"The power of observation is crucial in scientific research."

"The thought that I might have discovered something which would be of value in treating disease was, of course, uppermost in my mind."

"The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantitie…"

"My laboratory was always a bit chaotic, but I knew where everything was."

"I found penicillin and have given it free for the benefit of humanity. Why should it become a profit-making monopoly of manufacturers in another country?"