Leeuwenhoek, Antoni van (1632–1723)

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Editor: Jonathan Dewald
Date: 2004
Europe, 1450 to 1789: Encyclopedia of the Early Modern World
Publisher: Charles Scribner's Sons
Document Type: Biography
Pages: 3
Content Level: (Level 4)
Lexile Measure: 1250L

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About this Person
Born: October 24, 1632 in Delft, Netherlands
Died: August 26, 1723
Nationality: Dutch
Occupation: Microscopist
Other Names: Leeuwenhoek, Anton van; Leeuwenhoek, Antonie van; van Leeuwenhoek, Anton; Leeuwenhoek, Anthony van; van Leeuwenhoek, Antoni
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Page 475


LEEUWENHOEK, ANTONI VAN (1632–1723), Dutch microscopist. Born the son of a basket maker on 24 October 1632 in Delft, Leeuwenhoek had little formal education. He moved when he was sixteen to Amsterdam, where he was trained and employed by a draper. In 1654 he returned to Delft, married his first wife, Barbara, and established his own drapery business. One child from this first marriage survived, his daughter Maria, who became her father's lifelong companion.

Leeuwenhoek entered civic life in 1660, when he became chamberlain to the sheriffs of Delft. In 1669 he passed the exam to become a city surveyor, and in 1679 he became official wine gauger to the city of Delft. His first wife died in 1666; Leeuwenhoek married his second wife, Cornelia, in 1671, and she died in 1695.

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Leeuwenhoek's career as a tradesman and civic figure took a sharp turn in 1673, when he was introduced to the Royal Society of London by a letter from Reinier de Graaf (1641–1673), a prominent anatomist of Delft. De Graaf said that Leeuwenhoek had devised microscopes that were far superior to any then known, and he included a paper by Leeuwenhoek that offered observations of bits of mold, the eye and sting of a bee, and a louse. The secretary of the Society, Henry Oldenburg, was interested and encouraged further correspondence. Over the next fifty years, Leeuwenhoek wrote more than three hundred letters to the Royal Society. He read and wrote only Dutch, so these letters had to be translated into Latin for publication. The extracts printed in the Society's Philosophical Transactions constitute the bulk of Leeuwenhoek's published scientific work.

We do not know how Leeuwenhoek became interested in either microscopy or lens making. It has been suggested that his use of the draper's glass to examine woven cloth might have been a stimulus, but probably his acquaintance with de Graaf and Cornelius's Gravesande, another Delft anatomist, was more important. Whatever the stimulus, by 1671 Leeuwenhoek was making his own microscopes, and they had a unique design. Whereas the microscopes made by Robert Hooke (1635–1703) and other contemporaries were compound instruments, with both an objective lens and an eyepiece, Leeuwenhoek built simple microscopes, with a single beadlike lens mounted between two small thin metal sheets, usually brass. The object to be viewed was mounted on a pin on one side of the lens, and the eye was placed, almost touching the lens, on the other. The microscopes were successful because the tiny spherical lenses were exquisitely ground, or, in a few cases, blown. The measure of their success is what Leeuwenhoek was able to see through them.

In 1674 Leeuwenhoek examined cloudy water from a nearby lake and discovered it was teeming with tiny "animalcules," which we recognize as protozoa. Two years later, while continuing to study his tiny animals, he discovered in an infusion of pepper water some creatures that were much smaller, so small that, in his words, a million would not occupy the space of a grain of sand. Leeuwenhoek had discovered bacteria (although he never recognized them as a radically different form of life from protozoa). The Royal Society was quite excited by Leeuwenhoek's discovery of microscopic life, which he announced in his famous letters of 7 September 1674 and 9 October 1676, and other microscopists scurried to see for themselves. This was not easy, as no one had microscopes with the resolution of Leeuwenhoek's, but eventually his claims were confirmed.

Leeuwenhoek's other most notable achievement was the discovery of spermatozoa, which he announced in a letter of November 1677. He observed these first in humans, then in dogs, and eventually in more than thirty different species. After persistent study, he came to argue that each sperm was the seed of an individual creature and would give rise to the next generation if properly nourished in the womb. Since most contemporaries argued that the female provided the seed and the male merely some sort of fertilizing power, this was a radically new theory of generation. Leeuwenhoek believed that every element of an adult form was contained in a single sperm. However, he did not, as is sometimes stated, ever claim to see the form of a human within a human sperm.

Leeuwenhoek made other notable discoveries and observations. He was one of the pioneers of plant anatomy, taking a special interest in wood structure. He made a series of detailed studies of blood, observing the red blood cells, and was actually able to see single cells circulating through the capillaries in the tail of an eel, which he announced in a letter of 7 September 1688.

Leeuwenhoek became quite a famous figure in Delft (which, except for two early excursions, he never left). He entertained visitors willingly, although this proved quite time consuming in later life. The future James II of England (ruled 1685–1688) and Tsar Peter I of Russia (ruled 1682–1725) were among those who journeyed to Delft to see Leeuwenhoek and his wonders. When Leeuwenhoek had mastered a particular specimen, he would set up a permanent stand in his house, with a microscope devoted to that specimen, so that a visitor could go from station to station and observe swamp water, blood, insect parts, and other exotica without wasting time. This required a great number of microscopes, and it is estimated that Leeuwenhoek built over five hundred in his lifetime. Twenty-six, Page 477  |  Top of Article made of silver, were presented to the Royal Society after his death, with specimens attached; sadly, these have disappeared. But nine of his microscopes have survived and are the treasures of museums in Utrecht, Leiden, Rotterdam, Antwerp, and Munich.

One rather odd feature of Leeuwenhoek's life is that he was executor, in 1676, for the estate of the artist Jan Vermeer (1632–1675). Although other interaction between the two figures cannot be documented, it has been suggested that Vermeer learned optics from Leeuwenhoek, or perhaps vice versa, and it has been further suggested that Leeuwenhoek was the sitting subject for two of Vermeer's famous paintings, The Astronomer (1668) and The Geographer (1668–1669).

Although the Philosophical Transactions of the Royal Society was the primary forum for Leeuwenhoek's discoveries throughout his life, he did supervise the separate publication of several collections of those letters, in both Dutch and Latin, beginning in 1684 and continuing to 1722. However, he never wrote any kind of a synthesis of his work. Leeuwenhoek died in his home, at the age of ninety, on 26 August 1723, shortly after dictating a last letter to the Royal Society.


Primary Source

Leeuwenhoek, Antoni van. Alle de brieven. 12 vols. Amsterdam, 1939–.

Secondary Sources

Dobell, Clifford. Antony van Leeuwenhoek and His "Little Animals": Being Some Account of the Father of Protozoology and Bacteriology and His Multifarious Discoveries in These Disciplines. New York, 1958.

Fournier, Marian. The Fabric of Life: Microscopy in the Seventeenth Century. Baltimore, Md., 1996.

Palm, Lodewijk C., and Harry A. M. Snelders, eds. Antoni van Leeuwenhoek, 1632–1723: Studies on the Life and Work of the Delft Scientist Commemorating the 350th Anniversary of His Birthday. Amsterdam, 1982.

Schierbeek, Abraham. Measuring the Invisible World: The Life and Works of Antoni van Leeuwenhoek. London, 1959.


Source Citation

Source Citation   

Gale Document Number: GALE|CX3404900628