Dutch microscopist, Antonie van Leeuwenhoek is credited with the discovery of bacteria. Leeuwenhoek did not receive any formal higher education and got interested into glass grinding (after a number of different professional changes, ranging from draper, surveyor, wine assessor and minor city official). He was very successful with glass grinding and made microscopes that offered very high magnification (as high as 500 times or 500x). He observed a large number of substances (animal tongue, rainwater, teeth plaque, bee stings, etc.) and made observations of prokaryotic and eukaryotic organisms and sent the details to the Royal Society of London. He reported on his observations of microorganisms, seen in various samples of rainwater, canal, sea and well waters, in a letter dated 9 October, 1676. These observations are regarded as the first reports of bacteria. He also reported on very small organisms present in teeth plaque in 1683.
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