Plunkett's Caustic

or Ointment. A caustic paste composed of the bruised plant of Ranunculus acris and of it, J/ammu/a, each 24 parts; arsenious acid, 3 parts; sulphur, 5 parts. These are mixed into a paste, rolled into balls, and dried in the sun. When used the ball must be reduced to a pasty consistence by rubbing with yolk of egg.