"It is the lone worker who makes the first advance in a subject; the details may be worked out by a team, but the prime idea is due to enterprise, thought, and perception of an individual."

"I have been very lucky in my scientific career. I have stumbled on things by accident."

"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."

"Penicillin sat on my bench for ten years while I was called a quack."

"One sometimes finds what one is not looking for."