POTASSIUM SULPHATE AND TAR TRATES.—These salts in large doses act as irritant poisons, producing severe ab dominal pain, vomiting, etc. The treat ment of poisoning by these salts consists in the evacuation of the stomach and the administration of warm demulcent drinks and opium. Cardiac stimulants may be needed, and warm external applications are usually indicated.
Therapeutics.
Caustics.—The caustic alkalies possess a very high diffusive power, and pene trate and destroy the tissues widely and deeply; so that certain precautions should be observed in their use lest the amount of tissue destroyed be larger than desired. When potassa is used as a caus tic, the surrounding parts should be pro tected by adhesive plaster in one or more layers, a central hole having been cut out through which the caustic may have access to the skin. The size of the hole should be rather less than the area to be acted upon, as the eschar is apt to be larger than the area to which the caustic has been applied. The caustic in the form of the fused potassa is moistened slightly and rubbed firmly upon the sur face till it assumes a dull-bluish look, and till the cuticle is softened and easily rubs off. The spot should then be washed
with dilute vinegar, to neutralize any of the remaining a poultice ap plied to facilitate the separation of the slough and to ease the pain.
Potassa alone is often more powerful than is desired, and it is commonly com bined with quicklime, forming potassa cum calce, or Vienna paste, which must be moistened with alcohol before use.
Potash and Vienna paste have been extensively used to destroy cancerous growths, to limit sloughing ulcers, to re move the thickened, indurated edges of chronic ulcers, and to open boils, car buncles, and indolent or deep-seated ab scesses. They are said to prevent scar ring. They have also been employed in the treatment of warts, nmvi, malignant pustules, and phagechena. Caustic potash has been used by surgeons in the post operative treatment of fistula in ano, to keep the cut edges apart until the deeper parts of the wound are filled with granu lations.