“ His taste for mathematics led him to the study of astronomy. He next turned his attention to anatomy, and, being himself shortsighted, devoted his inquiries mainly to the question of vision and the formation of the eye. In this pursuit he made more than 800 dissections. He then learned all that was then to be learned in chemistry, and wrote a Latin poem on salt. ”

“ At the age of twenty he was recognized as one of the most promising scholars of the time. He went in 1651 to Paris, where he formed a friendship with Gabriel Naudé, conservator of the Mazarin library. ”