foot bones, and several skeletons of small animals. Also some 25 jars containing animals in preservative fuels (alcohol, formalin), some anatomically prepared to show inner organs (1830–1910). Part of the collection in the room was prepared by Jan van der Hoeven (1802–1868), professor of Zoology, Comparative Anatomy, Anthropology, Mineralogy and Geology at the University of Leiden. His portrait is on display. Van der Hoeven studied members of 'exotic races' (as it was called at the time), and produced a large amount of visual materials (drawings, engravings, lithographs). Three of these visual studies are on display. 13 Collection: Petrus Koning Anatomical wax models by Petrus Koning (1787–1834), anatomical gouaches 14 Temporary exhibition space 15 Temporary exhibition space 16 Electricity and light This room is dedicated to the scientific and technical progress in fields of electricity and optics in the 19th century. Inventions like telegraphy and the camera had a revolutionary and lasting impact on everyday life. The room shows a collection of 'microscopes (compound, binocular, achromatic, inverted) (1730–1860) and attributes. A set of instruments for optical chemical analysis (1850–1900): a crystal goniometer, a polarimeter, a saccharimeter, a spectroscope, a bunsen burner, a solution tube, gas-discharge tubes. Devices to study, demonstrate and explain the physical qualities of light: prisms and lenses, a heliostat and carbon arc lamp (with clockwork)(1820–1870). A collection of applied optics: a camera, sextant, stereoscope, several telescopes, mechanical lantern slides, a repeating reflecting circle (?), a phantascope (two discs, one with slits, one with images, which when rotating in opposite directions create a cinematographic effect), a projection lantern (1770–1860). Several telescopes: achromatic telescopes (1770 and 1850) and a reflecting telescope (1830). Several electrostatic devices: batteries composed of leyden jars and electrical machines (1770–1800) that were used to generate electricity. A variety of electrostatic toys and experimentation kits (1770–1820) to amuse and educate the public. Some show cases still to do. 17 Zander Devices Devices for physiotherapy using the method of Swedish physician Gustav Zander, developed ca. 1865. These devices featured on two world exhibitions. Their success led to 120 Zander institutes worldwide. 18 Specialisation in medicine 19 The Anatomical world of Dr Auzoux French doctor Louis Auzoux (1797–1870) pioneered the use of papier-mâché for highly detailed and colored anatomical models, with detachable parts, which allowed mass production for educational purposes. A selection of the many models on display: many human body parts, for example a box set with a