|Antonie van Leeuwenhoek (1673)|
Just as Galileo used his telescope to open the hu man ho ri zon to the planets and stars of space, so van Leeuwenhoek used his microscope to open human awareness to the microscopic world that was invisibly small and that no one had even dreamed existed He dis covered protozoa bacteria, blood cells, sperm, and capillary s His work founded the science of mi cro bi ol ogy and opened tissue studies and plant studies to the microscopic world. He com pleted hu man un der stand ing of the circulatory system.
Anton van Leeuwenhoek was born in 1632 in Delft, Holland With no advanced schooling, he was apprenticed as a cloth merchant and as sumed that buying and selling cloth would be his career.
But van Leeuwenhoek was curious about the world and in ter ested in math e mat ics. Completely self taught he learned enough math to moonlight as a sur veyor and read what he could about the nat u ral world around him. He never learned any language other than Dutch, so he was never able to read any of the sci en tific papers and research (all written in Latin or French).
Microscopes existed in Holland by 1620. Christian Huygens and Robert Hooke were the first two scientists to make sci en tific use of microscopes Both designed and built two-lens microscopes (two ground glass lenses inside a thin metal barrel). In 1657 van Leeuwenhoek looked through his first mi cro scope and was fascinated He tried a two-lens microscope but was disappointed by its dis tor tion and low res o lu tion. When he built his first mi cro scope, he used a highly curved single lens to gain greater magnification.
By 1673 van Leeuwenhoek had built a 270-power microscope that was able to see objects only one-one-millionth of a meter in length. Van Leeuwenhoek remained very secretive about his work and never allowed others to see his microscopes or setup.
Van Leeuwenhoek started his microscopic studies with objects he could mount on the point of a pin a bee’s mouth parts, fleas, human hairs, etc. He described and drew what he saw in precise detail. By 1674 he had developed the ability to focus on a flat dish and turned his attention to l liquids water drops, blood cells, etc.
Those 1674 stud ies were where he made his great discovery He discovered a host of microscopic protozoa (bacteria) in every water drop. He had dis cov ered mi cro scopic life, in vis i ble to the human eye.
Van Leeuwenhoek expanded his search for these unseeable small creatures and found them everywhere on human eye lashes, on fleas, in dust, and on skin. He drew and described these tiny creatures with ex cel lent, precise drawings.
Each drawing often took days to complete As an amateur, Van Leeuwenhoek had to work at his sci ence in the evenings and early morning hours when not at work. Embarrassed by his lack of language skills and by his poor spelling (even in Dutch), van Leeuwenhoek felt hes i tant to publish any ar ti cles about his wondrous findings.
Be gin ning in 1676, he agreed to send letters and drawings to the Royal Society of London. They had them translated into English That extensive collection of letters (written and collected over many decades formed the first and best map of the microscopic world. What van Leeuwenhoek observed shat tered many scientific beliefs of the day and put him decades if not centuries ahead of other researchers.
He was the first to claim that bac te ria cause infection and disease (No one else believed it until Pasteur proved it in 1856.) Van Leeuwenhoek saw that vinegar kills bacteria and said that it would clean wounds. Again, it was two centuries before his belief became standard medical practice.
It was also 200 years before anyone built a better microscope But with his marvelous mi cro scope, van Leeuwenhoek discovered the crit i cally important microscopic world.
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