"The greatest reward for a scientist is the advancement of knowledge."

"The public will not understand the dangers of using penicillin indiscriminately."

"I certainly did not plan to revolutionise all medicine by discovering the world's first antibiotic, or killer of bacteria. But I suppose that is exactly what I did."

"It is not an exaggeration to say that the discovery of penicillin has saved millions of lives."

"I am sometimes asked what I think of the future of penicillin. I think it has a great future, but it must be used wisely."