Claude Bernard
(1813 - 1878)
Compiled by Peter Ellis

From peasant to hero of France, Claude Bernard's life was a not so smooth climb up the ladder of success. His work provided a new insight into the way organisms lived and his ideas are still being pursued today. Drama or Science? Claude Bernard had a very poor childhood. His father's wine growing business failed as did his attempts to be a teacher and he died leaving his peasant wife penniless. Claude attended a Jesuit school but when he left at the age of 18 he had no qualifications.

He started work as an apprentice to an apothecary on the outskirts of Lyon. His work was boring but Claude entertained himself when he could by attending the theatre. Writing his own plays when he should have been working annoyed his employer and so in 1834 he set off for Paris to try his luck with his play Arthur de Bretagne. A critic read it and recommended that he had better try a different career.

Claude took a course in medicine and despite his poverty and shyness he just about succeeded in passing the exam to get a trainee position in a hospital. He began research with the famous doctor Francois Magendie. Magendie had discovered the function of the nerves attached to the spinal column and was impressed by Claude's skill in dissecting.

Claude's weakness in exams returned however, and he failed to pass the exam that would get him a job teaching medicine. Working as a research assistant didn't provide much pay so he had to find another way of making a living. A friend suggested that he get married and so he did, to the daughter of a rich doctor. His wife provided the money to keep him but their marriage was stormy and unhappy.

The experimental physiologist

In 1847 Claude became Magendie's deputy and began a series of experiments that lead to important discoveries. First he showed that the pancreas, a small organ situated towards the back of the abdomen produces substances that break down molecules of fat. He also showed that the bulk of digestion takes place in the small intestine rather than in the stomach as was thought at the time.

Next he studied the liver and discovered glycogen, a large carbohydrate similar to starch. Claude showed that the liver builds this molecule from smaller molecules such as glucose and it acts as a temporary store of energy for the rest of the organs of the body. Then he discovered the nerves that control the blood supply to the organs. For instance, in cold weather the nerves restrict the supply of blood to the skin so conserving heat while in hot weather they allow the blood vessels to expand to encourage heat loss from the skin.

Claude realised that the body has control mechanisms producing hormones that maintain body temperature and the levels of nutrients and waste products. This was later called homeostasis.

Whereas earlier scientists like Magendie had made discoveries by observation alone, Claude developed a new science of experimental physiology where he deduced hypotheses and tested them on his subjects. He showed that haemoglobin in red blood cells carries oxygen and that it can be replaced by carbon monoxide with possibly fatal results, and he revealed how the poison curare affects nerves.

Fame

Claude's discoveries brought him recognition and in 1854 he followed Magendie as professor at the College de France. The French Emperor, Napoleon III provided him with a laboratory at the Museum of Natural History. After 1860 however his health deteriorated. Ironically he suffered from pancreas and liver problems. He did less and less experimental work, but instead, back home in Saint-Julien, he devoted his time to writing his Introduction to the Study of Experimental Medicine. This remained a model textbook for many years. In 1868 he was elected to the French Academy of Sciences, an event which prompted the final separation from his wife.

On New Year's Day 1878, Claude caught a cold that developed into a kidney infection and he died a month later. In recognition of his great scientific discoveries the French government arranged his funeral - the first French scientist to be honoured in this way.

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