Antonie van Leeuwenhoek

(click to enlarge)
Antonie van Leeuwenhoek, detail of a portrait by Jan Verkolje; in the Rijksmuseum, Amsterdam. (credit: Courtesy of the Rijksmuseum, Amsterdam)

(born Oct. 24, 1632, Delft, Neth. — died Aug. 26, 1723, Delft) Dutch microscopist. In his youth he was apprenticed to a draper; a later civil position allowed him to devote time to his hobby: grinding lenses and using them to study tiny objects. With his simple microscopes — skillfully ground, powerful single lenses capable of high image quality — he observed protozoa in rainwater and pond and well water and bacteria in the human mouth and intestine. He also discovered blood corpuscles, capillaries, and the structure of muscles and nerves, and in 1677 he first described the spermatozoa of insects, dogs, and humans. His research on lower animals argued against the doctrine of spontaneous generation, and his observations helped lay the foundations for the sciences of bacteriology and protozoology.

For more information on Antonie van Leeuwenhoek, visit Britannica.com.

Anton van Leeuwenhoek

Library of Congress

[b. Delft, Holland, October 24, 1632, d. Delft, August 26, 1723]

Leeuwenhoek made single-lens microscopes with exquisite lenses; with them he became the first person to see ciliated protists, which he called "animalcules" and "wretched beasties." He also discovered Hydra, rotifers, bacteria, and the sperm of dogs and other animals.

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.

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.

— JENNIFER KOSLOW

The Dutch naturalist and microscopist Anton van Leeuwenhoek (1632-1723), using simple microscopes of his own making, discovered bacteria, protozoa, spermatozoa, rotifers, Hydra and Volvox, and also parthenogenesis in aphids.

Anton van Leeuwenhoek was born on Oct. 24, 1632, at Delft. His schooling was informal, probably including some mathematics and physical sciences but no languages. At the age of 16 he was sent to Amsterdam to become an apprentice at a linendraper's shop where he remained for about 6 years.

In 1654 Van Leeuwenhoek returned to Delft and married Barbara de Mey, who was to bear him five children. He bought a house and shop and set up in business as a draper. He remained there for the rest of his life. His wife died in 1666 and in 1671 he remarried; his second wife bore him one child.

In 1660 Van Leeuwenhoek was appointed chamberlain to the sheriffs of Delft, an office which he held for 39 years. Little is known of his activities for the next 13 years; however, in his spare time he must have begun to grind lenses to make simple microscopes. As early as 1668 he took one of his microscopes on a visit to England and used it to examine chalk from the cliffs in Kent.

In 1673 Regnier de Graaf, a brilliant young physician of Delft, wrote a letter about Van Leeuwenhoek's work to Henry Oldenburg, Secretary of the Royal Society in London. This letter was published in Philosophical Transactions, and Oldenburg wrote to the author requesting further communications. Thus began a correspondence with the Royal Society which was to continue until Van Leeuwenhoek's death. All his observations were described in letters (at least 200), either to the Royal Society or to his friends, that were written in his own language, Nether-Dutch. He never wrote a scientific paper or a book. His letters are full of random observations, with little coherence, and were written in a conversational style. Despite the casual way in which he described his observations, he never confused the facts with his speculations, and so it is possible to identify easily many of the organisms he studied from his detailed descriptions.

The Royal Society elected him a fellow in 1680, an honor which pleased him although he never found time to visit London to sign the register. His discoveries soon made him famous, and many came to visit him in Delft. His enthusiasm for the study of nature never waned even in old age, and despite his infirmities he still continued to make observations and send letters to the Royal Society. After his death on Aug. 26, 1723, his daughter Maria sent a cabinet to the Royal Society which her father had prepared 22 years previously, containing 26 of his microscopes made from silver.

Van Leeuwenhoek's Microscopes

Apart from those microscopes sent to the Royal Society, Van Leeuwenhoek left 247 completely finished microscopes, most of which had an object mounted in front of the lens, and also 172 lenses mounted between metal plates. Properly speaking, the instruments were not microscopes at all but simple magnifying glasses. Each consisted of a single biconvex lens of remarkable clarity which was mounted between two metal plates. The lens was fixed, and the object to be examined was raised or lowered and rotated upon its axis by a coarse-threaded-screw. The lenses were of exceptional optical quality and had magnifying powers ranging from 50 to 200. The short (about 1 millimeter) focal lengths of the lenses would have necessitated placing the eye almost in contact with the lens, and it is not clear how Van Leeuwenhoek obtained the necessary illumination to achieve his remarkable results. He was always very secretive about his methods. Clifford Dobell suggested that he might have discovered some simple method of dark-ground illumination, whereas Barnett Cohen pointed out that the optical properties of spherical drops of fluid containing the objects under observation may have been used by Van Leeuwenhoek.

Microscopical Observations

Van Leeuwenhoek's curiosity was insatiable, and he examined everything he could with his microscopes, ranging from samples of about 200 biological species to mineral objects; he even attempted to observe the explosion of gunpowder.

Van Leeuwenhoek gave clearer descriptions of red blood cells than either of his contemporaries Marcello Malpighi and Jan Swammerdam. He first described them in 1674 and estimated their size to be, in modern terminology, 8.5 microns in diameter (the correct value is 7.7 microns). In 1682 he clearly described the nucleus within the red blood cells of fish, and in 1683 he noticed the sedimentation of erythrocytes from a suspension and their lysis upon addition of water. His description of the blood capillaries in the intestine in 1683 was accompanied by comments on a different type of capillary which contained "a white fluid, like milk"; he had discovered the lymphatic capillaries.

In 1677 Van Leeuwenhoek examined fresh semen, in which he observed living spermatozoa. His unique observations on microorganisms probably began in 1674, when he examined water from a lake near Delft. He gave the first description of the common green alga Spirogyra but also observed smaller organisms, which were probably free-living protozoa. Dobell believed that Van Leeuwenhoek saw Vorticella, Monas, Bodo caudatus, and Colpidium.

Van Leeuwenhoek also discovered parasitic protozoa, describing the flagellate Giardia in a sample of his feces, which also contained bacteria which can be identified as Spirochaeta. In a letter written in 1683 he describes and illustrates five different kinds of bacteria present in his own mouth: these can readily be identified as a motile bacillus, Selenomonas sputigena, a micrococcus, Leptothrix buccalis, and a spirochete. He continued to make observations on microorganisms until 1716, and while studying free-living protozoa, he also discovered other organisms such as Volvox, Hydra, and rotifers.

Van Leeuwenhoek's discovery of microorganisms has tended to overshadow his other work, which has not received full recognition. He was one of the first comparative anatomists, since he often followed a structure in several different species. As a pioneer of microdissection, he succeeded in obtaining results which are remarkable even by modern standards. Between 1680 and 1701 he carried out a series of microdissections, mainly on insects, and one of his most original discoveries was parthenogenesis in aphids. The parent aphids did not contain eggs, but young aphids just like the parent.

An Assessment

Van Leeuwenhoek's insatiable curiosity, coupled with remarkable tenacity and skill, makes him one of the most outstanding scientists of all time. In his own modest way he realized how rare his gifts were and also that other people's motives were not always those of a true student of nature. In a 1715 letter he noted: "Some go to make money out of science, or to get a reputation in the learned world. But in lens-grinding and discovering things hidden from our sight, these count for nought. And I am satisfied too that not one man in a thousand is capable of such study, because it needs much time … and you must always keep thinking about these things if you are to get any results. And over and above all, most men are not curious to know: nay, some even make no bones about saying, What does it matter whether we know this or not?"

Further Reading

The Collected Letters of Antoni van Leeuwenhoek was edited by a committee of Dutch scientists (8 vols., 1939-1967). A work on Van Leeuwenhoek and His Clifford Dobell, Antony van Leeuwenhoek and His "Little Animals" (1932). See also Abraham Schierbeek, Measuring the Invisible World (1959).

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.

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, 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.

Bibliography

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.

—WILLIAM B. ASHWORTH, JR.

Antonie van Leeuwenhoek
Portrait of Antonie van Leeuwenhoek (1632-1723) by Jan Verkolje
Born	October 24, 1632(1632-10-24) Delft, Netherlands
Died	August 26, 1723 (aged 90) Delft, Netherlands
Residence	Netherlands
Nationality	Dutch
Fields	Microscopist
Known for	Discovery of protozoa First red blood cell description
Religious stance	Dutch reformed

Antonie Philips van Leeuwenhoek (in Dutch also Anthonie, Antoni, or Theunis, in English, Antony or Anton) ^[1] (born on October 24, 1632 – baptized on November 4, and died on August 26, 1723 – buried on August 30) was a Dutch tradesman and scientist from Delft, the Netherlands. He is commonly known as "the Father of Microbiology", and considered to be the first microbiologist. He is best known for his work on the improvement of the microscope and for his contributions towards the establishment of microbiology. Using his handcrafted microscopes he was the first to observe and describe single celled organisms, which he originally referred to as animalcules, and which we now refer to as microorganisms. He was also the first to record microscopic observations of muscle fibers, bacteria, spermatozoa and blood flow in capillaries (small blood vessels). Van Leeuwenhoek never wrote books, just letters.

Contents 1 Life 2 Early involvement with the microscope 3 Eventual recognition by the English Royal Society 4 Discoveries 4.1 Lenses secret 5 Religious interpretations of Van Leeuwenhoek's discoveries 6 Possible Vermeer connection 7 Footnotes 8 Bibliography 9 See also 10 External links

Life

Antonie van Leeuwenhoek was born in Delft, the Netherlands, on October 24, 1632. He was the son of the basket maker Philip Thonisz and Grietje Jacobs van den Berch. The Leeuwenhoeks lived in a comfortable brick house on Leeuwenpoort Street.^[2] Before his sixth birthday two of his younger sisters and his father had died, and his mother was left with five young children. About three years later she married Jacob Molijn and Antonie van Leeuwenhoek was sent to boarding school in the village of Warmond, near Leiden.^[3] Soon after he was invited by an uncle to live with him in Benthuizen, a village northeast of Delft. At age 16, his stepfather died and his mother decided it was time for Antonie to learn a trade.^[4] He secured an apprenticeship with a Scottish cloth merchant in Amsterdam as a bookkeeper and casher. In 1653, Van Leeuwenhoek saw his first simple microscope, a magnifying glass mounted on a small stand used by textile merchants, capable of magnifying to a power of 3. He soon acquired one for his own use. In 1654, he left Amsterdam, moved back to Delft for the rest of his life and started his own lucrative drapery business there. On July 11, he married Barbara de Mey, the daughter of a cloth merchant and settled as a linen-draper. He was registered as Anthoni Leeuwenhouck. Four out of his five children died young. In 1660, he was appointed chamberlain of the Lord Regents of Delft. In 1666 his wife died and in 1671 he married Cornelia Swalmius, the daughter of a minister. Van Leeuwenhoek outlived his second wife, who died in 1694.^[5]

View of Delft by Johannes Vermeer, 1660-1661

Antonie van Leeuwenhoek did not learn Latin, or attend university, but in 1669 he obtained a degree in surveying; it is possible he was involved in Subdivision Plans for the city of Delft. Demonstrable is his appointment in 1676 as a bailiff. In 1679 he got a post as a gauger, an inspector of wine and beer at the local publicans, who were heavily taxed for the amount that was sold. Obviously the burgomasters gave Van Leeuwenhoek cushy jobs, usually called sinecures, as Antonie was a reliable and smart man.

Early involvement with the microscope

Replica of microscope by Van Leeuwenhoek

Van Leeuwenhoek's interest in microscopes and a familiarity with glass processing led to one of the most significant, and simultaneously well-hidden, technical insights in the history of science. By placing the middle of a small rod of soda lime glass in a hot flame, Van Leeuwenhoek could pull the hot section apart like taffy to create two long whiskers of glass. By then reinserting the end of one whisker into the flame, he could create a very small, high-quality glass sphere. These spheres became the lenses of his microscopes, with the smallest spheres providing the highest magnifications. An experienced businessman, Leeuwenhoek realized that if his simple method for creating the critically important lens was revealed, the scientific community of his time would likely disregard or even forget his role in microscopy. He therefore allowed others to believe that he was laboriously spending most of his nights and free time grinding increasingly tiny lenses to use in microscopes, even though this belief conflicted both with his construction of hundreds of microscopes and his habit of building a new microscope whenever he chanced upon an interesting specimen that he wanted to preserve.

Van Leeuwenhoek used samples and measurements to estimate numbers of microorganisms in units of water.^[6][7] Van Leeuwenhoek made good use of the huge lead provided by his method. He studied a broad range of microscopic phenomena, and shared the resulting observations freely with groups such as the English Royal Society.^[8] Such work firmly established his place in history as one of the first and most important explorers of the microscopic world.

Eventual recognition by the English Royal Society

After developing his method for creating powerful lenses and applying them to a thorough study of the microscopic world, Van Leeuwenhoek was introduced via correspondence to the English Royal Society by the famous Dutch Physician Reinier de Graaf. He soon began to send copies of his recorded microscopic observations to the Royal Society. In 1673 his earliest observations were published by the Royal Society in its journal: Philosophical Transactions. Amongst these published observations were Van Leeuwenhoek's accounts of bee mouthparts and stings.

Despite the initial success of Van Leeuwenhoek's relationship with the Royal Society, this relationship was soon severely strained. In 1676 his credibility was questioned when he sent the Royal Society a copy of his first observations of microscopic single-celled organisms. Previously, the existence of single-celled organisms was entirely unknown. Thus, even with his established reputation with the Royal Society as a reliable observer, his observations of microscopic life were initially met with skepticism. Eventually, in the face of Van Leeuwenhoek's insistence, the Royal Society arranged to send an English vicar, as well as a team of respected jurists and doctors, to Delft, to determine whether it was in fact Van Leeuwenhoek's ability to observe and reason clearly, or perhaps the Royal Society's theories of life itself that might require reform. Finally in 1680, Van Leeuwenhoek's observations were fully vindicated by the Society.

Antonie van Leeuwenhoek is buried in the Oude kerk in Delft

Van Leeuwenhoek's vindication resulted in his appointment as a Fellow of the Royal Society in that year. After his appointment to the Society, he wrote approximately 560 letters to the Society and other scientific institutions over a period of 50 years. These letters dealt with the subjects he had investigated. Even when dying, Van Leeuwenhoek kept sending letters full of observations to London. The last few also contained a precise description of his own illness. He suffered from a rare disease, an uncontrolled movement of the midriff, which is now named Van Leeuwenhoek's disease.^[9] He died at the age of 90, on August 26, 1723 and was buried four days later in the Oude Kerk (Delft).

In 1981 the British microscopist Brian J. Ford found that Van Leeuwenhoek's original specimens had survived in the collections of the Royal Society of London.^[10] They were found to be of high quality, and were all well preserved. Ford carried out observations with a range of microscopes, adding to our knowledge of Van Leeuwenhoek's work.

Discoveries

Microscopic Section through one year old ash tree (Fraxinus) wood, drawing made by Van Leeuwenhoek.

During his lifetime Van Leeuwenhoek ground over 500 optical lenses. He also created over 400 different types of microscopes, only nine of which still exist today. His microscopes were made of silver or copper metal frames holding hand-ground lenses. Those that have survived the years are able to magnify up to 275 times. It is suspected, though, that Van Leeuwenhoek possessed some microscopes that could magnify up to 500 times. Although he has been widely regarded as a dilettante or amateur, his scientific research was of remarkably high quality.^[11]

Van Leeuwenhoek's main discoveries are:

• the infusoria (protists in modern zoological classification), in 1674
• the bacteria, (e.g. large Selenomonads from the human mouth), in 1676
• the spermatozoa in 1677. Van Leeuwenhoek had troubles with Dutch theologists about his practice.
• the banded pattern of muscular fibers, in 1682.^[12]

In 1687 he reported his research on the coffee bean. He roasted the bean, cut it into slices and saw a spongeous inside, he had never seen before. The bean was pressed, and then an oil appeared. He boiled the coffee with rain water twice, set it aside (and probably drank it slowly).^[13]

He was visited by Leibniz, William III of Orange and his wife, the Amsterdam burgomaster (the mayor) Johan Huydecoper, the latter very interested in collecting and growing plants for the Hortus Botanicus Amsterdam and all gazed at the tiny creatures. Nicolaes Witsen sent him a map of Tartaria and a mineral found near the origin of the river Amur.^[14] In 1698 Van Leeuwenhoek was invited in the boat of tsar Peter the Great, who went off to Delft, curiously. On the occasion Van Leeuwenhoek presented the tsar an "eel-viewer", so Peter could study the blood circulation, whenever he wanted.

Lenses secret

Van Leeuwenhoek's microscopes by Henry Baker

With skills, however, Van Leeuwenhoek maintained throughout his life that there were aspects of their construction "which I only keep for myself", including in particular his most critical secret of how he created lenses. For a long time nobody could reconstruct Van Leeuwenhoek's know-how. But in the 1957, C.L. Stong used thin glass thread fusing instead of polishing, and successfully created some working samples of a Leeuwenhoek design microscope.^[15] Such a method was also discovered independently by A.Mosolov and A.Belkin in the Novosibirsk State Medical Institute.^[16]

Religious interpretations of Van Leeuwenhoek's discoveries

Van Leeuwenhoek was a Dutch Reformed Calvinist.^[17] He often referred with reverence to the wonders God designed in making creatures great and small. He believed that his amazing discoveries were merely further proof of the great wonder of God's creation.^[18][19]

The Geographer by Johannes Vermeer

Van Leeuwenhoek's discoveries of how smaller organisms procreate just as larger organisms do, did eventually overturn the traditional belief of the time in the spontaneous generation of such organisms. This belief was generally held by the 17th century scientific community, and was also tacitly endorsed by the 17th century Church. Still, the Church's position on the exact nature of the spontaneous generation of smaller organisms was ambivalent.^[20] Possibly because Van Leeuwenhoek's discoveries of microscopic life appeared at the time to pose no direct challenge to any Church doctrines such as the doctrine of creationism, the Church made no effort to challenge or question any of Van Leeuwenhoek's discoveries in any way.

Possible Vermeer connection

Van Leeuwenhoek was a contemporary of another famous Delft citizen, painter Johannes Vermeer, who was baptized just four days earlier. It has been suggested that he is the man portrayed in two of Vermeer's paintings of the late 1660s, The Astronomer and The Geographer. However, others argue that there appears to be little physical similarity. Because they were both relatively important men in a city with only 24,000 inhabitants, it is likely that they were at least acquaintances. Also, it is known that Van Leeuwenhoek acted as the executor when the painter died in 1675. ^[21]

In A Short History of Nearly Everything (p. 236) Bill Bryson alludes to rumors that Vermeer's mastery of light and perspective came from use of a camera obscura produced by Van Leeuwenhoek. This is one of the examples of the controversial Hockney–Falco thesis, which claims that some of the Old Masters used optical aids to produce their masterpieces.

Footnotes

1. ^ Leeuwenhoek was christened as Thonis and always signed his name Antonij, which corresponds with Antony in modern English. His given name can also be found written as Anton, Anthon, Anthony, Antonie, Antony, Anthonie, Antoni, Antonio and Anthoni. Leeuwenhoek, believing that he was by then an established figure, added a 'van' to his name in 1686. See http://www.archief.delft.nl/
2. ^ Payne p. 23
3. ^ Payne p. 26
4. ^ Payne p. 27
5. ^ Life and work of Antoni van Leeuwenhoek of Delft in Holland; 1632-1723 (1980) Published by the Municipal Archives Delft, p. 3.
6. ^ Egerton, F. N. 1967. Van Leeuwenhoek as a founder of animal demography. Journal of the History of Biology 1:1–22.
7. ^ Frank N. Egerton (2006) A History of the Ecological Sciences, Part 19: Leeuwenhoek's Microscopic Natural History. Bulletin of the Ecological Society of America: Vol. 87, No. 1, pp. 47-58. doi:10.1890/0012-9623(2006)87[47:AHOTES]2.0.CO;2
8. ^ UCMP Hooke bio
9. ^ Life and work of Antoni van Leeuwenhoek of Delft in Holland; 1632-1723 (1980) Published by the Municipal Archives Delft, p. 9
10. ^ The discovery by Brian J Ford of Leeuwenhoek's original specimens, from the dawn of microscopy in the 16th century
11. ^ Ford, Brian J. (1992), From Dilettante to Diligent Experimenter: a Reappraisal of Leeuwenhoek as microscopist and investigator, Biology History, 5 (3), available at http://www.brianjford.com/a-avl01.htm
12. ^ A disease in the city of Kampen (1736, The Netherlands) which originated (caused) by "little animals". These 'bloedloze dieren' (bloodless animals, the Invertebrata) are — most likely — the little animals described in the work of Antonie van Leeuwenhoek (Evert Valk, a physician about an epidemic in the city of Kampen {The Netherlands} during the year 1736)
13. ^ May, 9, 1687, Missive 54.
14. ^ Driessen, J. (1996) Tsaar Peter de Grote en zijn Amsterdamse vrienden, p. 35, 95, 96.
15. ^ A glass-sphere microscope
16. ^ A.Mosolov; A.Belkin (1980). "Secret of Antony van Leeuwenhoek?". Nauka i Zhizn (Science and Life) 09-1980: 80–2. http://school-collection.edu.ru/catalog/res/d9e6fc1e-b690-4d72-b4d0-091511481301/?sort=order&from=3709fea8-1ff7-26a5-c7c0-32f1d04346a8&interface=electronic&subject=22&rubric_id%5B%5D=39211. 
17. ^ The religious affiliation of Biologist A. van Leeuwenhoek
18. ^ "The Religion of Antony van Leeuwenhoek". 2006. http://www.adherents.com/people/pl/Antony_van_Leeuwenhoek.html. Retrieved 2006-04-23. 
19. ^ A. Schierbeek, PhD, Editor-in-Chief of the Collected Letters of A. v. Leeuwenhoek, Formerly Lecturer in the History of Biology in the University of Leyden, Measuring the Invisible World: The Life and Works of Antoni van Leeuwenhoek F R S, Abelard-Schuman (London and New York, 1959), QH 31 L55 S3, LC 59-13233. This book (223 pp.) contains excerpts of Leeuwenhoek’s letters and focuses on his priority in several new branches of science, but makes several important references to his spiritual life and motivation.
20. ^ "Catholic Apologetics International/ Robert Sungenis". 2006. http://www.catholicintl.com/scienceissues/rationis-seminalis-print.htm. Retrieved 2006-04-23. 
21. ^ Van Berkel, K. (February 24 1996). Vermeer, Van Leeuwenhoek en De Astronoom. Vrij Nederland (Dutch magazine), p. 62–67.

Bibliography

• Alma Smith Payne, The Cleere Observer: A biography of Antoni van Leeuwenhoek, Macmillan, London, 1970.
• Dobell, C. (1932, 1960) Anthony van Leeuwenhoek and his little animals.

See also

• Scientific Revolution

External links

Wikimedia Commons has media related to: Anton van Leeuwenhoek

• Dutch online biography of Van Leeuwenhoek
• Vermeer connection website
• University of California, Berkeley article on Van Leeuwenhoek
• Works by Antoni van Leeuwenhoek at Project Gutenberg
• Retrospective paper on the Leeuwenhoek research by Brian J. Ford.
• Images seen through a van Leeuwenhoek microscope by Brian J. Ford.
• Instructions on making a Van Leeuwenhoek Microscope Replica by Alan Shinn

Persondata
NAME	Leeuwenhoek, Antonie van
ALTERNATIVE NAMES
SHORT DESCRIPTION	Scientist
DATE OF BIRTH	October 24, 1632
PLACE OF BIRTH	Delft, Netherlands
DATE OF DEATH	August 26, 1723
PLACE OF DEATH	Delft, Netherlands

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