"The most pleasing part of my life has been spent in the pursuit of knowledge."

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

"I have often found that the best way to learn is to teach."

"The most important discoveries have often been made by accident."

"It is a pity that the practice of inoculation has not been more generally adopted; for if it had, many lives might have been saved."