Gottfried Leibniz wrote Letter L-522 to Leeuwenhoek about his observations and teaching his methods to students
Collected Letters number: 318
Collected Letters volume: 20
Text of the letter is in Alle de Brieven / The Collected Letters vol. 17 Letter no. 318, p. 348 (2018). It is not yet available at the DBNL - De Digitale Bibliotheek voor de Nederlandse Letteren.
Leibniz's letter continued discussion of several topics from Letter L-521.
He discussed the Italian medical doctor Antonio Vallisnieri, who renounced Leeuwenhoek’s position on the role of sperm, and Nicolaas Hartsoeker, who – according to Leibniz – was too impetuous to be a good observer.
Leibniz appealed to Leeuwenhoek to describe the advantages of the microscope.
Your honour could attain something useful, not only through his own observations, but also with a detailed description of all the beneficial steps needed for microscopic observations; so that others might be encouraged, and their paths would be more paved.
Those who claim that through science one cannot make money, are mistaken; because nowadays you can see the benefits of genuine research, in many places, one is inclined to pay knowledgeable people rather well.
He asked about Leeuwenhoek's views on movement and the senses, especially pain. In a long P.S. "In order that not so much empty paper remains", Leibniz discussed membranes and blood vessels.
Sämtliche Schriften und Briefe, Transkriptionen des Briefwechsels 1715, Leibniz-Archiv Hannover, no. 376, p. 496-498.
