An example of this instrument is held in the Billings Microscope Collection of the Medical Museum of the Armed Forces Institute of Pathology in Washington D.C. (AFIP 49099-60-4713-268). It is described in the catalogue as the "monkey microscope". It has been suggested that these instruments relate to Charles Darwin's opinion that homo sapiens were descended from the primates. This was misinterpreted in the press at the time and caused a furor; subsequently a number of cartoons were published illustrating Darwin as an ape or monkey.
A similar, but gilded, example was sold in these rooms on 27 November 1997 for £1955.