Claude Bernard was a French physiologist who was one of the great scientific investigators.
He is known by his work on digestive processes, metabolism, especially the discovery of the glycogenic function of the liver and of the action of pancreatic juice, and on the vasomotor mechanism. He was the first to define the terms “milieu interieur” (the environment within) and homeostasis.
Bernard was the Founder of Endocrinology and also made important discoveries in chemistry, pharmacology, and neurophysiology.
He was a leading figure in the development of experimental science as a system of hypothesis, proof, and refutation. He was one of the first to establish the use of the scientific method in medicine and to suggest the use of blind experiments to ensure the objectivity of scientific observations.
Bernard's first paper, which appeared in 1843, gave an account of the chorda tympani nerve.
Claude Bernard's first important work was on the functions of the pancreas gland, the juice of which he proved to be of great significance in the process of digestion.
In 1857 he discovered glycogen, the starch like substance in the liver, in the course of this he was led to the conclusion, which throws light on the causation of diabetes.
Bernard also did valuable work on the vasomotor system, demonstrating that certain nerves control the dilation and constriction of blood vessels. He showed how nerves controlled the diameter of blood vessels, and hence blood flow (1858).
He also carried out important work on the actions of drugs, such as the opium alkaloids, curare (curarine) and carbon monoxide, on the sympathetic nerves.
From 1860 he turned to the philosophy of science.
He emphasized the need in planning experiments for a clear hypothesis to be stated, which may then be either proved or disproved.
“Art is I; science is we”-wrote Bernard.
He coined the terms “milieu intérieur” (the environment within) and homeostasis. His concept of the internal environment of the organism led to the present understanding of homeostasis.
Bernard’s phrase: “The constancy of the internal environment is the condition for the free and independent life” (1878) has become well known.
Historian of science Bernard Cohen of Harvard University called Bernard "one of the greatest of all men of science".
During his study in the Medical Faculty of the College de France, he was brought into contact with the great physiologist, François Magendie and from 1841 he worked as an assistant in his laboratory.
In 1843 he received the honorary degree of Doctor Of Medicine for his investigation, into the role of gastric juice in digestion.
He taught at several major French institutions such as Medical School: MD, Collège de France (1843),
University: DSc, Collège de France (1853).
In 1847 he was appointed Magendie's deputy-professor at the college de France and in 1855, after his death, he succeeded him as full professor. Soon he had been chosen the first chair of physiology at the Sorbonne.
In 1860 he was elected a foreign member of St. Petersburg Academy of Sciences. In 1868 he was admitted a member of the Académie française. In the same year he was elected a foreign member of the Royal Swedish Academy of Sciences and in 1869 he was elected Senator of France for life.
He received his early education in the Jesuit school of that city, and then proceeded to the college at Lyon, which, however, he soon left because his family could not afford to continue his education.
He was apprenticed to a pharmacist in Lyons and began writing plays and vaudeville comedy to earn money.
At the age of twenty-one in 1834 he went to Paris, armed with prose drama in five acts, Arthur de Bretagne. But the critic dissuaded him from adopting literature as a profession, and urged him rather to take up the study of medicine.
This advice Bernard followed, and in due course, in 1834, he became interne at the Paris hospital Hotel Dieu. In 1839 he graduated from the Medical Faculty of the College de France.
In this way he was brought into contact with the great physiologist, François Magendie and from 1841 he worked as an assistant in his laboratory.
In 1845 Bernard married Françoise Marie (Fanny) Martin for convenience. His marriage was arranged by a colleague and her dowry helped finance his experiments.
He died in Paris on the 10th of February 1878.
When he died he was accorded a public funeral – an honor which had never before been bestowed by France on a man of science. He was interred in Le Père Lachaise Cemetery in Paris.