Samarium nitrate, ca. 1900
Erbium nitrate, ca. 1900
Lanthanum oxide mixed with praseodymium oxide, ca. 1900
Neodymium nitrate, ca. 1900
Yttrium oxide, 1925
Europium nitrate, ca. 1900
Praseodymium-neodymium nitrate, ca. 1900
Cerdium oxide, ca. 1900
Donor: Wilhelm Prandtl, Ludwig-Maximilians-Universität, München.