Elements No. 70, 71 and 72: Discoveries and Controversies

Abstract

The history of the discovery of the two last rare earth elements, ytterbium and lutetium, is a history of two priority disputes separated by a period of 16 years. The principal concern of the later and more bitter controversy was element 72, which is not a rare earth, but a zirconium homologue. Nonetheless, from a historical point of view the discovery of hafnium is an integral part of the discovery histories of the rare earths, which would be incomplete without hafnium. The two main contestants in the priority disputes, Georges Urbain and Carl Auer von Welsbach, were specialists in rare earth chemistry and highly regarded for their many contributions to this branch of chemistry. As an indication of their stature in the chemical community, both were nominated several times for a Nobel prize. Auer was nominated 10 times between 1918 and 1929, and Urbain 56 times between 1912 and 1936 (Crawford et al. 1987). All of Auer’s nominations came from either Germans or Austrians, and almost all of Urbain’s nominations were French. Their disagreements over the discoveries of elements did not, apparently, hurt their reputation. But it may well have contributed to the Swedish Nobel Committee’s decision not to award either of them the valued award.