Arthur Peter König (September 13, 1856,

Krefeld Krefeld ( , ; li, Krieëvel ), also spelled Crefeld until 1925 (though the spelling was still being used in British papers throughout the Second World War), is a city in North Rhine-Westphalia, Germany. It is located northwest of Düsseldorf, i ...

– October 26, 1901,

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 ...

) devoted his short life to physiological optics. Born with congenital

kyphosis Kyphosis is an abnormally excessive convex curvature of the spine as it occurs in the thoracic and sacral regions. Abnormal inward concave ''lordotic'' curving of the cervical and lumbar regions of the spine is called lordosis. It can result fr ...

he studied in

Bonn The federal city of Bonn ( lat, Bonna) is a city on the banks of the Rhine in the German state of North Rhine-Westphalia, with a population of over 300,000. About south-southeast of Cologne, Bonn is in the southernmost part of the Rhine-Ruhr r ...

and

Heidelberg Heidelberg (; Palatine German language, Palatine German: ''Heidlberg'') is a city in the States of Germany, German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914 ...

, moving to Berlin in the fall of 1879 where he studied under

Hermann von Helmholtz Hermann Ludwig Ferdinand von Helmholtz (31 August 1821 – 8 September 1894) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The Helmholtz Association, ...

, whose assistant he became in 1882. After obtaining a doctoral degree in 1882 he qualified for a professorial position in 1884. In 1890 he became director of the physical department of the Physiological Institute of the University of Berlin. In the same year he married Laura Köttgen with whom he had a son,

Arthur Arthur is a common male given name of Brittonic languages, Brythonic origin. Its popularity derives from it being the name of the legendary hero King Arthur. The etymology is disputed. It may derive from the Celtic ''Artos'' meaning “Bear”. An ...

, who became an astronomer. Circulatory problems caused by his kyphosis resulted in his premature death in 1901.Source of biographical information: M. Richter, Arthur König zum Gedächtnis, Die Farbe 5 (1956) No.1/2, 1–6. Originally working in physics, he began in 1883 to concentrate on

physiological optics 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 an ...

where he published over thirty papers, some of seminal importance. Among these are the 1886 paper (together with Conrad Dietrici) ''Fundamental sensations and their sensitivity in the spectrum'', an empirical determination of what in fact is the spectral sensitivity of the human rod and

cone A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines con ...

sensors of vision.A. König, Die Grundempfindungen und ihre Intensitäts-Vertheilung im Spectrum, Sitzungsberichte der Akademie der Wissenschaften zu Berlin, 29 July 1886, 805–829. Earlier attempts at such measurements, but based on much simpler technology, had been made in 1860 by the English physicist

James Clerk Maxwell James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and ligh ...

(1831–1879). Using newly development spectrophotometric equipment and modifications of the experimental procedure König and Dieterici published a more detailed paper in 1892, determining the "fundamental sensations" not only of subjects with normal color vision ( trichromats) but also of dichromats and monochromats.A. König, Die Grundempfindungen in normalen und anomalen Farbsystemen und ihre Intensitätsvertheilung im Spectrum, Zeitschrift für Psychologie und Physiologie der Sinnesorgane 4 (1892) 241–347. With these measurements König provided evidence for the conjecture that the most common form of

color blindness Color blindness or color vision deficiency (CVD) is the decreased ability to color vision, see color or differences in color. It can impair tasks such as selecting ripe fruit, choosing clothing, and reading traffic lights. Color blindness may ...

, dichromacy, is due to the absence of one cone type in the eye. Averaged König functions were widely used in psychophysical color stimulus calculations until new data based on a slightly different method and involving many more observers were determined by J. Guild and W. D. Wright in the later 1920s, resulting in the recommendations of standard observer data by the Commission Internationale de l'Eclairage (CIE, International Commission on Illumination) in 1931. KoeFig2

Other important investigations involve the sensitivity of the normal eye for differences in wavelength of light, dependence of the Newton/Grassmann laws of color mixture on light intensity, validity of Fechner's law at different light intensities, brightness of spectral hues at different light intensities, and the similarity between the perceptual sensitivity of the rod cells and the absorption spectrum of the rod photopigment,

rhodopsin Rhodopsin, also known as visual purple, is a protein encoded by the RHO gene and a G-protein-coupled receptor (GPCR). It is the opsin of the rod cells in the retina and a light-sensitive receptor protein that triggers visual phototransduction ...

. König was very active as an editor. In 1889 he became the sole editor of Verhandlungen der Deutschen Physikalischen Gesellschaft. From 1891 on, together with the psychologist H. Ebbinghaus, he edited the journal Zeitschrift für Psychologie und Physiologie der Sinnesorgane. After Helmholtz's death in 1894 König took on the task of completing preparations for the second edition of the former's Handbuch der physiologischen Optik (1896, Treatise on physiological optics) to which he added a bibliography of vision consisting of nearly 8,000 titles. König's 32 papers on physiological optics were published posthumously in book form in 1903.A. König, Gesammelte Abhandlungen zur physiologischen Optik, Leipzig: Barth, 1903.

References

{{DEFAULTSORT:Konig, Arthur 1856 births 1901 deaths 19th-century German physicists People from Krefeld People from the Rhine Province