PTISAN, is properly barley decorticated, or deprived of its hulls, by beating in a mortar, as was the ancient practice, though the cooling potion, obtained by boiling such barley in water, and afterwards sweetening the liquor with liquorice-root, is what at present goes by the name of ptisan; and to render it laxative, some add a little fena, or other herb of the same intention.