Antonie Philips van Leeuwenhoek ( ; ; 24 October 1632 – 26 August 1723) was a Dutch microbiologist and microscopist in the Golden Age of Dutch art, science and technology. A largely self-taught man in science, he is commonly known as "the Father of Microbiology", and one of the first microscopists and microbiologists.Chung, King-thom; Liu, Jong-kang: Pioneers in Microbiology: The Human Side of Science. (World Scientific Publishing, 2017, ). "We may fairly call Leeuwenhoek "The first microbiologist" because he was the first individual to actually culture, see, and describe a large array of microbial life. He actually measured the multiplication of the bugs. What is more amazing is that he published his discoveries." Van Leeuwenhoek is best known for his pioneering work in microscopy and for his contributions toward the establishment of microbiology as a scientific discipline.
Raised in Delft, Dutch Republic, Van Leeuwenhoek worked as a draper in his youth and founded his own shop in 1654. He became well-recognized in municipal politics and developed an interest in lensmaking. In the 1670s, he started to explore microbial life with his microscope.
Using single-lensed microscopes of his own design and make, Van Leeuwenhoek was the first to observe and to experiment with microbes, which he originally referred to as , or . He was the first to relatively determine their size. Most of the "animalcules" are now referred to as unicellular organisms, although he observed multicellular organisms in pond water. He was also the first to document microscopic observations of muscle fibers, bacteria, spermatozoa, red blood cells, and crystals in gouty tophi, and was among the first to see blood flow in capillaries. Although Van Leeuwenhoek did not write any books, he described his discoveries in chaotic letters to the Royal Society, which published many of his letters in their Philosophical Transactions.
Early life and career
Antonie van Leeuwenhoek was born in Delft, Dutch Republic, on 24 October 1632. On 4 November, he was baptized as Thonis. His father, Philips Antonisz van Leeuwenhoek, was a basket maker who died when Antonie was five years old. His mother, Margaretha (Bel van den Berch), came from a well-to-do brewer's family. She remarried Jacob Jansz Molijn, a painter and the family moved to Warmond around 1640. Antonie had four older sisters: Margriet, Geertruyt, Neeltje, and Catharina.Dobell, pp. 19–21. When he was around ten years old his step-father died. He was sent to live in Benthuizen with his uncle, an attorney. At the age of 16 he became a bookkeeper's apprentice (casher) at a linen-draper's shop at Warmoesstraat in Amsterdam,Dobell, pp. 23–24. which was owned by William Davidson. Van Leeuwenhoek left there after six years.The curious observer. Events of the first half of Van Leeuwenhoek's life. Lens on Leeuwenhoek (1 September 2009). accessed 20 April 2013.Huerta, p. 31.
In July 1654, Van Leeuwenhoek married Barbara de Mey in Delft, with whom he fathered one surviving daughter, Maria (four other children died in infancy). He would live and study for the rest of his life at Hypolytusbuurt in a house he bought in 1655. He opened a draper's shop, selling linen, yarn and ribbon to seamstresses and tailors. His status in Delft grew throughout the years. In 1660 he received a lucrative job as chamberlain for the sheriffs in the city hall, a position which he would hold for almost 40 years. His duties included maintaining the premises, heating, cleaning, opening for meetings, performing duties for those assembled, and maintaining silence on all matters discussed there.
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 wine imports and taxation.Dobell, pp. 33–37. His wife had died in 1666, and in 1671, Van Leeuwenhoek remarried to Cornelia Swalmius with whom he had no children.Dobell, pp. 27–31.
Van Leeuwenhoek was a contemporary of another famous Delft citizen, the painter Johannes Vermeer, who was baptized just four days earlier. It has been suggested that he is the man portrayed in two Vermeer paintings of the late 1660s, The Astronomer and The Geographer, but 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, living both close to the main market, it is likely they knew each other. Van Leeuwenhoek acted as the executor of Vermeer's will when the painter died in 1675.Van Berkel, K. (24 February 1996). Vermeer, Van Leeuwenhoek en De Astronoom. Vrij Nederland (Dutch magazine), pp. 62–67.
Van Leeuwenhoek's religion was "Dutch Reformed" and Calvinist. Like Jan Swammerdam he often referred with reverence to the wonders God designed in making creatures great and small, and believed that his discoveries were merely further proof of the wonder of creation.A. Schierbeek, 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, . This book contains excerpts of Van 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.
Microscopic study
While running his draper shop, Van Leeuwenhoek wanted to see the quality of the thread better than what was possible using the magnifying lenses of the time. He developed an interest in lensmaking, although few records exist of his early activity. By placing the middle of a small rod of soda lime glass in a hot flame, one can pull the hot section apart to create two long whiskers of glass. Then, by reinserting the end of one whisker into the flame, a very small, high-quality glass lens is created. Significantly, a May 2021 neutron tomography study of a high-magnification Leeuwenhoek microscope captured images of the short glass stem characteristic of this lens creation method. For lower magnifications he also made ground lenses.Klaus Meyer: Das Utrechter Leeuwenhoek-Mikroskop. In: Mikrokosmos. Volume 88, 1999, S. 43–48. To help keep his methods confidential he apparently intentionally encouraged others to think grinding was his primary or only lens construction method.
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 editor of the journal, Henry Oldenburg, with a ringing endorsement of Van Leeuwenhoek's microscopes which, he claimed, "far surpass those which we have hitherto seen". In response, in 1673 the society published a letter from Van Leeuwenhoek that included his microscopic observations on mold, bees, and lice.Dobell, pp. 37–41. Then, in 1674, Van Leeuwenhoek made his most significant discovery. Starting from the assumption that life and motility are similar, he determined that the moving objects observed under his microscope were little animals. He later recorded his observations in his diary.
Van Leeuwenhoek's work fully captured the attention of the Royal Society, and he began corresponding regularly 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.Dobell, pp. 41–42. By the time 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 Dutch; he never published a proper scientific paper in Latin. He strongly preferred to work alone, distrusting the sincerity of those who offered their assistance.Dobell, pp. 43–44. The letters were translated into Latin or English by Henry Oldenburg, who had learned Dutch for this very purpose. He was also the first to use the word animalcules to translate the Dutch words that Leeuwenhoek used to describe microorganisms. Despite the initial success of Van Leeuwenhoek's relationship with the Royal Society, soon relations became severely strained. His credibility was questioned when he sent the Royal Society a copy of his first observations of microscopic single-celled organisms dated 9 October 1676. 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 some skepticism.
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 that might require reform. Finally in 1677,Schierbeek, A.: "The Disbelief of the Royal Society". Measuring the Invisible World. London and New York: Abelard-Schuman, 1959. n.p. Print. Van Leeuwenhoek's observations were fully acknowledged by the Royal Society.Full text of "Antony van Leeuwenhoek and his "Little animals"; being some account of the father of protozoology and bacteriology and his multifarious discoveries in these disciplines;". Recall.archive.org. accessed 20 April 2013.
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 honour, although he did not attend the induction ceremony in London, nor did he ever attend a Royal Society meeting.Dobell, pp. 46–50. He had his portrait painted by Jan Verkolje with the certificate signed by James II of England on the table beside him.
Scientific fame By the end of the seventeenth 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.Dobell, pp. 52–53. In 1673, his first letter was published in the journal of the Royal Society of London. He was visited over the years by many notable individuals who gazed at the tiny creatures. One of the first was Jan Swammerdam. Around 1675, it was Johan Huydecoper, who was very interested in collecting and growing plants for his estate Goudestein, becoming in 1682 manager of the Hortus Botanicus Amsterdam. Christiaan Huygens, Leibniz (1676), John Locke (1678, 1685), James II of England (1679), William III of Orange, Mary II of England and Thomas Molyneux (in 1685) visited. In October 1697, Van Leeuwenhoek visited the Tsar Peter the Great on his boat, moored in the Schie or the Arsenaal. On this occasion, he presented the Tsar with an "eel-viewer", so Peter could study blood circulation whenever he wanted. In 1706, it was Govert Bidloo; in 1714, Richard Bradley (botanist); and, in 1716, Herman Boerhaave and Frederik Ruysch. To the disappointment of his guests, Van Leeuwenhoek refused to reveal the cutting-edge microscopes he relied on for his discoveries, instead showing visitors a collection of average-quality lenses.Dobell, pp. 54–61.
Techniques