"It is not enough to discover a thing; one must also know how to use it."

"It is not often that one finds a substance that is both highly bactericidal and non-toxic to animal tissues."

"My work was not a flash of genius, but a gradual unfolding of facts."

"The public will probably never understand the difficulties that beset the path of the original investigator."

"I never thought of myself as a genius. I just kept looking."