Carl Axel Arrhenius

Carl Axel Arrhenius (29 March 1757 – 20 November 1824) was a Swedish chemist. He is most widely known as the discoverer of a mineral which turned out to contain a plethora of new chemical elements: the rare-earth metals, all of which are chemically very similar to each other. It is very difficult to find any one of these without impurities of the others.

Arrhenius was born in Stockholm. He became interested in mineralogy and chemistry after he met Peter Jacob Hjelm at the Swedish Royal Mint laboratory. Arrhenius was a lieutenant at the Svea Artillery Regiment stationed in Vaxholm. He then took part in the campaign against Finland in 1788. He was promoted to Feldzeugmeister and lieutenant colonel at the Svea artilleriregemente and was sent to the command of the manufacture of gunpowder in Sweden in 1816.

Arrhenius's chemical studies started at the Royal Mint's (Kungliga Myntet) laboratory, where he studied the characteristics of powder as an artillery officer. During his visit to Paris during 1787–88, he met the French chemist Antoine Lavoisier, "the father of modern chemistry". Upon his return to Sweden became an ardent defender of the revolutionary ideas in chemistry promoted by Antoine Lavoisier.

During his time in Vaxholm, Arrhenius visited the feldspar mine in the village of Ytterby on the island of Resarön, near Vaxholm. He found a dark mineral which he named ytterbite and sent to the chemist Johan Gadolin at the University of Åbo for further analysis. This permitted the discovery of four new elements by various chemist: yttrium, terbium, erbium, and ytterbium, and eventually the rest of the rare-earth metals, including scandium, lanthanum, cerium, neodymium, and thulium.

Arrhenius became a member of the Royal Swedish Academy of War Sciences 1799, and of the Royal Swedish Academy of Sciences 1817.