On August 27, 1723, Dutch biologist Leeuwenhoek passed away.

Anton Leeuwenhoek (1632~1723) was a Dutch microscope and naturalist. Born in Delft. Become talented by self-study. Worked as an apprentice, ran a grocery store, and worked as a doorman at City Hall. His greatest contribution was to discover the microbial world (known as tiny animals at the time) using a homemade microscope. His microscope has a magnification of 50-300 times and a simple structure. There is only one lens mounted between two metal sheets. In front of the lens There is a short metal rod. At the tip of the rod, the sample to be observed is placed, and the focus is adjusted through a focusing screw. Using this microscope, Anton Leeuwenhoek clearly saw bacteria and protozoa. For the first time, a brand new biological world-the microbial world was revealed. Due to his epoch-making contributions, he was elected a fellow of the Royal Society in 1680. He loved making magnifying glasses and microscopes, and made more than 400 microscopes and magnifying glasses throughout his life. He bequeathed to the Royal Society a cabinet containing 26 instruments and some lenses. His main work was a collection of papers entitled "The Mysteries of Nature"(1695~1719). In 1688, microvessels were discovered by observing the tail of tadpoles under a microscope, which together with Malpiki confirmed Harvey's theory of blood circulation. Protozoa and sperm were discovered in 1675; bacteria were discovered in 1681, laying the foundation for microbiology and medicine. In 1723, when 91-year-old Leeuwenhoek was dying, he presented some of the microscopes, magnifying glasses, and secrets to making sophisticated instruments he had made to the Royal Society.