Claude Bernard

Template:Short description Template:For Template:Distinguish Template:Use dmy dates Template:Infobox scientist Claude Bernard (Template:IPA; 12 July 1813 – 10 February 1878) was a French physiologist. I. Bernard Cohen of Harvard University called Bernard "one of the greatest of all men of science".<ref>Template:Cite book</ref> He originated the term milieu intérieur and the associated concept of homeostasis (the latter term being coined by Walter Cannon).<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

Life

Bernard was born in 12 July 1813 in the village of Saint-Julien,<ref name=W1914>Template:Cite journal</ref> near Villefranche-sur-Saône. He received his early education in the Jesuit school of that town, then attended college at Lyon, which he soon left to become assistant in a druggist's shop.<ref name=W1914/> He is sometimes described as an agnostic,<ref>Template:Cite book</ref> and even humorously referred to by his colleagues as a "great priest of atheism". Despite this, after his death Cardinal Ferdinand Donnet claimed Bernard was a fervent Catholic,<ref>Template:Cite journal</ref> with a biographical entry in the Catholic Encyclopedia.<ref>Template:Cite web</ref> His leisure hours were devoted to the composition of a vaudeville comedy, and the success it achieved moved him to attempt a prose drama in five acts, Arthur de Bretagne.<ref name=chisholm/> Arthur de Bretagne,<ref name="marduel">Template:Cite web</ref> was published only after his death.<ref>Template:Cite book</ref> A second edition appeared in 1943.<ref name="marduel" /><ref>Template:Cite book</ref>

In 1834, at the age of twenty-one, he went to Paris to present this play to critic Saint-Marc Girardin, but was dissuaded from adopting literature as a profession. Girardin urged him to take up the study of medicine instead.<ref name=W1914/> Bernard followed his advice, later becoming an interne at the Hôtel-Dieu de Paris. There, he met physiologist François Magendie, who served as physician at the hospital. Bernard became preparateur (lab assistant) at the Template:Lang in 1841.<ref name=chisholm/>

Memorial plaque in Paris marking the site of Claude Bernard's laboratory from 1847 until his death in 1878.

In 1845, he married Marie Françoise "Fanny" Martin for convenience; the marriage was arranged by a colleague and her dowry helped finance his experiments. In 1847 he was appointed Magendie's deputy-professor at the college, and in 1855 he succeeded him as full professor. In 1860, Bernard was elected an international member of the American Philosophical Society.<ref>Template:Cite web</ref> His field of research was considered inferior at the time, and the laboratory assigned to him was a "regular cellar."<ref name=VR1928>Template:Cite book</ref>

Bernard was chosen around this time to be the inaugural Chair of physiology at the Sorbonne, but no laboratory was provided for his use. After speaking with Bernard in 1864, Louis Napoleon built a laboratory at the Muséum national d'Histoire naturelle in the Jardin des Plantes for him. At the same time, Napoleon III established a professorship which Bernard accepted, leaving the Sorbonne<ref name=chisholm/> in 1868. In the same year, he was also admitted a member of the Académie française and elected a foreign member of the Royal Swedish Academy of Sciences.

When he died on 10 February 1878, he was given a public funeral, which France had never allowed for a man of science.<ref name=chisholm>Template:Cite EB1911</ref><ref name=W1914/> He was interred in Père Lachaise Cemetery in Paris.

Career

Portrait by Marcel Mangin

Oil painting depicting Bernard with his pupils

Claude Bernard

Bernard's first major work was on the functions of the pancreas. His discovery that the juices are a significant part of the digestive process won him the prize for experimental physiology from the French Academy of Sciences.<ref>Template:Cite news</ref> Bernard discovered that ether introduced to the stomach or duodenum induced pancreatic secretions. The physiologist William Bayliss, credited Bernard's work as influential in the latter's discovery of Secretin, the first hormone to be isolated.<ref>W M Bayliss, E H Starling The mechanism of pancreatic secretion J Physiol. 1902 Sep 12;28(5):325–353</ref>

In perhaps his most famous experiment, Bernard discovered the glycogenic function of the liver.<ref>Template:Cite journal</ref> The liver, in addition to secreting bile, also produces the sugars that can cause hyperglycemia, which helped advance study of diabetes mellitus and its causes.<ref>Template:Cite journal</ref> In 1851, while examining the effects produced in the temperature of various parts of the body by each section of the nerve or nerves belonging to them, he noticed that division of the cervical sympathetic nerve resulted in more active circulation and more forcible pulsation of the arteries in certain parts of the head. A few months later, he observed that electrical excitation of the upper portion of the divided nerve had the contrary effect. This discovery of the vasomotor system also established the existence of both vasodilator and vasoconstrictor nerves.<ref name=W1914/>

Bernard's scientific discoveries were made through vivisection, of which he was the primary proponent in Europe at the time. In his description of the single-mindedness of scientists trying to prove their theories, he wrote: "[h]e does not hear the animals' cries of pain. He is blind to the blood that flows."<ref>Template:Cite book</ref> His use of vivisection disgusted his wife and daughters, who returned at home once to discover that he had vivisected the family dog.<ref>Template:Cite book</ref> The couple was officially separated in 1869 and his wife went on to actively campaign against the practice of vivisection.<ref>Template:Cite web</ref> Some in the scientific community were also uncomfortable with the practice. The physician-scientist George Hoggan spent four months observing and working in Bernard's laboratory, later writing that his experiences there had "prepared [him] to see not only science, but even mankind, perish rather than have recourse to such means of saving it."<ref>Template:Cite news</ref> Hoggan was a founding member of the National Anti-Vivisection Society in the mid-1870s.<ref>Template:Cite book</ref><ref name="Bekoff 2013">Template:Cite book</ref>

Milieu intérieur, the "internal environment", is the key concept with which Bernard is associated. He explained that the body is "relatively independent" of the outside world, and that a healthy "internal environment" adapts to deficiencies in the surrounding environment, thus keeping the physiology balanced.<ref name="lectures">Template:Cite book</ref> This is the underlying principle of what would later be called homeostasis,<ref>Template:Cite book</ref> a term coined by Walter Cannon.

Bernard was also interested in the physiological action of poisons, particularly curare and carbon monoxide gas. He is credited with first describing carbon monoxide's affinity for hemoglobin in 1857,<ref>Template:Cite journal</ref> although James Watt had drawn similar conclusions about hydrocarbonate's affinity for blood acting as "an antidote to the oxygen" in 1794 prior to the discoveries of carbon monoxide and hemoglobin.<ref>Template:Cite book</ref>

Throughout his career, Bernard sought to establish the use in medicine of what would later become the scientific method.<ref>Template:Cite journal</ref> In An Introduction to the Study of Experimental Medicine (1865),<ref name=CB>Template:Cite book</ref> he emphasized the importance of trusting evidence over clout, even if it "contradicts a prevailing theory,"<ref>Bernard (1957), p. 164.</ref> as "[t]heories are only hypotheses" proven or disproven by facts.<ref>Bernard (1957), pp. 56, 165.</ref> He criticized scientists who cherry-picked their data only to prove their own hypotheses.<ref name="Bernard 1957, p. 38">Bernard (1957), p. 38.</ref> Unlike many scientific writers of his time,Template:Citation needed Bernard wrote using the first person when discussing his own experiments and thoughts.<ref>Bernard (1957)</ref>

Further reading

• "Re-appraising Claude Bernard's Legacy. History and Philosophy of the Life Sciences", a collection from History and Philosophy of the Life Sciences, edited by Laurent Loison
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External links

• Template:Gutenberg author
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• Biography, bibliography, and links on digitized sources in the Virtual Laboratory of the Max Planck Institute for the History of Science
• 'Claude Bernard': detailed biography and a comprehensive bibliography linked to complete on-line texts, quotations, images and more.
• The Claude Bernard Museum
• Template:In lang Claude Bernard's works digitized by the BIUM (Bibliothèque interuniversitaire de médecine et d'odontologie, Paris), see its digital library Medic@.