Editing Phlogiston theory (section)

=== ''Terra pinguis''===
In 1667, [[J. J. Becher|Johann Joachim Becher]] published his book {{Lang|la|Physica subterranea}}, which contained the first instance of what would become the phlogiston theory. In his book, Becher eliminated fire and air from the classical element model and replaced them with three forms of the earth: {{Lang|la|terra lapidea}}, {{Lang|la|terra fluida}}, and {{Lang|la|terra pinguis}}.<ref name="morris2">{{cite book|url=https://books.google.com/books?id=-V9jM4FkUacC|title=Making modern science: A historical survey|last=Bowler|first=Peter J|publisher=University of Chicago Press|year=2005|location=Chicago|page=60|isbn=9780226068602}}</ref><ref>Becher, ''[http://gallica.bnf.fr/ark:/12148/bpt6k84226t Physica Subterranea]'' p. 256 ''et seq.''</ref>  {{Lang|la|Terra pinguis}} was the element that imparted oily, [[Sulfur|sulphurous]], or combustible properties.<ref name="brock2">{{cite book|title=The Norton history of chemistry|last=Brock|first=William Hodson|publisher=W. W. Norton|year=1993|isbn=978-0-393-03536-0|edition=1st American|location=New York|url-access=registration|url=https://archive.org/details/nortonhistoryofc00broc}}</ref> Becher believed that {{Lang|la|terra pinguis}} was a key feature of combustion and was released when combustible substances were burned.<ref name="morris2" /> Becher did not have much to do with phlogiston theory as we know it now, but he had a large influence on his student Stahl. Becher's main contribution was the start of the theory itself, however much of it was changed after him.<ref name="White">{{Cite book|title=The History of Phlogiston Theory|last=White|first=John Henry|publisher=AMS Press Inc.|year=1973|isbn=978-0404069308|location=New York}}</ref> Becher's idea was that combustible substances contain an ignitable matter, the {{Lang|la|terra pinguis}}.<ref name="Leicester">{{Cite book|title=A Source Book in Chemistry|last1=Leicester|first1=Henry M.|last2=Klickstein|first2=Herbert S.|publisher=Harvard University Press|year=1965|location=Cambridge, Massachusetts}}</ref>