Antonie van Leeuwenhoek was born in Delft, Dutch Republic, on October 24, 1632. On 4 November he was baptized as Thonis. His father, Philips Antonisz van Leeuwenhoek, was a basket maker who died when Antonie was only five years old. His mother, Margaretha (Bel van den Berch), came from a well-to-do brewer's family, and remarried Jacob Jansz Molijn, a painter. Antonie had four older sisters, Margriet, Geertruyt, Neeltje, and Catharina. When he was around ten years his step-father died. He attended school in Warmond for a short time before being sent to live in Benthuizen with his uncle, an attorney. At the age of 16 he became a bookkeeper's apprentice at a linen-draper's shop in Amsterdamowned by the Scottish William Davidson.
Van Leeuwenhoek married Barbara de Mey in July 1654, with whom he would have one surviving daughter, Maria (four other children died in infancy). That same year he returned to Delft, where he would live and study for the rest of his life. He opened a draper's shop, which he ran throughout the 1650s. His wife died in 1666, and in 1671 Van Leeuwenhoek remarried Cornelia Swalmius, with whom he had no children.His status in Delft had grown throughout the years. In 1660 he received a lucrative job as chamberlain for the Delft sheriffs' assembly chamber in the City Hall, a position which he would hold for almost 40 years. In 1669 he was appointed as a land surveyor by the Court of Holland; at some time he combined it with another municipal job, being the official "wine-gauger" of Delft and in charge of the city's wine imports and (wine) taxation.
Van Leeuwenhoek was a contemporary of another famous Delft citizen, the painter Johannes Vermeerwho 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, because Van Leeuwenhoek acted as the executor of Vermeer's will, after the painter died in 1675.
While running his draper's shop, Van Leeuwenhoek wanted to see the quality of the thread, better than the then-current magnifying lenses available. Therefore, he began to develop an interest in lensmaking, although few records exist of his early activity. 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 to create two long whiskers of glass. Then, by 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.
Recognition by the Royal Society
After developing his method for creating powerful lenses and applying them to the study of the microscopic world, Van Leeuwenhoek introduced his work to his friend, the prominent Dutch physician Reinier de Graaf. When the Royal Society in London published the groundbreaking work of an Italian lensmaker in their journal Philosophical Transactions of the Royal Society, De Graaf wrote to the journal's editor Henry Oldenburg with a ringing endorsement of Van Leeuwenhoek's microscopes which, he claimed, "far surpass those which we have hitherto seen". In response the Society published in 1673 a letter from Van Leeuwenhoek, which included his microscopic observations on mold, bees, and lice.Van Leeuwenhoek's work fully captured the attention of the Royal Society, and he began regularly corresponding with the Society regarding his observations. At first he had been reluctant to publicize his findings, regarding himself as a businessman with little scientific, artistic, or writing background, but De Graaf urged him to be more confident in his work. When Van Leeuwenhoek died in 1723, he had written some 190 letters to the Royal Society, detailing his findings in a wide variety of fields, centered on his work in microscopy. He only wrote letters, in his own colloquial flavor of Dutch; he never published a proper scientific paper. He strongly preferred to work alone, distrusting the sincerity of those who offered their assistance.The letters were translated into Latin or English by Henry Oldenburg, who had learned Dutch in order to be able to do so.
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 both skepticism and open ridicule. Eventually, in the face of Van Leeuwenhoek's insistence, the Royal Society arranged for Alexander Petrie, minister to the English Reformed Church in Delft, Benedict Haan, at that time Lutheran minister at Delft, and Henrik Cordes, then Lutheran minister at the Hague, accompanied by Sir Robert Gordon and four others 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 1677 Van Leeuwenhoek's observations were fully vindicated by the Royal Society.
Antonie van Leeuwenhoek was elected to the Royal Society in February 1680 on the nomination of William Croone, a then-prominent physician.Van Leeuwenhoek was "taken aback" by the nomination, which he considered a high honor, although he did not attend the induction ceremony in London, nor did he ever attend a Royal Society meeting.
By the end of the 17th century, Van Leeuwenhoek had a virtual monopoly on microscopic study and discovery. His contemporary Robert Hooke, an early microscope pioneer, bemoaned that the field had come to rest entirely on one man's shoulders. He was visited over the years by many notable individuals, such as Russian Tsar Peter the Great. To the disappointment of his guests, Leeuwenhoek refused to reveal the cutting-edge microscopes he relied on for his discoveries, instead showing visitors a collection of average-quality lenses. An experienced businessman, Van 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. He made about 200 microscopes with different magnification.
Van Leeuwenhoek was visited by Leibniz, William III of Orange and his wife, the burgemeester (the mayor) Johan Huydecoper of Amsterdam, the latter being 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. In 1698 Van Leeuwenhoek was invited to visit the Tsar Peter the Great in his boat. On this occasion Van Leeuwenhoek presented the Tsar an "eel-viewer", so Peter could study the blood circulation, whenever he wanted.
Antonie van Leeuwenhoek made more than 500 optical lenses. He also created at least 25 single-lens microscopes, of differing types, of which only nine survived. These microscopes were made of silver or copper frames, holding hand-made lenses. Those that have survived are capable of magnification up to 275 times. It is suspected 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.
The single-lens microscopes of Van Leeuwenhoek were relatively small devices, the biggest being about 5 cm long.They are used by placing the lens very close in front of the eye, while looking in direction of the sun. The other side of the microscope had a pin, where the sample was attached in order to stay close to the lens. There were also three screws that allowed to move the pin, and the sample, along three axes: one axis to change the focus, and the two other axes to navigate through the sample.
Van Leeuwenhoek maintained throughout his life that there are aspects of microscope construction "which I only keep for myself", in particular his most critical secret of how he made the lenses. For many years no-one was able to reconstruct Van Leeuwenhoek's design techniques. However, in 1957 C.L. Stong used thin glass thread fusing instead of polishing, and successfully created some working samples of a Van Leeuwenhoek design microscope. Such a method was also discovered independently by A. Mosolov and A. Belkin at the Russian Novosibirsk State Medical InstituteVan Leeuwenhoek used samples and measurements to estimate numbers of microorganisms in units of water. He also 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 British Royal Society. Such work firmly established his place in history as one of the first and most important explorers of the microscopic world. Antonie van Leeuwenhoek was one of the first people to observe cells, much like Robert Hooke.
- the infusoria (protists in modern zoological classification), in 1674
- the bacteria, (e.g., large Selenomonads from the human mouth), in 1676
- the vacuole of the cell.
- the spermatozoa in 1677.
- the banded pattern of muscular fibers, in 1682.
In 1687 Van Leeuwenhoek reported his research on the coffee bean. He roasted the bean, cut it into slices and saw a spongeous interior. The bean was pressed, and an oil appeared. He boiled the coffee with rain water twice, set it aside.
Like Robert Boyle and Nicolaas Hartsoeker, Van Leeuwenhoek was interested in the dried cochineal, trying to find out if the dye came from a berry or an insect.
Antonie van Leeuwenhoek's religion was "Dutch Reformed" Calvinist. 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. Van Leeuwenhoek's discovery that smaller organisms procreate similarly to larger organisms challenged the contemporary belief, generally held by the 17th century scientific community, that such organisms generated spontaneously. The position of the Church on the exact nature of the spontaneous generation of smaller organisms was ambivalent.
By the end of his life, Van Leeuwenhoek had written approximately 560 letters to the Royal Society and other scientific institutions concerning his observations and discoveries. Even during the last weeks of his life, Van Leeuwenhoek kept sending letters full of observations to London. The last few 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. 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. They were found to be of high quality, and were all well preserved. Ford carried out observations with a range of single-lens microscopes, adding to our knowledge of Van Leeuwenhoek's work.
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