Microscope Museum

Collection of antique microscopes and other scientific instruments

 

      

Antoni van Leeuwenhoek dual lenses microscope replica, EXEMPLAR EX LONDINIO MMXXV (2025)

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Antoni van Leeuwenhoek (1632 - 1723) was a Dutch microscopist who was the first to observe bacteria and protozoa, and is many times referred to as the father of microbiology. Van Leeuwenhoek made microscopes consisting usually of a single high-quality lens of very short focal length. At the time, such simple microscopes were preferable to the compound microscope, which increased the problem of chromatic aberration. Van Leeuwenhoek’s methods of microscopy remain something of a mystery. During his lifetime he made more than 500 lenses, most of which were very small (no larger than a pinhead) and usually mounted them between two thin brass plates, riveted together. A large sample of those lenses were found to have magnifying powers in the range of 50 to, at the most, 300 times. This is a replica of an antique Antoni van Leeuwenhoek microscope, made in April 2025, illustrating a quite unusual dual lenses type of microscope made by Van Leeuwenhoek. The replica is made of brass and contains two 4.5 mm diameter glass beads as lenses, enclosed within two brass plates riveted together. One of the sides is engraved with “EXEMPLAR EX LONDINIO MMXXV”, and the other side with the Roman numeral “I”. Only three of these dual lenses microscopes were probably made by Van Leeuwenhoek, as these are only mentioned three times in the 1747 auction catalogue when all his little lenses and microscopes were sold after the death of Van Leeuwenhoek’s daughter Maria, and 24 years after Van Leeuwenhoek’s death. It is unclear why Van Leeuwenhoek made this type of dual-lenses microscopes and, unfortunately, no surviving microscope of this type is known to exist today. The only drawing suggesting the use of these dual lenses microscopes by Van Leeuwenhoek appears in a book of travels published in 1753 by Zacharias Conrad von Uffenbach, in which he described a visit he made to Van Leeuwenhoek in 1710 to see his discoveries (Figure 1). However, this diagram portrays a somewhat implausible layout for the microscope. As Van Seters pointed out in his 1933 article entitled “Leeuwenhoek’s microsceopen, praepareer- en observatie-methodes” published in Bijdragen tot de Geschiedenis der Geneeskunde (Vol. 13, pp. 217-235), Uffenbach’s diagram of Van Leeuwenhoek’s dual lenses microscope is quite primitive and, upon closer inspection, is likely to be inaccurate. For example, the screw that raises the object extends through the crosspiece, which is incorrect. It is also puzzling why the plates are depicted so thickly, and it is implausible that they could be detached with four screws to change lenses. According to Uffenbach, the objects were clamped in small tongs, which could be adjusted and fixed with screws, instead of needles (which are usually found in all known Van Leeuwenhoek’s microscopes). In his 1933 article, Van Setter’s included a diagram with his suggestion for a simpler version of Van Leeuwenhoek’s dual lenses microscopes (Figure 2). Van Leeuwenhoek made and used other types of microscopes to observe and study different types of samples, including his usual single-lens microscope, but also three-lenses microscopes and eel/fish viewers. Figure 3 below shows a selection of replicas of these microscopes making part of this collection.

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Figure 1. Van Leeuwenhoek’s dual lenses microscope as illustrated in the 1753 book of travels by Zacharias Conrad von Uffenbach (Vol. III, pp. 349 – 360; publisher: Frankfurt-Leipzig: Ulm-Memmingen). Please see text above for details.

 

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Figure 2. Van Leeuwenhoek’s dual lenses microscopes as suggested by Van Seters in his 1933 article “Leeuwenhoek’s microsceopen, praepareer- en observatie-methodes” published in Bijdragen tot de Geschiedenis der Geneeskunde (Vol. 13, pp. 217-235).

 

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Figure 3. Replicas of different types of microscopes associated with Antoni van Leeuwenhoek: (A) Standard type of single-lens microscope; (B) Dual lenses microscope; (C) Three-lenses microscope; (D) Aquatic/eel viewer microscope; (E) Eel viewer/showcase for visitors microscope; and (F) Fish viewer microscope. All these replicas are engraved with “EXEMPLAR EX LONDINIO MMXXV”.