Right. And how would they produce it.
From
Wikipedia:
Hydrochloric acid was first discovered around 800 AD by the alchemist Jabir ibn Hayyan (Geber), by mixing common salt with sulfuric acid ("vitriol"). Jabir discovered many important chemicals, and recorded his findings in over 20 books, which carried his chemical knowledge of hydrochloric acid and other basic chemicals for hundreds of years. Jabir's invention of the gold-dissolving aqua regia, consisting of hydrochloric acid and nitric acid, was of great interest to alchemists searching for the philosopher's stone.
Out of rock. Right. What kind of rock would it be? An acid rock?
Regarding Sulfuric Acid (aka Vitriol):
The discovery of sulfuric acid is credited to the 8th century Muslim chemist and alchemist, Jabir ibn Hayyan (Geber). The acid was later studied by 9th century Persian physician and alchemist Ibn Zakariya al-Razi (Rhazes), who obtained the substance by dry distillation of minerals including iron(II) sulfate heptahydrate, FeSO4 • 7H2O, and copper(II) sulfate pentahydrate, CuSO4 • 5H2O. When heated, these compounds decompose to iron(II) oxide and copper(II) oxide, respectively, giving off water and sulfur trioxide, which combine to produce a dilute solution of sulfuric acid. This method was popularized in Europe through translations of Arabic and Persian treatises, as well as books by European alchemists, such as the 13th-century German Albertus Magnus.
So, yes, from stones. Sort of. And note that the compounds involved have more period-appropriate names, and other uses that could make them worth adding to Dwarf Fortress:
Iron(II) sulfate, aka Ferrous Sulfate, Green vitriol, or Iron vitriol.
Copper(II) sulfate, aka Cupric Sulfate, Blue vitriol, or Copper vitriol.
Most notably, they are used to color glass, and as dyes (in China, as early as the Song Dynasty -- ~1100 AD.) They were obtained when water would accumulate in the appropriate sorts of mines.
Hmm,
this page looks useful...