Alchahest

The universal solvent. It is brewed from a potion base, 2 drams of powdered mercury, a pinch of every metal and element but one, a carat each of at least twelve different powdered gemstones, a dram each of seven herbs, and one drop apiece of mammal, reptile, fish and bird blood.

Alchahest eats through whatever it touches at 1 cubic ft. per second for d20 x 3 seconds. The one metal or element left out of the recipe is immune, and that material (or an aludel) is the only thing that can hold it. A mere splash does 1-100 points of damage to a living creature, and a direct hit from a full vial vaporizes its target outright, unless it is a guardian, an arch demon, an arch devil or a being of deific power.

It kills more alchemists than anything else: whenever an attempt fails, there is a 15% chance of a mishap, rolled on the Alchemical Mishap Table. A dose is priced at 1000 G.P. All advanced substances call for an aludel and an athanor in a fully equipped laboratory. Each takes two weeks to make, with a success chance of 75% +1% per level of ability (99% at most).