model of female sexual organs plus almost 20 embryonic stages, models of the womb for every month of pregnancy. For purposes of comparative anatomy: models of brain or nervous system of diverse animals, models of blood circulation in diverse animals (e.g. a turtle, a crocodile), models of stomach or alimentary canal (e.g. octopus, honey bee). 20th century 20 Chemistry: Dutch First Nobel Prize Dutch scientist Jacobus Henricus van 't Hoff (1852–1911) was the first person to receive the Nobel Prize in Chemistry, for his discovery of the laws of chemical dynamics and osmotic pressure in solutions. In the room hangs a painted portrait of van 't Hoff. His golden Nobel prize medal, and a lab journal are also shown. Also a variety of elementary equipment for a chemical laboratory: a distilling apparatus for water (1860), dilatometers, thermometers, hydrometers, alcohol meters, an oleometer, a colorimeter (1880), pycnometers (some with thermometer), pipettes, burettes, volumetric flasks, a boiling flask, a spectral burner and spectroscope (1880), polarimeters, a kipp generator (1850), sample collections of experimental chemicals (some in wooden boxes), an evaporating basin, gas burners, an oxyhydrogen voltmeter, apparatus for electrolysis, an analytical balance, cork presses, a refractometer (1910), a flash point apparatus for petroleum, a circular slide rule. 21 Physics: Factories of Science In the early years of the 19th century, 4 Dutch physicists received a Nobel Prize in quick succession. This room is dedicated to their work and legacy. In 1902 Hendrik Lorentz (1853–1928) and Pieter Zeeman (1865–1943). For their combined work on and discovery of the Zeeman effect, where spectral lines split under the influence of a magnetic field. In 1910 Johannes Diderik van der Waals (1837–1923) thermodynamicist famous for his work on an equation of state for gases and liquids. In 1913 Heike Kamerlingh Onnes (1853–1926). Onnes was the first to liquefy helium (1908), and the discoverer of superconductivity. For many years his laboratory was the coldest place on earth. On display are a helium liquefier and associated tools, devices to measure superconductivity (e.g. rheostats), and to automatically record measurements: a cathode tube, a thermograph, drum recorders and a paper tape recorder. Also large (from today's perspective) devices, mostly made from wood and copper, to measure and display electricity (1900–1930): volt meters, a resistance box, radio valves, a universal bridge, mirror galvanometers, a quadrant electrometer . Apparatuses to study radiation: a Wilson cloud chamber, an electrometer with ionization chamber, X-ray,