The discovery of penicillin may be one of the greatest accidents in medical history. Penicillin, found in common molds, is a potent antibacterial medication. Its discovery opened the door to a variety of new "miracle drugs" that have saved the lives of millions. In the early twentieth century, scientists had been looking for some kind of antibacterial agent to treat infections that could attack nearly every organ in the body. The only drugs that had been used to treat bacterial infections were quinine, arsenic and sulfa drugs, but these were highly toxic. Scottish bacteriologist Alexander Fleming discovered penicillin by accident in 1928. He was conducting research using several petri dishes of bacteria cultures, and one of the cultures was accidently left uncovered for several days. When Fleming found that the dish had become contaminated with a mold, he was about to discard the culture until he noticed that the...