Antoni van Leeuwenhoek, Dutch pioneer of microscopy, c 1660.

Engraving by A de Blois after the painting by Verkolje. It was probably as a result of his use of lenses to examine cloth as a draper's apprentice that led to Leeuwenhoek's (1632-1723) interest in lens making. Using microscopes he asembled himself, he discovered the existence of protozoa (1674), bacteria in tooth tartar (1676), blood corpuscles (1674) and blood capillaries (1683) among many other observations. In 1680, he was made a Fellow of the Royal Society in recognition of his work.