DE MORGAN, AUGUSTUS, an eminent mathematician, born in Madura, S. India; was professor of Mathematics in London University from 1828 till his death, though he resigned the appointment for a time in consequence of the rejection of a candidate, James Martineau, for the chair of logic, on account of his religious opinions; wrote treatises on almost every department of mathematics, on arithmetic, algebra, trigonometry, differential and integral calculus, the last pronounced to be “the most complete treatise on the subject ever produced in England”; wrote also “Formal Logic” (1806-1871).

DEMOSTHENES, the great Athenian orator, born in Athens; had many impediments to overcome to succeed in the profession, but by ingenious methods and indomitable perseverance he subdued them all, and became the first orator not of Greece only, but of all antiquity; a stammer in his speech he overcame by practising with pebbles in his mouth, and a natural diffidence by declaiming on the sea-beach amid the noise of the waves; while he acquired a perfect mastery of the Greek language by binding himself down to copy five times over in succession Thucydides’ “History of the Peloponnesian War”; he employed 15 years of his life in denunciation of Philip of Macedon, who was bent on subjugating his country; pronounced against him his immortal “Philippics” and “Olynthiacs”; took part in the battle of Cheronea, and continued the struggle even after Philip’s death; on the death of Alexander he gave his services as an orator to the confederated Greeks, and in the end made away with himself by poison so as not to fall into the hands of Autipater (385-322 B.C.).  See CTESIPHON.

DEMPSTER, THOMAS, a learned Scotchman, born in Aberdeenshire; held several professorships on the Continent; was the author of “Historia Ecclesiastica Gentis Scotorum,” a work of great learning, but of questionable veracity; has been reprinted by the Bannatyne Club; his last days were embittered by the infidelity of his wife (1579-1625).

DENARIUS, a silver coin among the Romans, first coined in 269 B.C., and worth 81/2 d.

DENBIGH (6), the county town of Denbighshire, in the Vale of the Clwyd, 30 m.  W. of Chester; manufactures shoes and leather.

DENBIGHSHIRE (117), a county in North Wales, of rugged hills and fertile vales, 40 m. long and 17 m. on an average broad, with a coal-field in the NE., and with mines of iron, lead, and slate.

DENDERA, a village in Upper Egypt, on the left bank of the Nile, 28 m.  N. of Thebes, on the site of ancient Tentyra, with the ruins of a temple in almost perfect preservation; on the ceiling of a portico of which there was found a zodiac, now in the museum of the Louvre in Paris, and dates from the period of Cleopatra and the early Roman emperors, and has sculptured portraits of that queen and her son Caesarion.

DENGUE, a disease peculiar to the tropics, occurs in hot weather, and attacks one suddenly with high fever and violent pains, and after a relapse returns in a milder form and leaves the patient very weak.