About: http://webisa.webdatacommons.org/13616845

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	Though saltpeter had been utilised for weapons since the 14th century, its nature and properties were a mystery which were investigated by successive generations of alchemists, natural philosophers and military technicians.
http://www.w3.org/ns/prov#wasQuotedFrom	history.ac.uk