But in the late 1500s and early 1600s, individual alchemists called the medicines they cooked up in their labs ‘secrets’. It turns out that Tycho Brahe, mostly known for his study of astronomy, had his own basement laboratory for mixing medicines—including some particular elements. The authors examined cross sections of the shards for 31 trace elements using mass spectrometry by converting sample molecules into charged ions. “Tungsten is very mysterious,” Kaare Lund Rasmussen, archaeometry expert at the University of Southern Denmark, said in a statement. “Maybe Tycho Brahe had heard about this and thus knew of tungsten’s existence,” Rasmussen speculated.