(b. Liegnitz, Germany [now Legnica, Poland], 27 January 1839; d. Bad Nauheim, Germany, 6 June 1914)
Hugo Kronecker was the brother of the mathematician Leopold Kronecker. After attending the grammar school at Liegnitz, he went to Berlin, where he began studying medicine around 1859–1860. He soon took a great interest in physiology, taught at that time by du Bois-Reymond. He continued his studies at Heidelberg, where at the institute he took part in investigations of the physiology of the muscles carried out by Hermann von Helmholtz and W. Wundt. After further studies at Pisa, he returned to Berlin. There he took the doctorate in 1863 under du Bois-Reymond with a thesis on the problem of the fatigue of the muscles. In 1865 he was registered as a medical practitioner. He received his clinical training at Berlin as the personal assistant of his friend, Ludwig Traube, who was a follower of the so-called physiological school in medicine. He also worked under Wilhelm Kühne. Kühne was at the time in charge, under Virchow, of the chemico-physiological laboratory in the Charité Hospital in Berlin.
In 1868 Kronecker moved to Leipzig, where he worked in the Physiologische Anstalt directed by Carl Ludwig. After a temporary absence, during which he participated as a medical officer in the Franco-Prussian war of 1870–1871, Kronecker became Ludwig’s assistant; in the same year, he qualified as a lecturer with a significant dissertation in the field of the physiology of muscles. In 1875 he was appointed senior lecturer at the Physiologische Anstalt, where he stayed until 1877. In that year young physiologists from many countries were working at Ludwig’s laboratory; among them were S. von Basch, Baxt, Bowditch, Buchner, Flechsig, M. von Frey, W. Gaskell, Gaule, Merunowicz, A. Mosso, G. Schwalbe, and Scäfer. Kronecker was of great aid to them, in part because of his outstanding knowledge of foreign languages and his congeniality. From 1878 to 1884 Kronecker was in charge of the “special physiological department” of the Institute of Physiology at Berlin, directed by du Bois-Reymond. Once again he helped the foreigners studying at the Berlin institute, among them the Russians N. E. Wedenskij, Th. Openchowski, D. von Ott, N. W. Jastrebov, and D. V. Kireev. In addition S. von Basch from Vienna and Francis Gotch from England worked under him.
When he was appointed successor to Paul Grützner as full professor for physiology at Bern in 1884, many foreigners worked at his institute, especially after the “Hallerianum,” a new building attached to the institute had been constructed. He took a great part in founding the International Physiological Congress. The first one took place at Basel in 1889. Kronecker held his chair at Bern until his sudden death at Bad Nauheim of a perforated aortic aneurysm. He was seventy-five. After his death obituaries appeared throughout the world. His extreme amiability, his noble character, his generosity as a host, his sociability, and his merits as a scientist were praised in all of them.
Kronecker’s scientific investigations were mainly centered around questions concerning the muscles, the heart and circulation, the mechanism of deglutition, saline infusion, and mountain sickness. Because most of the works appeared under his name and those of his collaborators, and some only under the name of the latter, it is often difficult to assess the share contributed by Kronecker himself. His methodological talents were spoken of very highly. He improved the proofs for the all-or-none law applied to the heart (1873) as well as the method of the isolated heart (1874). Almost simultaneously with E. J. Marey, he described the refractory period of the heart (1874). A device for irrigating and measuring the pressure of the isolated heart is named after him. He also discovered a blood substitute in saline solution. He reported on the life-saving NaCl injection in 1884.
Kronecker made an essential contribution to the development of the first clinically applicable indirect method of measuring the blood pressure, carried out at Berlin by S. von Basch (1880). Together with S. J. Meltzer he worked on the deglutition reflex, its speed, and its dependence on the nervous system. Throughout his life Kronecker defended the theory of the neurogenic origin of the automatism of the heart beat, which later was shown to be mistaken. He constructed a much-used calibrated induction coil for the excitation of living organs and on several occasions dealt with questions concerning the excitability of the skeletal muscle and of the heart muscle.
When he was at Bern, most of his research dealt with the problem of mountain sickness. Kronecker argued against the oxygen-deficiency theory put forward by Paul Bert, favoring a mechanical theory—that is, he regarded a congestion of the lung vessels by pulmonary edema as its cause. This theory, too, was mistaken and Bert’s theory of oxygen-deficiency was proven right. In 1894 Kronecker led an expedition to Zermatt for the investigation of these pulmonary disturbances. The purpose of the expedition was to draw up an expert’s report on the possible dangers of the quick ascent up Jungfrau mountain on the cable-railway line, which was then in the planning stage (1892). The monograph “Mountain Sickness” (1903) presents the results of his work.
I. Original Works. Among Kronecker’s more important publications are “De ratione qua musculorum defatigatio ex labore eorum pendeat,” Ph.D. dissertation, University of Berlin, 1863; “Über die Ermüdung und Erholung der quergestreiften Muskeln” (Habilitation thesis), in Arbeiten aus der Physiologischen Anstalt zu Leipzig 1871 (Leipzig, 1872), PP. 177–265; “Das charakteristische Merkmal der Herzmuskelbewegung,” in Beiträge zur Anatomie und Physiologie als Festgabe für Carl Ludwig zum 15. Oktober 1874 gewidmet von seinen Schuelern (1874), PP. CLXXIII–CCIV; “Über die Speisung des Froschherzens,” in Archives für Anatomie und Physiologie, Physiologische Abteilung (1878), 321–322; “Die Genesis des Tetanus,” ibid. (1878), 1–40, written with William Stirling; “Über die Form des minimalen Tetanus,” ibid. (1877), PP. 571–573; “Über den Mechanismus der Schluckbewegung,” ibid. (1880), 296–299; ibid. (1880), 446–447; ibid. (1881), 465–466; and ibid. (1883) (Suppl. Band), 328–362, written with S. J. Meltzner.
For further reference, see Kronecker and Schmey, “Das Coordinationszentrum der Herzkammerbewegungen,” in Monatsberichte der Preussischen Akademie der Wissenschaften zu Berlin (1884), 87–89; “Ueber graphische Methoden in der Physiologie. Z. Instrumentenkunde,” 1 (1881), 26–28; and “Ueber Störungen der Coordination des Herzkammerschlages,” in Zeitschrift für Biologie, n.s., 34 (1896), 529–603.
II. Secondary Literature. For detailed obituaries, see S. J. Meltzner, “Professor Hugo Kronecker,” in Science, 40 (1914), 441–444; and Paul Heger, “Hugo Kronecker,” in Münchener medizinische Wochenschrift, (1914), PP. 1629–1631. Short obituaries include A. Loewi, “Hugo Kronecker,” in Deutsche medizinische Wochenschrift, (1914), PP. 1437–1438; and anonymous works in Lancet (1914), 92 , 270–271; British Medical Journal (1914), 2 , 491; Corr. Blatt für Schweizer Ärzte, Jg. XLIV (1914), 848–850; E.A.S. (E. A. Schäfer?), “JHugo Kronecker 1839–1914,” in Proceedings of the Royal Society, Ser. B, 89 (1917), 14–50. A short biography in Biographisches Lexikon der hervorragenden Ärzte aller Zeiten und Völker, Ii, repr. by Haberling, III (Berlin–Vienna, 1931), 616–617.
For a bibliography of Kronecker’s works consults Royal Society, Catalogue of Scientific Papers, 8 (1879), 128, 10 (1894), 467–468. See also H.-J. Marseille, “Das physiologische Lebenswerk von Emil du Bois-Reymond mit besonderer Berücksichtigung seiner Schüler,” diss. (Münster, 1968).
K. E. Rothschuh