page_title: Carl Auer von Welsbach
section_title: Lutetium and ytterbium
hierarchical_section_title: Carl Auer von Welsbach / Rare earths / Lutetium and ytterbium
caption_attribution_description: Ytterbium, a soft silvery metallic element.
context_page_description: Carl Auer von Welsbach, who received the hereditary title Freiherr von Welsbach
  was an Austrian scientist and inventor, who separated the ore didymium into the elements neodymium and praseodymium in 1885. He was also one of three scientists to independently discover the element lutetium, separating it from ytterbium in 1907, setting off the longest priority dispute in the history of chemistry.
  He had a talent not only for making scientific advances, but also for turning them into commercially successful products.
  His work on rare-earth elements led to the development of the ferrocerium "flints" used in modern lighters, the gas mantle, which brought light to the streets of Europe in the late 19th century, and the metal-filament light bulb.
  He took the phrase "plus lucis", meaning "more light", as his motto.
context_section_description: 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 other's 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.
caption: Ytterbium
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