Astringents.—Agents that cause contraction of muscular fibre: alum, catechu, oak-bark, tannic acid.

EXTERNALLY ADMINISTERED.

Medicines that Act upon the Skin and External Parts by Direct Application.

Refrigerants.—Agents that diminish morbid heat of a part: salt and cold water, solutions of acetate and subacetate of lead.

Discutients.—Agents that dispel enlargements: compounds of iodine, soap liniment, camphor.

Rubefacients.—Agents that cause heat or redness of skin without blistering: liniments of ammonia, tar and turpentine, vinegar.

Vesicants.—Agents that produce blisters: cantharides, tartar emetic, croton-oil, hot water.

Caustics.—Agents that decompose the part to which applied: carbolic, nitric, sulphuric, and hydrochloric acids; chlorides of antimony and zinc, corrosive sublimate, nitrate of silver, sulphate of copper, hot iron.

Pyogenics.—Agents that induce suppuration of wounds: liniment and ointment of turpentine, black hellebore.