(L. Scandia: Scandinavia) On the basis of the Periodic System, Mendeleev predicted the existence of ekaboron, which would have an atomic weight between 40 of calcium and 48 of titanium.

The element was discovered by Nilson in 1878 in the minerals euxenite and gadolinite, which had not yet been found anywhere except in Scandinavia. By processing 10 kg of euxenite and other residues of rare-earth minerals, Nilson was able to prepare about 2g of highly pure scandium oxide. Later scientists pointed out that Nilson's scandium was identical with Mendeleev's ekaboron. 
A Periodic Table of the Elements at Los Alamos National Laboratory