Although Fleming found the potential of penicillin in 1928, he did not put it into practice. He studied its capabilities and knew it had the potential for greatness, but he never actually realized it himself: Fleming had difficulty finding a way to take penicillin out of the petri dish and put it to use in live specimens. How, then, did penicillin come to be known as the greatest medical development in history? What really happened--two scientists named Howard Florey and Ernst Chain developed penicillin as the functional antibiotic we know today.