About: http://webisa.webdatacommons.org/89736209

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	I am looking through my books and other reference materials right now, trying to answer this question, particularly in reference to Scentemental's second post, in which he mentions the existence of other such substances.
http://www.w3.org/ns/prov#wasQuotedFrom	basenotes.net