Assertion: metal's oxide | /r/HasProperty | earth
Facets:
value: at that time
type: TEMPORAL
Source sentences:
text: Arrhenius's "ytterbite" reached Johan Gadolin, a Royal Academy of Turku professor, and his analysis yielded an unknown oxide (earth) that he called yttria.
text: At the time of their discovery in the 18th century, they were found to be a component of complex oxides, which were called “earths” at that time.