Claude François Geoffroy (1729 – 18 June 1753) was a French

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...

. In 1753 he proved the

chemical element A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its ...

bismuth Bismuth is a chemical element; it has symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs nat ...

to be distinct from lead, becoming the official discoverer of the element. Before this time, bismuth-containing minerals were frequently misidentified as either

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

, tin, or

antimony Antimony is a chemical element; it has chemical symbol, symbol Sb () and atomic number 51. A lustrous grey metal or metalloid, it is found in nature mainly as the sulfide mineral stibnite (). Antimony compounds have been known since ancient t ...

ores. His observations on the matter were published in the ''Mémoires de l’académie française'' in 1753. He became a master

apothecary ''Apothecary'' () is an Early Modern English, archaic English term for a medicine, medical professional who formulates and dispenses ''materia medica'' (medicine) to physicians, surgeons and patients. The modern terms ''pharmacist'' and, in Brit ...

in 1748, and in 1752 he was admitted to the

Académie des sciences The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...

as a supernumerary adjoint chemist. He died on 18 June 1753, (age 23 or 24).Centenaire de l'Ecole supérieure de pharmacie de l'université de Paris: 1803
by Léon Guignard He is known as Claude Geoffroy the Younger to distinguish him from his father Claude Joseph Geoffroy the Older (1685–1752), also a French chemist and apothecary, member of the Académie des sciences.

References

18th-century French chemists 1729 births 1753 deaths Discoverers of chemical elements {{france-chemist-stub