Karl Ewald Konstantin Hering

Karl Ewald Konstantin Hering was one of the greatest personalities among the German physiologists of his time. He mastered the problem of visual space perception and challenged the colour-vision theory of Hermann von Helmholtz, postulating three types of receptors, each capable of a dual response to pairs of colours yellow-blue, red-green, or black-white. His work on sense physiology also had a great influence on the evolution of modern psychology. Not surprisingly, his name is eponymously associated with Josef Breuer, one of the founders of modern psychology and psychoanalysis.

Hering was the son of a village parson. He attended the Univesity of Leipzig, studying under Ernst Heinrich Weber (1795-1878), Gustav Theodor Fechner (1801-1887), Otto Funke (1828-1878), and the zoologist Julius Victor Carus (1823-1903). With Carus he spent the winter of 1858-1859 on Sicily to study the genital and excretory organs of Alciopida, a genus of ringed worms. These were the subject of his doctoral dissertation at the University of Leipzig in 1860.

From 1960, Hering practiced medicine and worked as an assistant at the policlinic directed by Ernst Leberecht Wagner (1829-1888), professor of general pathology and pathological anatomy. In 1862 he was habilitated as Dozent (lecturer) in physiology. At that time he began his studies of the physiology of vision.

Professor in Vienna and Leipzig
In 1865 Carl Friedrich Wilhelm Ludwig (1816-1895) moved to the new chair of physiology at Leipzig, and Hering succeeded him in the chair of physiology at the military Medico-Surgical Academy, the Josephinum, or Josephs-Akademie, in Vienna. Besides continuing his work on binocular vision, he now also turned to other fields of physiology. The most famous results of these studies were his discovery, with Josef Breuer, of what is now known as the Hering-Breuer reflex.

When the Josephinum was abolished in 1870, Hering was appointed to Jan Evangelista Purkyne's (1787-1869) chair of physiology in Prague. He remained there for twenty-five years, probably never becoming very popular with the locals, since he emphasized the importance of German science and German culture there. In 1882 he was a very important factor in the foundation of the German University in Prague and as a consequence did not accept an invitation to move to Strassburg. At Prague he devoted most of his energy to research in sensory physiology, mainly of vision, and to more general conceptions.

In 1895, this time at Leipzig, Hering succeeded Carl Ludwig once more and remained there for the rest of his life, studying colour phenomena and devising new experiments and instruments for their demonstration in support of his color theory.

Teacher and scientist
Hering was a good teacher but, like many in those days, welcomed controversy and public debate. For example, when he was 29, he attacked Georg Meissner (1829-1905), then professor at Göttingen, on careless mistakes in his studies on vision. In turn he himself was criticised by Hermann Helmholtz for some of his new approaches and ideas. Although Hering had the power to generalize and penetrate to basic problems, his approach could not lead to a significant advance and his theory had little heuristic value.

Hering was responsible for the "psycho-physical theory" of heredity, "that facultative memory, the automatic power of protoplasm to do what it has done before, is the distinctive property of all living matter." His belief that the transmission and reproduction of parental characters are the result of the organism's preconscious memory of the past was an idea subsequently reiterated by Samuel Butler.

Hering attracted many people to work with him including Henry Head (1861-1940) from England and the famous German ophthalmologist Carl von Hess (1863-1923) and Wilhelm Biedermann (1852-1929), a well known physiologist. His son, Heinrich Ewald Hering (1866-1948), achieved eponymic fame in his own right – Hering’s nerves – and held the chair of physiology at Köln.

Most of Hering's articles appeared in Poggendorff’s Annalen (1863, 1865), Archiv für Anatomie und Physiologie (1864, 1865), Archiv für mikroskopische Anatomie (1867), Wiener akademische Sitzungsberichte (1866-1882), Archiv für Ophthalmologie (1869), Jahrbuch Lotos (1880-1888), Archiv für die gesamte Physiologie (1887-1898), and Beiträge zur Physiologie.

• Beiträge zur Physiologie. Zur Lehre vom Ortsinne der Netzhaut.
  5 parts, Leipzig, Engelmann. 1861-1864.
• Die Lehre vom binokularen Sehen. Leipzig, Engelmann, 1868.
• Die Selbststeuerung der Athmung durch den Nervus vagus.
  Sitzungsberichte der kaiserlichen Akademie der Wissenschaften. Mathematisch–naturwissenschaftliche Classe, Wien, 1868, 57 Band, II. Abtheilung: 672-677.
  Sitzungsberichte der Mathematisch-Naturwissenschaftlichen Classe der Kaiserlichen Akademie der Wissenschaften
• Über das Gedächtnis als eine allgemeine Function der organisirten Materie.
  Vortrag. Kaiserliche Akademie der Wissenschaften Wien, 30. Mai, 1870. Wien, 1870.
  A first edition of this book is an extremely rare collector's item.
• Zur Lehre vom Lichtsinne.
  Sitzungsberichte der kaiserlichen Akademie der Wissenschaften, Wien, 1872, 1873.
• Ueber Farbenblindheit, Muskelgeräusche des Auges.
• Ueber den Bau der Wirbelthierleber.
• Zur Lehre vom Leben der Blutzellen.
• Ueber den Einfluss der Athmung auf den Kreislauf.
• Ueber das Gedächtniss als eine allgemeine Function der organisirten Materie.
• Grundzüge einer Theorie des Temperatursinnes. 1877.
• Zur Lehre vom Lichtsinne: Sechs Mittheilungen an die Kaiserl. Akademie der Wissenschaften in Wien. 2nd edition, 1878, Wien: C. Gerold's Sohn.
• Zur Lehre vom Ortsinne der Netzhaut. Leipzig: Engelmann, 1878.
• Der Raumsinn und die Bewegung des Auges. In Ludimar Hermann (1838-1914), editor: Handbuch der Physiologie, Leipzig, 1879, III, part 1: 343-601.
  English translation by C. A. Radde: Spatial Sense and Movements of the Eye. 1942, Baltimore, MD: American Academy of Optometry
• Temperatursinn.
  L. Hermann, editor, Handbuch der Physiologie: III, part 2. Leipzig, 1879.
• Beiträge zur allgemeinen Nerven- und Muskel-Physiologie. 1879-1882.
• Über die specifischen Energien der Nervensystem. 1884.
• Zur Theorie der Vorgänge in der lebendigen Substanz. 1888
• Zur Theorie der Nerventätigkeit. Leipzig, 1899.
• Grundzüge der Lehre vom Lichtsinne.
  In Graefe-Saemisch, volume 3 (4 volumes). Berlin, 1905-1920
• Fünf Reden von Ewald Hering.
  His addresses, edited by Heinrich Ewald Hering. Leipzig, Engelmann, 1921. Obituaries by:
  
• Nathan Zuntz (1847-1920) in Deutsche Medizinische Wochenschrift, Berlin, 1918, 44: 215.
  
• F. B. Hofmann in Münchener medizinische Wochenschrift, Berlin, 1918, 65: 539. With bibliography.
  
• Erich Tschermak von Seysenegg (1871-1962) in Medizinische Klinik, 1918, 14: 329.
• Paul von Grützner (1847-1919):
  Zum 70. Geburtstag von Ewald Hering.
  Deutsche Medizinische Wochenschrift, Berlin, 1904, 30: 1175.
• Franz Hillebrand (1863-1926):
  Ewald Hering. Ein Gedenkwort der Psychophysik. Berlin, 1917.
• Vladislav Kruta (1908-1979):
  Karl Ewald Konstantin Hering. In: Charles Coulston Gillispie. Editor in chief: Dictionary of Scientific Biographies. New York, Charles Scribner’s Sons, 1970, pp. 299-301.
• Barry G. Firkin and J. A. Whitehead:
  E. Hering (1834-1918). In their: Dictionary of Medical Eponyms. Parthenon Publishing Group, 1989, pp. 232-233. Hering's works until 1917 are listed in Charles Robert Richet’s (1850-1935) Dictionnaire de physiologie (Paris, F. Alcan, 1895-1928) of which he was a collaborator.