"The bacteriologist is a detective. He must follow every clue, however small."

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

"I have been accused of being untidy. I confess to being untidy, but I have never allowed my untidiness to interfere with my work."

"I am often asked if I foresaw the impact of penicillin. My honest answer is no."

"The greatest joy of a scientist is to see his work used for the benefit of mankind."