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Johann Nepomuk Czermak

Born  1828
Died  1873

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German physiologist, born June 17, 1828, Prague; died September 16, 1873, Leipzig.

Biography of Johann Nepomuk Czermak

Johann Nepomuk Czermak is remembered mainly for his contribution to the scientific development of laryngoscopy and its reception as a method of clinical examination.

Czermak’s father and grandfather were physicians in Prague, and his uncle, Joseph Julius Czermak (1799-1851), was professor of advanced anatomy and physiology in Vienna. Czermak studied in his native city of Prague, then in Vienna (1845), Breslau (1847), and Würzburg (1849-1850). He early gained the advantage of the advice and sponsorship of Jan Evangelista Purkyne (1787-1868), then professor of physiology in Breslau, who deeply influenced his scientific interests throughout his life. Indeed, many of Czermak’s research subjects were further developments of topics studied by Purkyne. This included the structure of the teeth, subjective visual phenomena, touch, vertigo, and phonetics.

Czermak received his doctorate in Prague after returning from a long journey. He became professor of physiology on Graz in 1855, then in Krakow in 1856, and Pest 1858 to 1860. He resigned his tenure in Pest and returned to Prague where he worked in his private institute. In 1865 he followed a call to Leipzig, where he died three years later as extraordinary professor of honour after having suffered for years from diabetes mellitus.

It was his interest in the movements of the muscles in speech and the conditions for producing certain unusual sounds - e.g., the Arabic gutturals - that led Czermak to use the laryngeal mirror in his research.

In 1855 Manuel Patricio Rodriguez Garcia (1805-1906), a singing teacher, published observations of his own larynx and vocal cords made with a small dental mirror introduced into the throat and using sunlight reflected by another mirror. Garcia was interested in movements connected with the production of the singing voice and did not anticipate the importance of laryngoscopy for medicine. Attempted again two years later by a Vienna neurologist, Ludwig Türck (1810-1868), laryngoscopy did not seem either practical or promising. Czermak, interested in physiological phonetics, substituted artificial light for sunlight and made other improvements.

In his lectures in several European countries he brought home to physicians its usefulness and importance, thus opening a new and important field of practical medicine.

The first pioneers in the use of the laryngoscope were, however, the Dutchman Karel van den Borek and the German physician Friedrich Hoffmann (1660-1742). Se Artikkel i 11.

Czermak was also the first (not Friedrich Eduard Rudolph Voltolini (1819-1889), as is sometimes stated, to use the same means for dorsal rhinoscopy. In phonetics he showed that the voice generated in the larynx does not participate in the production of vowels, but that both the voice and the acoustic conditions of the «joined pipe» (i.e., throat, mouth, and nasal cavities) play an important role in consonants.

In the physiology of sensations Czermak made the first systematic investigation of the spatial localisation of skin sensibility, that is, of the two-point threshold in relation to the size of the (Ernst Heinrich) Weber (1795-1878) sensory circles (1855), postulated a general sense for duration of different specific sensations (Zeitsinn) and laid down a program for the investigation of the time sense (1857).

He also contributed greatly to physiological experimental techniques, and some of his devices were widely used. He propagated the teaching of physiology by demonstration and designed for the purpose a model institute called a «spectatorium», which was built and opened in Leipzig nine months before his death.

Czermak possessed a great talent of innovation and presentation. He presented his research on the influence of the nervus sympathicus on the excretion of saliva, and the rapid spread of the pulse waves, as well as themes of microscopic histology in original ways. However, his only really pioneering results were in the field of laryngology, where the use of Garcia’s laryngoscope as an investigative instrument enabled him to break new ground. His private laboratory in Leipzig was of the highest class for its time.

Unable to comply with the requirements arising from the natural aspirations of Czechs, Poles, and Hungarians to develop teaching in their own languages at their universities, Czermak had to move several times and worked for some time as an independent scientist. He was afflicted with diabetes in his last years and was apprehensive of an early death - his father, uncle, and other male relatives had died in their forties. Czermak died at the age of forty-five, before he could finish his major theoretical work, «Die Principien der mechanischen Naturauffassung.»


  • Manuel Garcia:
    Observations on the human voice.
    Proceedings of the Royal Society, London, 1854-1855, 7: 399-410.
  • F. Voltolini:
    Die Rhinoskopie und Pharyngoskopie.
    Festschrift für den ärztlichen Verein Breslaus zum Jubiläum der Universität Breslau. 1861; 2nd edition, 1879. Johann Nepomuk Czermak:
  • Über den Kehlkopfspiegel.
    Wiener medizinische Wochenschrift, 1858, 8: 196-198.
  • Der Kehlkopfspiegel und seine Verwertung in Physiologie und Medizin. Leipzig, 1860.
  • Zur Physiologie des Gesichtssinnes. (On acccomodation phenomena).
  • Über den Raumsinn der Haut.
  • Gesammelte Schriften. 2 parts in 3 volumes. Leipzig, 1879.

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