About: http://webisa.webdatacommons.org/22486583

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	Throughout the 1800s, chemists found a number of substances which they proposed as the missing element, but these turned out to be impure forms of other elements.
http://www.w3.org/ns/prov#wasQuotedFrom	wisegeek.com