Iodine, element 53, was first isolated in 1813 by French chemist Joseph Louis Gay-Lussac, who named it ione, after the Greek ίον (ion), or violet. In 1814, the British chemist Humphry Davy, who was competing with Gay-Lussac for discovery and identification of the substance, altered its name to the familiar iodine, after ίώδης (iodes) or violet-colored, + the usual -ine suffix. From the Philosophical Transactions of the Royal Society of that year:

The name ione has been proposed in France for this new substance from its colour in the gaseous state, from ίον viola. [...] The name ione, in English, would lead to confusion. By terming it iodine, from ίώδης violaceous, this confusion will be avoided, and the name will be more analogous to chlorine and fluorine.1

Iodine has the chemical symbol I.

1Oxford English Dictionary, iodine, 2nd Edition, 1989, Oxford University Press, accessed 9 October 2009,

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