Carl Auer von Welsbach

Lutetium and ytterbium

The rare earth element lutetium was independently discovered by three scientists at around the same time in 1907: French scientist Georges Urbain, Austrian Auer von Welsbach, and American Charles James. All three were successful in separating the substance then known as ytterbium into two new fractions. To name the newly discovered fraction, Urbain suggested the name "lutecium", for the Roman city of Lutetia that preceded Paris. Auer von Welsbach suggested the name "cassiopeium". James' work was not yet published when the others' work appeared, and he did not involve himself in subsequent disputes. Lutetium, a slight modification of Urbain's name, was eventually accepted after a long battle between Urbain and Welsbach.

A lawsuit (Wagner v. Coleman) was brought against Coleman. The company changed its formulation to use non-radioactive materials, which apparently cost less and last longer.

Metal-filament light bulb Auer von Welsbach then started work on development of metal-filament mantles, first with platinum wiring, and then osmium. Osmium is very difficult to work with, but he developed a new method, which mixed osmium oxide powder with rubber or sugar into a paste, which is then squeezed through a nozzle and fired. The paste burns away, leaving a fine wire of osmium.

Welsbach's flints consisted of pyrophoric alloys, 70% cerium and 30% iron, which when scratched or struck would give off sparks. This system remains in wide use in cigarette lighters today. In 1907 he formed Treibacher Chemische Werke GesmbH to build and market the devices.

Between 1907 and 1918, Auer von Welsbach focused on isolating preparations of actinium and thorium as by-products of radium extraction. He presented a major paper on his spectroscopic work and the separation of radioactive elements in 1922. The following photographs show scientific equipment from Auer von Welsbach's laboratory, from "Spektroskopische Methoden der analytischen Chemie" (1922).

In 2008 (150 years after his birth), Auer von Welsbach was selected as a main motif for a high-value collectors' coin: the Austrian €25 Fascination Light.

He was also depicted on postage stamps of 1936, 1954 and 2012.

Awards and honors 1900, Elliott Cresson Medal, The Franklin Institute Awards, Philadelphia, PA, USA 1901, raised to the hereditary nobility by Franz Joseph I of Austria, with the title of Freiherr Auer von Welsbach 1920, Werner von Siemens Ring 1921, Wilhelm Exner Medal, inaugural awardee, Austrian Industry Association, Austria 1988, the Welsbach Museum at Althofen was opened in April, 1998 2011, National Inventors Hall of Fame, North Canton, Ohio, USA