animal colony, or by the different organs, tissues, and cells of a single organism. The figure of a hydroid colony, Hydractinia, shows how members, primarily and fundamentally the same in structure, become set apart as nutritive, reproductive, sensitive, and protective. The same division of labour or predominance of special functions in different individuals is beautifully illustrated in the Siphonophora-such as the Portuguese Man-of-war (q.v.). At a much higher level, vivid illustrations of the same fact may be found among the social Ants (q.v.) and Bees (q.v.). But division

Hydractinia echinata (after Allman):

of labour in some degree is essential to every organism. Even in a single unit mass or cell, it is hardly possible for all the parts to be entirely in the same external and internal conditions; certain portions become more contractile, others more sensitive, others more nutritive, and so on. In a ball of cells, such as Volvox, the inequality in the conditions becomes more marked; the inside cells are not in the same state as their outside neighbours; they thus become seats of different vital processes, and distribution of function or division of labour is the result. The same process may be traced in the gradual evolution of tissues and organs, as also in the development of special 'persons' with limited and preponderant functions in animal colonies. When the predominance of some function has been established, it brings with it difference of structure. This differentiation or, when it concerns a colony, polymorphism is the structural side of the physiological fact of the division of labour. See COLONIAL ANIMALS, DIMORPHISM, HYDROZOA, &c.

e, nutritive individuals; b, reproductive; e, protective; and d, sensi.

tive individuals.

Divorce is the disruption of the legal tie between husband and wife. The desire to obtain a release from the matrimonial bond has existed under all systems of law or custom. In early times, such release was often permitted on very easy conditions. The Romans of the late republie and the empire permitted divorce at the will of either spouse; but a husband divorcing without cause forfeited the wife's dowry. The Emperor Constantine was the first to prohibit divorce at the mere will of the parties; after some fluctuations in the state of the law, the grounds which would justify husband and wife respectively in divorcing were settled by Justinian. These changes in the law were partly due to the introduction of Christianity.

The Jewish law of divorce is contained in Deut. xxiv. 1-4. The Christian view of marriage is declared in Matt. xix. 9; Mark, x. 9-12; Luke, xvi. 18; and 1 Cor. vii. Marriage was held by the early Christians to be a sacred tie, not to be dissolved except for unfaithfulness. By the canon law it was regarded as a sacrament, and the tie could not be broken, even in the case of adultery, except by a papal dispensation. In cases of misconduct, a separation a mensa et thoro might be decreed; or if the marriage had not been regularly contracted, it might be declared null ab initio. Suits for

separation, or for a declaration of nullity, belonged to the ecclesiastical courts. These rules of the canon law were not uniformly adopted by European states; but in 1562 the Council of Trent established in Catholic countries the rule that marriage should be deemed indissoluble, even after adultery.

Many of the Reformers disputed the Catholic view of marriage. For reasons stated by Milton in his tract on the subject, they permitted a certain liberty of divorce. But in England the old rule held its ground till 1857-58; marriage could only be dissolved by a special act of parliament. A husband petitioning for such an act was required first to sue for a separation, and to bring an action for damages against the seducer of his wife. Divorce, therefore, was possible only for the

rich.

By an Act of 1857 the jurisdiction in divorce and matrimonial causes was transferred to a new civil court, which since 1873 has formed part of the High Court of Justice, Probate, Divorce, and Admiralty Division. A decree of divorce may now be pronounced by a single judge, trying the case with or without a jury; but the decree is a decree nisi (i.e. a decree, unless cause be shown to the contrary), which cannot be made final until six months have elapsed. A husband may obtain a divorce on the ground of his wife's adultery; he may also obtain damages against the co-respondent. Till 1923 a wife might obtain a divorce on the ground of the husband's adultery only if aggravated by cruelty, incest, bigamy, rape, &c., or by desertion without cause for two years. The law was therefore unequal as between husband and wife; a reason given for the inequality was that unfaithfulness on the part of a wife throws doubt on the legiti macy of the children of the marriage, while unfaithfulness on the part of the husband does not. A strong commission, presided over by Lord Gorell, considered the whole subject, and in 1912 reported in favour of equality of the sexes, and of greater facilities for the poor. The majority favoured extension of the grounds of divorce. Bills framed to give effect to the commission's recommendations failed to become law; but the Matrimonial Causes Act (1923) placed the wife on the same footing as the husband. Mere desertion, however long continued, is not ground for a divorce, but for an action for restitution of conjugal rights. The husband may be ordered to pay an alimentary allowance to his divorced wife; and the court may make orders in respect of the custody, maintenance, and education of the children of a dissolved marriage. A petitioner who is himself or herself in fault is not entitled to the remedy of divorce; thus, the petition of a husband may be dismissed on the ground of recrimination, if he has himself been unfaithful; and if the wife, as sometimes happens, refuses to press the countercharge, it may be the duty of the King's Proctor to intervene and call the attention of the court to the facts. The petision or connivance, if, for example, the husband tion may also be dismissed on the ground of colluhas encouraged another man to make improper advances to his wife; or on the ground of condonation, if he has continued to cohabit with her after discovering her offence. Similar rules apply to the petition of a wife. The confession of an accused party is evidence against him or her; but proof of this nature ought to be received with caution. If the respondent is of unsound mind, and therefore unable to plead, the petitioner will not be allowed to proceed with his case. Divorced persons are free to marry again; they cannot require a clergyman of the Church of England to marry them; but a clergyman who refuses must permit the use of his church for the purpose.

In Scotland, since the Reformation, the courts

have decreed divorce, on the petition of either spouse, on the ground of adultery. An Act of 1573 makes desertion without cause for four years a ground for an action of adherence; and, if redress is not obtained by that means, decree of divorce may be pronounced. It is not permitted that marriage should take place between offending parties. In case of divorce, the offending party forfeits all pecuniary benefit which might accrue from the marriage (see ALIMENT). Separation may be obtained on the ground of ill-usage, and perhaps desertion. Bars to divorce are condonation, connivance, collusion, but not recrimination.

In France divorce was established during the Revolution, abolished under the Empire, and restored by a law of 1884, which permits husband or wife to claim a divorce on the ground of adultery, cruelty, or conviction for any infamous crime. In most Protestant countries divorce is granted for adultery, and other reasons. In all Mohammedan countries divorce is extraordinarily easy for the husband, a few words of repudiation practically sufficing to loose the marital bond.

In America the laws of the States vary. In South Carolina divorce is entirely unknown. In most of the States, adultery, ill-usage, and desertion are now regarded as good reasons for divorce; in some, drunkenness, imprisonment, and even incompatibility of temper are added to the list. There are in the United States no ecclesiastical or other specially constituted matrimonial courts; as a general rule, the civil courts have jurisdiction to dissolve the marriage of a party who is a citizen thereof, or domiciled therein.

Questions frequently arise as to the competency of a court to annul a marriage contracted in another country on grounds which would not in that country be regarded as sufficient. general rule, the courts of a country have jurisdiction in matrimonial causes over all persons

As a

bona fide domiciled therein. But the English courts would probably refuse to recognise the dissolution of an English marriage by a foreign court on grounds not held sufficient in England.

See S. B. Kitchin, A History of Divorce (1912); the Reports of the Divorce Commission (1912); also MARRIAGE, ADULTERY, HUSBAND AND WIFE, PARENT AND CHILD.

Dix, JOHN ADAMS, American statesman and soldier, born in Boscawen, New Hampshire, 24th July 1798, was appointed cadet in 1812, and lieutenant in 1814, and while on the staff of General Jacob Brown studied law, afterwards being admitted to the Washington bar. In 1828, with the rank of captain, he resigned his commission; in 1830 he was appointed adjutant-general, and from 1833 to 1840 was secretary of state and superintendent of schools for the state of New York. He was for four years a democratic United States senator, and secretary of the treasury from 1861 to the end of Buchanan's administration. At the outbreak of the civil war he raised seventeen regiments, and in July 1861, with the rank of major-general of volunteers, he took command of the Department of Maryland, where he rendered effective service to the cause of the Union; from 1863 to the close of the war he commanded the Department of the East. He was appointed minister to France in 1866, and elected governor of New York by the Republicans in 1872. He died in New York City, 21st April 1879. His memoirs were published (1883) by his eldest son, the Rev. Dr Morgan Dix.

Dixie, or DIXIE'S LAND, a term which came, by a popular error, to be identified with the South and Southern institutions during the civil war. It is derived from a Northern negro refrain, which was sung in New York about the beginning of the 19th century, and which expressed the supposed regrets

of the slaves of a man Dixie, who had shipped his slaves to the South as the abolition sentiment grew stronger. This rude chant afterwards was developed into the melody that for a time became the rival of Yankee Doodle.

Dixmuyde (Fr. Dixmude), a small town of West Flanders, on the Yser, was, with its church of St Nicolas, almost entirely destroyed in the Great War.

writer and traveller, was born in Manchester, 30th Dixon, WILLIAM HEPWORTH, an English June 1821, early became a merchant's clerk, but soon determined to devote himself to a literary life. He had already written much, and even edited for two months a Cheltenham paper, when in 1846 he settled in London. In 1854 he was called to the bar, but did not practise. A series of papers, published in the Daily News, on "The Literature of the Lower Orders," and another on 'London Prisons,' attracted considerable attention. The latter reappeared in a volume published in 1850. Before this, but in the same year, he published John Howard, and the Prison World of publisher to accept it, yet when published it went Europe. It was with difficulty he could induce a through three editions in one year. Dixon now devoted himself principally to historical biography. In 1851 appeared the first edition of his William Penn, a work called into existence by the onslaught made by Macaulay on the eminent Quaker, in which Dixon undertook, not without success, to disprove the great historian's charges. In 1852 was published his Life of Blake, and in 1860 his Personal History of Lord Bacon, two works which petent critics. From 1853 to 1869 Dixon was were indeed popular, but failed to satisfy comeditor of the Athenæum. His books of travel, all (1865), New America (1867), Free Russia (1870), bright and interesting, include The Holy Land (1879). The White Conquest (1875), and British Cyprus His Spiritual Wives he issued in 1868. brought an action for libel against the Pall Mall Accused of indecency in his Free Russia, he Gazette, and was awarded a farthing damages. His historical works include Her Majesty's Tower (4 vols. 1869-71), The History of Two Queens (Catharine of Aragon and Anne Boleyn; novels are unimportant. 1873-74), and Royal Windsor (1878-80). London, 27th December 1879. He died suddenly in

vols. His

of North America, separating Queen Charlotte Dixon Entrance, a strait on the west coast Islands from the Prince of Wales Archipelago, and so dividing British territory from a part of Alaska.

Dizful, a town in the Persian province of Arabistan, about 190 miles W. of Ispahan, on the river Diz, here crossed by a handsome bridge of twenty arches. It has over thirty-five sacred tombs, and nearly as many mosques; but half the town consists of subterranean excavations in the rock, on account of the heat. It has a large trade in indigo, and is noted for the manufacture of reedpens, which are exported to India and Constantinople. Pop. 35,000. Fourteen miles SSW. lie the ruins of ancient Susa.

Djerablus, or JERABLUS. See CARCHEMISH ; also HITTITES.

Djezzar (i.e. butcher'), the name given, on account of his cruelty, to Achmed Pasha, famous for his obstinate defence of Acre against Napoleon I. He was born in Bosnia about 1735, and rose, through murder and treason, from the condition of a slave to be pasha of Acre. In the beginning of 1799 the French entered Syria from Egypt, and advanced from victory to victory till they reached Acre, which was laid siege to on the 20th March. By advice of Sir Sidney Smith, Djezzar was

near Raab in Hungary, where his father, a Bohemian by birth, was stationed in garrison. He studied mainly at Prague, in 1772 entered the Jesuit order, and was successively a teacher, a family tutor, and the editor of a critical journal. In 1792, at the expense of the Royal Bohemian Scientific Society, he made a journey to Denmark, Sweden, and Russia, to search after the fate of those Bohemian books and MSS. which the Swedes had carried off from Prague during the Thirty Years' War. Till his death, January 6, 1829, he was reckoned one of the highest authorities on all matters connected with Bohemian history and literature. Among his works are Scriptores rerum Bohemicarum (1784), a history of the Bohemian language and literature (1792), a German-Bohemian dictionary (1802-21), Glagolitica (1807), and Institutiones Linguæ Slavonica (1822). See his Life in German by Palacky (1833).

Dobrudja (also spelt Dobrudscha, Dobrutcha, or, by Rumanians, Dobrogea), the south-eastern portion of Rumania, between the lower Danube and the Black Sea, transferred to the kingdom by the Berlin Congress of 1878, which fixed the southern limit at a line from Silistria on the Danube to Mangalia on the sea-coast. A slice from Bulgaria was added by the war of 1913. The northeast of this region is occupied by marshes and the delta of the Danube; the rest mostly a treeless steppe, too dry for farming, on which large herds of cattle, horses, and sheep are raised. The climate is malarious and unwholesome, and the inhabitants are a feeble folk. Rumanians and Bulgarians are the most numerous; many Circassians formerly settled here, Tatars and Turks having since 1878 gone to Turkish territory; but there are still many Turks and Russians, and some Germans.

Dobson, HENRY AUSTIN, poet, was born at Plymouth, 18th January 1840. He was educated at Beaumaris, Coventry, and Strasburg, and at first intended to follow the profession of his father -a civil engineer-but in 1856 entered the Board of Trade, where he remained till 1901. In poetry he practised especially the more artificial forms of French verse, the rondeau, the ballade, and the villanelle. In these he showed rare perfec tion of form, often informed with true natural pathos, and revealed genuine satirical strength. His chief collections of verse are Vignettes in Rhyme and Vers de Société (1873), Proverbs in Porcelain (1877), At the Sign of the Lyre (1885), The Sundial (1890), Beau Brocade (1892), The Story of Rosina (1895), and Carmina Votiva (1901). The Old World Idylls (1883) consisted in great part of pieces selected from the first two. A collected edition of his poems was published in one volume in 1897. In prose Dobson published Lives of Hogarth, Fielding, Steele, Bewick, Goldsmith, Horace Walpole, Richardson, Fanny Burney (1903), and others. He wrote the critical notices of Hood, Gay, Praed, and Prior for Ward's English Poets' (1880); contributed articles on the three last named, and on Fielding, Goldsmith, Hogarth, and Richardson to Chambers's Encyclopædia; and edited Eighteenth-century Essays (1882), Gay's Fables (1882), The Vicar of Wakefield (1883), Le Barbier de Séville (1884), Selections from Steele (1885), and Fanny Burney's Diary and Letters. His Eighteenth-century Vignettes appeared in 1892-96, A Paladin of Philanthropy in 1899, Side-walk Studies in 1902, Rosalba's Journal in 1915, Later Essays in 1921. He died 2nd September 1921.

Dobson, WILLIAM, portrait-painter, was born in London in 1610, and succeeded Vandyck as king's serjeant-painter and groom of the privy chamber. He attended the king at Oxford, where he painted his portrait, and those of the Prince of Wales, Prince

Rupert, and other members of the court. The disturbances of the time and his own careless habits threw his affairs into confusion, and he was imprisoned for debt, and died in poverty, 28th October 1646, shortly after his release. His finest portraits. are lifelike and well executed, resembling those of Vandyck. Examples are preserved at Coombe Abbey, Bridgewater House, Devonshire House, the National Portrait Gallery, and at Hampton Court, where is the excellent painting of himself and wife.

Doce'tæ (from the Gr. dokeō, 'I appear or seem') was the name given in the early church to those heretics who held that the human nature of Jesus Christ was a semblance and not a reality. The docetic tendency originates in the oriental and Alexandrian notion that matter is as such imperfect and impure; and the Gnostic and Manichæan heretics found it impossible to conceive the essential union of the divine nature with a body composed of matter. The difficulty was got over in one of three ways: the body of Christ was either considered a real earthly body, but not belonging essentially to his nature, and only assumed for a time; or it was declared to be a mere appearance or illusion (as by Marcion, the Ophites, the Manichæans); or, finally, it was believed to be a heavenly body, composed of ethereal substance, though having the appearance of being material (as by Basilides, Bardesanes, Tatian, Valentine). Clement of Alexandria and Origen are most free from traces of Docetism; the Priscillianists and Bogomiles may be reckoned amongst the Docetæ. See GNOSTICISM, and the works on the History of Dogma.

Dock. The large genus Rumex of the order Polygonacea is usually divided into Docks and Sorrels, the latter distinguished not only by their peculiarly acid taste, but by hastate leaves and usually dioecious flowers (see SORREL); those of the docks proper being generally hermaphrodite. They are large perennial herbaceous plants, natives. chiefly of temperate climates, with large generally lanceolate or ovate leaves, and panicles of small greenish flowers. They have great tap-roots, and are with difficulty eradicated from pastures. They also multiply rapidly by seed. The best mode of dealing with them is generally found to be repeated cutting away of their leaves and shoots, by which the plants are killed. Many of the species prefer watery places. Several of the European ones have found their way to North America, where they have reinforced the indigenous species as troublesome weeds. The large astringent roots of various species, notably of the Great Water-dock (R. Hydrolapathum), as also of the Monk's Rhubarb (R. alpinus), were much esteemed in medicine until superseded by more powerful remedies. They have also been used in dyeing.

Dock, an inclosure for the accommodation of shipping, of which there are three principal types wet docks, with entrances that can be closed; tidal docks, being harbours or basins with unclosed entrances; and dry, or graving, docks, to contain a vessel out of the water for repair. Floating docks are a type of dry dock.

At most ports, and particularly at British ports, a system of either wet or tidal docks is required, in order to provide the necessary sheltered quayagespace for shipping, There are, however, certain ports naturally endowed with a large and more or less sheltered deep-water basin, small tidal range, and absence of strong currents; and at such ports, as, for example, New York, the construction of wet or tidal docks is not required. But dry or floating docks are a necessary part of the equipment of every large modern port.

It is at ports where there is a great rise and fall

of tide, such as Liverpool or Bristol, where the range of tide is over 30 feet, or on the Thames, where it is over 20 feet, that wet docks are most necessary. When the range of tide is small, however, as on the east coast of North America, where it varies from 1 foot 8 inches at Baltimore or Galveston to 9 feet 6 inches at Boston, there are no wet docks, strictly speaking, but simply tidal basins excavated to a great depth under the low-water level. As the cost of dock walls and quays increases enormously with each additional foot of depth of foundation, it will be understood that, where there is a large tidal range and where shipping of great draft is to be accommodated, a tidal quay-wall will be very costly in comparison with a wet dock quay-wall, which would be less in height usually by nearly the amount of the tidal range. Owing to the increased draft of shipping in recent years, engineering costs govern the choice between the two types even more largely than hitherto. Generally at ports where the tidal range exceeds about 12 feet, a system of wet docks is constructed in preference to a system of tidal basins or open quays.

Wet docks are basins in which the water is maintained at a level nearly constant, being usually that of high-water of the tide. Entrance is gener

ally gained by means of a Lock (q.v.), having two sets of gates separated by the length of the largest vessel using the dock. Vessels can thus enter or depart during a considerable period when the state of the tide outside is within a few feet of the level of the water in the dock. Occasionally arrangements for locking can be made to pass in vessels at any state of the tide. Frequently, for the sake of economy both in space and in cost, locks have only one set of gates, so that vessels can enter or depart only at or very near the hour of high-water.

The use of wet docks enables vessels always to keep afloat, thus avoiding straining by taking the ground; also, they save vessels from moving vertically up and down the quays with the rise and fall of the tide, thus securing that the quays shall not be sometimes too high and at other times too low for convenience in shipping and discharging cargoes. On the other hand, time required to lock vessels out and in wet docks, and the trouble of entering the dock, are inconveniences.

Wet docks are usually surrounded by quay or wharf walls of masonry or concrete, but where the chief purpose is for laying up vessels and not for loading or unloading, the shore-margin is sometimes only a natural sloping beach. For keeping

up the water-level in a wet dock pumping is sometimes resorted to, but feed-water reservoirs are occasionally constructed. The tendency of the bottom to silt up by deposits of fine mud is of common occurrence, particularly in some situations, and dredging or some other means must be employed from time to time to keep the dock reasonably clear. Small docks are occasionally emptied for the purpose of cleaning. Dock-gates, when on a small scale, are opened and closed by means of chains worked by hand, but when on a large scale they are operated by hydraulic or electric machinery. Small dock-gates are constructed of timber, but wide and deep dock entrances are closed either by steel gates or by a single steel caisson or sliding door.

An example of a large modern wet dock is the new Royal Albert Dock, London. The new wet dock extends over an area of 64 acres, has a length of 4500 feet, a breadth varying from 500 feet to 700 feet, and a depth of water of 38 feet over the greater part of its area. The design provides berth accommodation simultaneously for fourteen of the largest ships entering the Port of London. Entrance from the river Thames is gained through a lock 800 feet long by 100 feet wide, divisible into two

compartments and controlled by three pairs of hydraulically operated steel gates, while a passageway 100 feet wide connects the former Albert Dock with the new dock. A conspicuous feature is the increased quayage obtained by the construction parallel to the south wall of seven reinforced concrete jetties, each 520 feet long, and connected with the quay by a bridge, thus allowing barges to pass freely between the jetties and the quay wall. The jetties are equipped with cranes of various capacities, chiefly 3-ton, electrically operated, with an outreach capable of transferring cargoes from vessels either into barges lying alongside the quay or on to the quay itself. Two auxiliary selfpropelled floating derricks of 100 tons and 10 tons capacity deal with unusually heavy loads. Extensive storage accommodation is provided, with rail and road facilities. On the north side there are three two-storey reinforced concrete warehouses, each 1100 feet long by 120 feet wide, and on the south side there are seven single-storey steel sheds, from 480 feet to 520 feet in length and 120 feet in breadth. A graving dock, 750 feet long, is situated at the end of the wet dock, and is fitted with extensive ship-repairing plant. This dock is emptied by electric pumping machinery of 1750 horse-power, discharging the water through two pipes 48 inches in diameter.

An instance of a wet dock designed for a particular trade is that constructed at Ellesmere Port, at the sea end of the Manchester Ship Canal. This dock is designed specially for the safe handling of highly inflammable oil traffic. Every care has been taken in its lay-out and construction to prevent outbreak of fire. The dock is in an isolated situation on the north side of the canal, and is capable of accommodating one large oil-tank ship, and for easy access is placed at a convenient angle with the canal. The dimensions are: length, 600 feet; width, 100 feet; depth of water, 30 feet; and width at entrance, 80 feet. In order to prevent spread of burning oil or escape of oil, the vessel to be discharged is shut off from the canal traffic by means of a floating reinforced concrete caisson, 82 feet 6 inches long, placed across the dock entrance. The depth of caisson is only 10 feet. While the vessel is discharging no fires or lights are permitted on board, and the crew is removed. Steam generating plant ashore supplies steam through underground pipes to operate the ship's pumps for discharging the oil. The storage-tanks belonging to various oil companies being on the south side of the canal, the oil supply-pipes are led under the bed of the canal by a tunnel, 6 feet in diameter and 466 feet long, cut in sandstone. The tunnel terminates in a vertical shaft 60 feet deep at each end, the one shaft being 6 feet and the other 8 feet in diameter.

Tidal docks require no particular description; they are merely basins surrounded by quay-walls, and having open entrances permitting the free ebb and flow of the tide, as at Glasgow, Greenock, Shanghai, and Southampton. The Port of Glasgow consists of a series of tidal docks, which are situated on the river Clyde some 15 miles above Greenock. Being of the open type, they are open to traffic at all states of the tide, and congestion in the channel at times of high-water is thus obviated. The total water-area of the port, only 75 acres in 1873, is now 540 acres, and the total length of quayage, which includes numerous wharfs on the river side, is about 11 miles. The largest docks are Princes Dock, Queen's Dock, and Rothesay Dock. Princes Dock has a water-area of 35 acres, and a quay area of about 40 acres, including sheds and roads. Three basins, together with a canting basin, have a depth of from 20 feet to 25 feet at low-water, or 12 feet deeper at high-water, and