The Discoveries of Anton van Leeuwenhoek

Antonie van Leeuwenhoek was born in Delft, Holland in 1632. He made his discoveries in a very unusual fashion. He spent the majority of his life as a linen-draper in his hometown where he also served as chamberlain to the town sheriffs. Around 1668, he began building simple, hand-crafted microscopes to observe the world around him. Some of the things he observed under a microscope included pieces of chalk and scrapings from his own teeth. Until his death in 1723, van Leeuwenhoek documented his many observations and discoveries in over 200 conversational letters written to the Royal Society in London. In those letters, he included detailed, accurate drawings created by a professional local illustrator that showed observations including his discovery of bacteria.

In 1665, a British scientist Robert Hooke began studying living things under a microscope lens. Microscopes of the 17th century were not as sturdy as present-day options but both Hooke and Leeuwenhoek were still able to see and identify the earliest notations of cells. Although van Leeuwenhoek did not invent the microscope, he contributed greatly to microscope history. In his lifetime, van Leeuwenhoek built roughly 500 microscopes and at least 172 lenses. Although simple in construction, these scopes would be considered powerful magnifying glasses today. Van Leeuwenhoek's viewing devices could magnify objects up to 200 times and offered unheard-of clarity for the time. Some historians have speculated that van Leeuwenhoek discovered a simple method of dark-ground illumination, the process of observing living matter using scattered light.

Under his homemade microscopes, van Leeuwenhoek discovered microscopic entities including bacteria, protozoa and spermatozoa. In his early observations, he referred to bacteria as “animalcules.” Van Leeuwenhoek was also the first to observe free-living and parasitic microscopic protists, blood cells and nematodes. Likewise, van Leeuwenhoek discovered the tiny multi-cellular aquatic animals known as rotifers, hydra and the single-celled volvox.

In his scientific observation of aphids, van Leeuwenhoek discovered the process of parthenogenesis. This form of asexual reproduction from an unfertilized ovum was groundbreaking in microscope history. While he did not directly discover muscle fibers, van Leeuwenhoek was the first to observe them and capillary blood flow under the microscope. While van Leeuwenhoek was perceived as being secretive about his methods, there may have been even more Antonie van Leeuwenhoek discoveries than those known by the modern scientific community. Because his methods and the microscope itself were new concepts, he presented to other scientists of his time like Robert Hooke, revealed his discoveries to royalty and published his findings to the Royal Society of Science. Some of his perceived reticence in presenting his discoveries were faith based and also because he was not first a scientist by trade.