1925 deaths

Felix Christian Klein (German: [klaɪn]; 25 April 1849 – 22 June 1925) was a German mathematician and mathematics educator, known for his work in group theory, complex analysis, non-Euclidean geometry, and the associations between geometry and group theory. His 1872 Erlangen program classified geometries by their basic symmetry groups and was an influential synthesis of much of the mathematics of the time.
During his tenure at the University of Göttingen, Klein was able to turn it into a center for mathematical and scientific research through the establishment of new lectures, professorships, and institutes. His seminars covered most areas of mathematics then known as well as their applications. Klein also devoted considerable time to mathematical instruction, and promoted mathematics education reform at all grade levels in Germany and abroad. He became the first president of the International Commission on Mathematical Instruction in 1908 at the Fourth International Congress of Mathematicians in Rome.

Stéphen François Emile Liégeard (29 March 1830 – 29 December 1925) was a French lawyer, administrator, deputy, writer and poet. He gave the name "Côte d'Azur" (Azure Coast) to the French Riviera.

Hermann Johannes Karl Fehling (14 July 1847 - 11 November 1925) was a German obstetrician and gynecologist who was a native of Stuttgart. He was the son of the chemist Hermann von Fehling (1811-1885).
In 1872 he received his medical doctorate from the University of Leipzig, and following graduation remained in Leipzig as an assistant to obstetrician Carl Siegmund Franz Credé (1819-1892). In 1877 he became director of the Württemberg state midwifery school in Stuttgart, and later accepted a teaching job at the University of Tübingen (1883).
In 1887 he became a professor of obstetrics at the University of Basel, and afterwards served as a professor at the Universities of Halle (1894) and Strasbourg (1900). In the aftermath of World War I, Fehling along with other German professors were expelled from the University of Strasbourg. He eventually settled in Baden-Baden, where he died in 1925.
Hermann Fehling is considered to be one of the leading gynecologists of his era, and made contributions in his research of disorders that included eclampsia, rachitic pelvis and puerperal osteomalacia. In 1877, with Heinrich Fritsch (1844-1915), he founded the journal Zentralblatt für Gynäkologie.

Gerhard Hessenberg (German: [ˈgɛʁ.hart ˈhɛsənˌbɛrk]; 16 August 1874 – 16 November 1925) was a German mathematician who worked in projective geometry, differential geometry, and set theory.

Georg Otto Ledderhose (15 December 1855 – 1 February 1925) was a German surgeon, professor and pioneering traumatologist.

Edgar Demange (April 22, 1841 in Versailles – February 1925 in Paris) was a French jurist. He was, with Fernand Labori, the lawyer of Alfred Dreyfus during his trials in 1894 and 1899.

Maximilian Oberst (October 6, 1849 – November 18, 1925) was a German physician and surgeon born in Regensburg.
He studied medicine in Munich, and from 1874 to 1877 was an assistant in the surgical department at a hospital in Augsburg. From 1877 he worked as an assistant to Richard von Volkmann at Halle, obtaining his habilitation in 1881. In 1884 became an assistant professor at the University of Halle, and from 1894 to 1920 was director and chief physician at the Krankenhaus Bergmannstrost in Halle. In 1919 he attained the title of professor ordinarius (full professor).
He is credited for introducing a method of block anesthesia ("Oberst-block") for use in minor surgery of the finger. In 1882 he published Die Amputationen unter dem Einflusse der antiseptischen Behandlung ("Amputations under the influence of antiseptic treatment").

Léon-Gervais-Marie Maquenne (2 December 1853 – 10 January 1925) was a French chemist and plant physiologist born in Paris.
From 1871 he worked in the laboratory of agricultural chemistry at the Ecole d'agriculture in Grignon. Here, he was a student of Pierre Paul Dehérain (1830-1902). In 1883 he became préparateur at the Muséum national d'histoire naturelle, where from 1885 to 1898 he served as an assistant to the chair of Physiologie végétale. In 1898 he succeeded Georges Ville (1824-1897) as chair of Physique végétale, a position he held on to until 1925. In 1904 he became a member of the Académie des sciences.
Among Maquenne's contributions was research involving the chemical make-up of sugar alcohols. He was able to resolve the chemical constitution of inositol and demonstrated it to be a hexahydroxycyclohexane.He is credited with invention of the so-called "Maquenne block", an apparatus used for determining the melting point of chemical compounds.

Paul Héger (1846–1925) was a Belgian biologist, and was born to Constantin Héger and Claire Zoë Parent.
Paul Hèger assisted Earnest Solvay (famous for Solvay Process) along with Hendrik Lorentz (Dutch physicist who shared noble with Pieter Zeeman for Zeeman effect) in the formation of Solvay enterprise who arrange Solvay conferences.
Hèger was professor at Universitè Libre de Bruxelles and a close collaborator of Ernest Solvay. He wrote in 1912 the rules of institute of Physics with Dutch physicist Hendrick Lorentz 1902 Nobel Laureate.

Dr. Antoine Depage (Watermael-Boitsfort, 28 November 1862 – The Hague, 10 June 1925), was the Belgian royal surgeon, the founder and president of the Belgian Red Cross, and one of the founders of Scouting in Belgium.Depage married Marie Picard in 1893 and they had three children. Marie Depage died on 7 May 1915 in the sinking of RMS Lusitania when it was torpedoed by a German submarine.