rot continues to grow, weakening the timber. The timber may dry out without destroying the fungus, which recommences developing when moisture is again present. The use of some kinds of sound-deadening material, such as wet cement, coal-ashes, etc., is very favorable to the development of dry rot. Only dry gravel or coarse sand should be used. Coal-cinders, etc., are alkaline, and the spores of Merulius lachrymans can be germinated only in the presence of alkalies. Timber that is well seasoned and protected by paint will not be attacked by dry rot. A number of fungi attack the wood of trees, causing what is often called dry rot. Most of these fungi belong to the class of toadstools and shelf fungi, and sometimes are seriously destructive. This form of rot is caused on appletrees by Polyporus hispidus; on oak, alder, poplar, locust, and larch by Polyporus sulphureus; on larch, Scotch and white pine, by Polyporus Schweinitzii; on conifers by Fomes pinicola, etc. Dædalea quercina is a common saprophyte upon oak-stumps and oak-trees. The mycelium of this species forms leathery mats and is believed to be parasitic. The decomposing oak wood assumes a grayish brown color. DRY STOVE. See GREENHOUSE.

DRY TORTU’GAS. A group of ten islets belonging to Monroe County, Florida, and situated at the extreme west end of the Florida Keys in latitude 24° 37′ N. (Map: Florida, B 5). They are of coral formation, low, and are partially covered with mangrove bushes. Fort Jefferson, on one of them, was a penal station during the

Civil War.

DUAL (Lat. dualis). A technical term of grammar, used to denote that form of the noun, pronoun, adjective, or verb which refers exclusively to two persons or things. The dual number differs, therefore, from the singular number, which relates to one alone, and from the plural number, which relates indefinitely to many. The dual is regularly found in Sanskrit and in an cient Greek; and in Latin it appears in the pronoun ambo (both), and in the numerals duo (two), octo (eight, i.e. two sets of four), and probably in viginti (twenty, i.e. two sets of ten). It is not generally found in the Teutonic languages; yet the Gothic has it in the verb, and the Anglo-Saxon shows traces of it in two pronominal forms. It occurs in the Semitic languages, e.g. the Arabic and the Hebrew, though in the latter only in the nouns.

DUAL CONTROL. See EGYPT.

DU'ALINE (from dual, Lat. dualis, relating to two). A variety of dynamite invented by Dittmar. The absorbent, viz. cellulose derived from wood fibre, is nitrated and saturated with nitroglycerin. The composition of dualine is said to be, nitro-glycerin, 50 parts; fine sawdust, 30 parts; and potassium nitrate, 20 parts.

DUALISM (Lat. dualis, relating to two). In philosophy, the theory that the universe is explicable only as a whole with two fundamentally different kinds of constituent elements. The ancient dualism of matter and form has in modern times been replaced by a dualism of mind and matter. Among modern philosophers Descartes was the first to emphasize the radical difference between thinking substance (mind) and extended substance (matter). The difficulty

If

suggested by this view was to explain how mind and matter interact as they apparently do in experience. This perplexity caused some of his followers to deny interaction and assert concomitance of variation (see OCCASIONALISM); it caused others to deny the truth of dualism altogether (see MONISM; SPINOZA; LEIBNITZ). Since Descartes's day the question has been in constant debate, and even to-day there is no unanimity among philosophers as to the relative truth of dualism and its rivals. Within recent years the interest awakened by scientific psychology has brought the problem more to the fore, but even in psychology there is no consensus on the subject. (See PARALLELISM.) Only a brief constructive criticism can be undertaken here. The sole source from which a satisfactory solution can be obtained is experience. Does experience present us with one or two or even more absolutely different and fundamentally unrelated elements? In the first place, the contents of experience, the various sensations, centrally and peripherally aroused, the affections and volitions, are, without question, qualitatively different. These differences may shade into each other (see CONTINUITY, LAW OF), but no recognition of this fact can negative the fact of difference. monism (q.v.) denies the qualitative difference, it is of course false. Some monism does this. But other forms of monism are more subtle. While admitting the existence of various differences, they assert that these differences are various manifestations of a simple substance. Their views stand or fall with the conception of substance (q.v.). But as the only tenable conception of substance seems to be that it is a synthetic unity of various quantities, it would seem that while it is possible, and no doubt correct, to think of the universe as one connected system, or, in other words, a synthetic unit, it is just as necessary to think of the differences within the unity. If monism be defined as the doctrine of the fundamental oneness of things, it is compatible with pluralism if that is defined as the doctrine of the fundamental plurality of things; since in a synthetic unity neither the unity is more fundamental than the differences, nor the differences than the unity. But is dualism compatible with monisin and pluralism thus harmonized? Evidently it is, if pluralism means that all the differences in the universe can be reduced to two classes, the psychical and the physical, however these may be differentiated from each other, and if it asserts that the differences between these classes cannot be obliterated; for, as we see, tenable monism does not deny differences, but asserts unity. Dualism is inconsistent with pluralism only if dualism denies the existence of more specific distinctions than those of psychical and physical. This dualism never does. Dualism is inconsistent with monism only if it denies the possibility of recognizing the psychical and the physical as two aspects of one and the same experience. Dualism sometimes does this, and when it does it is false, for it overlooks the fact that the psychical and the physical are distinctions found correlated within the unity of experience. But dualism need not deny the correlation of physical and psychical within a synthetic unity. while yet insisting upon their irreducible differences. Thus we find that monism, dualism, and pluralism are mutually compatible, if the fact

fairs, whose dismissal she brought about in 1770. The death of Louis XV. caused her retirement from the Court. Some time after the outbreak of the Revolution she went to London to see about the recovery of her jewels, which had been stolen. On her return, Robespierre caused her to be arrested, July, 1793. In November she was tried before the Revolutionary Tribunal, and accused of "having wasted the treasures of the State, of conspiracy against the Republic, and with having, in London, worn mourning for the late King." She was condemned to death and was sent to the guillotine, December 7, 1793. Most of the accounts given of Madame du Barry are unreliable. She was the victim of much slander, and stories concerning her amours are rarely trustworthy. The Mémoires (6 vols., Paris, 1829-30; Engl. trans., 1830, 1896), published under her name, have no real value. Consult: Douglas, Life and Times of Madame du Barry (London, 1896); Lacretelle, Histoire de France pendant le dixhuitieme siècle (Paris, 1830); Vatel, Histoire de Madame du Barry, etc. (Versailles, 1880); Goncourt, La Du Barry (Paris, 1880).

DUBBS, JOSEPH HENRY (1838—). An American Reformed clergyman, born at North Whitehall, Pa., and educated at Franklin and Marshall College, Lancaster, Pa., and at Mercersburg Theological Seminary. He is professor of history and archæology in Franklin and Marshall College, to which position he was appointed in 1875. He engaged in interesting researches bearing on the early history of the German churches in Pennsylvania. His principal publications. include a Historic Manual of the Reformed Church (1885); Home Ballads and Metrical Versions (1888); History of the Reformed Church (1895); Leaders of the Reformation (1900); and contributions to the Encyclopædia Britannica, the Schaff-Herzog Encyclopædia, and similar works.

A

DUBLIN (Ir. Dubh-linn, Black Pool). maritime county in the east of Leinster Province, Ireland, bounded on the north by Meath, on the east by the Irish Sea, on the south by Wicklow, and on the west by Kildare and Meath (Map: Ireland, E 3). Area, 354 square miles. The coast, indented by creeks and bays, is 70 miles long, and is skirted by several isles. Dublin is the best-cultivated county in Ireland. The chief crops are oats, wheat, potatoes. There are important fisheries of turbot, brill, sole, plaice, cod, haddock, and oysters. The manufactures (chiefly of cottons, stockings, and embroidered muslins) are mostly confined to Dublin and the vicinity of the metropolis, and are of more value than in any other Irish county. The chief towns are Dublin, the capital of Ireland, and Kingstown. Unlike other Irish counties, Dublin County shows an increase of popu lation from 378,560 in 1841 to 447,260 in 1901. DUBLIN. The capital of Ireland, in Dublin County and the Province of Leinster, at the mouth of the river Liffey, in Dublin Bay on the east coast of Ireland (Map: Ireland, E 3). It is situated in latitude 53° 23′ N. and longitude 6° 20′ W. (observatory). It is built on land reclaimed from the sea, and is generally flat. The river, running from west to east between granite walls and parapets, divides the city into two almost equal portions joined by several bridges. On each side there is a spacious roadway, with

tall houses and excellent shops. Near the cus tom house there are several large docks in communication with the Royal and Grand canals; the former connecting Dublin with the North Shannon and the west of Ireland, the latter with the southern portion of the same river and the south. The harbor and docks are protected by two large breakwaters. In the newer parts of Dublin the streets run at right angles and are remarkable for their breadth. The most imposing is Sackville Street, which is 120 feet broad. At its north end is the Rotunda, with Rutland Squarein its centre are the beautiful Ionic portico of the general post-office and Nelson's monument (upward of 130 feet high). A feature of Dublin is its squares, which are numerous, spacious, and sometimes well-kept. The southeast and northeast quarters contain many beautiful squares, with splendid streets and terraces. The centre, and the northwest quarter are the great emporiums of trade, and the residence of the middle classes, many of whom have private houses in the suburbs. The southwest division, part of which is called the 'Liberties,' once the seat of the silk trade, is the slum district. The streets in this quarter are narrow, crooked, and irregular. The city is surrounded by a circular road' nearly nine miles in length, forming a favorite drive and promenade.

There are numerous places of worship, Catholie and Protestant, monasteries, convents, priories, and a Jewish synagogue. The most remarkable among the Protestant churches are Saint Patrick's Cathedral, founded in 1190, and restored by the munificence of a single individual, and Christ Church, which has also undergone restoration; and among the Catholic, Saint Mary's, Saint Saviour's, Saint Augustine's, Saint Kilvin's. The public buildings include the Bank of Ireland, formerly the House of Parliament, Trinity College, the custom house, and the four courts. Dublin Castle has no pretensions to architectural beauty. There are monuments of William III. in College Green, now a paved street; of Nelson, the Duke of Wellington, Goldsmith, Burke, Grattan, and many others on various public sites. The environs of Dublin are especially beautiful. Rathmines, a southern suburb, has become a large township, and is the favorite residence of the wealthier part of the mercantile community. Glasnevin, on the north, deserves special notice as the favorite residence of the poet Tickell, of Addison, Steele, Parnell, Swift, Sheridan, and many other celebrities. In the cemetery at Glasnevin lie the remains of Curran, O'Connell, and Tom Steele. Park is a magnificent area of over

in

Phoenix

1750 acres, some parts level, in others with broken ground, having a large amount of timber and brushwood, which shelter herds of deer. affords ample scope for military reviews, and is extensively used by the inhabitants of Dublin

for recreation.

It

The Lord Lieutenant or Viceroy of Ireland holds his court in Dublin Castle during the winter months, and in the summer removes to the Lodge, situated beyond

season

Phoenix Park.

of Dublin

(See DUB

The chief educational institution is Trinity College and University. LIN, UNIVERSITY OF.) There are also a Catholic university, which has a very successful medical school, and many literary and scientific so

cieties. There are two botanic gardens one at Glasnevin, belonging to the Royal Dublin Society, and one near Donnybrook, connected with the university. The hospitals, asylums, orphan ages, and other charitable institutions are numerous, and liberally maintained.

The

The municipal affairs are under the control of a town council of sixty members, comprising Lord Mayor, aldermen, and councilors. The civie spirit is progressive. The city owns docks and wharves, water-supply, markets, municipal tenements, electric lighting plant, maintains parks, zoülogical gardens, museum and library, art gallery, and model school. The metropolitan police force has jurisdiction over the surround ing country within eight miles of the castle. The city sends four members to Parliament. chief manufactures are porter, whisky, and poplin, and there are glass-works, cotton and linen factories, and foundries. Dublin has a large import, but a decreasing export trade. Its chief imports are grain, raw cotton, metal ores, timber, petroleum, sugar, cork, and butter; exports wool, manure, iron and steel manufactures, whisky. Over 8000 vessels enter and clear a gross tonnage of 4,850,000 annually. The total value of imports and exports averages $12,500,000. Dublin's shipping comprises 214 sailing and 103 steam vessels of 61,667 tons. Much of the inland traffic is carried on by the canals above mentioned and by the railways extending to all parts of Ireland. Dublin is the seat of a United States consulate. Population of municipal borough, in 1891, 268,587; in 1901, 289,108; and of the metropolitan police district, in 1891, 345,959; in 1901, 373,179.

HISTORY. Frequently called Bally Ahelee town of the hurdle ford-from the ford of hurdles that spanned the river in this vicinity, this name was probably antedated by the perpetuated Dubh-linn-the black pool-and the Eblana of Ptolemy. Christianity was introduced by Saint Patrick, who, in 448, baptized the King of Baile-atha-cliath. From the ninth century until 1170, with interruptions, Dublin was held by the Danes. The Anglo-Norman Conquest by Henry II. finally dispossessed them. James II. held a Parliament here in 1689 and founded a mint, and in Saint Patrick's Cathedral William III. returned thanks for the victory of the Boyne. Lord Fitzgerald (q.v.) planned to seize the city and castle during the rebellion of 1798, but was captured before the attempt was made, and Robert Emmet (q.v.) also made an unsuccessful attempt in 1803. On May 6, 1882, Lord Cavendish, the newly appointed Secretary for Ireland, and the Under-Secretary Burke was murdered in Phoenix Park. Consult: Gilbert, History of Dublin (3 vols., Dublin, 1854-59); "Greater Dublin." in London Municipal Journal (1889); Gerald, Picturesque Dublin, Old and New (London, 1897); Gross, "Dublin," in Bibliography of British Municipal History (New York, 1897). DUBLIN, UNIVERSITY OF. The chief, and for many years the only institution for higher eduration in Ireland. The first University of Dublin was established in connection with Saint Patrick's Cathedral in 1320, but, lacking an endowment, was never successful, and perished, probably at the dissolution of the cathedral foundation by Henry VIII. The present foundation, better known as Trinity College, is unique in hav

ing the organization and functions of both a college and a university. In 1591 Queen Elizabeth issued a charter incorporating a college, as 'the mother of an university,' with the title of the College of the Holy and Undivided Trinity, near Dublin.' It was expected that other colleges would be formed about this nucleus, and that a university after the English model would gradually arise in the Irish capital. This expectation was, however, disappointed, and though the institution has flourished, it has not been in the way expected. The new foundation received little but its charter from the Queen; the corporation of Dublin gave to it the grounds and ruins of the suppressed monastery of All Hallows, and a building fund was raised by subscription among the Irish gentry. The first chancellor was William Cecil, Lord Burghley, Elizabeth's great minister, who was also chancellor of Cambridge. The first five provosts were Cambridge men, and by this connection the influence of the English university on the Irish foundation was very strong. The exclusive royal patronage and control by the English Crown promised much, but under Elizabeth the college was but poorly supported and led a precarious existence. James 1. supplied an endowment of some £400 a year as a pension, together with certain estates in Ulster, which insured its future. In 1601 the English troops defeated the Spanish at Kinsale, and in commemoration of their victory subscribed £1800 from the arrears of their pay to establish a library for the college. The two trustees of this fund were Dr. Challoner and Mr., later Archbishop, Ussher. Subsequently the collection of Ussher was, with some difficulty, purchased by the officers and soldiers of the army of the Commonwealth of Ireland, and from these two unusual contributions the foundation of the present collection was laid. The original constitution of the university, meanwhile, having been found defective, new statutes were framed and issued under the direction of Archbishop Laud in 1637. A considerable part of these are still in force. Under the present system, the administration rests in the hands of a board consisting of the provost and senior fellows, in connection with the visitors, a council (since 1874), and the senate. The provost is appointed by the Crown and is the chief officer of the college. The board consists of the provost and senior fellows of the college, and carries on ordinary college business. The council consists of the provost, four members of the senate chosen by the senior fellows, four by the junior fellows, four by the professors not fellows, and four by the senate at large. The council cooperates with the board in regulating the studies and the appointment of professors. The senate consists of the chancellor, vice-chancellor, and all masters and doctors of the university whose names are on its books. The fellows are of two grades, senior and junior. The senior fellows comprise the chief officers of the college; the junior fellows form the bulk of the tutorial force of the college. Fellows, chosen primarily by examination, are promoted by seniority. There is a considerable body of professors, some forty in all, besides lecturers, and some specia! instructors. There are seventy scholarships, besides many prizes. As at Cambridge, the old distinctions among undergraduates still exist. There are five classes of students; noblemen,

from the fruits is effected either by simply shaking the latter in large bags or by boiling them with water.

American dragon's blood is derived from the Pterocarpus draco, and similar resins are produced by the Dracæna draco, the Croton draco, and the Eucalyptus resinifera.

True dragon's blood is a colorless and tasteless substance melting above 80° C.; it is opaque, of a deep reddish-brown color, brittle, smooth, with a shining shell-like fracture, and when burned emits an odor resembling that of benzoin. It is nearly insoluble in water, but is soluble in alcohol, benzene, carbon disulphide, and many oils. It was formerly used in medicine; at present, however, it is employed exclusively in the preparation of varnishes and lacquers.

DRAGON'S MOUTH (Sp. Boca del Drago). A short strait on the coast of Venezuela, South America, which connects the Gulf of Paria with the Atlantic, and separates the north end of the island of Trinidad, on the east, from the Paria peninsula on the west (Map: West Indies, Q 9).

DRAGON-TREE. See DRACENA DRACO. DRAGOON'. See CAVALRY and MOUNTED IN

FANTRY.

DRAGUIGNAN, drå'ge'nyäN'. The capital town of the Department of Var, France, on a tributary of the Argens, 40 miles northeast of Toulon (Map: France, N 8). It is situated in a valley surrounded by hills, the slopes of which are covered with vineyards and olive plantations. Its principal buildings are the prefecture, the court-house, a hospital, and a museum containing pictures by Rembrandt, Teniers, and Panini. It has manufactures of coarse woolens, leather, hosiery, silks, soap, brandy, oil, and earthenware. Population, in 1901, 9671. The town was founded in the fifth century. During the Middle Ages it was strongly fortified. The fortifications were destroyed in the civil wars, but were reconstructed in 1615. It replaced Toulon as the capital of the department in 1793.

DRAINAGE. In law, a right to discharge surface water from one's land upon the land of another. The civil law of Rome recognized a natural right of drainage as between adjacent lands of different elevations, the rights of the owners of such lands being governed by the law of nature. By that law, which has been adopted in Pennsylvania, Illinois, California, and Louisiana, the lower proprietor is bound to receive the surface waters which naturally flow from the estate above, provided the servitude has not been increased by the industry of man.

No such right exists by the common law, and it is held in most of the United States, as well as in England, that the lower proprietor may lawfully obstruct the flow of surface water upon his land from that of his neighbor, though the latter is not liable for any damage which may result from the natural flow of such water upon the lands of the former. In both systems of law, however, a riparian proprietor may drain his land into a natural watercourse which flows over or by his land, and no obstruction of the stream by the lower proprietor which prevents such drainage will be permitted. This is a natural, as distinguished from an acquired, right of the riparian proprietor, and is therefore strictly analogous to the natural servitude of

drainage of the civil law above alluded to. It exists ex juræ naturæ and is incapable of alienation, of release, or of severance from the land. See Barkley vs. Wilcox, 86 New York Reports, 140.

Apart from this limited natural right of drainage, the common law recognizes also an easement of drainage, which may be acquired by grant or prescription over the land of another. This may exist with or without an artificial construction, and may be superficial or subterranean. The common-law right of eavesdropping is one form of this easement, though its usual form is the right to construct and maintain an artificial drain and to discharge water through the same into and through the adjoining premises. The familiar right of the householder in a city or village to discharge water into a public or municipal drain is of this nature. The right is violated by any interference or obstruction caused by the owner of the lower or 'servient' estate, whether intentional or not, and may be enforced by an action for damages or by injunction to prevent a threatened interference. The easement carries with it the right to enter on the premises affected by it in order to repair the drain and keep it open; but it is, like other easements, carefully restricted to the amount and kind of user included in the terms of the grant. See EASEMENT; SERVITUDE; WATERCOURSE; and the authorities there referred to.

DRAINAGE (from drain, AS. drehnian, dreahnian, drinian, Icel. dragna, from AS.. Goth. dragan, Icel. draga, OHG. tragan, Ger. tragen, Engl. draw, drag). The removal of surplus water from the soil by means of canals, open ditches, and drains, or other conduits which are either porous or else laid with open joints. In its larger sense the term drainage applies to the reclamation of extensive areas of land either under water or in the condition of marsh or swamp, and consequently unfit for habitation or cultivation. In agriculture drainage implies the removal of surface or subsoil water from a more limited area which it is desired to put under specific cultivation, and generally is understood to involve the use of tile drains, as will be described below. The name drainage is also used to denote a system of sewerage for the removal of liquid household wastes, as well as the surface and subsoil water of towns and cities. This aspect of the subject will be found treated fully under the head of SEWERAGE AND DRAINAGE.

con

RECLAMATION OF LAND. In reclaiming large tracts of land, often of great fertility, but which are at so slight an elevation above the sea or the neighboring streams that they can be rendered fit for cultivation and habitation by artificial means only, dikes or embankments are structed to keep out the flood waters and a system of canals built to collect and carry off the superfluous water. In the case of marsh lands the method employed depends upon the elevation and conformation of the land to be drained, but all lands may be divided into two general classes-those that can be drained by gravitation and those in which the water must be pumped out, either all or a part of the time. Many coast lands are so low that the water will run off only at low tide, and such lands are protected from high tide by embankments. The water is gathered by a network of subsidiary