Fick, Adolf Eugen

(b. Kassel, Germany, 3 September 1829; d. Blankenberge, Belgium, 21 August 1901)

physiology, physical medicine.

Fick’s father, Firedrich Fick, a senior municipal architect in Kassel, was instrumental in reorganizing street constrution in that city. His mother, Nanni Sponsel, had nine children, of whom Adolf was the youngest. Two of his brothers were professors (one of anatomy and the other of law) at Marburg when Fick began to study there. In the winter semester of 1847-1848, he began his work in mathematics and physics, fields for which he possessed great aptitude, although he soon switched to medicine.

The descendant of Protestant émigrés from Salzburg, Fick was raised in that faith. He was a man of high moral sense, pious but without any formal church affiliation. He married Emilie von Coelln on 24 October 1862. They had five children, two of whom died in early childhood. One son became a jurist; another became an anatomist in Berlin.

As a medical student at Marburg, Fick was guided in anatomy not only by his brother Ludwig but also by his early friendship with Carl Ludwig, then lecturing at Marburg on anatomy and physiology. Fick became one of the main proponents (with Carl Ludwig) of the new orientation of physiology toward physics, to which Hermann von Helmholtz, Ernst Brücke, and Emil du Bois-Reymond also subscribed. It was their objective to determine quantitatively. whenever possible, the fundamental capabilities of the organism’s components and to explain them on the basis of general physicochemical laws of nature. Fick wrote his first scientific paper, an investigation on the torque exerted by the motor muscles of the femur in the hip joint (1849), when he was still a student. In this he demonstrated his gift for planning, executing, and mathematically evaluating mathematical-physical research of physiological processes. In the fall of 1849 he contrinued his studies at Berlin, where he became friends with Helmholtz and du Bois-Reymond. In Berlin the anatomist Johannes Müller, because of his entirely different approach in theory and practice, was unable to exert any great influence on Fick, who was said, moreover, to have been then a genius in the art of enjoying a carefree student life.

Upon his return to Marburg, Fick obtained his doctorate on 27 August 1851, with a thesis on visual errors due to astigmatism. He then accepted the position of a prosector in anatomy with his brother but followed Carl Ludwig to Zurich six months later. This was the beginning of a scientific career characterized by an unusually diversified scientific output. Fick remained in Zurich from 1852 until 1868, first as prosector in anatomy with Ludwig until 1855, subsequently as associate professor of the anatomical and physiological auxiliary sciences until 1861, and later as full professor of physiology. In the winter semester of 1868 he assumed the same position in the Faculty of Medicine at Wurzburg, which he held for more than thirty years. In 1883 he moved into a new physiological institute.

During 1878-1879 Fick was rector of the University of Würzburg. He retired at the age of seventy, in 1899. On 21 August 1901 he died from the after effects of a cerebral hemorrhage. In 1929 his sons founded the Adolf Fick Fund, which every five years awards a prize for an outstanding contribution to physiology.

Fick’s lifework is concerned primarily with problems on the borderline between medicine, physiology, and physics. Accordingly, his monograph Medizinische Physik, published in 1856, when he was twenty-six years old, is most characteristic of the problems he preferred, particularly (1) molecular physics: diffusion of gases and water, filtration, endosmosis, and porous diffusion; (2) mechanics of solids, including the geometry of articulations, and the statics and dynamics of muscles; (3) hydrodynamics, as applied to the motion of fluids in rigid and/or elastic vessels (blood vessels), and pulse variations and their accurate recording; (4) sound; (5) the theory of heat in physics and physiology, the origin of heat, and the law of the conservation of energy in the body; (6) optics: the path of rays in the eye and ophthalmoscopy, the microscope, the horopter, and color perception and the theory of color sense; and (7) the theory of electricity: the origin, derivation, and measurement of bioelectric phenomena.

All of these fields were treated with great success by Fick. He showed himself to be an analyst who reflected in strict conformity with physical laws and arrived at the precise mathematical expression of physiological processes. In similar form he analyzed the mechanics of the saddle joint of the thumb (1854) and, in the same year, the torsional movement of the several muscles that move the bulbus oculi. In addition, he studied molecular biophysics, e.g., the expansion of bodies by heat (1854). He then examined, on the basis of the investigations of Brucke, Jolly, Ludwig, and Max Cloetta, the process of diffusion and developed a differential equation for the flow between a saturated sodium chloride solution and distilled water (1855). In experimental analysis, he introduced the collodion membrane into the study of porous diffusion in endosmosis (1857).

The physics of the vision process had occupied Fick since his doctoral thesis, “De errore optico,” which was concerned with perceptual illusions due to astigmatism (1851). He also analyzed the blind spot in the eye and the phenomenon of monocular polyopia through unequal ratios of curvature in the refractive media (1854). Beginning in 1853, Fick became interested in the sequence of excitation in the retina, in adaptation, in the phenomenon of the latent stage, and then in the slow initiation of retinal stimulation (1864). He reflected on the phenomena of color vision and arrived at a confirmation of Helmholtz’ three component theory (1880) but raised essential reservations in regard to Ewald Hering’s theory. Later, he was successful in building the first practical instrument for measurement of intraocular pressure, the ophthalmotonometer (1888). Fick had a particular gift for and ingenuity in constructing physiological measuring devices and developed, among other apparatus, an improved aneroid manometer for measurement of the pressure gradient in the vascular system and a pneumograph for recording peripheral variations of the thorax in breathing (1869-1897).

Fick also made outstanding contributions to hemodynamics. He developed a principle, which came to be called Fick’s law (1870), that permits calculation of the cardiac output from the measurement of the minute volume of oxygen consumption and arteriovenous oxygen difference in the living organism. The arteriovenous differences of oxygen level indicate the amount of oxygen per 100 cc. carried off by the blood flowing through the lung, and the oxygen consumption per minute indicates how many times per minute 100 cc. of blood have circulated through heart and lung; this result is called the minute volume, and its division by the heart rate yields the stroke volume.

Fick considered mathematical expression to be the most exact and, indeed, the only adequate language of science. In this spirit he theorized on the speed of the flow of blood in the vascular system, on its conditions, and on its measurability. He also introduced the principle of plethysmography. In this procedure the arm, for example, is placed in a rigid, water-filled vessel to which a narrow upright tube is attached. If the supply of blood to the arm exceeds the outflow of blood within the same interval, water is displaced and the meniscus in the tube will rise (1869). Fick also constructed a model of the bloodvessel ramifications from rigid and elastic tubes in order to simulate and analyze the pressure drop in the circulation, especially in the capillaries (1888).

Fiuck’s gift for mathematical-physical thinking is most clearly exhibited in his numerous studies on the nature of heat, on the causes of thermal expansion of bodies (1854-1855), and on the nature, magnitude, and origin of body heat. These problems occupied him again and again, and he maintained that questions of thermal production and consumption should be kept separate from temperature topography. He ascribed all processes of heat generation to the expenditure of chemical energy, which takes place, for instance, to provide the mechanical energy for muscular effort. This raises the question of the substances supplying the energy through their decomposition. Liebig declared them to be the proteins. In 1865 Fick decided the question during a climb of the Faulhorn, in Switzerland, by determining the energy consumed (in m. kg. of climbing effort) and through calculation of protein catabolism from the nitrogen passed in the urine. He found that protein is insufficient to provide the energy requirements.

Fick further investigated the generation of heat in the muscle with sensitive thermometers and related its magnitude to the effort of contraction produced. In order to increase accuracy in such investigations, he introduced the concept and the methodology of isotonic and isometric determination of the process of muscular contraction (1867,1872,1889). He constructed apparatus for measuring the output of m. kg. with the aid of a rotating wheel, the dynamometer (1891). He was always concerned with testing the validity of the law of the conservation of energy in the body. In this connection, Fick also encountered the need for adequate and graduated stimulation of muscles and nerves.

His physiology of stimulation attempted in this connection to find new quantifiable parameters. In contrast with generally held views. Fick found that contraction is a function not only of the intensity of nerve stimulation but also the duration of the stimulus. He demonstrated this specifically for the smooth muscle, in this case the shell adductor of mussels (1863). Fick further investigated electrotonus under optimum exact conditions (1866-1869) and the effect of transversal nerve stimulation. Notable was his successful attempt to demonstrate, against the opinion held by French scientists, that electrical stimulation of the anterior marginal bundles of the spinal cord was possible. He made this an occasion (1869) for an interesting discussion of his research principle of clarifying the fundamental properties of the elemental components of the animal organism, as opposed to a method of research preferring observations and tests of the entire animal.

The similarity of the physiological objectives of Helmholtz and Fick is astonishing. Both were particularly interested in the clarification of the physicochemical and quantitatively determinable processes. Both performed outstandingly in this field. The prerequisites here were always to work under the simplest possible arrangements, under constant or known conditions, or both, and to test the consequences produced by a measurable variation of one of the conditions. Causal analysis within the context of the exact natural sciences, quantification, construction of measuring devices and apparatus—these were the objectives and paths of the generation of German physiologists in the second half of the nineteenth century which included, besides Adolf Fick and Helmholtz. Carl Ludwig and many others.

Fick’s acumen was not concentrated in scientific analysis alone. He was also greatly interested in the methodology of scientific investigation, as his philosophical articles demonstrate. He dismissed the romantic physiology of Schelling and Hegel as “superior nonsense” (1870). Like Helmholtz, he followed Kant and believed the empiricism of John Stuart Mill to be inadequate. His epistemological attempt at refutation of Kirchhoff (1882) and his Philosophischer Versuch über die Wahrscheinlichkeiten (Würzburg, 1883) reflect these views.

Fick possessed a crystal-clear manner of thinking and writing. He was modest, without intellectual arrogance, and stood by his convictions fearlessly. When he realized the consequences of alcohol abuse, he ceaselessly called public attention to this problem. Among Fick’s disciples and collaborators were Friedriuch schenck, Magnus Blix, Johannes Gad, A. Gürber, and Jacques Loeb.

BIBLIOGRAPHY

I. Original Works. All of Fick’s publications were collected and published posthumously in Adolf Fick. Gesamelte Abhandlugen, 4 vols. (Würzburg, 1903-1905), with portraits, bibliographic data, and a biography by F. Scheneck. Among his writings are Medizinsche Physik (Brunswick, 1856); Compendium der Physiologie des Menschen mit Einschluss der Entwicklungsgeschichte (Vienna, 1860); Beiträge zur vergleichenden Physiologie der irritablen Substanzen (Brunswick, 1863); Lehrbuch der Anatomie und Physiologie der Sinnesorgane (Lahr,1864); Untersuchungen über electrische Nervenreizung (Brunswick, 1864); “Über die Entstehung der Muskelkraft,” in Viertelijahrsschrift der Naturforschenden Gesellschaft in Zürich, 10 (1865), 317 ff.; “Speziele Bewegungslehre,” in L. Hermann, Handbuch der Physiologie, I, Pt. 2. (Leipzig, 1879); “Dioptrik und Lichtempfindung,” ibid., III , Pt. 1 (Leipzig, 1879); Mechanische Arbeit und Warmeentwicklung bei der Muskeltatigkeit (Leipzig, 1882); and Mythermische Untersuchungen ausdem physiologischen Laboratorium zu Zürich and Würzburg (Wiesbaden, 1889).

The Journal publications are easily accessible in Gesammelte Abhandlungen and need not be listed here in detail.

II. Secondary Literature. Notices and obituaries are René du Bois-Reymond, “Nachruf,” in Naturwissenschaftliche Rundschau (Stuttgart),16 (1901), 576-577; Friedrich Fick, “Adolf Fick, Professor der Physiologie (1829–1901),” in Lebensläufe aus Franken, I (1919), 94 ff., a biography; Max von Frey, “Gedächtnisrede,” in Sitzungsberichte der Physikalische-medizinischen Gesellschaft zu Würzburg (1901), 65ff., with references to the literature; Adam Kunkel, “Nachruf,” in Münchener medizinische Wochenschrift,48 (1901), 1705-1708; Kurt Quecke, “Adolf Fick (1829-1901). Physiologe,” in Lebensbilder aus Kurhessen and Waldeck,4 (1950), 82-90; K.E. Rothschuh. Geschichte der Physiologie (Berlin-Göttinger-Heidelburg, 1953), pp. 150-153; F. Schenck, “Zum Andenken an A. Fick,” in Pflügers Archiv für die gesamte Physiologie des Menschen und der Tiere,90 (1902), 313-361, with portraits and biography, a good analysis of his work; Dietrich Trincker, “Adolf Fick,” in Neue deutsche Biographie, V (Berlin, 1961), 127-128; and Edger Wohlisch, “A. Fick und die heutige Physiologie,” in Die Naturwissenschaften,29 (1938), 585-591; and Biographisches Lexikon der hervorragenden Arzte..., II (Berlin-Vienna, 1930), 515-516.

K. E. Rothschuh