This metal was named Bismutum by Basile Valentin in 1450 and Wismut by Paracelsus in the 16th century. In his treatise De re metallica, which also dates from the 16th century, Agricola expressed the view that the metal was a variety of lead and called it Plumbum cinerum. Certain alloys used in the 15th century by Gutenberg contained bismuth. The name of the metal is derived from the German weisse masse (white substance). The basic nitrate Bi(OH)2O3 was used by painters in the 16th century and was known as blanc d’Espagne. Industrial production of the metal only began around 1830 in Saxony.