Maarten Etienne van Velden
Professor and "primus" of the University in Louvain. Defended the Copernican system.
1690 visited Huygens, who supported his position on Copernicus.
With Letter L-252 of 2 May 1695, Van Velden, a professor at the university in Louvain, initiated an exchange of letters by sending Leeuwenhoek two printed works and a box of flies. Over the following two years, Leeuwenhoek wrote four letters to Van Velden. Letter L-255 of 23 May 1695 and Letter L-261 of 12 July 1695 discuss flies and caterpillars. Letter L-306 of 26 October 1696 is a cover letter for a copy of Sesde Vervolg der Brieven, and Letter L-314 of 12 February 1697 is a letter of support for Van Velden’s controversial position on Copernicus’s ideas about the solar system.
In addition Letter L-252, Van Velden wrote two others in return, Letter L-256 of 30 May 1695 and Letter L-313 of 4 February 1697.