Microscope Museum

Collection of antique microscopes and other scientific instruments

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

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 three-lenses type of microscope made by Van Leeuwenhoek. The replica is made of brass and contains three 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 two of these three-lenses microscopes were made by Van Leeuwenhoek, as listed 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. A microscope with three lenses can be visualised on the cover image of the same auction’s catalogue (Figure 1 – see white arrow, and the enlarged image of the microscope), and in the widely known portrait of Van Leeuwenhoek made by Jan Verkolije in 1686 (Figure 2, see white arrow, and the enlarged image of the microscope). In both images, the microscopes contain only one adjustment screw and a single object needle, and a capillary tube for observation of liquids. It is unclear why Van Leeuwenhoek made this type of three-lenses microscopes and, unfortunately, no surviving microscope of this type is known to exist today. Van Leeuwenhoek made and used other types of microscopes to observe and study different types of samples, including the most well-known single-lens microscopes, dual-lenses microscopes and eel/fish viewers. Figure 3 below shows a selection of replicas of these microscopes making part of this collection.

Figure 1. Cover image of the 1747 auction catalogue when all Van Leeuwenhoek’s lenses and microscopes were sold after the death of his daughter Maria (left). The white arrow points to a three lenses microscope, which is enlarged in the right image.

Figure 2. Jan Verkolije’s 1686 portrait of Antoni van Leeuwenhoek (left). The white arrow points to a three lenses microscope, which is enlarged in the right image.

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”.