of the arts and sciences, who devotes his leisure to them as a means of
amusement and gratification, being thus nearly equivalent to _amateur_. It
is also used in reference to the trifler and dabbler in art and science. In
1734 a number of gentlemen founded in London a Dilettanti Society, which
published a splendid work on _Ionian Antiquities_, 1769, 1881 (4 vols.);
_Specimens of Ancient Sculpture_, 1809, 1835.
DILKE, Sir Charles Wentworth, English writer and politician, son and
grandson of men well known in their day, was born in 1843, died in 1911. He
graduated at Cambridge, and was called to the Bar. His first work, _Greater
Britain_, the result of a tour round the world from 1866 to 1867, became
very popular. In 1868 he was elected member of Parliament for Chelsea, and
he remained so up to 1885. After a few years' retirement (due to a divorce
case) he became member of Parliament for Forest of Dean. He was
Under-Secretary for Foreign Affairs, President of the Local Government
Board, &c. He succeeded his father as owner of the _Athenaeum_, and became
the proprietor of _Notes and Queries_. _The Present Position of European
Politics_, and _Problems of Greater Britain_, are among his works.
DILL, an umbelliferous plant, _An[=e]thum grave[)o]lens_, a native of the
southern countries of Europe, the fruits, commonly but erroneously called
seeds, of which are moderately warming, pungent, and aromatic, and are
employed medicinally as a carminative.
DILLENIA'CEAE, an order of plants, chiefly fine trees, inhabiting the East
Indies, allied to Ranunculaceae and Magnoliaceae.
DILLINGEN (dil'ing-en), an old town, Bavaria, on the Danube, formerly the
seat of a Jesuit university. Pop. 6291.
DILLON, John, Irish politician and agitator, born in Dublin in 1851, the
son of John Blake Dillon (1816-66), a leader of the Young Ireland party.
Educated at the Catholic University of Dublin and at the Royal College of
Surgeons, he became a doctor of medicine. He identified himself with the
Parnellite movement, and entered Parliament for Tipperary in 1880. An
ardent Nationalist, not hesitating to incite his compatriots to
lawlessness, he was sent to prison in 1888. Without a seat in Parliament
from 1883 to 1885, he was returned in the latter year for East Mayo, which
he represented thereafter. In 1918, after the death of John Redmond, he was
elected chairman of the Irish Nationalist party, which, however, owing to
the rise of the Sinn Fein party, was a nominal distinction only.
DILMAN', a town, Persia, province of Azerbijan, 75 miles west of Tabreez.
Pop. estimated at 15,000.
DILO'LO, a small lake in Angola, near the southern boundary of Belgian
Congo, lat. 11deg 22' S.; long. 22deg 34' E.: regarded as the source of the
Zambesi.
DIL'UENTS (Lat. _diluere_, to wash away), in medicine, are those substances
which are taken to increase the proportion of fluid in the blood. They
consist of water and watery liquors.
DILU'VIUM, the name formerly given by geologists to certain gravels and
comparatively recent deposits, which seemed to have been the result of a
rush of water or deluge.
DIME (Fr. _d[^i]me_, Lat. _decimus_, tenth), the term for the tenth part of
a dollar or ten-cent piece in the United States of America, a silver coin
whose English equivalent is about 5d. Hence the phrases _dime novels_,
_dime museums_, &c.
DIMENSIONS, ALGEBRAICAL. There are three dimensions in space: length,
breadth, and height or depth. An area is said to be of two dimensions
because it has length and breadth only; a volume is of three dimensions. In
algebra terms like x^2, xy are said to be of two dimensions because there
are two letters multiplied together, and their product would measure an
area if each letter denoted a length. Similarly, x^3, xyz are said to be of
three dimensions, and the meaning is extended to cover the product of any
number of letters. An expression of more than one term is said to be of the
same degree as its term of highest dimensions. For example, 3x^2y^2z^2 +
5xyz + 6x^3 + 3x^2y^2 is said to be of the sixth degree because x^2y^2z^2 =
x x x x y x y x z x z is of six dimensions.
DIMENSIONS, PHYSICAL. One of the aims of physical science is to express all
its measurements in terms of the three fundamental units of length, mass,
and time. A velocity, for example, is specified by the number of units of
length traversed in the unit of time, so that we may write v = l / t, or v
= lt^{-1}. On this account velocity is said to have the dimensions LT^{-1}.
Similarly, acceleration, being velocity added per unit time, has the
dimensions of velocity / time, or LT^{-2}; and force, being proportional to
mass and acceleration jointly, has the dimensions MLT^{-2}.
When a physical law is expressed as an equation connecting the numbers of
units of the quantities involved, every term in this equation must be of
the same dimensions in any one of the fundamental units. This is the
_Principle of Dimensions_, first stated by Joseph Fourier, founder of the
theory of the conduction of heat. In order to see its truth, we have only
to observe that an equation containing terms of different dimensions would
give inconsistent results if the unit of length were varied. Suppose it to
be suggested, for example, that the period of vibration t of a simple
pendulum of length l is given by the formula t = 2[pi]l/g, where g denotes
the acceleration of a falling body. The dimensions of the expression on the
right are L / (LT^{-2}), or T^2, whereas the term t on the left has
dimensions T^1. Suppose the unit of length is the foot and the unit of time
the second, so that g = 32, and let l = 3. We find in this case t =
6[pi]/32, so that the period is 3[pi]/16 seconds. But if we change the unit
of time to one minute, g becomes 32 x 60 x 60, and the formula gives t =
6[pi]/(32 x 60 x 60), so that the period is 3[pi]/(16 x 60 x 60) minutes.
The two results are obviously inconsistent. If, however, we take the
correct formula, namely t = 2[pi][sqrt](l/g), we find on trial that we
obtain the same value for the period however we change the unit of time or
the unit of length. Both sides are in this case of dimensions T^1.
The principle of dimensions provides therefore a useful check on the
accuracy of formulae. But it does much more than this. It often gives very
valuable information about the relations of physical phenomena in cases
where these relations are far too complicated to be completely worked out
by mathematical analysis. To mention but one example, it is by the use of
this principle that modern naval architecture is able to predict the
behaviour of ocean-going ships from experiments in ponds on small-scale
models.
DIMIN'UTIVE, in grammar, a word having a special affix which conveys the
idea of littleness, and all other ideas connected with this, as tenderness,
affection, or contempt. The opposite of _diminutive_ is _augmentative_. In
Latin, diminutives almost always ended in _-lus_, _-la_, or _-lum_; as
_Tulliola, meum corculum_, little Tullia my dear, or little heart;
_homunculus_, a manikin. The Italian is particularly rich in diminutives
and augmentatives, such compound diminutives as _fratellinucciettinetto_ (a
diminutive of _frate_, brother) being sometimes employed. Among English
diminutive affixes are _-kin_, as in _manikin_, a little man; _pipkin_, a
little pipe; _-ling_, as in _gosling_, a little goose; darling, that is,
_dearling_, or little dear; and _-et_, as in _pocket_, from _poke_, a bag
or pouch; _tablet_, a little table. Diminutives are not confined to nouns,
and _dandle_, _scribble_, _tipple_, are examples of diminutive verbs, and
_greenish_, _whitish_, are diminutives of adjectives. Diminutives are also
formed, in colloquial and familiar language, by adding _-y_ or _-ie_ to the
names, as _Charley_, _Mousie_, &c.
DIM'ITY, a stout cotton fabric, ornamented in the loom either by raised
stripes or fancy figures. It is usually employed white, as for bed and
bedroom furniture.
DIMORPH'ISM, in crystallography, the crystallization of a body in forms
belonging to two different systems, or in incompatible forms of the same
system, a peculiarity exhibited by sulphur, carbon, &c.
DIMORPHISM, in botany. See _Heterostyly_.
DINAJPUR', a town, Hindustan, Bengal, capital of a district of same name,
205 miles north of Calcutta; pop. 12,500.--The district covers an area of
about 4118 sq. miles; pop. 1,687,860.
DINAN (d[=e]-n[:a]n), a town, France, department of C[^o]tes-du-Nord
(Brittany), on the Rance, 14 miles south of St. Malo. It was besieged and
captured by the English under the Duke of Lancaster in 1359, but retaken by
Du Guesclin. It stands on a steep hill nearly 200 feet above the river, is
surrounded by high old walls pierced with four gates, and is a picturesque
and interesting old place. In the cathedral of St. Sauveur the heart of
Bertrand du Guesclin is buried. Pop. 11,410.
DINANT (d[=e]-n[:a]n), a town, Belgium, in the province and 14 miles S. of
Namur; picturesquely and strongly situated on the Meuse; a place of antique
appearance. The town house was once the palace of the Princes of Li['e]ge.
The town was destroyed by the Germans in 1914. It is one of the most
popular Belgian summer resorts. Pop. 7690.
DINA'PUR, a town, Hindustan, Patna district, Bengal, on the right bank of
the Ganges, about 12 miles north-west of Patna, cantonment and military
head-quarters of the district, with extensive barracks. The environs are
studded with handsome bungalows. Pop. 31,025.
DINAR (Lat. _denarius_), formerly an Arab gold coin, also a Persian coin;
at present the chief Serbian coin, value one franc.
DI'NAS BRICKS, an infusible kind of brick made of a peculiar rock,
containing 98 per cent of silica, with a little alumina, which occurs at
Dinas, in the Vale of Neath, in Glamorganshire, S. Wales. The rock is
crushed, moistened with water, and moulded by a machine.
DINDIGUL, a town of India, Madura district, Madras, with a fort on a rocky
height; manufactures cigars. Pop. 21,000.
DINDINGS, THE, properly two small islands, also called PANGKOR ISLANDS, in
the Straits of Malacca, belonging to the Straits Settlements, off the coast
of Perak (British). The name now includes a strip of territory on the Malay
Peninsula opposite; total area about 265 sq. miles, two-thirds of which is
covered by dense forests. Coco-nuts, coffee, and pepper are grown with
success. Lumut, on the mainland, has a fine natural harbour.
DIN'DORF, Karl Wilhelm, German classical scholar, born 1802, lived most of
his life at Leipzig, and died 1883. His chief publications were editions of
the Greek dramatists (_Poetae Scenici Graeci_) and works elucidative of
them and other Greek writers.
[Illustration: _Dinornis maximus_ (the Moa)]
DINGO, the native wild dog of Australia (_Canis Dingo_), of a wolf-like
appearance and extremely fierce. The ears are short and erect, the head
elongated, the tail rather bushy, and the hair of a reddish-dun colour. In
habit the dingo is rather fox-like, usually lying concealed throughout the
day and making predatory expeditions at night. It is very destructive to
sheep, killing more than it eats. It was probably introduced by prehistoric
man.
DING'WALL, a royal and parliamentary burgh and seaport of Scotland, county
town of Ross and Cromarty, situated at the head of Cromarty Firth. This
town, erected into a royal burgh in 1227, unites with Wick and other places
in returning a member to Parliament. Pop. 2590.
DINO'CERAS (Gr. _deinos_, terrible, _keras_, a horn), a fossil mammal found
in the Eocene strata of North America, in some respects akin to the
elephant and of equal size, but without a proboscis. Its bones were very
massive; it had two vertical tusks in the upper jaw, three pairs of horns,
and the smallest brain, proportionally, of any known mammal.
DINOR'NIS (Gr. _deinos_, terrible, _ornis_, a bird), an extinct genus of
large wingless birds--classed with the small existing Apteryx. The bones of
several species have been found in New Zealand. The largest must have stood
12 feet in height, several of its bones being at least twice the size of
those of the ostrich. The body seems to have been even more bulky in
proportion, the tarsus being short and stout in order to sustain its
weight. They do not appear to have become extinct until the seventeenth or
eighteenth century, and are spoken of as _moas_ by the natives, who buried
the eggs (more than 1 foot long) with their dead as provision for their
journey to the other world.
[Illustration: _Diplodocus Carnegii_, a gigantic Dinosaur. Length, 84 feet
9 inches; height at middle of back, 11 feet 5 inches]
DINOSAU'RIA (Gr. _deinos_, terrible, and _sauros_, a lizard), a group of
extinct reptiles, allied in skeletal structure both to the lizards and the
birds. While some were only 3 feet long, a large number attained gigantic
size. Atlantosaurus being 115 feet long. Many were carnivorous, but some of
the large heavy forms were herbivorous, and protected by bony spines or
plates. The Dinosaurs were the dominant land animals of the Jurassic and
Cretaceous periods.
[Illustration: Skull of _Dinotherium giganteum_]
DINOTHE'RIUM (Gr. _deinos_, terrible, _th[=e]rion_, beast), a genus of
extinct gigantic proboscidean mammals, precursors of the elephants, the
remains of which occur in Miocene formations in several parts of Europe.
The type-species (_D. giganteum_) is calculated to have attained the length
of 18 feet. It had a proboscis and also two tusks placed at the anterior
extremity of the lower jaw, and curved downwards somewhat after the manner
of those in the upper jaw of the walrus. The skull is best known from that
found in 1835 at Eppelsheim; but the skeleton can now be pieced together
from remains in various localities. The vertebrae resemble those of
mastodon. Dinotherium may have inhabited rivers or estuaries.
DI'OCESE (Gr. _dioik[=e]sis_, administration), the circuit or extent of a
bishop's jurisdiction. Each English diocese is divided into archdeaconries,
each archdeaconry (nominally) into rural deaneries, and each deanery into
parishes. In the Eastern Churches the term _eparchy_ is used for diocese.
See _Bishop_.
DIOCLE'TIAN (Gaius Valerius Diocletianus, surnamed _Jovius_), a man of mean
birth, a native of Dalmatia, proclaimed Emperor of Rome by the army A.D.
284. He defeated Carinus in Moesia (286), conquered the Allemanni, and was
generally beloved for the goodness of his disposition, but was compelled by
the dangers threatening Rome to share the government with M. Aurelius
Valerius Maximian. In 292 Galerius and Constantius Chlorus were also raised
to a share in the empire, which was thus divided into four parts, of which
Diocletian administered Thrace, Egypt, Syria, and Asia. As the result of
his reconstitution of the empire there followed a period of brilliant
successes in which the barbarians were driven back from all the frontiers,
and Roman power restored from Britain to Egypt. In 305, in conjunction with
Maximian, he resigned the Imperial dignity at Nicomedia, and retired to
Salona, in Dalmatia, where he cultivated his garden in tranquillity until
his death in 313. In the latter part of his reign he was induced to
sanction a persecution of the Christians.--BIBLIOGRAPHY: Gibbon, _Decline
and Fall_; P. Allard, _La Pers['e]cution de Diocl['e]tien_; A. J. Mason,
_The Persecution of Diocletian_.
DIODA'TI, Giovanni, Italian Protestant divine, born at Lucca, about 1576,
of a noble Catholic family. He was for some time professor, first of
Hebrew, then of theology, at Geneva, and in 1619 represented the Genevan
clergy at the Synod of Dort, and aided in drawing up the Belgic confession
of faith. He is most celebrated for a translation of the Bible into Italian
(1607), which is superior to his translation of it into French. He died at
Geneva in 1649.
DIODO'RUS of Agyrium, in Sicily, and therefore called SICULUS; a Greek
historian in the time of Julius Caesar and Augustus. His universal history,
in the composition of which he travelled through a great part of Europe and
Asia, occupied him thirty years, and consisted of 40 books, but only books
1-5 and 11-20, with certain fragments, are now extant.
DIOECIOUS (Gr. _di_, double, _oikos_, a house), in botany, a term applied
to plants which have flowers with stamens on one individual and those with
pistils on another; as opposed to _monoecious_. The willow, the yew, the
poplar, &c., are dioecious.
DIOGENES LAERTIUS, author of a sort of history of philosophy in Greek,
appears to have been born at Laerte, in Cilicia, and to have lived towards
the close of the second century after Christ; but no certain information
exists either as to his life, studies, or age. The work is divided into ten
books, and bears in MSS. the title, _On the Lives, Doctrines, and Apothegms
of those who have distinguished themselves in Philosophy_. It is full of
absurd and improbable anecdotes, but contains valuable information
regarding the private life of the Greeks, and many fragments of works now
lost. It was the foundation of the earlier modern histories of philosophy.
A translation of his work by C. D. Yonge was published in Bohn's Classical
Library.
DIOGENES (di-oj'[=e]-n[=e]z) OF APOLLONIA (Crete), known also as the
_Physicist_, a Greek philosopher of the fifth century B.C., who belonged to
the Ionian school, and considered air as the element of all things. He was
a pupil of Anaximenes and a contemporary of Anaxagoras.
DIOGENES OF SINOP[=E] (on the Black Sea), the most famous of the Cynic
philosophers, born about 412 B.C., died about 323 B.C. Having been banished
from his native place with his father, who had been accused of coining
false money, he went to Athens, and thrust himself upon Antisthenes as a
disciple. Like Antisthenes he despised all philosophical speculations, and
opposed the corrupt morals of his time; but while the stern austerity of
Antisthenes was repulsive, Diogenes exposed the follies of his
contemporaries with wit and good humour. As an exemplar of Cynic virtue he
satisfied his appetite with the coarsest food, practised the most rigid
temperance, walked through the streets of Athens barefoot, without any
coat, with a long beard, a stick in his hand, and a wallet on his
shoulders, and by night, according to the popular story, slept in a tub (or
large earthenware vessel). On a voyage to the Island of Aegina he fell into
the hands of pirates, who sold him as a slave to the Corinthian Xeniades.
The latter emancipated him, and entrusted him with the education of his
children. He attended to the duties of his new employment with the greatest
care, commonly living in summer at Corinth and in winter at Athens. It is
at Corinth that he is said to have had his famous interview with Alexander
the Great. The Macedonian conqueror was so struck with the philosopher's
self-possession that he went away remarking: "If I were not Alexander, I
should wish to be Diogenes". Of the many stories related of him the
majority are probably fictions; many, indeed, are chronologically
impossible. Concerned with practical wisdom, Diogenes established no system
of philosophy. To gain virtue, he maintained, man must avoid physical
pleasure, despise the conventions of society, and adopt a simple and
natural life. His enemies accused him of various scandalous offences, but
there is no ground for supposing him guilty of any worse fault than that of
elevating impertinence to the rank of a fine art. See _Cynics_.
DIOMEDES (d[=i]-o-m[=e]'d[=e]z), in Greek mythology, (1) the son of Mars
and Cyrene, and King of the Bist[)o]nes in Thrace, who fed his horses on
human flesh, and used to throw all strangers who entered his territories to
those animals to be devoured. He was killed by Hercules, who carried off
the horses. (2) One of the heroes at the siege of Troy, the son of Tydeus
and Deipyle, and King of Argos, one of the suitors of Helen. After she was
carried off, Diomedes engaged in the expedition against Troy, in which his
courage and the protection of Pallas rendered him one of the most
distinguished heroes. He wounded Aphrodite and Ares, and thrice assailed
Apollo; and by carrying off the horses of Rhoesus from the enemies' tents,
and aiding Ulysses in the removal of Philoctetes from Lemnos, he fulfilled
two of the conditions on which alone Troy could be conquered. Finally he
was one of the heroes concealed in the wooden horse by which the capture of
Troy was at length accomplished. Different accounts were given of his
after-life. He is often called _Diomede_.
DIONAE'A, a genus of plants, nat. ord. Droseraceae. Only one species is
known, _D. muscip[)u]la_ (Venus's fly-trap), a native of the sandy savannas
of Carolina and Florida. It has a rosette of root-leaves, from which rises
a naked scape bearing a corymb of largish white flowers. The leaves have a
dilated petiole and a slightly stalked 2-lobed lamina, with three short
stiff bristles on each lobe. The bristles are remarkably irritable, and
when touched by a fly, or other insect, the lobes of the leaf suddenly
close on and capture the insect. It dissolves the food thus captured by
means of digestive fluid similar to ordinary gastric juice.
DION CASSIUS, or DIO CASSIUS, a Greek historian, born about A.D. 155 at
Nicaea, in Bithynia. After accompanying his father to Cilicia, of which he
held the administration, he came to Rome about 180, and obtained the rank
of a Roman Senator. On the accession of Pertinax Dion was appointed
Praetor, and in the reign of Caracalla he was one of the Senators whom it
had become customary to select to accompany the emperor in his expeditions,
of which he complains bitterly. In 219 he was raised to the consulship, and
about 224 became Proconsul of Africa. In 229 he was again appointed Consul;
but feeling his life precarious under Alexander Severus, he obtained
permission to retire to his native town of Nicaea. The period of his death
is unknown. The most important of his writings, though only a small part is
extant, is a _History of Rome_, written in Greek and divided into eighty
books, from the arrival of Aeneas in Italy and the foundation of Alba and
Rome to A.D. 229.
DION CHRYSOSTOM, a Greek sophist and rhetorician and a favourite of Trajan;
born A.D. 50, died about A.D. 110. Eighty of his orations (in excellent
Attic) have been preserved.
DION OF SYRACUSE, in Greek history, a connection by marriage of the elder
and the younger Dionysius, tyrants of Syracuse, over whom he long exercised
great influence. He attempted to reform the younger Dionysius, but his
enemies succeeded in effecting his banishment. He afterwards returned and
made himself ruler of the city, but became unpopular, and in 353 B.C. one
of his followers, Callipus of Athens, caused him to be assassinated.
DIONYS'IA. See _Bacchanalia_.
DIONYS'IUS, ST., a disciple of Origen, and Patriarch of Alexandria in A.D.
248. He was driven from the city in 250, and in 257 was banished to Libya,
but was restored in 260. He died in A.D. 265.
DIONYSIUS OF HALICARNASSUS, in Caria, a Greek critic and teacher of
eloquence, born about 70 B.C. He went to Rome about 30 B.C., where he wrote
his _Roman Antiquities_, in twenty books, in which he relates (in Greek)
the early history of Rome and its government up to the times of the first
Punic War. We have the first nine books of this work entire, the tenth and
eleventh nearly so, and some fragments of the others. His rhetorical
writings are of greater value, especially his essays on the Greek orators.
He died about 6 B.C.--Cf. Sir J. E. Sandys, _A History of Classical
Scholarship_.