Anders Ekeberg. Portrait of Anders Gustaf Ekeberg, Swedish chemist and mineralogist (1767-1813). Ekeberg became a full professor at Uppsala in 1794 and was elected to the Royal Swedish Academy of Sciences. Around 1795 he began investigating yttrium, a newly discovered heavy metal and found that it contained another unknown heavy metal which he called tantalum. He introduced the theories of Lavoisier into Sweden, and had the distinction of being the teacher of the composer Berzelius.