What did Alexander Fleming invent?

Answer by  YarnGirl (333)

Alexander Fleming invented penicillin in 1928 through an accidental discovery. While searching for a cure for diseases, he accidentally left a sandwich out for several days. Upon his return he saw that it had gotten moldy. After experimenting with the mold on his sandwich he discovered that it was capable of killing germs.

Answer by  Ken56 (1160)

He was most famous for having discovered the enzyme lysozyme in 1923, and then the basic antibiotic substance from which penicillin was created. More of a discoverer than inventor.