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Jean Pierre Flourens

 
Scientist: Jean Pierre Marie Flourens
 

French physician and anatomist (1794–1867)

Flourens, who was born at Maureilhan in France, studied medicine at the University of Montpellier, graduating in 1813. Moving to Paris he was fortunate enough to be taken in hand by the powerful Georges Cuvier, serving as his deputy at the Collège de France from 1828. After Cuvier's death in 1832, Flourens succeeded him as professor of anatomy and secretary of the Académie des Sciences.

In 1824 Flourens published his highly influential Recherches expérimentales sur les propriétés et les fonctions du système nerveux dans les animaux vertébrés (Experimental Researches on the Properties and Functions of the Nervous System in Vertebrates) in which he demonstrated the main roles of different parts of the central nervous system. Extending the work of the Italian anatomist Luigi Rolando on the nervous system, Flourens removed various parts of the brain and carefully observed the resulting changes. Thus he found that removal of the cerebral hemispheres of a pigeon destroyed the sense of perception. Removal of the cerebellum destroyed coordination and equilibrium and excision of the medulla oblongata caused respiration to cease. He also exposed the spinal cord of a dog from head to tail and found that while stimulation lower down would produce movement there came a point higher up where no muscular reaction could be elicited. Flourens is also known for important work on the semicircular canals in the ear, demonstrating their function in balance.

Although Flourens assigned different roles to different anatomical parts of the brain he was not prepared to go further and localize different roles and powers within each part. It was not until 1870 that Gustav Fritsch and Eduard Hitzig were able to break this unitary picture and establish cerebral localization experimentally.

Flourens is also remembered for his attack on Darwin in his Examen du livre de M. Darwin (1864; Examination of Mr. Darwin's Book) in which he poured scorn on Darwin's “childish and out of date personifications.”

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Columbia Encyclopedia: Pierre Flourens
Flourens, Pierre (Marie Jean Pierre Flourens) (pyĕr flūräNs'), 1794–1867, French physiologist. He demonstrated the respiratory center in the medulla and the function of the cerebellum in muscular coordination and studied bone formation. He was long a professor at the Collège de France.
 
World of the Mind: (Marie Jean) Pierre Flourens
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(1794–1867). French physiologist, born at Maureilhan, Hérault, and who studied medicine at Montpellier, qualifying in 1813. He moved to Paris, where he was helped by the anatomist Georges Cuvier. He became a member of the Académie des Sciences in 1828, professor of comparative anatomy at the Collège de France in 1835, and a member of the Académie Française in 1840. He was a pioneer in techniques of ablation for investigating brain function.

An accomplished experimentalist, his findings led him to conclude that there is considerable diversification of function in the central nervous system: 'All sensory and volitional faculties exist in the cerebral hemispheres and must be regarded as occupying concurrently the same seat in these structures.' He likewise concluded that 'feeling, willing, and perceiving are but a single and essentially unitary faculty residing in a single organ (i.e. the cerebral hemispheres)'. These findings have been widely taken to imply that the various categories of psychological function are not discretely localized in the cerebral cortex — a view that held sway for some 60 years until Paul Broca's claim that articulate speech in man is localized in a small area of the left cerebral hemisphere.

As might be anticipated, Flourens was a convinced opponent of phrenology and his work did much to discredit the standing of F. J. Gall. And he is often held, not wholly with justice, to have anticipated the views of Karl Lashley on the cerebral localization of psychological function. His important work on the effects of cerebral ablation in animals is Recherches expérimentales sur les propriétés et les fonctions du système nerveux dans les animaux vertébrés (1824).

(Published 1987)

 
Wikipedia: Jean Pierre Flourens
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Jean Pierre Flourens
Jean Pierre Flourens
Jean Pierre Flourens
Born 15 April 1794
Maureilhan
Died 6 December 1867
Nationality French
Fields physiologist
Known for anesthesia

Marie Jean Pierre Flourens (15 April 1794 - 6 December 1867), father of Gustave Flourens, was a French physiologist, the founder of experimental brain science and a pioneer in anesthesia.

He was born at Maureilhan, near Béziers, in the département of Hérault. At fifteen he began studying medicine at Montpellier, where in 1823 he received the degree of doctor. In the following year he went to Paris, carrying an introduction from A. P. de Candolle, the botanist, to Georges Cuvier, who received him kindly, and took an interest in him. At Paris Flourens engaged in physiological research, occasionally contributing to publications; and in 1821, at the Athénée, he gave a course of lectures on the physiological theory of the sensations, which attracted much attention amongst men of science.

In 1825, Flourens pioneered the experimental method of carrying out localized lesions of the brain in living rabbits and pigeons and carefully observing their effects on motricity, sensibility and behavior. His intention was to investigate localisationism, i.e., whether different parts of the brain had different functions, as the Austrian physician Franz Joseph Gall, the founder of phrenology, was proposing. The trouble was that Gall did not use a proper scientific approach to this affirmations, and the Academy of Sciences of Paris, acting on order of the emperor Napoleon Bonaparte, asked to Flourens to solve the matter.

Flourens was able to demonstrate convincingly for the first time that the main divisions of the brain were indeed responsible for largely different functions. By removing the cerebral hemispheres, for instance, all perceptions, motricity, and judgment were abolished. The removal of the cerebellum affected the animal's equilibrium and motor coordination, while the destruction of the brainstem (medulla oblongata) caused death. These experiments led Flourens to the conclusion that the cerebral hemispheres are responsible for higher cognitive functions, that the cerebellum regulates and integrates movements, and that the medulla controls vital functions, such as circulation, respiration and general bodily stability. On the other hand, he was unable (probably because his experimental subjects have relatively primitive cortices) to find specific regions for memory and cognition, which led him to believe that they are represented in a diffuse form around the brain. So, different functions could indeed be ascribed to particular regions of the brain, but that a finer localization was lacking.

The paper which published his results, entitled Recherches experimentales sur les propriétés et les fonctions du système nerveux dons les animaux vertébrés (Experimental Researches on the Properties and the Functions of the Nervous System in Vertebrate Animals), was the subject of a highly commendatory report by Cuvier, adopted by the French Academy of Sciences in 1822.

Flourens was chosen by Cuvier in 1828 to deliver a course of lectures on natural history at the College de France, and in the same year became, in succession to LAG Bosc, a member of the Institute, in the division "Economic rurale.” In 1830 he became Cuvier's substitute as lecturer on human anatomy at the Jardin du Roi, and in 1832 was elected to the post of titular professor, which he vacated for the professorship of comparative anatomy created for him at the museum of the Jardin the same year. In 1833 Flourens, in accordance with the dying request of Cuvier, was appointed a perpetual secretary of the Academy of Sciences; and in 1838 he was returned as a deputy for the arrondissement of Béziers. In 1840 he was elected, in preference to Victor Hugo, to succeed Jean François Michaud at the French Academy; and in 1845 he was created a commander of the légion d'honneur, and in the next year a peer of France.

In March 1847 Flourens drew the attention of the Academy of Sciences to the anesthetic effect of chloroform on animals.

On the revolution of 1848 he withdrew completely from political life; and in 1855 he accepted the professorship of natural history at the College de France. He died at Montgeron, near Paris on 6 December 1867.

Bibliography

Besides numerous shorter scientific memoirs, Flourens published:

  • Essai sur quelques points de la doctrine de la revulsion et de la derivation (Montpellier, 1813)
  • Experiences sur le système nerveux (Paris, 1825)
  • Cours sur la génération, l'ovologie, et l'einhryologie (1836)
  • Analyse raisonnée des travaux de G. Cuvier (1841)
  • Recherches sur le développement des os et des dents (1842)
  • Anatomie générale de la peau et des membranes muqueuses (1843)
  • Buffon, histoire de ses travaux et de ses idées (1844)
  • Fontenelle, ou de la philosophie moderne relativement aux sciences physiques (1847)
  • Théorie expérémentale de la formation des os (1847)
  • Œuvres complètes de Buffon (1853)
  • De la longévété humaine et de la quantité de vie sur le globe (1854), numerous editions
  • Histoire de la découverte de la circulation du sang (1854)
  • Cours de physiologie comparée (1856)
  • Recuesi des lloges historiques (1856)
  • De la vie et de l'intelligence (1858)
  • De la raison, du genie, et de la folie (1861)
  • Ontologie naturelle (1861)
  • Examen du livre du M. Darwin sur l'Origine des Espèces (1864).

External links and references

Cultural offices
Preceded by
Joseph Michaud
Seat 29
Académie française

1840–1867
Succeeded by
Claude Bernard

 
 

 

Copyrights:

Scientist. A Dictionary of Scientists. Copyright © Market House Books Ltd 1993, 1999, 2003. All rights reserved.  Read more
Columbia Encyclopedia. The Columbia Electronic Encyclopedia, Sixth Edition Copyright © 2003, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/  Read more
World of the Mind. The Oxford Companion to the Mind. Second Edition. Copyright © Oxford University Press, 2004. All rights reserved.  Read more
Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Jean Pierre Flourens" Read more