Helmholtz, HERMANN

LUDWIG FERDINAND VON, 1821-1894. Prof. of Physiology at Königsberg 1850, Bonn 1855, and Heidelberg 1858; Prof. of Physics at Berlin 1871; Director of the Physical Institute at Char lot ten berg 1887; ennobled 1883; investigator of the highest importance in several fields; author of mathematical memoirs on the motion of the earth's atmosphere. Conservation of Force, 1847-54; Sensations of Tone, 1862; Physiological Optics, 1866; Popular Lectures, 1865-76.His son, ROBERT, 1860-1888, was author of two memoirs on the radiation of light and heat from gases, which are the foundation of our knowledge of this subject as applied to the atmosphere.