Although mirrors have existed for millennia, it was a Germa…

Although mirrors have existed for millennia, it was a German chemist who, in 1835, made a crucial discovery that enabled their modern manufacture. Simply add sugar to ammoniacal silver nitrate, pour the mixture onto glass, and you have a mirror.
Justus von Liebig revolutionized mirror manufacturing in 1835 by developing a silvering process that involved applying a thin layer of metallic silver to a pane of glass through a chemical reaction. This discovery had several major consequences: Replacement of mercury: Before 1835, an amalgam of mercury and tin was used. This process was particularly toxic for mirror makers, especially in Venice. Democratization: By making manufacturing safer, faster, and less expensive, this innovation enabled the mass production of mirrors. Accessibility: Once considered luxury items reserved for the elite, mirrors became everyday objects accessible to all social classes from the 20th century onward. The Liebig process remains the basis for the industrial manufacturing of most of our mirrors today.