"It is a wonderful thing to be able to save lives with a simple substance."

"The discovery of penicillin was a matter of chance, but the application of it was a matter of hard work."

"It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them."

"The story of penicillin has been told so often that it is almost a cliché."

"It is a matter of great satisfaction to see penicillin saving so many lives."