Antoni van Leeuwenhoek (layu-wen-hook) was born in Delft, a city in the western Netherlands, on October 24, 1632. His father was a basket-maker, while his mother's family were brewers. Antoni was educated as a child in a school in the town of Warmond. In 1676 he served as the trustee of the estate for Jan Vermeer, a famous painter, who had had been born in the same year as Leeuwenhoek and is thought to have been friends with him. Also some time before 1668, Antoni van Leeuwenhoek learned to grind lenses, and made simple microscopes, and began observing with them. He seems to have been inspired to take up microscopy after having seen a copy of Robert Hooke's illustrated book Micrographia, which illustrated Hooke's own observations with the microscope and was very popular
Leeuwenhoek used double-convex lenses mounted between brass plates and held close to the eye. He viewed objects on pinheads, magnifying them up to 300 times this a lot better than any earlier compound microscopes. In 1668 he confirmed and developed the discovery by Italian anatomist Marcello Malpighi of the capillary systems, he showed how the red corpuscles circulated through the capillaries of a rabbit's ear and the web of a frog's foot. In 1674 Leeuwenhoek gave the first accurate description of red blood corpuscles. Leeuwenhoek was not a good artist so he hired an illustrator to prepare drawings of the things he saw, to go with his written descriptions.
Later he observed what he called animalcules, which today are known as protozoa and bacteria in pond water, rainwater, and in human saliva. In addition in 1677 he described the spermatozoa of both insects and humans. He was the first to observe human sperm under the microscope. Leeuwenhoek believed that sperm contained a child in miniature, which grew larger inside the female's body. Two centuries of experiment and debate followed. Then in 1879, with the use of imp