Amritha vennai or Sawveera Kuzhambu is a siddha medicine for external use. This medicine is in paste form and made up of mercuric cloride and butter. It is prepared by grinding one part of mercuric cloride (veeram) with hundred and fifty parts of butter. This medicine is used for the treatment of ulcers, boils, carbuncles, abscesses, and scorfula. This medicine is for strict external use only.