Leeuwenhoek's aquatic microscope, c 1722.
© Science Museum / Science & Society Picture Library
Engraving taken from Leeuwenhoek's 'Arcana Naturae Detecta' (1722). It was probably as a result of his use of lenses to examine cloth as a draper's apprentice, that started Dutch microscopy pioneer Antoni van Leeuwenhoek (1632- 1723) interest in lens making. Using microscopes he assembled 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.