Antoni van Leeuwenhoek


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Antoni van Leeuwenhoek, painting by Jan Verkolje .
Microscopic section through an annual ash wood, created by Antoni van Leeuwenhoek.

Antoni van Leeuwenhoek [ ˈantoːnɛɪ̯ ˈvɑn ˈleːwənhuk ] ( pronunciation ? / I ) (also Antony , Anthonie or Antonie ; *  October 24, 1632 in Delft ; November 4, 1632 baptized as Thonis Philipszoon ; †  August 26, 1723 ibid) was a Dutch naturalist , Builders and users of light microscopes . Audio file / audio sample

Life

Grave slab of van Leeuwenhoek and his daughter Maria in the Oude Kerk in Delft

Leeuwenhoek was the son of a basket maker who died early in 1638. He later called himself "van Leeuwenhoek" because the house where he was born was in Delft on Leeuwenpoort , the "Lion Gate". The mother was a daughter of the brewer Pieter Van Den Berch, she sent her son to a high school near Leiden . The uncle introduced him to the basics of mathematics and philosophy. In 1648 he went to Amsterdam at the behest of his mother , because he was to become an accountant there. However, he took a job at a Scottish cloth merchant. In 1654 he returned to Delft, where he spent the rest of his life. He bought a house, opened a cloth shop and became chamberlain to the city court. As a reliable and clever person, he was appointed to be the verifier for alcoholic beverages in 1679 (he was licensed as a surveyor as early as 1669 (cf. Meyer 1998: 15-24)). He was with the painter Jan Vermeer friends and after his death in 1675 his executor . Since Vermeer 's scholarly pictures The Astronomer and The Geographer are very similar to van Leeuwenhoek, it is possible that the scientist was a model for the two paintings.

Van Leeuvenhoek died at an old age, on August 26, 1723, almost exactly two months before his 91st birthday in Delft, where he was buried in the Oude Kerk . The inscription on his tomb reads:


“Here Anthony van Leeuvenhoek rusts, outste lit van de Konincklyke Sosyteyt in Londe. Buildings within the city of Delft on October 24th 1632 and overleeden on August 26th 1723 out synde 90 years 10 days and 2 days. Dead the leeser: Heeft elk, o wandelaer, alom ontzagh voor hoogen ouderdom en wonderful gaven. Soo set eerbiedigh here uw stap. This is where de gryse weetenschap buried in Leeuvenhoek. en Maria van Leeuvenhoek desselfs doctor born in Delft on September 22nd, 1656 en overbleeden on April 25th, 1745 "

“This is where Anthony van Leeuwenhoek, the oldest member of the Royal Society in London, rests. Born on October 24, 1632 in Delft and died on August 26, 1723 at the age of 90 years, 10 months and 2 days. To the reader: If everyone, oh wanderer, is in awe of old age and has wonderful gifts, take your step here respectfully. This is where gray science rests in Leeuwenhoek. And Maria van Leeuwenhoek the same daughter, who was born on September 22nd, 1656 in Delft and died on April 25th, 1745. "

- Funerary inscription in the Oude Kerk in Delft

Act

Leeuwenhoek could afford to pursue his hobby, microscopy. He learned the art of lens grinding and built his own microscopes. The light microscope made of composite lenses as we know it today was in use even before Leeuwenhoek was born, but the lenses in particular showed defects. They were insufficiently ground and had inclusions, so that the microscopes gave poor results, especially in the higher resolution range; but he built those that consisted of only one tiny lens, which was of perfect quality. With these he achieved magnifications of up to 270 times, which by far exceeded the performance of the first multi-lens microscope.

He mounted his tiny, biconvex lenses between brass plates and held them close to the eye. This enabled him to look at objects that he had attached to the tips of needles. In 1668, he confirmed the discovery of the capillary system (see blood circulation ) by the Italian anatomist Marcello Malpighi and showed how red blood cells circulated through the capillaries of a rabbit ear and a frog leg. In 1674 he provided the first precise description of red blood cells. These were discovered in 1658 by his colleague and competitor in microscopic research, Jan Swammerdam .

In 1675 he observed protozoa and bacteria - both he called Animalcula (little animals) - in pond water, rainwater and in human saliva . However, this observation was initially commented on with exceptional derision by the Royal Society . However, the verification of his information confirmed this, so that he was appointed a member in 1680; but he never attended a meeting. In 1683 he discovered bacteria in his own dental plaque and that of control persons. In 1699 he became a corresponding member of the Académie des Sciences in Paris.

In 1677 he was the first (after his student Johan Ham) to describe spermatozoa (sperm cells) from insects and humans, which he also referred to as Animalcula, and contradicted the prevailing theory of the spontaneous generation of the smallest living beings; Instead, like Swammerdam, he postulated the new doctrine of preformation that was emerging at the time , according to which the animalcules represented already fully trained people in the sperm head. Accordingly, he was one of the animal culists who rejected any involvement of the egg cell in human development that went beyond a pure nutritional function; Swammerdam, on the other hand, as an ovist, represented the opposite. To refute the spontaneous generation, Leeuwenhoek further demonstrated that grain beetles , fleas and mussels develop from eggs and not, as was believed at the time, spontaneously arise from dirt or sand.

He further described the striations of the muscles and the network that the cells of the heart muscle form.

The secret of his microscope

Leeuwenhoek made more than 500 microscopes, some within a very short time. However, grinding a lens is a very tedious process. He never published his method, it is believed that the lenses were melted and not exclusively created by grinding. He could have heated a stick made of soda-lime glass in the middle and stretched the glass into a thin hair by pulling the ends of the stick apart. If such a hair end is heated again, a tiny glass ball is created, the lens of the microscope. It is also believed that he used multi-lens microscopes with a tripod in addition to the hand-held single-lens models. After Leeuwenhoek's death, it would be almost 150 years before microscopes with a comparably high resolution could be constructed again.

Discoveries

He described three forms of bacteria: bacilli , cocci and spirilla . However, he kept the art of lens making a secret.

Leeuwenhoek had not studied, but learned the trade of cloth merchant. He therefore couldn't speak Latin , in which all scientific papers were published at the time. In April 1673, Reinier De Graaf , a Delft-born member of the Royal Society of London , reported that he had heard of the excellent quality of van Leeuwenhoek's microscopes. From that point on, he was allowed to send his work to the Royal Society. He received visits from eminent figures such as Queen Anne of Britain , the Tsar of Russia, Peter the Great , and Leibniz .

While the telescope was immediately used to observe space and to discover previously invisible details and celestial bodies , hardly anyone before Leeuwenhoek had the idea of ​​using microscopes to look for structures or objects that are so small that they cannot be seen with the naked eye are visible. Until then, it was limited to examining small but visible objects like insects with lenses. Leeuwenhoek, on the other hand, discovered the realm of the microscopic ( animalcula ). It is possible that he also developed a camera obscura , which could explain the level of detail in the work of his friend Jan Vermeer. After his death, he gave 26 of his microscopes to the Royal Society.

Eponyms

literature

  • M. Leewenhoeck, Regnerus de Graaf: A Specimen of Some Observations Made by a Microscope, Contrived by M. Leewenhoeck in Holland, Lately Communicated by Dr. Regnerus de Graaf. Phil. Trans. January 1, 1673 8: 6037-6038; doi : 10.1098 / rstl.1673.0017 ( full text )
  • Antony van Leewenhoeck: Observations, Communicated to the Publisher by Mr. Antony van Leewenhoeck, in a Dutch Letter of the 9th of Octob. 1676. Here English'd: concerning Little Animals by Him Observed in Rain-Well-Sea. and Snow Water; as Also in Water Wherein Pepper Had Lain Infused. Phil. Trans. 1677 12: 821-831; doi : 10.1098 / rstl.1677.0003 ( full text )
  • Mr. Leewenhoeck: Mr. Leewenhoecks Letter Written to the Publisher from Delff the 14th of May 1677, Concerning the Observations by him Made of the Carneous Fibers of a Muscle, and the Cortical and Medullar Part of the Brain; as Also of Moxa and Cotton. Phil. Trans. 1677 12: 899-895; doi : 10.1098 / rstl.1677.0027 ( full text )
  • Doctor Anthonius Lewenhoeck: Observationes D. Anthonii Lewenhoeck, De Natis E Semine Genitali Animalculis. Phil. Trans. 1677 12: 1040-1046; doi : 10.1098 / rstl.1677.0068 ( full text )
  • Robert D. Huerta: Giants of Delft: Johannes Vermeer and the natural philosophers; the parallel search for knowledge during the age of discovery. Bucknell University Press, Lewisburg, Pa., USA 2003, ISBN 0-8387-5538-0 .
  • Clifford Dobell: Antony van Leeuwenhoek and his "Little Animals". John Bale, Sons and Danielsson, London 1932; Reprint: Dover, New York 1960, ISBN 0-486-60594-9 .
  • Klaus Meyer: Secrets of Antoni van Leeuwenhoek. Pabst Science Publishers, Lengerich 1998, ISBN 3-931660-89-3 .
  • Barbara I. Tshisuaka: Leeuwenhoek, Antony van. In: Werner E. Gerabek , Bernhard D. Haage, Gundolf Keil , Wolfgang Wegner (eds.): Enzyklopädie Medizingeschichte. De Gruyter, Berlin / New York 2005, ISBN 3-11-015714-4 , p. 833 f.
  • Paul de Kruif : Antoni van Leewuwenhoeck. The first microbe hunter. In: Paul de Kruif: Microbe hunters. (Original edition: Microbe Hunters. Harcourt, Brace & Co., New York 1926). Orell Füssli Verlag, Zurich / Leipzig 1927; 8th edition ibid. 1940, pp. 9-29.

Individual evidence

  1. https://www.myheritage.de/names/margriet_van%20den%20berch
  2. ^ List of members since 1666: Letter L. Académie des sciences, accessed on January 11, 2020 (French).
  3. Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. [1]

Web links

Commons : Anton van Leeuwenhoek  - collection of images, videos and audio files