Editing Propionic acid (section)

==History==
Propionic acid was first described in 1844 by [[Johann Gottlieb]], who found it among the degradation products of sugar.<ref>Johann Gottlieb (1844) [https://babel.hathitrust.org/cgi/pt?id=uva.x002457921;view=1up;seq=581 "Ueber die Einwirkung von schmelzendem Kalihydrat auf Rohrzucker, Gummi, Stärkmehl und Mannit"] (On the effect of molten potassium hydroxide on raw sugar, rubber, starch powder, and mannitol), ''Annalen der Chemie und Pharmacie'', '''52''' :  121–130.  After combining raw sugar with an excess of potassium hydroxide and distilling the result, Gottlieb obtained a product that he called "Metacetonsäure" (meta-acetone acid) on p. 122:  ''"Das Destillat ist stark sauer und enthält Ameisensäure, Essigsäure und eine neue Säure, welche ich, aus unten anzuführenden Gründen, Metacetonsäure nenne."''  (The distillate is strongly acidic and contains formic acid, acetic acid, and a new acid, which for reasons to be presented below I call "meta-acetone acid".)</ref> Over the next few years, other chemists produced propionic acid by different means, none of them realizing they were producing the same substance.  In 1847, French chemist [[Jean-Baptiste Dumas]] established all the acids to be the same compound, which he called propionic acid, from the [[Greek language|Greek]] words πρῶτος (prōtos), meaning ''first'', and πίων (piōn), meaning ''fat'', because it is the smallest {{chem|H(CH|2|)|n|COOH}} acid that exhibits the properties of the other [[fatty acid]]s, such as producing an oily layer when salted out of water and having a soapy [[potassium]] [[Potassium propionate|salt]].<ref>Dumas, Malaguti, and F. Leblanc (1847) [http://gallica.bnf.fr/ark:/12148/bpt6k2982c/f785.item.r=.zoom "Sur l'identité des acides métacétonique et butyro-acétique"] [On the identity of metacetonic acid and butyro-acetic acid], ''Comptes rendus'', '''25''' :  781–784.  Propionic acid is named on p. 783:  ''"Ces caractères nous ont conduits à désigner cet acide sous le nom d'''acide propionique'', nom qui rappelle sa place dans la séries des acides gras:  il en est le premier."'' (These characteristics led us to designate this acid by the name of ''propionic acid'', a name that recalls its place in the series of fatty acids:  it is the first of them.)</ref>