Early form Box Microscope, 1710-1720

 

The "box microscope" (microscope à boîte) refers to a style of early to mid 18th century instruments, made predominantly in France. This is a compound microscope having a box-shaped base, intended solely to house a big mirror for substage illumination. While earlier, 17th century compound microscopes were designed to examine opaque specimens under reflected epi-illuminated light such as Hooke's microscope, illuminated by a candle from below like the Marshall microscope or pointed against a window such as Campani's or Joblot's microscopes, this instrument was the first one to contain a sub-stage inclined mirror. This concept became standard from this point on, throughout the history of the microscope, only to be replaced with the electric bulb during the middle of the 20th century.

The microscope in this collection reflects very early features within the category. The optical tube contained originally three lenses (eye, field, objective). It is made of pasteboard coated with black vellum and held in place by a brass ring and spring friction sliding along the brass rod for focusing. It has an internal cardboard draw-tube coated with pink paper. The eye lens is mounted in a turned fruit wood housing and topped with a turned dust cap. The field lens, now missing, was fixed to the inner part of the tube. Only one objective was originally supplied with this microscope, screwed by a perforated cap into the turned fruit wood nosepiece. That there were no more objectives can be learned by the size of the small flat accessory drawer fitted to the base of the box, where only small and flat accessories could be stored. 

The box is constructed of mahogany. The top of the box forms the mounting base for the brass support pillar. As opposed to the other known box microscopes, the front of the box does not have any removable cover, but rather, it has a circular opening lined with a decorative veneer (probably of rosewood), revealing the square plane mirror inside. The mirror may be tilted by turning brass wingnuts on either side of the box. On the top of the box is mounted a rotatable slide holder and a rotating stage forceps for holding specimens. The box is supported by four wooden mushroom-like knobs. While the lack of the removable cover and the elevated box over the four knobs are unique and absent from other microscopes of this category, they do appear in a depiction of the box microscope in the painting entitled: Attributes of Science (1731) by Jean Siméon Chardin (1699-1779), now exhibited in the Jacquemart-André Museum in Paris.  The microscope depicted there is standing on four knobs and has an opening in the box facing the mirror but without a removable cover, as in our instrument. At the same time, the optical unit has a draw tube, as in other instruments in the category. All these attributes suggest an early date for our specimen, not much later than the first depiction of the box microscope by Pierre Polinière in 1709 (see below). Because by 1731 the box microscope was already perceived (by Chardin) as an "attribute of science", we may assume that by that time it was already circulating among natural philosophers for a significant length of time. As Stenger (2014)  points out, the ring and spring friction focusing system was abandoned around 1745, when the production of box microscopes was taken over by leading makers such as Georg Friedrich Brander (1713-1783) of Augsburg , and Claude Siméon Passemant (1702-1769) of Paris.

Based on these data, a tentative date of roughly 1710-1720 is attributed.

Polinière, Pierre. 1709. Expériences de physique, Paris:  de Laulnes, Jombert et Quillau,

The first to describe a box microscope, and perhaps also to invent it, was Pierre Polinière (1671-1734), an early investigator of electricity and electrical phenomena who also helped to introduce the scientific method in French universities. In his book Expériences de physique (first published in 1709), in an engraving of scientific instruments, a first representation of a box microscope appears. He describes it as follows (translation by Alexandre Piffault):

AB made of two tubes, one inside the other: the first contains two lenses, the second a glass in B”. So it’s drawtube microscope resting on “FM, which is a cubic case open at the front. The top FH is pierced in the middle to hold a lenticular glass (a convex lens serving as a condenser). R is a pair of tweezers for holding small objects. LM is a flat mirror inclined at an angle of 45 degrees to the horizontal. The mirror is fixed.

Polinière was the first to place a flat mirror under the stage inside a cubic box with an open front. This way he solved the problem of lighting the object to be examined, freeing the user’s hands. He increased the strength of the light source using a condenser lens, and he was also the first to fix the tweezers to the stage for holding objects” (Stenger 2014: 12-15).

Jean Siméon Chardin (1699-1779), Attributes of Science (1731)  Jacquemart-André Museum, Paris

References

  • Clay, R. & Court, T. 1932. The History of the Microscope. London.

  • Polinière, P. 1709. Expériences de physique. Paris.

  • Stenger, A. 2014. Histoire illustrée du microscope à boite / Illustrated History of the box microscope.  Paris.

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