing. It turns out that the mold, called Penicillium notatum, was producing a substance later called antibiotics that could treat bacterial infections.
It was a medical breakthrough. For the first time, something was available that could prevent and treat infections. Shortly after, people were able to mass produce penicillin, allowing a wide range fatal diseases and infections to be treated during the Second World War.
