Alumen

Powdered alum is a safe, efficient, but slow emetic. About a half-hour usually elapses after it is swallowed before the emesis occurs. It acts mechanically, produces no considerable nausea, and leaves behind no depression. As an emetic, its only use is in croup and diphtheria, administered with the view to cause a detachment of the false membrane. Some effect has been ascribed to the local action of the alum in its passage along the throat, but this opinion is scarcely tenable.

Administration

A tea-spoonful of powdered alum may be administered in sirup, honey, or mucilage. It can be repeated, if need be, every half-hour.