Davy

Sir HUMPHRY, Bart., (dā've,) an eminent English chemist and natural philosopher, B. 1778, early became known by his attainments in the natural sciences. In 1799, he published his E ays on Heat and Light, with a New Theory of Respiration; and, one year afterward, Researches, Chemical and Philosophical. In 1802, he became profe or of chemistry in the Royal Institution, London, where for many years his lectures attracted the admiration of the scientific world. In 1820, he was elected President of the Royal Society. D. at Geneva, 1829. Besides the works above mentioned, Sir Humphry was author of Elements of Chemical Philosophy (1812); Elements of Agricultural Chemistry (1813); and Consolations in Travel (1830.) Deacone , Davy Safety-lamp. (Mining.) See MARSH-GAS. Daw, (dau.) (Zool.) See CORVIDE. Dawn, (daun.) (Meteorol.) See TWILIGHT. Dawson, (dau'sn,) in Georgia, a N. co.; area, about 200 sq. m.; C. Dawsonville. Pop. 4,369.-In Nebraska, a central co.; area, abt. 1,450 sq. m. Pop. 103. Day, (da.) (A.S. dæg. ] (Ast.) In its original acceptation this term meant the interval between sunrise and sunset. We still use it in this sense when we compare day with night. Another familiar usage of the term refers to the completion by the sun of his apparent circuit of the heavens, as either from sunrise to sunrise, or from sunset to sunset, or, more exactly than either, from sou thing to sou thing. The former has been called the artificial, the latter the natural day, though it would be difficult to a ign a reason for the use of the first of these titles to describe a purely natural phenomenon. The word day is often taken in a larger sense, so as to include the night also, or to denote the time in which the earth makes a complete revolution with respect to the celestial bodies. Hence it expre es different intervals, according as the body with which the earth's *rotation is compared is fixed or not. The astronomical, called also the solar and the apparent day,is the time which elapses between two consecutive returns of the same terrestrial meridian to the centre of the sun. Astronomical days are not equal, because the velocity of the earth in its orbit, and by consequence the apparent daily motion of the sun, are greater in winter than in summer; also, the obliquity of the ecliptic causes the sun's apparent daily motion in right ascension to be le at the equinoxes than at the tropics. The astronomical day begins at noon, and is counted on through twenty-four hours to the following noon. The civil, or mean solar day, is the time employed by the earth in revolving on its axis, as compared with the sun, supposed to move at a mean rate in its orbit. In this way of reckoning, the days are all of the same length; but the noon, or any given hour of the civil day, sometimes precedes and sometimes comes after the noon or corresponding hour of the astronomical day. Most nations begin the civil day at mean midnight. The Babylonians, Syrians, and Persians, like the modern Greeks and the natives of the Balearic Isles, began their day at sunrise; the Jews, ancient A then i ans, Chinese, and other Orientals, at sun-setting; and the ancient Egyptians at noon. The sidereal day is the period which elapses between the times at which a star pa es over the meridian on two succe ive days. The most ancient astronomical observations show that this interval has always remained of the same length. It is divided into 24 sidereal hours, which are subdivided in to sidereal minutes and seconds. It is used universally by astronomers in their observatories, though its commencement is still determined by the apparent pa age of the sun acro the meridian. Day-fly. (Zool.) See EPHEMERA. Day-lily. (Bot.) See HEMEROCALLIS. Days of Grace. (Com.) A customary number of days allowed for the payment of a bill of exchange after it becomes due. Three days of grace are allowed in the [s. 267] Zell's Condensed Cyclopedia U U. States and in Great Britain. (dā'tun,) a large and important city of Ohio, C. of Montgomery co., at the junction of the Mad and Great Miami rivers, 66 m. W.S.W. of Cincinnati. Among its many noble public buildings may be noticed the County Court-House, constructed of white marble after the design of the Greek Par the non. D. is a place of considerable manufacturing prominence. Pop. 30,473. (de'kn.) [Gr. diakonos, an attendant.] (Eccl.) This word in its more extended sense is used,both in Scripture and by ecclesiastical writers, to designate "any person who ministers in God's service;" but in a more restricted sense it expre es an inferior minister of the Christian Church. In the Roman Catholic Church, the deacon's office is to incense the officiating priest, to incense the choir, to put the mitre on the bishop's head at the pontifical ma , and to a ist at the communion. He is attended by the sub-deacon, who, according to the doctrine of that Church, being in one of the holy orders, is bound to celibacy, . In the Church of England, the form of ordaining a deacon declares that it is his office to a ist in the distribution of the holy communion, in which, agreeably to the practice of the ancient Church, he is confined to the administration of the wine to the communicants. He may not pronounce the absolution. He is not capable of any ecclesiastical promotion; yet he may be chaplain to a family, curate to a beneficed clergyman, or lecturer to a parish church. In Presbyterian churches, the deacons distribute the wine and bread to the communicants. (dē'kn-ěs.) (Same der iv.) (Eccl.) A female deacon in the Primitive Church. One part of her office was to a ist the priest at the baptizing of women, to undre them for immersion, and to dre them again, that the whole ceremony might be performed with all the decency becoming so sacred an action. The office was discontinued in the 6th cent., but the name has been retained. In monasteries, for instance, the nuns who have the care of the altar are called deacone es. [s. 267]