Notable : Famous : Founder/ originator

Michel Victor Pachon (May 26, 1867 – 1938) was a French physiologist born in Clermont-Ferrand.
In 1892 he earned his doctorate at the University of Paris, and later became a chief assistant in Paris to physiologists Charles Richet (1850-1935) and Eugène Gley (1857–1930). In 1911 he became a professor of physiology at the medical faculty of the University of Bordeaux. Today, this institution is named "Faculte de médecine Victor Pachon" in his honor.

Pachon is remembered for his work involving blood pressure and oscillometry; which is defined as the measurement of oscillations used in cardiovascular and respiratory physiology. In 1909 Pachon developed a sphygmographic oscillometer for measuring arterial blood pressure. Pachon's oscillometer was widely used by doctors and technicians during the first half of the twentieth century.

Louis Ombrédanne (5 March 1871 – 4 November 1956) was a French pediatric and plastic surgeon born in Paris. He was the son of general practitioner Emile Ombrédanne.
In 1902 he became surgeon to Parisian hospitals, becoming a professor of surgery in 1907. From 1921 to 1940 he was head of pediatric surgery at the Hôpital Necker.
Ombrédanne's primary field of research was development of new methods of surgery. In 1906 he was the first to describe the use of the pectoralis minor muscle for breast reconstruction following mastectomy. He also introduced transscrotal orchiopexy for surgical repair of an undescended testis.

In 1907, after two fatal anesthetic accidents, Ombrédanne created a prototype of an inhaler as a safe anesthetic device. It consisted of a tin container as reservoir that was fitted with felt to absorb ether, a graduated air inlet, and a respiratory reserve chamber. This device was tested successfully on over 300 patients, and design modifications were later made.
In 1929 Ombrédanne provided an early description of malignant hyperthermia, a condition he described as pallor with hyperthermia in newborns during anesthesia. The disorder is historically referred to as "Ombrédanne syndrome".

Louis Xavier Édouard Léopold Ollier (French: [ɔlje]; 2 December 1830 – 26 November 1900) was a French surgeon, known for his pioneering work in reconstructive surgery and orthopedics.

Giuseppe Oddo (9 June 1865 – 5 November 1954) was an Italian chemist. The Oddo–Harkins rule is named after him and William Draper Harkins. He published his findings in 1914 in a German journal.

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").

Siegfried Oberndorfer (24 June 1876 in Munich – 1944 in Istanbul) was a Jewish-German physician, pathologist, and cancer researcher.

Adelchi Negri (16 July 1876 – 19 February 1912) was an Italian pathologist and microbiologist born in Perugia.
He studied medicine and surgery at the University of Pavia, where he was a pupil of Camillo Golgi (1843–1926). After graduation in 1900, he became an assistant to Golgi at his pathological institute. In 1909 Negri became a professor of bacteriology, and the first official instructor of bacteriology in Pavia. On 19 February 1912 he died of tuberculosis at age 35.
Negri performed extensive research in the fields of histology, hematology, cytology, protozoology and hygiene. In 1903 he discovered the eponymous Negri bodies, defined as cytoplasmatic inclusion bodies located in the Purkinje cells of the cerebellum in cases of rabies in animals and humans. He documented his findings in an article titled Contributo allo studio dell'eziologia della rabbia, published in the journal Bollettino della Società medico-chirurgica. At the time, Negri mistakenly described the pathological agent of rabies as a parasitic protozoa. A few months later, Paul Remlinger (1871–1964) at the Constantinople Imperial Bacteriology Institute correctly demonstrated that the aetiological agent of rabies was not a protozoan, but a filterable virus.
Negri went on, however, to demonstrate in 1906 that the smallpox vaccine, then known as "vaccine virus", or "variola vaccinae", was also a filterable virus. During the latter part of his career, he became interested in malaria and was at the forefront in efforts to eradicate it from Lombardy. In 1906 he married his colleague Lina Luzzani and six years later, at the age of thirty-five, died of tuberculosis.

Eduard Müller (4 January 1876, in Annweiler am Trifels – 30 December 1928, in Marburg) was a German internist and neurologist.
He studied medicine at several German universities, receiving his doctorate from the University of Erlangen in 1898. Following graduation, he spent two years as an assistant at the psychiatric clinic in Freiburg under Hermann Emminghaus and Alfred Hoche, then afterwards worked as an assistant to Carl Weigert at the Senckenberg Institute of Pathology in Frankfurt am Main.In 1903 he became an assistant in Adolph Strümpell's clinic, initially at Erlangen, and then in Breslau. In 1909 he relocated to the University of Marburg as an associate professor and director of the medical polyclinic. In 1921 he attained a full professorship.With bacteriologist Georg Jochmann, he developed the "Müller-Jochmann test", a method of differentiating between tuberculous and non-tuberculous pus.

Augustin Marie Morvan (7 February 1819 in Lannilis – 20 March 1897 in Douarnenez) was a French physician, politician, and writer. He is best known for treating the first recorded case of the eponymous Morvan's syndrome, a rare neurological disorder marked by acute insomnia. Morvan served as a deputy to the French National Assembly that inaugurated the Third Republic in 1871. In Brest, France, where he began his medical studies, the Rue Augustin Morvan and the Hôpital Augustin Morvan are named after him.