Page:Collier's New Encyclopedia v. 01.djvu/47

ACLAND radical (HO·OC), once if they are monobasic, twice if dibasic, etc. They are also classed as monatomic, diatomic, etc., according as they are derived from a monatomic or diatomic alcohol, etc. Many organic acids occur in the juices of vegetables, some in animals, as formic acid in ants.

ACLAND, SIR HENRY WENTWORTH DYKE, an English sanitarian, born in 1815. He was an expert on cholera and the various forms of plague. From 1857 to 1894 he was Professor of Medicine at Oxford, besides serving on various sanitary bodies. He was author of "Memoirs of the Cholera," etc. He died Oct. 16, 1900.

ACNE, a genus of skin diseases containing those characterized by pustules, which, after suppurating imperfectly, become small, hard, red, circumscribed tubercles on the skin, resolving themselves but slowly. Among the leading species of the genus are (1) the A. simplex, consisting of small vari, which break out on the face, the shoulders, and the upper part of the back; (2) A. follicularis, or maggot-pimple; (3) the A. indurata, or stone-pock; and (4) the A. resaceæ, or carbuncle face.

ACOLYTE, in the Roman Catholic Church, one of the inferior orders of the clergy, whose office it is to attend upon the deacons and subdeacons in the ministry of the altar, to light and hold the candles, to bear the incense, to present the priest with wine and water, etc. In the primitive Church, the acolytes were in holy orders, and ranked next to the subdeacons; but, at the present time, the duties of the acolyte are very often performed by laymen and chorister boys.

ACONCAGUA, a province of the republic of Chile, bounded N. and W. by the province of Quillota, E. by the Andes, and S. by Santiago. Area, 5,406 square miles. The mountain Aconcagua is the loftiest of the Andes, being 23,910 feet above the level of the sea. Productions are maize, wheat, beans, pumpkins, melons, and other garden produce; vineyards and orchards are plentiful, and in summer numerous flocks are pastured on the slopes of the Andes. Gold is found and copper is worked in mines. Pop. about 130,000. Chief town San Felipe. On the S. side of the mountain Aconcagua rises a river of the same name.

ACONITE, a plant of the genus aconitum, the aconitum napellus, familiarly known as the monk's-hood, or wolf's-bane. Its active principle, the aconitine, is a virulent poison. It is a native of Europe, and is cultivated as a garden plant for the sake of its handsome purple flowers.

ACONITINE, or ACONITIA, a powerful vegetable alkaloid, prepared from the root of the aconitum napellus (aconite). It is one of the most virulent of poisons, but, at the same time, a very valuable medicine. An ointment containing aconitine is often used in cases of neuralgia, acute rheumatism, and diseases of the heart. Its narcotic action is so active that a fiftieth of a grain may endanger the life of an adult. The most effectual antidote in case of poisoning is warm water, administered till it produces vomiting, after which stimulant remedies should be applied internally and externally.

ACORN, the well known fruit of the oak. In the early ages, acorns constituted a principal part of the food of man. (Ovid's "Metamorphosis," i, 106; Vergil's "Georgics," i, 8.) At present they are used for the feeding of pigs, etc.

ACORN SHELL, the popular name for the balanus and other cirripeds, which inhabit a tubular shell whose base is usually formed of calcareous laminæ. Its shell is composed of many pieces, and thus capable of enlargement to the wants of the inclosed animal. These curious, but common, shells are found in all seas. They are affixed to marine bodies, and their peduncle is sometimes found a foot long.

ACORUS, a genus of plants, order orontiaceæ. Theacorns calamus, or sweet flag, a member of this genus, is the only native aromatic plant of northern climates. It blossoms during the months of May and June.

ACOUSTICS. See SOUND.

ACQUI (ak´wē), a district of north Italy, province of Alessandria, on the N. side of the Ligurian Apennines. Area, 445 square miles. Productions, corn and fruit. Silk worms are reared as a branch of industry.

Acqui, its capital on the Bormida, 18 miles S. S. W. of Alessandria. It has commodious sulphur baths. Pop. about 18,000.

ACRE, (1) Originally, any field, whatever its superficial area.

(2) From about the time of Edward I. the word became more definite, and its limits were prescribed by the Statutes 31 and 35 Edward I., and 24 Henry VIII. By the Act 5 George IV., the varying measures of the acre current in the kingdom were reduced to one uniform standard. The imperial acre contains