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

"It is not wise to use penicillin as a prophylactic against every little infection."

"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."

"I hope that my work will inspire others to pursue scientific discovery."

"The mere fact that a substance has bactericidal powers does not mean that it can be used for the treatment of septic infections."