Antoni van Leeuwenhoek (1632-1723), a fabric merchant from Delft, the Netherlands, used tiny glass spheres to study various microscopic objects at high magnification with surprisingly good resolution. A contemporary of Sir Isaac Newton, Christiaan Huygens, and Robert Hooke, Van Leeuwenhoek is said to have made over 400 microscopes and bequeathed 26 of them to the Royal Society of London. (A handful of these microscopes are extant in various European museums.) Using his single-lens microscope, Leeuwenhoek observed what he called animalcules—or microorganisms, to use the modern terminology—and made the first drawing of a bacterium in 1683. He kept detailed records of what he saw and wrote about his findings to the Royal Society of London and the Paris Academy of Science. His contributions have made him the father of scientific microscopy.