Editing Potassium (section)

===Potash===
{{main|Potash}}
Potash is primarily a mixture of potassium salts because plants have little or no sodium content, and the rest of a plant's major mineral content consists of calcium salts of relatively low solubility in water. While potash has been used since ancient times, its composition was not understood. [[Georg Ernst Stahl]] obtained experimental evidence that led him to suggest the fundamental difference of sodium and potassium salts in 1702,<ref name="1702Suspect">{{cite book|url = https://books.google.com/books?id=b-ATAAAAQAAJ&pg=PA167|page = 167|title = Chymische Schriften|last1 = Marggraf|first1 = Andreas Siegmund|date = 1761}}</ref> and [[Henri Louis Duhamel du Monceau]] was able to prove this difference in 1736.<ref>{{cite journal|url = http://gallica.bnf.fr/ark:/12148/bpt6k3533j/f73.image.r=Memoires%20de%20l%27Academie%20royale%20des%20Sciences.langEN|journal = Mémoires de l'Académie Royale des Sciences|title = Sur la Base de Sel Marin|last = du Monceau|first = H. L. D.|pages = 65–68|language = fr|date = 1702–1797|access-date = 2011-05-09|archive-date = 2019-08-21|archive-url = https://web.archive.org/web/20190821202241/https://gallica.bnf.fr/ark%3A/12148/bpt6k3533j/f73.image.r%3DMemoires%20de%20l%27Academie%20royale%20des%20Sciences.langEN|url-status = live}}</ref> The exact chemical composition of potassium and sodium compounds, and the status as chemical element of potassium and sodium, was not known then, and thus [[Antoine Lavoisier]] did not include the alkali in his list of chemical elements in 1789.<ref name="weeks">{{cite journal|doi = 10.1021/ed009p1035|title = The discovery of the elements. IX. Three alkali metals: Potassium, sodium, and lithium|year = 1932|last1 = Weeks|first1 = Mary Elvira|author-link1=Mary Elvira Weeks|journal = Journal of Chemical Education|volume = 9|issue = 6|pages = 1035|bibcode = 1932JChEd...9.1035W}}</ref><ref name="disco">{{cite journal|jstor = 228541|pages = 247–258|last1 = Siegfried|first1 = R.|title = The Discovery of Potassium and Sodium, and the Problem of the Chemical Elements|volume = 54|issue = 2|journal = Isis|year = 1963|doi = 10.1086/349704|pmid = 14147904|s2cid = 38152048}}</ref> For a long time the only significant applications for potash were the production of glass, bleach, soap and [[gunpowder]] as potassium nitrate.<ref>{{cite journal|doi = 10.1021/ed003p749|title = Historical notes upon the domestic potash industry in early colonial and later times|year = 1926|last1 = Browne|first1 = C. A.|journal = Journal of Chemical Education|volume = 3|issue = 7|pages = 749–756|bibcode = 1926JChEd...3..749B}}</ref> Potassium soaps from animal fats and vegetable oils were especially prized because they tend to be more water-soluble and of softer texture, and are therefore known as soft soaps.<ref name="g73" /> The discovery by [[Justus Liebig]] in 1840 that potassium is a necessary element for plants and that most types of soil lack potassium<ref>{{cite book|url = https://archive.org/details/dieorganischech01liebgoog|title = Die organische Chemie in ihrer Anwendung auf Agricultur und Physiologie|publisher = F. Vieweg und Sohn|author = Liebig, Justus von|date = 1840| language = de}}</ref> caused a steep rise in demand for potassium salts. Wood-ash from fir trees was initially used as a potassium salt source for fertilizer, but, with the discovery in 1868 of mineral deposits containing [[potassium chloride]] near [[Staßfurt]], Germany, the production of potassium-containing fertilizers began at an industrial scale.<ref>{{cite book|author=Cordel, Oskar |title=Die Stassfurter Kalisalze in der Landwirthschalt: Eine Besprechung ...|url=https://books.google.com/books?id=EYpIAAAAYAAJ|date=1868|publisher=L. Schnock| language = de}}</ref><ref>{{cite book|url = https://books.google.com/books?id=J8Q6AAAAcAAJ|title = Die Kalidüngung in ihren Vortheilen und Gefahren|last1 = Birnbaum| first1= Karl|date = 1869| language = de}}</ref><ref>{{cite book|url = https://books.google.com/books?id=qPkoOU4BvEsC&pg=PA417|title = Fertilizer Manual|isbn = 978-0-7923-5032-3|author = United Nations Industrial Development Organization and Int'l Fertilizer Development Center|date = 1998|pages=46, 417| publisher=Springer }}</ref> Other potash deposits were discovered, and by the 1960s Canada became the dominant producer.<ref>{{cite journal|jstor = 3103338|pages = 187–208|last1 = Miller|first1 = H.|title = Potash from Wood Ashes: Frontier Technology in Canada and the United States|volume = 21|issue = 2|journal = Technology and Culture|year = 1980|doi=10.2307/3103338| s2cid=112819807 }}</ref><ref>{{cite journal|doi = 10.2113/gsecongeo.74.2.353|title = Potash and politics|year = 1979|last1 = Rittenhouse|first1 = P. A.|journal = Economic Geology|volume = 74|issue = 2|pages = 353–7| bibcode=1979EcGeo..74..353R }}</ref>