"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."

"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…"

"Did you make a convert of the obstinate antivaxinist at Lello?"

"I shall endeavor still further to prosecute this inquiry, an inquiry I trust not merely speculative, but of sufficient moment to inspire the pleasing hope of its becoming essentially beneficial to man…"

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