DERG, LOUGH, an expansion of the waters of the Shannon, Ireland, 24 m. long, from 2 to 6 broad; also a small lake in the S. of Donegal, with small islands, one of which, Station Island, was, as the reputed entrance to St. Patrick’s Purgatory, a place of pilgrimage to thousands at one time.

DERVISHES, a name given to members of certain mendicant orders connected with the Mohammedan faith in the East.  Of these there are various classes, under different regulations, and wearing distinctive costumes, with their special observances of devotion, and all presumed to lead an austere life, some of whom live in monasteries, and others go wandering about, some of them showing their religious fervour in excited whirling dances, and others in howlings; all are religious fanatics in their way, and held sacred by the Moslems.

DERWENTWATER, one of the most beautiful of the Cumberland lakes, in the S. of the county; extends S. from Keswick; is over 3 m. long, and over 1 m. broad; is dotted with wooded islands, and is overlooked by Skiddaw; it abounds with perch.

DERWENTWATER, EARL OF, a Jacobite leader; was 3rd Earl and the last; several warrants were issued for his apprehension in 1714; he joined the Jacobite rising in 1715; was taken prisoner at Preston, and beheaded on Tower Hill, London, next year, after trial in Westminster Hall, confession of guilt, and pleadings on his behalf with the king.

DERZHAVEN, GABRIEL, a Russian lyric poet, born at Kasan; rose from the ranks as a common soldier to the highest offices in the State under the Empress Catharine II. and her successors; retired into private life, and gave himself up to poetry; the ode by which he is best known is his “Address to the Deity” (1743-1816).

DESAIX, LOUIS CHARLES ANTOINE, a distinguished French general, born at the Chateau d’Ayat, Auvergne, of a noble family; entered the army at 15; commanded a division of the Army of the Rhine in 1796, and after the retreat of Moreau defended Kehl against the Austrians for two months; accompanied Bonaparte to the East, and in 1799 conquered Upper Egypt; contributed effectively to the success at Marengo, and fell dead at the moment of victory, shot by a musket-ball; he was an upright and a chivalrous man, known in Egypt as “the just Sultan,” and in Germany as “the good general” (1768-1800).

DESAUGIERS, MARC, a celebrated French composer of songs and vaudevilles; “stands second to Beranger as a light song-writer,” and is by some preferred to him (1772-1827).

DESAULT, a French surgeon, born in dep. of Haute-Saone; his works contributed largely to the progress of surgery (1714-1795).

DESBARRES, JOSEPH FREDERICK, military engineer and hydrographer, aide-de-camp of General Wolfe at Quebec; fortified Quebec; surveyed the St. Lawrence; revised the maps of the American coast at the outbreak of the American war; died at Halifax, Nova Scotia, aged 102 (1722-1824).