Alexander Fleming lived on a farm in Scotland. Fleming was a scientist. One day he went on a holiday.
When Fleming came back from his holiday. When he returned he found a sample that he was suppose to throw away. He looked at the sample and found that there was mould in there. Fleming examined the mould and found that it can heal people.
Fleming Managed to grow the mould. Fleming tested if the mould would heal people. He tested the mould on someone. He found out that it worked. So he decided to sell it. Fleming called it penicillin.