Antonie Leeuwenhoek, van

First name
Last name
Leeuwenhoek, van
Date of Birth
Date of Death
Born in
Died in

The Dutch optician Anthony van Leeuwenhoek crafted highly sophisticated single-lens microscopes, small bi-convex lens framed in two flat and thin metal plates riveted together, allowing magnifications up to 300-fold (a design of Hudde made in the 1660s). He was introduced to the Royal Society by Reinier de Graaf (1641–73) in 1673. Van Leeuwenhoek was a loyal correspondent of the Royal Society—from 1673 onwards, about 560 letters—and bequaethed twenty-six of a total of about two hundred of his best microscopes with specimens to the institution (cf. Palm, 1989, p. 198). See: NNBW, vol. 9, cols 922–6; DSB, vol. 8, pp. 126–30; Ford, 1992.

Like Spinoza's own work in optics during the 1660s, Van Leeuwenhoek had also enraptured himself with the laborious fabrication of single-lens microscopes (at least from late 1673 onwards). With his excellent microscopes, he performed observations resulting in some astonishing discoveries in the fields of protistology and bacteriology. In March and April 1677, Van Leeuwenhoek published brief scientific reports in the Royal Society’s Philosophical Transactions of his intricate examinations of single-cell so-called animalcules, microorganisms including algae, protozoa, rotifera and bacteria in waters (Philosophical Transactions, 25 March 1677: pp. 821–31; 844–6). The descriptions of these observations caused a sensation and discussion among scholars in the Royal Society. Van Leeuwenhoek’s discoveries would ultimately lead to the development of germ theory (cf. Feuer, 1987, p. 237). Since many (like Christiaan Huygens) questioned the credibility of his findings, then, it was resolved to organise an international team of eight respected, credible clergymen, jurists and physicians who were asked to write a witness report about Van Leeuwenhoek’s microscopic observations.


Jan Swammerdam