Alchemical Symbolism in the VMS

[bi3mw]

Hmm, so saltpetre alone actually makes little sense. It would simply burn off when heated. It should actually be a salt (or a salt solution) that can dissolve or at least bind substances. I have no idea whether such a salt exists.
I only know that vitriol and alums were also used to make sulphuric acid and nitric acid. So I would guess a mixture of salts. The resulting acids would then have the properties needed.

....
Geber is also considered the discoverer of the mineral acids sulphuric acid and nitric acid. He obtained the former by "distillation" from the salts alum and vitriol, the latter by adding saltpetre (potassium nitrate) to the salt mixture *.

* The product was the so-called "aqua dissolutiva".

Edit: the whole thing can also be distilled: You are not allowed to view links. Register or Login to view.?t%3D4333