Antonie van Leeuwenhoek
Antonie van Leeuwenhoek discovered microorganisms using lenses he made himself and never told anyone how. Born in Delft in 1632, the son of a basket maker, he was apprenticed to a cloth merchant and spent his working life as a draper and a minor city official — chamberlain, surveyor and wine gauger. He had no university education and read no Latin, which meant he could not read most of the science of his day. Drapers used small magnifying lenses to count threads, and that is where he began. He developed a method of making tiny glass spheres of very short focal length, mounted in a brass plate with the specimen on a pin. His instruments were single-lens devices barely larger than a thumb, and they reached magnifications of two hundred and possibly five hundred times — far beyond the compound microscopes of the period, which were limited by aberration. He never explained the method, and it was not reproduced for two centuries. He looked at everything: pond water, pepper infusions, rainwater, saliva, blood, semen, the scrapings from his own teeth. In 1674 he described what he called animalcules moving in a drop of water — the first observation of protozoa — and in 1676 bacteria, which were not seen again for a hundred years. He also described red blood cells, spermatozoa, muscle fibres, capillaries and the life cycle of insects, disproving spontaneous generation. He reported it in Dutch in some 190 letters to the Royal Society, which had them translated and made him a Fellow in 1680. He died in 1723 at ninety.
- Lived: 1632 CE – 1723 CE
- Nationality: Dutch
- Roles: scientist, microscopist, merchant
