Background
Claude Bernard was born on July 12, 1813, in the village of Saint-Julien, France, the son of Pierre Bernard, a winegrower, and Jeanne Saulnier. Bernard’s mother Jeanne belonged to a family of peasants.
physician physiologist scientist teacher
Claude Bernard was born on July 12, 1813, in the village of Saint-Julien, France, the son of Pierre Bernard, a winegrower, and Jeanne Saulnier. Bernard’s mother Jeanne belonged to a family of peasants.
Bernard studied at a Jesuit school, where he learned Latin and in addition to that it is necessary to point out that the school did not impart any scientific education to its students; however that did not stop him from being curious about the sciences.
In 1831, at the age of 18, Bernard moved to the local college at Lyon but he did not stay there long enough to earn a degree and instead became an apprentice at a chemist shop in the same city.
Bernard was also a purveyor of the arts and wrote plays in his leisure time. In 1834 he went to Paris in order to become a playwright, however famous critic of the day Saint Marc-Giradin discouraged him and instead asked him to stick to life sciences.
In 1834, Bernard enrolled in the Faculty of Medicine at the University of Paris (metonymically known as the Sorbonne), and in 1839 he passed the examination for an internship.
In 1853, Claude Bernard was granted the degree of doctor of natural sciences from the Collège de France.
A protégé of Pierre Rayer, he worked at the Charité and, as an intern on the staff of François Magendie, at the Hôtel Dieu. What he admired in Magendie, however, was less the clinician than the physiologist, the bold experimenter, and the aggressive skeptic. It was in Magendie’s laboratory at the Collège de France that Bernard, even before the end of his clinical studies, discovered his real vocation: physiological experimentation.
From 1841 to December 1844, Bernard worked as préparateur (lab assistant) to Magendie at the Collège de France, assisting him in experiments concerning the physiology of nerves (especially the problem of "recurrent sensitivity" of the spinal nerve roots), the cerebrospinal fluid, the question of the seat of oxidation in the body of horses (by important experiments with cardiac catheterization), and the physiology of digestion. In order to carry out his own research, Bernard installed a very modest private laboratory in the Cour du Commerce-Saint-André. He also made use of the adjoining laboratory of Jules Pelouze, where he enjoyed the intelligent help of his friend Charles-Louis Barreswil. It was Magendie who taught Bernard to use animal vivisection as the principal means of medical research and to be suspicious of generally accepted theories and doctrines. But Bernard knew how to go beyond the empiricism and skepticism of his master and to create an especially productive method of research on living creatures.
Although he had graduated Doctor of Medicine degree in Paris on December 7, 1843, Bernard never practiced medicine and always entertained ambivalent feelings about physicians. Nevertheless, his work was such that it laid new foundations for the profession. His doctoral thesis, Du suc gastrique et de son rôle dans la nutrition (1843), was a work both useful to medicine and dedicated to pure science, since it furnished new facts on gastric digestion and the transformations of carbohydrates in the animal organism.
In 1844 Bernard failed to pass the examinations for a teaching post with the Faculty of Medicine. Nevertheless, he resigned his position with Magendie. After having tried vainly to organize a free course in experimental physiology (in collaboration with his friend Charles Lasègue), Bernard resigned himself to giving up scientific research and to setting up as a country doctor in his native village.
Rather than resolve his economic embarrassments in this way, however, Bernard decided to take the advice of Pelouze, and in July 1845 he married a daughter of a Paris physician. This match was to become a source of unhappiness, but for the moment his wife’s dowry enabled Bernard to continue his physiological research.
In 1847 Bernard became Magendie’s deputy at the Collège de France. This period was marked by a veritable explosion of discoveries, beginning in 1846, when Bernard solved the mystery of the carnivorous rabbits. Puzzled one day by the chance observation that some rabbits were passing clear — not cloudy — urine, just like meat-eating animals, he inferred that they had not been fed and were subsisting on their own tissues. He confirmed his hypothesis by feeding meat to the famished animals. An autopsy of the rabbits yielded an important discovery concerning the role of the pancreas in digestion: the secretions of the pancreas broke down fat molecules into fatty acids and glycerin. Bernard then showed that the principal processes of digestion take place in the small intestine, not in the stomach as was previously believed.
His work on the pancreas led to research on the liver, culminating in his second great discovery, the glycogenic function of the liver. In 1856 Bernard discovered glycogen, a white starchy substance found in the liver. He found that this complex substance was built up by the body from sugar and served as a storage reserve of carbohydrates that could be broken down to sugars as needed, thereby keeping the sugar content of the blood at a constant level. Bernard’s discovery showed that the digestive system not only breaks down complex molecules into simple ones but also does the opposite, building up complex molecules from simpler ones. Simultaneously, he was nearing his third great achievement — explanation of the regulation of the blood supply by the vasomotor nerves. He discovered in this regard that the vasomotor nerves control the dilation and constriction of blood vessels in response to temperature changes in the environment. For example, in cold weather, the blood vessels of the skin constrict in order to conserve heat, while in hot weather they expand to dissipate excess heat. This control mechanism, like the glycogenic functions of the liver, illustrates how the body maintains a stable internal environment in the midst of changing external conditions — a fundamental phenomenon known as homeostasis.
Bernard also conducted important studies on the effects of such poisons as carbon monoxide and curare on the body. He showed that carbon monoxide could substitute for oxygen and combine with hemoglobin, thereby causing oxygen starvation. His experiments with curare showed how this dread poison causes paralysis and death by attacking the motor nerves, while having no effect on the sensory nerves. He demonstrated that, because of this selectivity, curare could be used as an experimental tool in differentiating neuromuscular from primary muscular mechanisms.
Within less than a decade, from obscurity in the shadow of Magendie, he had risen to a commanding position in science. In 1854 a chair of general physiology was created for him in the Sorbonne, and he was elected to the Academy of Sciences. When Magendie died in 1855, Bernard succeeded him as a full professor at the Collège de France. No laboratory had been provided for Bernard at the Sorbonne, but the French emperor Napoleon III, after an interview with him in 1864, remedied the deficiency, at the same time building a laboratory at the Museum of Natural History of the Jardin des Plantes. In 1868 Bernard left the Sorbonne to accept a newly established professorship in general physiology at this museum.
Magendie’s empirical method of conducting experiments without a guiding hypothesis was by then out of date, partly as a result of his own discoveries. Bernard’s historic role was to demonstrate the experimenter’s need for a guiding hypothesis to be either confirmed or refuted by the results.
For various reasons, a shift was occurring in Bernard’s scientific interests. The productive researcher was turning into a philosopher of science. Failing health after 1860 led him to spend more time at Saint-Julien, less time in the laboratory. Bernard suffered apparently from chronic enteritis, with symptoms affecting the pancreas and the liver. By way of compensation, the enforced leisure left him time for reflection, out of which would come his masterpiece, Introduction à la médecine expérimentale (1865; An Introduction to the Study of Experimental Medicine).
This work was planned as a preface, if a very long one, to a work of greater magnitude, never completed. Bernard’s aim in the Introduction was to demonstrate that medicine, in order to progress, must be founded on experimental physiology. The other points in his argument are that (1) the physical and chemical sciences provide the foundation for physiology, although it is not reducible to them; (2) the notion of "vital force" does not explain life; (3) vivisection is indispensable for physiological research; and (4) biology depends on recognizing that the processes of life are mechanistically determined by physicochemical forces. Still germane for modern science is his presentation of the concept of the milieu intérieur, or "internal environment," of the body.
Paul Bert succeeded Bernard in the Sorbonne when the latter transferred to the Museum of Natural History in 1868. Bernard’s own experiments were taking new directions. The phenomena common to animals and plants formed the subject of lectures published posthumously. He also began research on fermentation. His findings were published after his death by Berthelot and, because they conflicted with Pasteur’s views, cast a cloud over the microbe hunter’s memory of his late colleague.
Bernard’s health had declined precipitously in the autumn of 1877. On New Year’s Day, he caught a cold, and shortly afterwards inflammation of the kidneys set in. Soon he was confined to his bed. Claude Bernard died on February 10, 1878, in Paris, France, and was interred in Cimetière du Père Lachaise in Paris.
Claude Bernard was a physiologist known chiefly for his discoveries concerning the role of the pancreas in digestion, the glycogenic function of the liver, and the regulation of the blood supply by the vasomotor nerves. On a broader stage, Bernard played a role in establishing the principles of experimentation in the life sciences, advancing beyond the vitalism and indeterminism of earlier physiologists to become one of the founders of experimental medicine.
His most seminal contribution was his concept of the internal environment of the organism, which led to the present understanding of homeostasis — i.e., the self-regulation of vital processes.
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1999(Claude Bernard is one of the greatest of all men of scien...)
2017Although Claude Bernard is sometimes described as an agnostic or even an atheist, he was a fervent Catholic, with a biographical entry in the Catholic Encyclopedia.
Claude believed that science is carried forward through experimental methods but not through accepting the authority of academic and scholastic sources. In the experimental way, much is learnt and discovered. Experiments are a constant interchange between facts and theories, deductions and inductions. Basically there are some particular experiments that may lead to formulation of new theories.
Claude also explains the relationship between cause and effect. He says that scientists try to find the relationship of cause and effect by testing hypothesis. Theories are simply hypotheses that are verified by facts. Those verified by many facts are the best, but they are never final and therefore never to be believed.
Quotations:
"Observation is a passive science, experimentation an active science."
"In teaching man, experimental science results in lessening his pride more and more by proving to him every day that primary causes, like the objective reality of things, will be hidden from him forever and that he can only know relations."
"The experimenter who does not know what he is looking for will not understand what he finds."
"The investigator should have a robust faith - and yet not believe."
On June 26, 1854, Claude Bernard was elected to the Académie des Sciences.
Académie des sciences , France
1854
In 1868, Claude Bernard became a member of the Académie française.
Académie française , France
1868
In 1868, Claude Bernard was elected to the Royal Swedish Academy of Sciences.
Royal Swedish Academy of Sciences , Sweden
1868
In July 1845, Claude Bernard married Marie Françoise "Fanny" Martin, daughter of a Paris doctor. They had three children: a boy who died in infancy and two daughters, Jeanne-Henriette and Marie-Claude.
