About: http://webisa.webdatacommons.org/137224817

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	In 1925, Anton Eduard van Arkel and Jan Hendrik de Boer discovered a process where metallic thorium, along with other metals such as zirconium and titanium could be purified into the pure metal form.
http://www.w3.org/ns/prov#wasQuotedFrom	thenuclearmetals.com