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Posted by on Mar 11, 2017 in Tell Me Why |

Who Was Antonie Philips Van Leeuwenhoek?

Who Was Antonie Philips Van Leeuwenhoek?

Antonie Philips van Leeuwenhoek (1632-1723) was a Dutch scientist whose experiments with microscopes led to his becoming the first person to make observations of bacteria and other microbes. He had no formal education as a scientist, but first worked as a clerk in a textile business in Amsterdam. Later he opened his own business in his native town of Delft, where he spent much time experimenting with magnifying glasses. He ground more than 400 lenses and produced one-lens microscopes of high quality.

Through his microscope Leeuwenhoek discovered a new world of “tiny animals”, hundreds of thousands of which, he estimated, would scarcely equal the bulk of a large grain of sand. “How be it”, he wrote, “that I clean my mouth with salt every day, yet all the people living in the United Netherlands are not as many as the living animals I carry in my mouth?” He sent the results of a series of microscopic observations, begun in 1673, to the Royal Society in London.

Leeuwenhoek made a particular study of small forms of animal life. He was able to show that weevils, lice and fleas were not, as was thought, produced spontaneously or bred from dirt. He studied ants and proved that what had been thought to be their eggs were really chrysalises containing the perfect insects. He also demonstrated that mussels were not generated from sand and that eels were not the product of the dew, as had once been thought.

However, his work had little immediate effect on medical thinking. For many more years people went on thinking that tiny creatures were “spontaneously generated” and scientists were still reluctant to believe that far smaller creatures, germs, were capable of self-reproduction.

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 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 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 the 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 believed 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, and the burgemeester (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. 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.

Content for this question contributed by Marylee Bunch, resident of Olmsted Township, Cuyahoga County, Ohio, USA