Nicolaas Hartsoeker

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Nicolaas Hartsoeker (26 March 1656, Gouda - 10 December 1725, Utrecht) was a Dutch mathematician and physicist who invented the screw-barrel simple microscope[1] circa 1694.

Nicolaas was the son of Christiaan Hartsoeker (1626-1683), a Remonstrant minister in Moordrecht near Gouda. His father would take the family to Alkmaar in 1661 and finally to Rotterdam in 1669. Nicolaas started to make a living as a lensmaker in Rotterdam, and was instructed in optics by Antoni van Leeuwenhoek. In 1674, he and a fellow student, assisted by Van Leeuwenhoek, were the first to observe semen, a situation that would later lead to a priority dispute between Hartsoeker and Leeuwenhoek over the discovery of spermatozoids.

In 1677, Hartsoeker met Huygens, who he initiated in the making of lenses. In June 1678, Hartsoeker accompanied Huygens to Paris in the role as an assistant, where they made a great impression with their microscopes. Huygens failed to mention Hartsoeker even once in his publication in France however, leading to a fall-out between the two[2].

Hartsoeker returned to Rotterdam, where he married. His business as an instrument maker and wine merchant failed and in 1684 he moved his family to Paris, where he made instruments for the observatory and the academy, there to remain until 1698 [2].

It is often said that in 1694, while observing human sperm through a microscope, Hartsoeker believed that he saw tiny men inside the sperm, which he called homunculi or animalcules. However, he only postulated their existence as part of his Spermist theory of conception and never claimed to have seen them[3]. The 1694 "Essay on dioptrics", in which this hypothesis appears[citation needed], was a highly-lauded book, in fact tackling several misconceptions of the time. For example, Hartsoeker disavows the contemporary posiion (e.g. of Robert Hooke) that with refractor telescopes one soon would be able to see man-sized creatures on the moon, if any in fact existed[2].

At the end of the century, Hartsoeker had become quite famous. In 1699 he was elected member of the French and in 1704 of the Prussian Academy of Sciences, in both cases as one of the first foreign members. Czar Peter met him in Amsterdam and offered him the chair of mathematics in St Petersburg. Hartsoeker did no accept, but the czar did finance an observatory for him in Amsterdam. Later, in 1704, Hartsoeker accepted the offer of Johann Wilhelm, Elector Palatine to become "first mathematician and honorary professor of philosophy"[who?] at the University of Heidelberg. The last years of his life were spent in Utrecht[2].

[edit] Bibliography

  • Essai de dioptrique, 1694.
  • Principes de physique, 1696.
  • Traité de physique, 1696.

[edit] References

  1. ^ http://www.microscopy.fsu.edu/primer/museum/hartsoeker1694.html
  2. ^ a b c d Fokko Jan Dijksterhuis, "Constructive thinking: a case for dioptrics" in The Mindful Hand, History of Science and Scholarship in the Netherlands, vol. 9, pp. 59-82.
  3. ^ K.A. Hill Hartsoeker's Homonculus: a corrective note J Hist Behav Sci. 1985 Apr;21(2):178-9.