Editing 1820 in science (section)

==Chemistry==
* May – [[John Herapath]] draws up a partial account of the [[kinetic theory of gases]].<ref>{{cite journal|last=Herapath|first=J.|year=1821|title=A Mathematical Inquiry into the Causes, Laws and Principal Phæenomena of Heat, Gases, Gravitation, &c|journal=[[Annals of Philosophy]]|volume=9|pages=273–293|url=https://books.google.com/books?id=nCsAAAAAMAAJ&pg=RA1-PA273|accessdate=2011-10-28}}</ref>
* [[Joseph Bienaimé Caventou]] and [[Pierre Joseph Pelletier]] isolate the [[alkaloid]]s [[cinchonine]] and [[quinine]] from ''[[Cinchona]]'' bark.
* [[Solanine]] is first isolated from the berries of the European black nightshade (''[[Solanum nigrum]]'').<ref>{{cite journal|author=Desfosses|title=Extrait d'une lettre de M. Desfosses, pharmacien, à Besançon, à M. Robiquet|journal=Journal de Pharmacie|year=1820|volume=6|pages=374–376|url=https://babel.hathitrust.org/cgi/pt?id=mdp.39015062276103&view=1up&seq=468&skin=2021|series=2nd series|trans-title=Extract of a letter from Mr. Desfosses, pharmacist in Besançon, to Mr. Robiquet}}</ref>
* [[Friedrich Accum]]'s ''A Treatise on Adulterations of Food and Culinary Poisons'' is published in London.