Leeuwenhoek, Antoni van Health Article

LEEUWENHOEK, ANTONI VAN

Antoni van Leeuwenhoek (1632–1723) was born, and also died, in the city of Delft in the Netherlands. Although a linen draper by profession, Leeuwenhoek learned to make lenses and built over five hundred simple microscopes to conduct his numerous personal experiments. With these instruments, Leeuwenhoek investigated the natural world, including water, soil, and human excretions. Because he is considered the first person to have viewed and documented the existence of microscopic organisms, including bacteria, he has been called the first of the microbe hunters.

His lack of formal scientific training led Leeuwenhoek to concentrate on making observations rather than offering theories. Although he never published his work, Leeuwenhoek described his findings in a series of 165 letters to the Royal Society of London, beginning in 1673 and ending only with his death. His first letter, dated April 28, 1673, details his microscopic inspections of mold and bees.

His most famous letter is dated October 9, 1676. This letter communicates the results of a series of experiments on water infused with pepper. Leeuwenhoek began by examining some snow-water that he had kept sealed for three years. He noted no creatures. He then added some peppercorns to the solution, and, after three weeks, he discovered the sudden appearance of a tremendous number of "very little animals." Judging by his calculations of their number and size, historians have surmised that Leeuwenhoek had become the first person to see bacteria. Colleagues reproduced his experiments in the months that followed. Given contemporary medical theories, it did not occur to Leeuwenhoek that what he saw with his microscope was in any way connected to disease, but his observations laid a foundation on which further investigations were born.

JENNIFER KOSLOW

BIBLIOGRAPHY

Dobell, C. (1932). Anthony van Leeuwenhoek and His "Little Animals." Reprint. New York: Dover Publications, 1962.

Palm, L. C. (1982). Antoni van Leeuwenhoek, 1632–1723: Studies on the Life and Work of the Delft Scientist Commemorating the 350th Anniversary of His Birthday. Amsterdam: Rodopi B.V.