DERG 330 DERWENT Venice in 1874, but was physically un- equal to the strain of continued singing. For a while he gave up the career he had preferred, but gaining in strength later, he re-entered the profession and for a quarter of a century was one of the most successful and accomplished singers on either side of the Atlantic. DEBG, LOUGH, the largest lake ex- pansion of the river Shannon, between Tipperary and Galway and Clare, in Ireland; is 24 miles long, with an aver- age width of two miles; greatest depth, 80 feet. Its surface is about 100 feet above the sea. Another Lough Derg, in the S. of Donegal co., is 3 miles by 2^, has many small isles and rocks, and v/ild, dreary shores. Saint's Isle con- tains the remains of a priory. Station Island, the reputed entrance to St. Pat- rick's Purgatory, was long the most celebrated place of pilgrimage in Ire- land. DERMATOLOGY, that branch of science v.hich treats of the skin and its diseases. Dr. Aitken g:ives the following as the more common diseases of the skin: Erythema, urticaria, nettlerash, lichen, psoriasis, herpes, pemphigus or pompholyx, eczema, ecthyma, acne. The parasitic diseases are ringworm, or tinea tonsurans, favus, and itch or scabies. Many of these may appear in combina- tion, or as symptoms of general, con- stitutional, or febrile diseases; and, in addition to these, having various forms of cutaneous manifestation, are syphilis, purpura, leprosy, scurvy, and the like, with bronzed-skin or Addison's Disease (q. v.). DERMATOPHYTE, a parasitic plant infesting the cuticle and epidermis of men and animals, and giving rise to arious forms of skin disease, as ring- /Orm, etc. DERMESTES, a common genus of beetles in the section Pentamera, includ- ing several species of formidable vorac- ity. The most familiar of these is D. lardarius, often called the bacon beetle. In the open air it lives on dead animals; but within doors it attacks bacon, cheese, dried meats, furs, etc. The brovni larvae are equally voracious. Many other species are knovm on hides and the like. DERNBTJRG, BERNHARD, a Ger- man diplomat. By gradual promotions he reached the post of Colonial Minister in the Chancellorship of Biilow. The opening of the World War in 1914 found him in the United States where he entered upon a propaganda designed to arouse sympathy for Germany. In this he was fairly successful until the sink- ing of the Lusitania in May of 1915. He finally became so unpopular that he voluntarily left the United States and returned to Germany. There he exerted his influence to prevent war between the two nations, but the failure of his mis- sion in the United States made his in- fluence on the German Government of no importance. After the Revolution of 1919, Dernburg became a prominent leader of those voters in Germany who wished to prevent the complete capture of the German Government by the So- cialists, and yet did not wish for a re- turn of the former Imperial regime. Whether true or not, it was alleged that he and his party, the German People's party, were not hostile to a return to monarchy. DEROULEDE, PAUL (da-ro-lad'), a French poet; born in Paris, Sept. 2, 1846. His "Soldier Songs" (1872) and "Military Refrains" (1888) were im- mensely popular, and won him the presi- dency of the Patriotic League, an as- sociation intensely hostile to Germans. In 1900 he was sentenced to 10 years banishment for conspiring against he Republic. The Amnesty Act of 1905 re- duced the sentence to five years. He wrote a drama on patriotism, "The Het- man," and the semi-religious drama, "The Moabitess." He died in 1914. DERRICK, a lifting apparatus con- sisting of a single post or pole, sup- ported by stays and guys, to which a boom with a pulley or pulleys is at- tached, used in loading and unloading vessels, etc. Floating derricks of the strongest construction, with an immense boom and numerous blocks, are also used. DERRICK CRANE, a kind of crane combining the advantages of the com- mon derrick and those of the ordinary crane. The jib of this crane is fitted with a joint at the foot, and has a chain instead of a tension-bar attached to it at the top, so that the inclination, and con- sequently the sweep, of the crane can be altered at pleasure. DERVISH, a Mohammedan monk or religious fanatic, who makes a vow of poverty and austerity of life. There are several orders, some living in monas- teries, some as hermits, and some as wandering mendicants. Some, called dancing dervishes, are accustomed to spin or whirl themselves round for hours at a time, till they work themselves into a state of frenzy, when they are believed to be inspired. DERWENT, the name of four rivers in England, in Derbyshire, Yorkshire,
