Artificial ALUM, that prepared by art, in contradistinction from the native alum. It is also used for alum produced by causing burnt earthen vessels imbibe a large quantity of oil of vitriol; the effect of which is, that they are thereby reduced to a mucilage, which, being exposed to the open air, affords crystals of pure alum. Tobacco-pipes, wetted with spirit of sulphur, likewise afford beautiful crystals of plumose alum.