Origin. - The dried bark of Quercus alba L., collected from trunks or branches ten to twenty-five years of age, and deprived of the periderm. The oaks are shrubs or trees growing chiefly in the temperate zone, often forming extensive forests. The white oak is a stately tree, 60 to 80 feet (18-24 M.) high, found from Canada to Florida and west to Wisconsin and Eastern Texas.

Description and Properties. - In nearly flat pieces deprived of the corky layer, about 1/5 inch (5 Mm.), pale brown; inner surface with short, sharp, longitudinal ridges; tough and of a coarse, fibrous fracture, a faint, tan-like odor, and a strongly astringent taste. As found in the shops, it is usually an irregularly coarse fibrous powder, which does not tinge the saliva yellow.

Dose. - Seldom given in substance. A decoction is sometimes given internally, but the chief use of the drug is for external or local application.

Official Preparation

Fluidextractum Quercus - Fluidextracti Quercus - Fluidextract of Quercus (U. S. P.). - Prepared from the official quercus (Quercus Alba, U. S. P., 1890), the bark of the white oak. The medicinal properties depend upon the tannic,on-tained in the bark.

Dose, - Average dose: 15 minims (1 Cc), U. S. P.

Physiological Action. - The general action is that ot tannic acid.

Therapeutics. - Externally and Locally. - It is used for chapped nipples, gangrene, ulcers, and dermatatis venenata. It is of value as an ointment in hemorrhoids, prolapsus ani, anal fissure, and leu-corrhea. The drug is also serviceable in relaxed uvula and as a tooth-powder. It stains the linen, however, which somewhat limits its use. Pessaries made of the bark have been used to check uterine hemorrhage. For scrotal hernia the concentrated fluidextract is injected into the tissues for the purpose of exciting inflammation and consequent contraction of the hernial ring. It may be of service in diarrhea and dysentery.

Administration. - Externally it is used as a poultice - chiefly in the form of the powdered bark. The decoction is employed almost exclusively as an injection and for internal administration. The laity were formerly wont to roast the acorns and chew them, or grate them and mix the gratings with cocoa or chocolate, believing them to be a cure for diarrhea as well as for flatulent dyspepsia and scrofula.