Courtois
NAME: Courtois, Bernard
ACHIEVEMENTS: Discovered Iodine
NICKNAME/ALIAS: None
DATE AND PLACE OF BIRTH:
8 February 1777, Dijon, France
DATE AND PLACE OF DEATH AND AGE AT DEATH:
27 September 1838, Paris, France. Aged 61
DISCIPLINE: Chemist
FIELD: Chemistry
LANGUAGE: French
PARENTS:
Father: Jean-Baptiste Courtois
Mother: Marie Blez
SIBLINGS: 6
SPOUSE: Unknown
CHILDREN: Unknown
EDUCATION:
Ecole Polytechnique, Paris
MAJOR WORK:
None
LIFE AND TIMES:
Courtois's father, a saltpeter manufacturer, acted as laboratory assistant to the distinguished chemist Guyton de Morveau* and Courtois spent much of his early years around the laboratory. When his father followed de Morveau to Paris, Courtois was apprenticed to a pharmacist in Auxerre, south of the capital, for three years. In 1798 he enrolled at the new Paris Ecole Polytechnique, whose director then was Monge*.
Courtois' training was interrupted by military service and in 1799 he served as a pharmacist in the French army.
He then returned to Paris and worked in the laboratory of Thenard* with whom he had become friendly at the Polytechnique. Courtois returned to Dijon to run his father's business.
To produce saltpeter, it was necessary to add sulphuric acid to leached kelp (seaweed) ash. One day in 1811, he added too much sulphuric acid to the mixture and saw clouds of violet-coloured vapour arising from the solution. When the vapor condensed it formed dark crystals. He tried to analyse the crystals but did not have the funds to continue his investigation.
About a year later, Courtois told two chemists in Dijon of his find and asked them to continue investigating the crystals. They announced his discovery in 1813, and in the same year Gay-Lussac* at the Ecole Polytechnique established that the new substance was an element. It was Gay-Lussac who named the new element iodine* (because of its violet color) and acknowledged Courtois as its discoverer.
Courtois's saltpeter business collapsed after the end of the Napoleonic wars in 1815, when the demand for gunpowder decreased. Ironically, his discovery had helped the kelp industry which had also been under threat. The soda content of kelp had made it a useful product for bleaching but since Leblanc* discovered how to make soda artificially in 1789 the demand for kelp had fallen. It now rose again by virtue of being a workable source of iodine.
Courtois took up the manufacture of iodine but was unsuccessful. The Institute of France awarded him a prize of 6,000 Frs. in 1831.
ASSESSMENT: Courtois is remembered as the discoverer of iodine.
EXTRA CONNECTIONS: Daguerre* discovered that an iodized silver plate could produce a lasting photographic image.
ONELINER: Bernard Courtois, French discoverer of iodine
BIBLIOGRAPHY:
DSB
Toraude, L.G., Bernard Courtois et la Decourverte de l'Iode, Vigot Freres, Editeurs, Paris, 1921.