Vocation : Medical : Physician

Jean Hyacinthe Henri Vincent (22 December 1862 – 23 November 1950) was a French physician who was a native of Bordeaux. He was an associate professor at Val-de-Grâce, as well as medical inspector general with the French Army. Later he attained the chair of epidemiology at Collège de France.
Vincent is credited with the discovery of the organisms that cause an acute infection of the oral soft tissues, including the tonsils and pharynx.
This condition is caused by the combination of the fusiform bacilli (Bacillus fusiformis), and the spirochete (Borrelia vincentii). The disease was called Vincent's angina in honor of his discovery. Many publications using the term "Vincent's angina" date from the twentieth century, and the term is not so common in modern times. When the gums are involved, it was termed "Vincent's gingivitis". In modern times, Vincent's gingivitis is usually termed necrotizing ulcerative gingivitis (sometimes known as trench mouth).
He is also remembered for his work with vaccines, and his successful inoculations of the French Army against typhoid fever and paratyphoid fever, types A and B. He started these vaccinations in 1910, and they were continued during World War I. Marshals Joseph Joffre (1852–1931) and Ferdinand Foch (1851–1929) paid homage to Vincent and his medical work that saved countless lives.

August Karl Gustav Bier (24 November 1861 – 12 March 1949) was a German surgeon. He was the first to perform spinal anesthesia and intravenous regional anesthesia.

Célestin Sieur (La Chapelle-en-Lafaye, 27 December 1860 – Paris, 12 June 1955) was a French physician specializing in ENT surgery. The Sieur's sign is named after him.

Charles-Édouard Brown-Séquard FRS (8 April 1817 – 2 April 1894) was a Mauritian physiologist and neurologist who, in 1850, became the first to describe what is now called Brown-Séquard syndrome.

Leonardo Conti (German pronunciation: [ˈleːonaʁdo ˈkɔnti]; 24 August 1900 – 6 October 1945) was the Reich Health Leader and an SS-Obergruppenführer in Nazi Germany. He was involved in the planning and execution of Action T4 that murdered hundreds of thousands of adults and children with severe mental and physical handicaps. On 19 May 1945, after Germany's surrender, Conti was imprisoned and in October hanged himself to avoid trial.