Editing Potassium nitrate (section)

===From caves===
Major natural sources of potassium nitrate were the deposits crystallizing from cave walls and the accumulations of [[bat guano]] in caves.<ref>{{cite book |title=Notes on Making Saltpetre from the Earth of the Caves |author=Major George Rains |year=1861 |page=14 |publisher=Daily Delta Job Office |location=New Orleans, LA |access-date=September 13, 2012 |url=https://archive.org/stream/notesonmakingsal01rain |url-status=live |archive-url=https://web.archive.org/web/20130729072115/https://archive.org/stream/notesonmakingsal01rain |archive-date=July 29, 2013}}</ref> Extraction is accomplished by immersing the guano in water for a day, filtering, and harvesting the crystals in the filtered water. Traditionally, guano was the source used in [[Laos]] for the manufacture of gunpowder for [[Rocket Festival|''Bang Fai'']] rockets.<ref name="joshi14">{{cite journal |doi=10.56431/p-je383z |title=Environmentally and Economically Feasibility Manufacturing Process of Potassium Nitrate for Small Scale Industries: A Review |date=2014 |last1=Joshi |first1=Chirag S. |last2=Shukla |first2=Manish R. |last3=Patel |first3=Krunal |last4=Joshi |first4=Jigar S. |last5=Sahu |first5=Omprakash |journal=International Letters of Chemistry, Physics and Astronomy |volume=41 |pages=88–99 |doi-access=free}}</ref>

[[Calcium nitrate]], or lime saltpetre, was discovered on the walls of stables, from the urine of barnyard animals.<ref name=brit1/>