Edward Jenner — "The progress of science is slow, but it is sure."

"The human mind is a wonderful machine; but it is also a very delicate one."

"The joy I felt at the prospect before me of being the instrument destined to take away from the world one of its greatest calamities was so excessive that I sometimes found myself in a kind of reverie…"

"It is a fortunate circumstance, that the Cow Pox is not infectious; for if it were, it would be a source of great alarm."

"The cow-pox protects the human constitution from the infection of smallpox."

"The deviation of man from the state in which he was originally placed by nature seems to have proved to him a prolific source of diseases."