On 22 Jan 2002 at 3:41, Jorge Stolfi wrote: > "Vitriolo Romano" (Roman vitriol) seems to be copper sulfate. From > what I remember of freshman chemistry, the "prima acqua" may be just > water of crystallization; but I would not be surprised if it contained > some nitric acid... That will get rid of all spots and most of the face too :-) Cheers, Gabriel