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A scientist was doing some experiments studying germs. He had to leave and set his laboratory dishes down, not thinking about the open window in the room. When he returned, some mold had blown in through the window into his dishes, and he thought his experiment was ruined. He was about to throw it away when he decided to examine I and then he realized that the mold was actually dissolving the germs.
What is the story behind Penicillin?