"I have often wished that I had more time to devote to my favourite studies."

"The Cow Pox, when it has once taken place, is a security against the Small Pox for life."

"My mind is so completely absorbed in this subject, that I can think of nothing else."

"The human mind is capable of great things; but it is also capable of great errors."

"The true philosopher is he who is always learning, and who is never ashamed to confess his ignorance."