Bernard Courtois, also spelled Barnard Courtois, (8 February 1777 – 27 September 1838) was a French

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe th ...

credited with first isolating

iodine Iodine is a chemical element with the Symbol (chemistry), symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , ...

. By 1811 the

Napoleonic Wars The Napoleonic Wars (1803–1815) were a series of major global conflicts pitting the French Empire and its allies, led by Napoleon I, against a fluctuating array of European states formed into various coalitions. It produced a period of Fre ...

had made the government-controlled

saltpeter Potassium nitrate is a chemical compound with the chemical formula . This alkali metal nitrate Salt (chemistry), salt is also known as Indian saltpetre (large deposits of which were historically mined in India). It is an ionic salt of potassium ...

business taper off since there was by then a shortage of wood ashes with which potassium nitrate was made. As an alternative, the needed potassium nitrate was derived from seaweed that was abundant on the Normandy and Brittany shores. The seaweed also had another, yet undiscovered, important chemical. One day towards the end of 1811 while Courtois was isolating

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

and

potassium Potassium is the chemical element with the symbol K (from Neo-Latin '' kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmos ...

compounds from seaweed ash, he discovered

after he added

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular fo ...

to the seaweed ash. He was investigating corrosion of his copper vessels when he noticed a vapor given off. It was in the form of an unusual purple vapor.

Humphry Davy Sir Humphry Davy, 1st Baronet, (17 December 177829 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp. He is also remembered for isolating, by using electricity, several elements for ...

later records

Later life

Courtois was acknowledged by Humphry Davy and

Joseph Louis Gay-Lussac Joseph Louis Gay-Lussac (, , ; 6 December 1778 – 9 May 1850) was a French chemist and physicist. He is known mostly for his discovery that water is made of two parts hydrogen and one part oxygen (with Alexander von Humboldt), for two laws ...

as the true discoverer of iodine. He went into manufacturing high-quality iodine and its salts in 1822. In 1831 he was awarded 6,000 francs as part of the Montyon Prize by ''L'Academie royale des sciences'' for the medicinal value of this element. He struggled financially for the rest of his life and died 27 September 1838. He was 62 years old and had no assets left for his widow or son. In the year of his death, the ''Journal de chimie médicale'' drily noted his passing under the heading

Obituary An obituary ( obit for short) is an article about a recently deceased person. Newspapers often publish obituaries as news articles. Although obituaries tend to focus on positive aspects of the subject's life, this is not always the case. Ac ...

as:

"Bernard Courtois, the discoverer of iodine, died at Paris the 27th of September, 1838, leaving his widow without fortune. If, on making this discovery, Courtois had taken out a certificate of invention, he would have realized a large estate." as translated by

Notes

References

* Toraude, L. G., ''Bernard Courtois (1777–1838) et la découverte de l'iode (1811)'', Vigot Frères, Paris, 1921 * Smeaton, W. A., ''Guyton de Morveau's Course of Chemistry in the Dijon Academy'', Ambix 1961, 9, 53–69 {{DEFAULTSORT:Courtois, Bernard 19th-century French chemists 1777 births 1838 deaths Discoverers of chemical elements Scientists from Dijon 19th-century French photographers Iodine École Polytechnique alumni 18th-century French chemists