A herb with a caustic action on the skin, i.e. the milky juice of Sun Spurge (Euphorbia) has a corrosive effect upon warts and hard schirrhous lesions. Once used on small malignant spots to dry- up and enhance formation of a crust or scab that in the course of time might detach itself. Blood root.
A caustic substance that creates a mass of dead cells or scab