Charles Jules Henry Nicolle (September 21, 1866 Rouen - February 28, 1936) was a French bacteriologist who received the Nobel Prize in Medicine for his identification of lice as the transmitter of epidemic typhus.
In 1903 Nicolle became Director of the Pasteur Institute in Tunis, where he did his Nobel Prize-winning work on typhus. He was still director of the Institute when he died in 1936.
He also wrote fiction and philosophy through his life, including the books Le Pâtissier de Bellone, Les deux Larrons, and Les Contes de Marmouse.
He married Alice Avice in 1895, and had two children, Marcelle (b. 1896) and Pierre (b. 1898).
During his life Nicolle wrote a number of non-fiction and bacteriology books, including Le Destin des Maladies infectieuses; La Nature, conception et morale biologiques; Responsabilités de la Médecine, and La Destinée humaine.
In June 1909 Nicolle tested his theory by infecting a chimpanzee with typhus, retrieving the lice from it, and placing it on a healthy chimpanzee. Within 10 days the second chimpanzee had typhus as well. After repeating his experiment he was sure of it: lice were the carriers.
Further research showed that the major transmission method was not louse bites but excrement: lice infected with typhus turn red and die after a couple of weeks, but in the meantime they excrete a large amount of microbes. When a small quantity of this is rubbed on the skin or eye, an infection occurs.
He did not succeed in his effort to develop a practical vaccine. The next step would be taken by Rudolf Weigl in 1930.