and spongy, and covered with stagnant pools during most of the year. In the center is Lake Drummond, 6 miles long and 3 wide, the surface of which is 21 feet above the level of tide-water. The swamp is covered with forests of cypress, juniper, gum and cedar, and in its drier parts with beech and oak. Two large canals run through it, on which are carried great quantities of lumber for shipbuilding, railroad-ties, shingles, etc. The great swamp and several smaller ones near were noted hiding-places for escaping slaves before 1865.
Disper'sion, as used in physics, is a phenomenon which occurs when a beam of light composed of different colors is made to pass through a prism or through a diffraction-grating. When a beam of sunlight falls on a glass-prism, we find that the red, yellow, green and blue rays are each refracted in different directions. Dispersion for any particular substance is measured in the following manner: Consider any ray of light which is deviated by the prism through an angle D, and another ray whose deviation is D + d D. Then
T^. . dD Dispersion=-^-
It may be shown that, in the case of a thin prism for which the refractive indices of the two rays differ by d p,
d D dp. D "p,-1' and hence the dispersion is measured also by
d J* the fraction —~
r\
The explanation of dispersion lies in the fact that in any one medium, except ether, light-waves of different lengths travel with different speeds.
Disraeli (diz-ra'tt}, Benjamin, created Viscount Beaconfield in 1876, and a great English novelist, was born at London in 1804. He devoted himself for a time to literature and in 1826 published his first novel, Vivian Grey, which was quite popular. Others of his novels are C o nt ar ini Fleming, Henrietta Temple, Con-ingsby, Sybil, Tan-cred, The Young
Duke, Lothair and Endymion. His works were widely read, because many of them accurately described real persons in the society of his time. In 1837 he was elected to Parliament. His first speech was a fail-tire, the house refusing to listen to him; but as he sat down he said; "I shall sit
down now, but the time will come when you will hear me." He gradually became noted as an opponent of Sir Robert Peel, and, after the death of Lord Bentinck in 1848, he became the leader of the protectionist party in the house of commons. In 1852 he was appointed chancellor of the exchequer in the ministry of Lord Derby, and accepted the same position in 1858 in the new Derby ministry. Once more, in 1866, he joined Lord Derby in his third ministry, and was the main author of the reform-bill, which became law in 1867 and gave the right to vote to nearly a million men who had not been able to vote under the old law. Disraeli became prime-minister in 1868, but was defeated in a vote on Gladstone's bill regarding the Irish established church, and resigned in the same year. In 1874 he once more became prime-minister, and was specially occupied with the foreign policy of the country. He resigned in 1880, and died at London on April 19, 1881. See his Life, by Hitchman; also monographs by Brandes, Kebbel and Froude. His father, Isaac, was a famous literary antiquarian, writing such interesting books as Curiosities of Literature.
Dissent'er. The term dissenter has come to have in English history a very definite meaning. It refers to those who dissent from the doctrines of the Church of England, and it emphasizes the view, not that they differ from the church and thus are heretical or schismatical, but that they differ from the sentiment of the English people as it is organized in that church. A dissenter, moreover, is one who is bold in declaring his difference or opinion and in acting accordingly. Burke, in his great speech on American conciliation, speaking of New England as "the dissidence of dissent," thereby signified the resolve of New England's people that in matters of principle and conscience they would not submit to the government of the nation. The dissenting spirit is often referred to under the term: the Nonconformist conscience. In general it has stood for a stricter code of morals than that which is current among the English aristocracy, for strict subservience to biblical teaching and for ant i-imperialism. It has been accused of narrowness, of displaying more zeal than enlightenment and of applying abstract principles without regard to the facts of the case.
The earliest dissenters are the Lollards who in Richard II's reign attacked the immorality, worldliness and superstition of the Church of Rome; they came into conflict, thereby, with the national government in the reigns of Henry IV, V and VI. The typical dissenting spirit was aroused in the reign of Henry VlII by the translation and printing of the B'ble by
BENJAMIN DISRAELI
