- A dictionary of medical eponyms

Leonor Michaelis

Born  1875
Died  1949

Related eponyms

German-American biochemist, born January 16, 1875, Berlin; died October 10, 1949.

Biography of Leonor Michaelis

Leonor Michaelis studied in Berlin and Freiburg im Breisgau. He graduated in Freiburg in 1897 and received his doctorate in Berlin that year. He was then private assistant to Paul Ehrlich (1854-1915) in Berlin 1898-1899, assistant to Moritz Litten (1845-1907) in the Berlin city hospital at Urban 1899-1902, and 1902-1906 with Ernst Viktor von Leyden (1832-1910) in the cancer ward of the I. medical clinic. From 1906 to 1922 Michaelis was head of the bacteriological department at the Urban hospital, becoming professor extraordinary 1908.

From 1922 to 1926 Michaelis was professor of biochemistry at the University of Nagoya, Japan, and 1926-1929 resident lecturer in medical research at the Johns Hopkins University in Baltimore. From 1929 to 1940 he was with the Rockefeller Institute of Medical Research in New York. His main field of work was physical chemistry, in particular its use in biology and medicine.

Michaelis developed the equation with Menten to explain the relationship of the concentration of reactants on enzyme catalysed reactions. He discovered Janus Green and was the pioneer of the permanent wave since he found that keratin was soluble in thioglycolic acid. He died in New York City.

We thank Dr. Günter Krämer, Zürich, Switzerland, for information submitted.


  • Einführung in die Farbstoffchemie. Berlin, 1902.
  • Dynamik der Oberflächen.Dresden, 1909.
  • Einführung in die Mathematik für Biologen und Chemiker.
    Berlin, 1912; 3rd edition, 1927.
  • Die Wasserstoffionenkonzentration.
    Berlin, 1914; 2nd edition, 1922; unchanged reprint 1927, volume 2 titled Oxydations-Reductions-Potentiale, 1929.
  • Praktikum der physikalischen chemie.
    Berlin, 1921; 4th edition with Peter Rona (1871–), 1930; translated into French.
  • The effects of ions in colloidal systems. Berlin, 1925.
  • Die theoretische Grundlage für die Bedeutung der Wasserstoffkonzentration des Blutes. In Handbuch der normalen und pathologischen Physiologie. Volume 6, 1. Berlin, 1928.
  • J. S. Fruton:
    Michaelis, Leonor. In: F. L. Holmes, editor: Dictionary of Scientific Biography, Volume 18, Supplement II. New York, Charles Scribner’s Sons 1981: 620–625.

What is an eponym?

An eponym is a word derived from the name of a person, whether real or fictional. A medical eponym is thus any word related to medicine, whose name is derived from a person.

What is Whonamedit?

Whonamedit.com is a biographical dictionary of medical eponyms. It is our ambition to present a complete survey of all medical phenomena named for a person, with a biography of that person.


Whonamedit? does not give medical advice.
This survey of medical eponyms and the persons behind them is meant as a general interest site only. No information found here must under any circumstances be used for medical purposes, diagnostically, therapeutically or otherwise. If you, or anybody close to you, is affected, or believe to be affected, by any condition mentioned here: see a doctor.