Highly reflective metal which melts slightly above body temperature and wets glass. One of the few substances that expands as it solidifies m.p. 29.78 ºC; 85.6 ºF b.p. 2403 ºC; 4357.4 ºF density 5.904 g/cc (29.6 ºC) solid; 6.095 g/cc (29.8 ºC) liquid; 368.575 pound/cubic foot (85.3 ºF) solid; 380.498 pound/cubic foot (85.6 ºF) liquid;	memory peg
	1875 François Lecoq de Boisbaudran, France
	Gallia = France (Latin) unproven rumour says Lecoq named the element after himself ("le coq" [rooster] is "gallus" in Latin)

Gallium was discovered in 1875 by the French chemist Paul Émile (François) Lecoq de Boisbaudran (1838-1912). Spectroscopic examination of concentrates from a Pyrenea blende revealed emission lines whose positions corresponded to those predicted for eka-aluminum, a missing element between Aluminum and Indium in Mendeleyev's Periodic Table of the elements. Lecoq de Boisbaudran subsequently prepared this new element by electrolysis of caustic solutions and observed some of its properties.

He announced the discovery in his article "Caractères chimiques et spectroscopiques d'un nouveau métal, le gallium, découvert dans une blende de la mine de Pierrefitte, vallée d'Argelès (Pyrénées)" in 1875, without any explanation for the choice of the name (note):

Shortly after the naming of the new element the story came that the discoverer Lecoq de Boisbaudran has named the element after himself: gallium > gallus = cock = in French: le coq. Two years later, in 1877, Lecoq published "About a New Metal, Gallium" (note). In this second article he explained why he named the new metal Gallium, "On August 27, 1875, between three and four at night, I perceived the first indications of the existence of a new element that I named gallium in honor of France (Gallia)." France is Lecoq's native country and the place of discovery (cf. Francium).

In answer to a question of Svetla Baykoucheva on the Chemical Information Sources Discussion List of 16 March 1999

"Was the French chemist Paul-Emile LeCoq de Boisbeaudran still alive, when the chemical element he had discovered was named Gallium" Wade Lee wrote on the same day: "I have done extensive research on this matter along with a chemist colleague, Dr. Jimmie Edwards. He was indeed alive, and he himself named it, and specified that it was in honor of his country, France, aka Gallia.
During his lifetime, the false etymology arose that it was named after himself, Le Coq, in its latin form, Gallus. According to his obituary by Arnaud de Gramont, he was very anxious to deny this rumour during his life. The 'gallus' etymology is frequently cited in French dictionaries, and the 'gallia' etymology is usually quoted in the English language dictionaries, with the notable exception of the OED. The Third ed. of the OED will correct its entry. "

Despite this, almost all webpages with the periodical system mention the derivation > gallia and gallus simultaneously.

Illustrations:
Above Map of France ('Gallia') from the Epitome, published by Filips Galle in Antwerp, 1588 (this copy from the edition by J.B. Vrients, 1602).

← Gallium melts in your hand (melting point = 29.8 °C (85.6 F).

Further reading:

• Mary Elvira Weeks, Discovery of the Elements, comp. rev. by Heny M. Leicester (Easton, Pa.: Journal of Chemical Education, 1968), pp. 643-649.