Odorless, colorless gas which gives off a bluish light under high voltage m.p. -189.2 ºC; -308.6 ºF b.p. -185.7 ºC; -302.3 ºF density 0.0017837 g/cc; 0.1113528 pound/cubic foot	memory peg
	1894 Lord Rayleigh & Sir William Ramsay, England
	αργος (argos) = idle (Greek)

Sir William Ramsay (1852-1916) and Lord Rayleigh (born John William Strutt) published their discovery of argon in 1895: "Argon, a New Constituent of the Atmosphere" (note). Rayleigh was led into the investigation by small anomalies he found in measurements of the density of nitrogen purified by different methods. Those different methods led to different quantities of nitrogen, and thus to different proportions of nitrogen and a hitherto unsuspected atmospheric gas. Argon was the first noble gas isolated. Naturally there was no place for it in the periodic table as it then existed. Ramsay's subsequent work isolated helium and discovered neon, krypton, and xenon by the end of the century. Ramsay and Rayleigh were awarded Nobel Prizes in 1904. Note the plural "Prizes": Rayleigh was awarded the physics prize for argon, while Ramsay was awarded the chemistry prize for Argon and the family of noble gases (Giunta 1996).

Until 1957 the chemical symbol A was used (note).

An illustration of Ramsay's Argon Apparatus taken from his his book The Gases of the Atmosphere.

Etymology
From the Greek word αργον, neut. of αργος [argos] argos "idle," from α- "without" + εργον "work." = lazy, inactive. Argon, just as the other noble gases, hardly react with other elements.

Anglium, Hibernium, and Scotium

In 1897, William Ramsay addressed the British Association for the Advancement of Science and told about the discovery of Argon: "The discovery of argon at once raised the curiosity of Lord Rayleigh and myself as to its position in this table. With a density of nearly 20, if a diatomic gas, like oxygen and nitrogen, it would follow fluorine in the periodic table; and our first idea was that argon was probably a mixture of three gases, all of which possessed nearly the same atomic weights, like iron, cobalt, and nickel. Indeed, their names were suggested, on this supposition, with patriotic bias, as Anglium, Scotium, and Hibernium!" [After Anglia, Scotia, and Hibernia, the latin names of England, Scotland, and Ireland, which formed the United Kingdom]. Later, Norman Collie and Ramsay have demonstrated that argon is a simple substance, and not a mixture (note, see also Fontani et al. 2003).

Metargon

Immediately after the discovery of Neon, Ramsay and Travers thought to have discovered a new element, which they named Metargon. In his Nobel lecture Ramsay said about this:

"We were at this time misled in supposing that a second gas was present, showing a spectrum different from that of argon, but possessing almost the same density; we regarded it as bearing to argon the same relation as that of nickel to cobalt; and we christened it «metargon». This gas subsequently turned out to be argon in the main, but to contain carbon monoxide, owing to the use of an impure specimen of phosphorus containing carbon in removing the oxygen; but it gave us a great deal of trouble to make sure that it was not a new individual." (note).

Further reading:

• Mary Elvira Weeks, Discovery of the Elements, comp. rev. by Heny M. Leicester (Easton, Pa.: Journal of Chemical Education, 1968), pp. 756-757.
• Edelgasse. Gmelins Handbuch der anorganische Chemie, 8. Aufl.; System-Nummer 1 (1926).
• Univ. Coll. London, Dept. of Chemistry, The Discovery of Argon (source of both illustrations).
• Marco Fontani, Mariagrazia Costa, and Arnaldo Cinquantini, Dagli aloni pleocroici alla nascita della Terra. RICH-MAC Magazine 85, La Chimica e l'Industria, Ottobre 2003, pp. 65-67.
• Carmen J. Giunta, The Discovery of Argon: a Case Study in Scientific Method, Presented at the 211th ACS National Meeting, New Orleans, LA, March 24, 1996. (on-line)