"I shall not, I presume, be thought presumptuous in declaring, that the Cow Pox is the most efficacious, and the most safe, of all the methods that have been yet discovered, for eradicating the Small P…"

"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 most valuable possessions are those which we acquire by our own exertions."

"I have often reflected, with a degree of wonder, on the slow progress of human knowledge."

"The cow-pox is a mild disease, and never fatal; the small-pox is a formidable one, and often fatal. The cow-pox is not infectious; the small-pox is highly so."