Description

A rare Selligue-type prism with two convex sides or curvilinear surface through which light is projected onto opaque bodies on the stage of the microscope.

This kind of stage light condenser was introduced by Selligue with its new achromatic microscope in 1824.

The present example is not signed but attributable, without any dubt, to Nachet. The round base and the articulated arm are exactly from the Nachet’s work.

This condenser was described in the Nachet catalogue from 1856 to 1872 as “Prisme d’éclairage d’Amici, monté sur un pied spécial à mouvements articulés”.

We don’t know another example by or attributable to Nachet.

The prism is smaller than the French Selligue-type microscopes or in the later German Plossl microscopes.

The prism measures 33x25x15mm.

One arm is bent and there is a “play” in the screw who holds the prism but the prism is in genuine condition without cracks or any damage.

The round base measures 5,6cm and maximum height is 20,5 cm.