Antonie van Leeuwenhoek

Antonie Philips van Leeuwenhoek (1632-1723) was a Dutch chemist credited with developing the science of microbiology. Van Leeuwenhoek was a businessman who made microscopes and a self-taught scientist who discovered single-celled organisms, such as bacteria. Although he was often criticized for being an amateur with no scientific pedigree, van Leeuwenhoek shared his findings with the Royal Society, and the findings were widely accepted and initiated the branch of science known as microbiology.

Antonie van Leeuwenhoek was born in Delft, the Dutch Republic on October 24, 1632. He was born just four days after Johannes Vermeer—the famous artist who was also born in Delft. In 1648, van Leeuwenhoek became an apprentice at a draper’s shop in Amsterdam, where he stayed for six years.

In 1654, he married Barbara de Mey and returned to his hometown of Delft. Van Leeuwenhoek had his own draper's shop, served as camerbewaarder for the Delft sheriffs, and later served as wine-gauger for imports and taxes. Camerbewaarder is an untranslated Dutch word for a job thought to involve assisting regents running the city of Delft. Van Leeuwenhoek's first wife, Barbara, died in 1666 and in 1671 he remarried Cornelia Swalmius. Maria was his only child to survive childhood.

Van Leeuwenhoek lived for ninety years, which was rare for the seventeenth century. Through his development of a powerful microscope and his observations of single-celled organisms, he had a key role in the development of modern science. During his later years, he was visited by many prominent people of the age, including Peter the Great and the Queen of England.

Van Leeuwenhoek's motivation to develop magnifying lenses came from out his job working in his draper’s shop, where he wished to see the cloth fibers in greater detail. Through trial and error, he developed powerful lenses by putting a hot section of soda lime glass back into a flame. Throughout his life, van Leeuwenhoek made over 500 optical lenses and 25 single-lens microscopes. Some lenses could provide magnification of 275 times, which was remarkable for that particular age. It was the first time in history that someone could see the many microscopic animals, bacteria, and intricate detail of common objects. Van Leeuwenhoek kept his methods for making lenses secret. The method that involved fusing glass thread was recreated independently in 1965.

Van Leeuwenhoek used his microscopes to investigate tiny insects, blood, water, and skin in his spare time and corresponded with the Royal Society in London on his findings and was considered an amateur scientist. He was introduced to the Royal Society and its president, Robert Hooke, by the physician Constantijn Huygens and was elected to the Royal Society in 1680. Van Leeuwenhoek was the first to discover single-celled organisms, such as amoeba. He called microscopic organisms that he observed in rainwater, pond, well water, human mouth, and intestine "animalcules."

Van Leeuwenhoek’s discoveries of microorganisms helped disprove the theory of spontaneous generation of life. Van Leeuwenhoek was also able to show that similar to larger organisms, fleas were also created by reproduction instead of spontaneous generation.

The importance of Van Leeuwenhoek’s work opened up the world of microbiology with all its new potentials for understanding the world. The following are some of his major discoveries and observations:

• infusoria—tiny aquatic creates such as ciliates, euglenoids, protozoa, and algae
• bacteria
• the vacuole (storage areas) of cells
• spermatozoa
• white blood cells/red blood cells
• the pattern of muscular fibres