Ernst Julius Richard Ewald (14 February 1855 – 22 July 1921) was a German

physiologist Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical a ...

born in

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

. He was a younger brother to gastroenterologist

Carl Anton Ewald Carl Anton Ewald (30 October 1845 – 20 September 1915) was a German gastroenterologist who was a native of Berlin. He was the brother of physiologist Ernst Julius Richard Ewald (1855–1921). In 1870, he earned his medical doctorate in Berlin, ...

(1845–1915). In 1880, after finishing his studies in

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

and medicine, he became an assistant to physiologist Friedrich Goltz (1834-1902) at the

University of Strasbourg The University of Strasbourg (french: Université de Strasbourg, Unistra) is a public research university located in Strasbourg, Alsace, France, with over 52,000 students and 3,300 researchers. The French university traces its history to the ea ...

. In 1900 he succeeded Goltz as chair of physiology at

Strasbourg Strasbourg (, , ; german: Straßburg ; gsw, label=Bas Rhin Alsatian, Strossburi , gsw, label=Haut Rhin Alsatian, Strossburig ) is the prefecture and largest city of the Grand Est region of eastern France and the official seat of the Eu ...

, a position he maintained until 1918. Ewald is best remembered for his research of the

vestibular system The vestibular system, in vertebrates, is a sensory system that creates the sense of balance and spatial orientation for the purpose of coordinating movement with balance. Together with the cochlea, a part of the auditory system, it constitutes ...

of the

inner ear The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the ...

, which largely involved experiments performed on the semicircular canal system of pigeons. From these studies the so-called "Ewald laws" are derived, which deal with the effects of endolymph motion on body, head and eye movements and also on the phenomena of excitation-inhibition asymmetries in the vestibular system. * Ewald's first law: "The axis of nystagmus parallels the anatomic axis of the semicircular canal that generated it". * Ewald's second law: "Ampullopetal endolymphatic flow produces a stronger response than ampullofugal flow in the horizontal canal". * Ewald's third law: "Ampullofugal flow produces a stronger response than ampullpetal flow in the vertical canals (anterior and posterior semicircular canals). In 1892 he was given an award by the

Paris Academy of Sciences The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at th ...

for his monograph "''Physiologische Untersuchungen über das Endorgan des Nervus octavus''".

Selected writings

* ''Physiologische Untersuchungen über das Endorgan des Nervus octavus'' (1892). * ''Ist die Lunge luftdicht?'' (with

Rudolf Kobert Rudolf Kobert (3 January 1854 – 27 December 1918) was a German pharmacologist and toxicologist born in Bitterfeld. In 1877 he graduated from the University of Halle, afterwards working as an assistant to physiologist Friedrich Goltz (1834-1902) ...

). * ''Zur Physiologie des Labyrinths'' (1895) – physiology of the

labyrinth In Greek mythology, the Labyrinth (, ) was an elaborate, confusing structure designed and built by the legendary artificer Daedalus for King Minos of Crete at Knossos. Its function was to hold the Minotaur, the monster eventually killed by the ...

. * ''Die Physiologie des Kehlkopfs'' (1896) – physiology of the

larynx The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...

. * ''Eine neue Hörtheorie'' (1899) – new theory of hearing. * ''Schallbildertheorie und Erkenntnistheorie'', Z. Sinnesphysiol. 53, 213-217. (1914) – theory of sound patterns and

epistemology Epistemology (; ), or the theory of knowledge, is the branch of philosophy concerned with knowledge. Epistemology is considered a major subfield of philosophy, along with other major subfields such as ethics, logic, and metaphysics. Episte ...

References

Deutsche Biographie
(biography) * List of publications copied from an equivalent article at the

German Wikipedia The German Wikipedia (german: Deutschsprachige Wikipedia) is the German-language edition of Wikipedia, a free and publicly editable online encyclopedia. Founded on March 16, 2001, it is the second-oldest Wikipedia (after the English Wikipedia), ...

. {{DEFAULTSORT:Ewald, Ernst Julius Richard Scientists from Berlin Academic staff of the University of Strasbourg 1855 births 1921 deaths German physiologists