MÜLLER, Johannes, a German physiologist, born in Coblentz, July 14, 1801, died in Berlin, April 28, 1858. He was the son of a poor shoemaker, and was about to be apprenticed to a saddler when his talents attracted the attention of his teacher, and he prepared himself for the Roman Catholic priesthood. After attending in 1819 the university of Bonn, he took the degree of M. D. and went to Berlin, where under the influence of Hegel and Rudolphi he was induced to reject all systems of physiology which were not founded upon a severe philosophical observation of nature. Returning to Bonn in 1824, he lectured as private professor on anatomy, physiology, embryology, and related subjects; and in 1826 he became extraordinary professor of physiology and anatomy. In 1833 he was appointed to the chair of anatomy in the university of Berlin, then considered the first in Europe in that department of science. He founded the physico-chemical school of physiology, raising it from a speculative to a positive science, and reformed the study of medicine. He generally passed his vacations on the shores of the Mediterranean, where he became a favorite with the Italians. His publications, numbering upward of 100, embrace nearly every subject in comparative anatomy and physiology, not one of which failed to receive new and valuable illustrations from his hand. His most important work is the Handbuch der Physiologie (Coblentz, 1833), which has been translated into English by Dr. W. Baly (“Elements of Physiology,” 2 vols., London, 1837-'42), and into several other languages. Among his other works are: De Respiratione Fœtus (Leipsic, 1823), a prize dissertation; Zur vergleichenden Physiologie des Gesichtsinnes des Menschen und der Thiere (1826; English translation by Baly, 1848); Grundriss der Vorlesungen über die Physiologie (Bonn, 1827); Grundriss der Vorlesungen über allgemeine Pathologie (1829); and Ueber die organischen Nerven der erectilen männlichen Geschlechtsorgane, &c. (Berlin, 1835). He also wrote numerous dissertations on subjects not altogether physiological. Among these are: Horæ Ichthyologicæ (Berlin, 1849); Ueber die phantastischen Gesichtserscheinungen (Coblentz, 1826); Der Tabak in geschichtlicher, botanischer, chemischer und medizinischer Hinsicht (Berlin, 1832); Ueber die fossilen Reste der Zeuglodonten, &c. (1848); and Ueber Synopta digitata und über die Erzeugung von Schnecken in Holothurien (1852). His latest investigations were devoted to infusoria, and his Terminologia Entomologica was published at Brünn in 1850. He also founded several influential periodicals for the promotion of physiology, anatomy, and other sciences.