Raspail's Simple Chemical Microscope, By Louis-Joseph Deleuil (1795-1862). Paris, France, Circa 1835. Signed "Deleuil", to the pillar which mounts to one side of the box and supports a gimbaled mirror, rackwork-adjusted stage, and objective arm with thumbscrew horizontal adjustment, the fitted drawer houses three objectives and stage accessories Measurement: H. 15/20 cm. catalogue Note: This style of microscope was first made by the optician Louis Joseph Deleuil (1795-1862) in Paris. It was based on a design by the chemist François-Vincent Raspail (1794-1878), considered the Father of Histochemistry. The microscope is supplied with a full set of four objectives, and a glass stage insert. While Deleuil was the first optician to make one of these simple microscopes, the design became very popular and was copied by several of the other French manufacturers. This form of microscope has what is known as an “aquatic motion”. The use of the word “aquatic” to describe these types of microscopes is due to the fact that the stage can accommodate a large glass insert for preparations in water and that the horizontal arm holding the objective can be moved forward and back using the knob located at the back the arm. The arm can also swivel in an arc making it ideal for the observation of live aquatic organisms. Basically, this microscope is a updated version of the one popularized by John Ellis in the 18th century. In this case, Raspail adapted a microscope with an “aquatic motion” for his histochemical studies. Estimate: 400-600