DWIGHT 444 DYEING Columbia College, in each of which he founded a law school. He received the degree of doctor of laws from both Rut- gers and Columbia colleges, and was (non-resident) Professor of Constitution- al Law in Cornell University. He was also interested in philanthropic work, and served as president of the New York Prison Association, vice-president of the New York Board of State Commissioners of Public Charities, and as a member of the "Committee of Seventy," of New York City. In collaboration with Rev. E. C. Wines, D. D., he published "Prisons and Reformatories in the United States," and was associate editor of the "Amer- ican Law Register." He died in Clinton, N. Y., June 28, 1892. DWIGHT, TIMOTHY, an American Congregational clergyman; born in Northampton, Mass., May 14, 1752. He was president of Yale College from 1795 to 1817, and was a very conspic- uous figure in theology and education. His "Theology Explained and Defended" consists of a course of 173 sermons which has passed through as many as 100 edi- tions. In addition to theological works he wrote "Essay on Light"; "Observa- tions on Language"; "Travels in New England and New York," which is still widely quoted. He also wrote verse; an epic called "The Conquest of Canaan"; "Greenfield Hill," a pastoral; "The Tri- umph of Infidelity," a satire. He died in New Haven, Conn., Jan. 11, 1817. DWINA (dwe'na), the name of two important rivers of Europe. (1) The Northern Dwina has its origin in the confluence of the Suchona and the Jug, two streams rising in the S. of the gov- ernment of Vologda, and uniting in 60° 46' N. lat., 46° 20' E. Ion. The Dwina flows generally N. W. through a flat country to the 3ulf of Archangel, which it enters by three principal mouths, of which only the easternmost is useful for navigation. The length of the Dvdna is about 450 miles (with the Suchona, 760) ; its basin embraces over 140,000 square miles. Its chief tributaries are, on the left, the Vaga and Emza, and on the right the Pinega and the Vytchegda, the last having a course of some 625 miles, 500 being navigable. The volume of water poured down by this main tribu- tary increases the breadth of the Dwina from about one-third to nearly two-thirds of a mile; near Archangel it widens to over four miles. The river is free from ice from May to October, and is a valu- able channel of inland trade. Its waters also are rich in fish. (2) The Western Dwina rises in the government of Tver, not far from the sources of the Volga and the Dnieper, and flows at first W. S. W. in a course almost parallel to the latter stream. From Vitebsk it flows W. N. W. to the Gulf of Riga, which it en- ters after a course of about 580 miles, navigable from the confluence of the Mezha downward, though the numerous shallows and rapids greatly impede traffic. Its basin is estimated at 32,850 square miles; its average depth of 26 feet at Riga is increased to about 40, and its breadth of 1,400-2,400 feet is extended in some places to a mile during the heavy spring floods which overflow wide tracts of the low-lying lands on either bank. The Western Dwina is connected with the Dnieper, and so with the Black Sea by the Beresina canal, and by other canal systems with the Caspian Sea, and with the Neva and Gulf of Finland, etc. The territory bordering on the Dwina was the scene of almost incessant fighting during the World Wor. In 1920 the Polish and Russian Soviet armies carried on operations here, and the river be- came a part of the boundary between Poland and the Russian republic. See Poland. DYAKS, or DAYAKS, the Malay name for the race which constitutes the bulk of the aboriginal population of Bor- neo, divided into innumerable tribes dif- fering pretty widely in language, cus- toms, and degrees of savageness. Physi- cally they closely resemble the Malays, to whom they are doubtless akin, but are somewhat taller; they are intelligent, hospitable, and unsuspicious, and greatly excel the Malays in truthfulness and honesty. Even the most uncivilized tribes have many ingenious arts and in- dustries, weave cloth, make excellent steel weapons, and erect most serviceable suspension bridges with bamboo poles and withes. Their chief weapon is the blowpipe. The barbarous custom of sys- tematic head-hunting is dying out. The Sea-Dyaks were long famous as untam- able pirates. DYEING, the art of imparting colors to textile and other material, such as cotton, silk, wool, and leather. Dyeing has been practiced from time immemo- rial. Dyeing with colors obtained from natural products had reached a high state of perfection when Perkin, in 1856, introduced the first of the coal-tar colors. Since that date the progress of artificial color-making has been so rapid, and the application of the new dyes made so simple, that, excepting indigo, logwood and cutch, the old colors and processes are now practically driven out of use. If the fiber is of animal origin, such as silk or wool, a simple immersion in a bath containing the color will usually dye the fabric; but color so applied to a
