Skip to main content

Preyer, Thierry William


(b.. Moss Side, near Manchester, England, 4 July 1841 : d. Wiesbaden, Germany, 15 July 1897)


Preyer was educated first in London and then in Duisburg, following his immigration to Germany in 1857. He began to study science at Heidelberg in 1859, concentrating on physiology and chemistry, and received the doctorate in 1862. While still a student he traveled to Iceland with the geologist Ferdinand Zirkel. The results of their journey were published in 1862. Turning from natural science to medicine, Preyer studied in Paris with Claude Bernard and Charles-Adolphe Wurtz, and later in Berlin, Vienna, and Bonn. In 1865 Preyer qualified at Bonn as a lecturer in zoophysics and zoochemistry in the Faculty of Philosophy. The following year he received his medical degree at Bonn. In 1867 he qualified as a teacher of physiology at the Faculty of Medicine of the University of Jena, where in 1869 he succeeded Johann Nepomuk Czermak as professor of physiology and was appointed director of the Physiology Institute. Poor health obliged him to retire in 1888, and he spent the rest of his life as a private scholar in Wiesbaden.

Preyer’s initial scientific work dealt with physiological chemistry (hemoglobin, gases in the blood, curare) and sense physiology (myophysical law). His lactic acid theory of sleep (1876) became widely known. His most significant contributions, however, are in his writings on psychology, especially Die Seele des Kindes (1882). With this work Preyer established himself as one of the founders of modern developmental psychology—an approach by which the descriptive natural sciences could exhibit the attributes of the determinate and empirically oriented disciplines. Its prime method was the chronological arrangement of observations made throughout the psychological life of the child.

Preyer frequently tackled more general scientific problems. In Naturwissenschaftliche Thatsachen and Probleme (1880) he discussed the possibility that inorganic matter had emerged from living systems. The sole difference between them, he asserted, was that the former can come into being in various ways, whereas all living creatures derive from organic bodies and therefore must undergo a process of development. This development, which cannot be interrupted, goes as far back as the period when the earth was in a fluid, incandescent state; and Preyer interpreted movements Within it as themselves signs of life. All inorganic compounds were at first absent from the earth, which in Preyer’s view was teeming with life. Only with increasing cooling did compounds condense, and these became steadily more like protoplasm, the material basis for the evolution of the organisms.

Preyer’s definition of protoplasm, in Elemente der allgemeinen Physiologie (1883), directly challenged the view of the older biologists, who considered protoplasm to be a homogeneous substance. For Preyer it was a “mixture of solids and liquids, of very complex chemical compounds that in the present stage of life are going through rapid and uninterrupted decomposition and re—formation. “In his genetic system of the elements (1893) Preyer took into account Mendeleev’s periodic system as well as the periodic laws formulated by Julius Lothar Meyer and the seven divisions first recognized by John A. R. Newlands.


I. Original Works. Preyer’s earlier writings include Reise nach Island (Leipzig, 1862), written with F. Zirkel; Rétablissement de l’irritabilité des muscles roides (Paris, 1865); De haemoglobino observationes et experimenta (Bonn, 1866), his dissertation; Empfindungen (Berlin, 1867); Über einige Eigenschaften des Haemoglobins und Methaemoglobins (Bonn. 1868); Grenzen des Empfindungsvermögens und des Willens (Bonn, 1868); Die Blausäure, 2 vols. (Bonn, 1868-1879); Kampf ums Dasein (Bonn, 1869); Die fünf Sinne des Menschen (Leipzig, 1870); Die Blutkrystalle (Jena, 1871); Die Erforschung des Lebens (Jena, 1871); Das myophysisclic Gesetz (Jena, 1874); Aufgaben der Naturwissettschaften (Jena, 1876);. Über die Grenzen der Tonwahrnehmung (Jena, 1876); Über die Ursachen des Schlafes (Stuttgart, 1877): Kataplexie und Hypnotismus (Stuttgart, 1878); and Naturwissenschaftliche Thatsachen und Probleme (Berlin, 1880).

Later works include Die Entdeckung des Hypnotismus (Berlin, 1881); Farben- und Temperatursinn (Jena, 1881); Concurrenz in der Natur (Breslau, 1882); Die Seele des Kindes (Leipzig, 1882; 8th ed., 1912); Elemente der allgemeinen Physiologie (Leipzig, 1883); Ein neues Verfahren zur Herabsetzung der Korpertemperatur (Jena, 1884); Aus Natur- und Menschenleben (Stuttgart, 1885); Spezielle Physiologie des Embryo (Leipzig, 1885); Naturforschung und Schule (Stuttgart, 1887); Biologische Zeitfragen (Berlin, 1889); Über die Erhaltung der Energie. Briefe Robert von Mayers an Wilhelm Griesinger nebst dessen Antwortschreiben aus den Jahren 1842 bis 45 (Berlin, 1889), which Preyer edited; Der Hypnotismus (Vienna-Leipzig, 1890); Die geistige Entwickhurg in der ersten Kindheit, nebst Anweisung för Eltern dieseble zu beohachten (Stuttgart, 1893); Das genetische System der chemischen Elemente (Stuttgart, 1893); Der Prozess Czynski. That-bestand desselben und Gutachten über Willensbeschrdnk-ung durch hypnotisch-suggestiven Einfluss (Stuttgart, 1895); and Zur Psychologic des Schreibens (Hamburg, 1895; 2nd ed., Leipzig, 1912). See also Poggendorff, III, 1069-1070.

II. Secondary Literature. Two short biographies are in Biographisches Lexikon der herr’orragenden Ärzte der letzten fünfzig Jahre (Munich-Berlin, 1962), 1246; and Biographisches Lexikon hervorragender Ärzte des newizehnten Jahrhunmderts (Berlin Vienna, 1901), 1323-1325, with portrait.

A. Geus

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Preyer, Thierry William." Complete Dictionary of Scientific Biography. . 16 Sep. 2019 <>.

"Preyer, Thierry William." Complete Dictionary of Scientific Biography. . (September 16, 2019).

"Preyer, Thierry William." Complete Dictionary of Scientific Biography. . Retrieved September 16, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.