"I shall endeavour 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 mankind."

"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."

"I hope that some day the practice of producing cowpox in human beings will spread over the world - when that day comes, there will be no more smallpox."