Neodymium: Anhydrous Chloride Electrolysed in a Half Water-Cooled Copper Crucible, Barium Chloride Added for Heat (Weiss, Muthmann's Laboratory, 1902)

Neodymium was first made as a metal in Munich in 1902. Weiss dried neodymium chloride with ammonium chloride and electrolysed it in a tiny copper crucible cooled on its upper half, so the salt froze into its own lining. Because neodymium melts much higher than cerium, he dropped in pinches of barium chloride to make the bath hotter. Result: silver-white balls of neodymium metal, 14.5 g in the second run. Source: L. Weiss, Ueber die Darstellung der Metalle der Cergruppe durch Schmelzelektrolyse (dissertation, TH Munich, 1902), sections III, IV and VII. Chlorine comes off the anode; the original packing was asbestos. Picture: Plate I of the dissertation.