Bernard was born in 12 July 1813 in the village ofSaint-Julien,[4] nearVillefranche-sur-Saône. He received his early education in theJesuit school of that town, then attended college atLyon, which he soon left to become assistant in a druggist's shop.[4] He is sometimes described as an agnostic,[5] 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,[6] with a biographical entry in theCatholic Encyclopedia.[7] His leisure hours were devoted to the composition of avaudeville comedy, and the success it achieved moved him to attempt a prose drama in five acts,Arthur de Bretagne.[8]Arthur de Bretagne,[9] was published only after his death.[10] A second edition appeared in 1943.[9][11]
In 1834, at the age of twenty-one, he went to Paris to present this play to criticSaint-Marc Girardin, but was dissuaded from adopting literature as a profession. Girardin urged him to take up the study of medicine instead.[4] Bernard followed his advice, later becoming aninterne at theHôtel-Dieu de Paris. There, he met physiologistFrançois Magendie, who served as physician at the hospital. Bernard becamepreparateur (lab assistant) at theCollège de France in 1841.[8]
Memorial plaque in Paris marking the site of Claude Bernard's laboratory from 1847 until his death in 1878.
In 1845, he marriedMarie 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 theAmerican Philosophical Society.[12] His field of research was considered inferior at the time, and the laboratory assigned to him was a "regular cellar."[13]
When he died on 10 February 1878, he was given a public funeral, which France had never allowed for a man of science.[8][4] He was interred inPère Lachaise Cemetery in Paris.
Portrait byMarcel ManginOil painting depicting Bernard with his pupilsClaude Bernard
Bernard's first major work was on the functions of thepancreas. His discovery that thejuices of the pancreas play a significant role in thedigestive process won him the prize for experimental physiology from theFrench Academy of Sciences.[14] Bernard also discovered that introducingether into the stomach orduodenum induced pancreatic secretions. The physiologistWilliam Bayliss credited Bernard's work as influential in the latter's discovery ofsecretin, the firsthormone to be isolated.[15]
In perhaps his most famous experiment, Bernard discovered theglycogenic function of theliver.[16] The liver, in addition to secretingbile, also produces the sugars that can causehyperglycemia, which helped advance study ofdiabetes mellitus and its causes.[17] 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, Bernard noticed that division of thecervical sympathetic nerve resulted in more active circulation and more forcible pulsation of thearteries 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 thevasomotor system also established the existence of bothvasodilator andvasoconstrictor nerves.[4]
Bernard's scientific discoveries were made throughvivisection, 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."[18] His use of vivisection disgusted his wife and daughters, who returned at home once to discover that he had vivisected the family dog.[19] The couple was officially separated in 1869 and his wife went on to actively campaign against the practice of vivisection.[20] 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."[21] Hoggan was a founding member of theNational Anti-Vivisection Society in the mid-1870s.[22][23]
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.[24] This is the underlying principle of what would later be calledhomeostasis,[25] a term coined byWalter Cannon.
Bernard was also interested in the physiological action of poisons, particularlycurare andcarbon monoxide gas. He is credited with first describing carbon monoxide's affinity forhemoglobin in 1857,[26] althoughJames Watt had drawn similar conclusions abouthydrocarbonate's affinity for blood acting as "an antidote to the oxygen" in 1794 prior to the discoveries of carbon monoxide and hemoglobin.[27]
Throughout his career, Bernard sought to establish the use in medicine of what would later become thescientific method.[28] InAn Introduction to the Study of Experimental Medicine (1865),[29] he emphasized the importance of trusting evidence over clout, even if it "contradicts a prevailing theory,"[30] as "[t]heories are only hypotheses" proven or disproven by facts.[31] He criticized scientists whocherry-picked their data only to prove their own hypotheses.[32] Unlike many scientific writers of his time,[citation needed] Bernard wrote using the first person when discussing his own experiments and thoughts.[33]
^Simmons, John G. (2002).Doctors and Discoveries: Lives That Created Today's Medicine. Houghton Mifflin Harcourt. p. 17.ISBN978-0-618-15276-6.Upon his death on February 10, 1878, Bernard received a state funeral – the first French scientist to be so honored. The procession ended at Pere Lachaise cemetery, and Gustave Flaubert described it later with a touch of irony as 'religious and very beautiful'. Bernard was an agnostic.
^Bernard, Claude (1974).Lectures on the Phenomena of Life Common to Animals and Plants. Translated by Hoff, Hebbel E.;Guillemin, Roger; Guillemin, Lucienne. Springfield, Ill.: Charles C Thomas. p. 84.ISBN0-398-02857-5.
