SEM macrography of Leeuwenhoek microscopes S9 AM MicroscopyandAnalysis | Digital cameras and image analysis supplement January/February 2016 Introduction Antony Leeuwenhoek (1632-1723) was a draper and civic official in Delft, Netherlands, who visited London in 1666. Clearly he was inspired by Robert Hooke’s great work Micrographia (1665) 1 for he began his lengthy com- munication with the Royal Society of London by precisely reprising Hooke’s observations and listing them in the same order as Hooke; I have previously shown that he also used Hooke’s design for making his microscopes 2 . The observations published by Hooke were primarily of familiar subjects under low magnification – a louse, a flea, the sting of a bee, a mosquito larva, etc. – whereas Leeuwenhoek concentrated on truly microscopical objects including flagellates and rotifers, blood cells and, as his experience and abilities increased, ultimately bacteria. In consequence he became widely renowned as a pioneering investigative microscopist. In 1686, to reflect his growing importance, Leeuwenhoek resolved to adopt a change of name and was thereafter known as Antony van Leeuwenhoek. Other names by which he is known, including Antonie and Anton, are latter-day inventions by writers and were not current in Leeuwenhoek’s lifetime. His work was comprehensively examined in a definitive biography published by Clifford Dobell 3 . In 1981 it emerged that Leeuwenhoek’s original specimen packets still lay among his letters 4 and these gave us, for the first time, an indication of Leeuwenhoek’s precise and meticulous microscopical techniques 5 . This revelation led to a review that brought together the artefacts that Leeuwenhoek had bequeathed to science, notably the legacy represented by his surviving microscopes 6 . There are also some mounted lenses associated with Leeuwenhoek’s name, though it is his single-lens standard microscopes, based on the method of construction laid down by Hooke 2 , for which he is widely renowned. It has long been accepted that there were nine of these although I now believe that doubts could be entertained about several examples. Of the total, one was recently auctioned and cost the new owner almost half a million dollars. That microscope has since disappeared, and the owners remain obdurately determined to conceal its whereabouts 7 . Current Revelations The accepted number of nine standard Leeuwenhoek microscopes has recently increased from nine to twelve. The tenth was obtained by the Museum Boerhaave in Leiden under questionable circum- stances and was announced twenty years after it was identified, in an article for an obscure, and now defunct, journal. 8 Its existence had not been published by other scholars. In 2014 a silver microscope was revealed and we were asked to provide authentication. There was no reason to doubt its origins, though it lacked any Genuine or copy? Novel methods of authenticating new Leeuwenhoek microscopes Brian J Ford Madingley Hall, University of Cambridge, CB23 8AQ Figure 1, (left-right) 1 Replica of the brass Leeuwenhoek microscope at Utrecht University Museum 2 Example of a generic replica kindly produced for the author by Mr. Chris Kirby 3 Boerhaave Museum replica of a brass Leeuwenhoek by Mr. Arie de Vink 4 Camacho/Pallas microscope discovered in mud deposits from a Delft canal Scale bar = 10 mm