Microscope & Case / Caffieri
Compound Microscope and Case
Gilt bronze attributed to Jacques Caffieri
French, Paris, about 1751
Microscope of gilt bronze, enamel, shagreen, glass; case of wood, tooled and gilded leather, brass, lined with velvet, silver braid, and silver lace
86.DH.694
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Questions for Teaching

• What words would you use to describe the decoration on the base of this microscope?

• The base of this microscope is decorated in the Rococo style with curving scrollwork. Why do you think the maker added this artistic touch to a scientific object? What scientific instruments are made today that are decorated or designed by artists?

• What can we learn from looking through a microscope?

• We don't know who actually owned this microscope, but what can we guess about its owner just by looking at it?

• We know that King Louis XV owned a microscope just like this one. What do you think a king would be interested in learning about from a microscope?

• Wealthy collectors brought together natural specimens and animals from around the world to create cabinets of curiosities. Why do you think they referred to these specimens of nature as curiosities? What was happening in this time period that might have inspired such collections?

Background Information

This microscope combines the most contemporary scientific advancements with the height of Rococo artistic design. Functional and highly accurate, yet stylistically at the forefront of fashion, this microscope exemplifies the interest of the educated and enlightened French nobility in scientific discovery. A microscope such as this would be used to study natural specimens in a cabinet of curiosities. These cabinets were single rooms or even an elaborate series of rooms that contained a variety of natural specimens, including shells, fossils, minerals, bottles of preserved animals, and a variety of stuffed exotic animals such as armadillos and crocodiles.

This microscope is still functional, and its case, made of tooled leather, still holds the necessary accessories, such as tweezers and extra lenses, for viewing specimens. It also holds specimen slides of such items as geranium petals, hair, fly wings, and fleas. Some of the slides are from the 1800s, indicating that the instrument was in continual use for over a century.

The microscope was probably assembled under the guidance of the duc de Chaulnes (1714–1769). He was the first in France to apply the ocular micrometer to microscopes built under his supervision. The duc de Chaulnes was a respected member of the Academy of Science and was personally responsible for several significant improvements to the focusing precision of the measurement. Under his guidance, these improvements were executed by a scientific engineer who actually constructed the microscope. A gilt bronze worker would have been given the responsibility for constructing the gilt-bronze stand.

Visit the Devices of Wonder Web site to explore the microscope in detail. You can turn it around, open the drawers, and look at the accessories inside the case.

About Gilt Bronze
Gilding, the covering of surfaces with a thin layer of gold, is an ancient, exacting, and sometimes-dangerous craft. Bronze workers risked poisoning themselves with the mercury used in the bronze gilding process. Inhaling the mercury vapors eventually resulted in neurological damage and conditions ranging from involuntary muscular twitching to dementia.

Bronze pieces, such as the microscope, were first designed by a sculptor and then cast by a bronze worker. In the gilding process, a mixture of eight parts mercury to one part gold leaf is heated in a charcoal fire to make a paste that is brushed onto the bronze surface with a wire brush. The bronze is then placed in hot coals in order to evaporate the mercury. The heat expands the bronze, and gold is deposited into the surface of the metal. This process is repeated as often as necessary to make sure all of the details are infused with gold. The bronze is then cleaned with a brush, and certain parts are polished to a brilliant shine using a steel or stone burnisher. The final step in the gilding process is toning, in which the bronze is treated with various chemicals to acheive the desired shade of gold.