80x silver

Magnification 80x | Aperture in plates 0.70 mm
Body plates 32 mm x 19 mm | Pitch of main positioning screw 0.46 mm

This microscope is #6 in van Zuylen and Bracegirdle. It is #56 in Harting's catalogue of the 1875 exhibition.

It has silver hallmarks indicating a change of ownership between 1814 and 1831, well before any evidence of a market for Leeuwenhoekiana let alone historical scientific instruments in general.

It has a known provenance since 1847, when it was listed in an auction of the estate of Cornelius Anthonius Geisweit van der Netten (1771–1847). Van der Netten was a retired major-general, living in Delft. Een zilveren Mikroskoopje van Leeuwenhoek, it is perhaps one of the silver microscopes bought in 1747 by Nicolaas Snip, who was married to Anna Geisweit. It was purchased at the auction by the apothecary Andrinus Antonie Gijsbertus van Iterson (1803–1897), director and founder of a stearine candle factory in Gouda. In 1872, Van Iterson sold it to the Municipal Museum in Gouda. It has been on display at the Boerhaave Museum since 1946.

It is mentioned in a letter, dated 17 July 1875, in the archives of the Nederlandsche Dierkundige Vereeniging, cited by Van Zuylen, "On the microscopes" (p. 168). It is also discussed in Fournier's Early Microscopes (p. 21) and Ford's Leeuwenhoek Legacy (pp. 137, 157).