in 1928, Alexander Fleming, a Scottish doctor and scientist, was working at a hospital in London. He was trying to find ways to fight bacteria. at that time many people died because of bacterial infections; sometimes from very small cuts.
Fleming was studying a dangerous bacteria called staphylococci. He was in a hurry because he was going to go on holiday, so he forgot to was all his equipment in the laboratory before he left. There was one dish in which staphylococci was growing.
When Fleming came back from holiday a few weeks later, he noticed that there was something in the dish. He didn't know what the thing was, but he saw that it was stopping the harmful staphylococci bacteria from growing. Fleming called it penicillin.
He knew that penicillin could be an important discovery, and so he did some experiments with it. However, Fleming was not a chemist and he found it difficult to make pure penicillin. He asked some scientific colleagues to help him, but nobody seemed interested in producing penicillin. Fleming had to wait more than ten years before two brilliant scientists, Howard Florey and Ernst Chain finally found an easy way to produce the drug.
By May 1940, Florey's research team dad enough penicillin to experiment with animals fer the first time. In a simple experiment they gave a dangerous bacteria to eight mice. One hour later, they gave penicillin to only four of the mice. After a few hours the four mice with penicillin were fine, but the other four were all dead! When Florey heard of the result the next day he said, 'It looks like a miracle!'
During World War II penicillin saved many lives, and in 1945 Fleming, Florey and Chain won the Nobel Prize for medicine.