"The air is a subtle, invisible, and elastic fluid."

"I have always been of the opinion, that the best way to understand the nature of things, is to examine them by experiments."

"I once kept a viper in a sealed glass jar until it died, to observe the effects of air deprivation."

"I have often observed that those who are most forward to censure others, are generally the most faulty themselves."

"I have often observed that those who are most desirous of learning, are generally the most humble."