Even in corona times, researchers and illustrators of the NWO program have come to us in recent years Visualizing the unknown once every two months in the Rijksmuseum Boerhaave’s restoration studio in Leiden. With the original microscopes of Antoni van Leeuwenhoek (1632-1723), they tried to see what the old master saw according to his own letters and notes.
He wrote hundreds of letters about it, most of them to the Royal Academy in London. About unprecedented details in membranes, wood, blood, semen. Movement of ‘animals’ in ditch water. Liquid blood. algae. nerves. lyrics. Drawings. It was, it is said in the history books and the Leiden Museum, the beginning of microbiology and the discovery of an unknown world.
No one, writes former Boerhaave director Dirk van Delft in his dazzling biography of the researcher, saw what Van Leeuwenhoek said he saw, not even now. Which begs the question to what extent Van Leeuwenhoek really saw what he claimed. Wasn’t there, on the edge of the observable, every now and then imagination and wishful thinking in power? For Van Delft, Antoni’s sharp eyes, angelic patience and persistence were ‘a winning combination’.
An enthusiastic amateur
But he was an amateur, Antoni van Leeuwenhoek. Cloth merchant in Delft, with a socially prestigious job at the town hall as chamberlain, who in his spare time mixed lenses, experimented and looked at everything available. It is not certain that he looked at his own fresh semen, as tradition says. In any case, the researcher always hides whether he could have killed himself.
Exactly about the person Van Leeuwenhoek, historian and former journalist Van Delft skillfully, but a little verbose, is actually very little known. There are not many sources, nor are there many traces: even only about eleven of his famous microscopes are known. No one knows if these are the best because the Delft maker never sold them, preferring to keep them for himself. He even gave a relative gimmick to the Russian Tsar Peter the Great, who visited Delft out of curiosity in 1697.
Antoni van Leeuwenhoek was born in Delft in 1632, the son of a basket maker who did good business as a packer in the pottery town of Delft. In 1637 his father died, his mother remarried and shortly afterwards Antoni went to boarding school in Warmond. Why is there just one of the countless question marks surrounding Van Leeuwenhoek’s personal life. What is known is that as a young man he worked in the Amsterdam fabric trade, probably learned some English there and in particular encountered magnifying glasses for the first time: magnifying glasses for looking at and inspecting yarns and fabrics. In 1654 he established himself as an independent fabric merchant in Delft with a shop and house in Gouden Hoofd.
How this lead to a reputation as the founder of microbiology with his homemade supermicroscopes also remains a bit of a mystery to Van Delft. It is certain that in 1663 he was introduced as a microscopist by the Delft physician Reinier de Graaf to the Royal Society in London, then one of the most prestigious learned societies in the world. In 1680 he even became a member, although he barely spoke English. In 1684 the letters he wrote to John Locke about his numerous observations were collected and published. That book, full of fantastic drawings, remains the most important historical source for Van Leeuwenhoek’s discoveries.
Moreover, Van Leeuwenhoek’s letters are a genre in themselves, with close observations, personal outpourings, ideas and learned digressions. A sign of enthusiastic amateurism, according to some. A sign of genius, others say, as Leonardo da Vinci’s sketchbooks are.
Van Leeuwenhoek is popular. In 2018, his microscope almost became ‘Holland’s showpiece’ in an Avrotros TV show. In 2004, he was number four on the list of the greatest Dutch players of all time by KRO. The man and his work apparently appeal to the imagination. But what do we know about him? Very little personal, and even how he developed his microscope and got it so good, we don’t really know due to lack of sources. And why him?
In his book, Van Delft places great emphasis on the question of why the diligent amateur Van Leeuwenhoek was able to join the Royal Society in London. And why not, for example, his much more learned and serious contemporary Jan Swammerdam. Historians can argue about this for years, but for the average reader it’s a bit far. Like the bits of inaccessible 17th-century Dutch that Van Delft weaves through his entertaining stories. If the book is supposed to give proud Dutch a little more insight into their favorite Van Leeuwenhoek, it doesn’t quite succeed.
Dirk van Delft: Invisible Life – Antoni van Leeuwenhoek and the wonderful world of microbiology. Prometheus; 312 pages; €27.50.