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The New Gresham Encyclopedia. Deposition to Eberswalde

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Title: The New Gresham Encyclopedia. Deposition to Eberswalde

Author: Various


        
Release date: April 12, 2011 [eBook #35843]
                Most recently updated: January 7, 2021

Language: English

Other information and formats: www.gutenberg.org/ebooks/35843

Credits: Produced by Jonathan Ingram, Keith Edkins and the Online
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*** START OF THE PROJECT GUTENBERG EBOOK THE NEW GRESHAM ENCYCLOPEDIA. DEPOSITION TO EBERSWALDE ***




Produced by Jonathan Ingram, Keith Edkins and the Online
Distributed Proofreading Team at https://www.pgdp.net





Transcriber's note: A few typographical errors have been corrected: they
are listed at the end of the text.

       *       *       *       *       *


In the pronunciation guides [=e] signifies "e macron"; [)e] "e breve"; [a:]
"a with diaeresis below"; [.a] "a with dot above"; [n.] "n with dot below";
[:a] "a with diaeresis"; ['e] "e with acute"; [`e] "with grave"; [^e] "with
circumflex"; and so forth.

THE

NEW . GRESHAM

ENCYCLOPEDIA

VOLUME . IV . PART . 1

[Illustration]

_The_ GRESHAM . PUBLISHING
COMPANY . _Limited_

66 CHANDOS STREET . STRAND
LONDON W.C.2.
1922

       *       *       *       *       *







LIST OF PLATES

       *       *       *       *       *

VOLUME IV PART 1

DEPOSITION to EBERSWALDE

       *       *       *       *       *

PLATES

                                                                  Page

  DIAMONDS                                                         18
  DOGS                                                             62

       *       *       *       *       *







CONTRIBUTORS TO VOLUME IV

ADOLPHE ABRAHAMS, O.B.E., B.A., M.D., late Major, R.A.M.C.

GEORGE E. ALLAN, D.Sc., Lecturer in Electricity, University of Glasgow.

C. O. BANNISTER, F.I.C., Assoc. R.S.N., Professor of Metallurgy, University
of Liverpool.

F. F. P. BISACRE, O.B.E., M.A., B.SC., A.M.Inst.C.E.

R. N. RUDMOSE BROWN, D.SC.

A. Y. CATTO, O.B.E., Lieutenant, R.N.

GRENVILLE A. J. COLE, F.R.S., Professor of Geology, Royal College of
Science, Ireland.

W. G. CONSTABLE, M.A., Fellow of St. John's College, Cambridge.

ARTHUR O. COOKE, Author of _A Book of Dovecotes_.

J. R. AINSWORTH DAVIS, M.A., F.C.P., former Principal of The Royal
Agricultural College, Cirencester.

JOHN DOUGALL, M.A., D.Sc., F.R.S.E., Gold Medallist of the Royal Society of
Edinburgh.

MONTAGU DRUMMOND, M.A., Director of Research, Scottish Station for Research
in Plant Breeding.

S. L. ETHERTON, B.Sc.

REV. WILLIAM FULTON, D.D., B.Sc., Professor of Systematic Theology,
University of Aberdeen.

R. N. HAYGARTH, B.A., B.Sc., Queens' College, Cambridge.

W. A. HISLOP, M.B., late Captain, R.A.M.C.

D. J. MACKELLOR, B.Sc., Lecturer in Electrical Engineering, Royal Technical
College, Glasgow.

DONALD A. MACKENZIE, Folklorist; Author of _Egyptian Myth and Legend_, &c.

MAGNUS MACLEAN, M.A., D.Sc., M.Inst.E.E., M.Inst.C.E., Editor of _Modern
Electrical Engineering_, &c.

F. A. MUMBY, Editor of _The Great World War_.

D. G. OGILVY, LL.B.

R. F. PATTERSON, M.A., formerly Foundation Scholar of St. John's College,
Cambridge, and Charles Oldham (University) Shakespeare Scholar.

ANGELO S. RAPPOPORT, Ph.D., B. [`e]s L.

JAMES RITCHIE, M.A., M.D., Professor of Bacteriology, University of
Edinburgh.

JOHN J. ROSS, M.A., F.R.A.S.

G. ELLIOT SMITH, M.A., M.D., F.R.S., Professor of Anatomy, University of
London.

C. S. STOCKS, D.S.O., Major, Indian Army; Instructor in Military
Organization, Royal Military College, Sandhurst.

M. M. J. SUTHERLAND, D.Sc., F.I.C.

ALAN C. THOMSON, D.S.O., A.M.Inst.C.E., late Lieutenant-Colonel, R.E.

G. E. TOULMIN, B.A., King's College, Cambridge.

THOMAS WOODHOUSE, Head of the Weaving and Designing Department, Dundee
Technical College and School of Art.

       *       *       *       *       *


KEY TO PRONUNCIATION

       *       *       *       *       *

The method of marking pronunciations here employed is either (1) by marking
the syllable on which the accent falls, or (2) by a simple system of
transliteration, to which the following is the Key:--

VOWELS

[=a], as in f_a_te, or in b_a_re.

[:a], as in _a_lms, Fr. _[^a]_me, Ger. B_a_hn = ['a] of Indian names.

[.a], the same sound short or medium, as in Fr. b_a_l, Ger. M_a_nn.

a, as in f_a_t.

[a:], as in f_a_ll.

_a_, obscure, as in rur_a_l, similar to _u_ in b_u_t, [.e] in h_e_r: common
in Indian names.

[=e], as in m_e_ = _i_ in mach_i_ne.

e, as in m_e_t.

[.e], as in h_e_r.

[=i], as in p_i_ne, or as _ei_ in Ger. m_ei_n.

i, as in p_i_n, also used for the short sound corresponding to [=e], as in
French and Italian words.

_eu_, a long sound as in Fr. j_e[^u]_ne = Ger. long _[:o]_, as in
S_[:o]_hne, G_[:o]_the (Goethe).

eu, corresponding sound short or medium, as in Fr. p_eu_ = Ger. _[:o]_
short.

[=o], as in n_o_te, m_oa_n.

o, as in n_o_t, s_o_ft--that is, short or medium.

[:o], as in m_o_ve, tw_o_.

[=u] as in t_u_be.

u, as in t_u_b: similar to [.e] and also to a.

[u:], as in b_u_ll.

[:u], as in Sc. ab_u_ne = Fr. _[^u]_ as in d_[^u]_, Ger. _[:u]_ long as in
gr_[:u]_n, B_[:u]_hne.

[.u], the corresponding short or medium sound, as in Fr. b_u_t, Ger.
M_[:u]_ller.

oi, as in _oi_l.

ou, as in p_ou_nd; or as _au_ in Ger. H_au_s.

CONSONANTS

Of the _consonants_, B, D, F, H, J, K, L, M, N, NG, P, SH, T, V, Z, always
have their common English sounds, when used to transliterate foreign words.
The letter C is not used by itself in re-writing for pronunciation, S or K
being used instead. The only consonantal symbols, therefore, that require
explanation are the following:--

ch is always as in ri_ch_.

_d_, nearly as _th_ in _th_is = Sp. _d_ in Ma_d_ri_d_, &c.

g is always hard, as in _g_o.

_h_ represents the guttural in Scotch lo_ch_, Ger. na_ch_, also other
similar gutturals.

[n.], Fr. nasal _n_ as in bo_n_.

r represents both English _r_, and _r_ in foreign words, which is generally
much more strongly trilled.

s, always as in _s_o.

th, as _th_ in _th_in.

_th_, as _th_ in _th_is.

w always consonantal, as in _w_e.

x = ks, which are used instead.

y always consonantal, as in _y_ea (Fr. _ligne_ would be re-written
l[=e]ny).

zh, as _s_ in plea_s_ure = Fr. _j_.

       *       *       *       *       *

THE NEW
GRESHAM ENCYCLOPEDIA

VOLUME IV

DEPOSITION OF A CLERGYMAN, the degradation of a clergyman from office,
divesting him (in churches which do not, like the Church of Rome, hold the
indelible nature of orders) of all clerical character.

D['E]P[^O]T (d[=a]'po or dep'[=o]), a French word in general use as a term
for a place where goods are received and stored; hence, in military
matters, a magazine where arms and ammunition are kept. The term is now
usually applied to a military station situated in the centre of the
recruiting district of a regiment, where recruits for this regiment are
received and where they undergo preliminary training before joining their
unit. In America it is the common term for a railway station.

DEPRIVATION, the removing of a clergyman from his benefice on account of
heresy or misconduct. It entails, of course, loss of all emoluments, but
not the loss of clerical character.

DE PROFUNDIS, in the liturgy of the Roman Catholic Church, one of the seven
penitential psalms, the 130th of the _Psalms_ of David, which in the
_Vulgate_ begins with these words, signifying 'Out of the depths'. It is
sung when the bodies of the dead are committed to the grave.

DEPTFORD (det'ford), a parliamentary and municipal borough, England, in the
counties of Kent and Surrey, on the right bank of the Thames, now forming
part of London. It has some manufactures of pottery, chemicals, and soap.
The old naval dockyard was shut up in 1869, but the royal victualling yard
is still the largest establishment of its kind. Deptford sends one member
to Parliament. Pop. 109,496.

DEPUTIES, CHAMBER OF, the lower of the two legislative chambers in France
and in Italy, elected by popular suffrage, and corresponding in some
respects to the House of Commons in Britain.

DE QUINCEY, Thomas, English author, was the son of a Manchester merchant,
and born at Greenhay, near Manchester, on 15th Aug., 1785, died at
Edinburgh, 8th Dec., 1859. In 1793 his father died, leaving the family a
fortune of L30,000. After attending some time the Bath and Manchester
grammar schools, where he showed precocious ability, especially in
classical studies, he importuned his guardian to send him to Oxford
University, and on being refused he ran away from school, ultimately
arriving in London in an absolutely destitute condition. His sufferings at
this time he has described in his _Confessions of an English Opium Eater_.
At length, in 1803, he matriculated at Oxford, and it was in the second
year of his course here that he began to take opium in order to alleviate
severe neuralgic pains. On leaving college he settled at Grasmere,
Westmoreland, in the vicinity of Wordsworth and Southey, and devoted
himself to literary work. Here or in London he remained till 1828, reading
voraciously, and writing for the _London Magazine_, _Knight's Quarterly
Magazine_, and _Blackwood's Magazine_. From 1828 to 1840 he lived in
Edinburgh, then removed with his family to Lasswade, which continued to be
his head-quarters. His writings, nearly all contributions to magazines, are
distinguished by power of expression, subtle thought, and an encyclopaedic
abundance of curious information. His work belongs to that class of
literature which he himself called "the literature of power", as
distinguished from "the literature of knowledge". He was eccentric in his
habits, incapable of managing money matters, but amiable and
polite.--BIBLIOGRAPHY: A. H. Japp, _Thomas De Quincey: his Life and
Writings_; H. S. Salt, _De Quincey_; J. Hogg, _De Quincey and His Friends_;
Sir L. Stephen, _Hours in a Library_; Arvede Barine, _Po[`e]tes et
N['e]vros['e]s_.

DERA GHAZI KHAN, a district and town in the Punjab, Hindustan. The former,
which is in Derajat division, has an area of 5606 sq. miles, and a
population of 445,000. The town has a population of 18,466, half Hindus and
half Mohammedans. It has extensive manufactures of silk, cotton, and coarse
cutlery.

DERA ISMAIL KHAN, a town in Hindustan, in the North-West Frontier Province,
several miles to the west of the Indus, which is here crossed by
boat-bridges, or boats, connecting the town with the Indus Valley railway.
Dera Ismail Khan is a staple place for cotton goods, has a cantonment, and
carries on a trade with Afghanistan. It is well laid out, has several
schools and a large bazaar. Pop. 35,131.

DERAJAT (-j[:a]t'), a commissionership of Hindustan, in the west of the
Punjab, occupying part of the valley of the Indus. It is well watered and
fertile, and contains numerous towns and villages. Pop. 1,800,000, mostly
Mohammedans.

DERBEND', or DERBENT', a fortified town in Daghestan, Transcaucasia, on the
west shore of the Caspian, an ancient place formerly belonging to Persia.
The manufactures consist of woollen stuffs, copper- and iron-ware, and
rose-water; and there is some trade in saffron, largely grown in the
vicinity. Pop. 32,718.

DERBY, Edward Geoffrey Smith Stanley, fourteenth Earl of, an English
statesman, born at Knowsley Park, Lancashire, 29th March, 1799, died there,
23rd Oct., 1869. In 1820 he was returned to the House of Commons as member
for Stockbridge. At first inclining to the Whig party, he joined Canning's
ministry in 1827, and in 1830 became Chief Secretary for Ireland in Lord
Grey's Government, greatly distinguishing himself by his speeches in favour
of the Reform Bill in 1831-2. The opposition led by O'Connell in the House
of Commons was powerful and violent, but Stanley, while supporting a Bill
for the reform of the Irish Church and the reduction of ecclesiastical
taxation, was successful in totally defeating the agitation for the repeal
of the Union. He warmly advocated the abolition of slavery, and passed the
Act for this purpose in 1833; but in the following year a difference of
opinion with his party as to the diversion of the surplus revenue of the
Irish Church led him to join the Tories. In 1841 he became Colonial
Secretary under Sir Robert Peel, but resigned on Peel's motion for repeal
of the corn laws. In 1851 and 1858 he formed ministries which held office
only for a short period; and again in 1860, when his administration
signalized itself by the reform of the government in India, the conduct of
the Abyssinian War, and the passing of a Bill for electoral reform (1867).
Early in 1868, owing to failing health, he resigned office, recommending
Disraeli as his successor. Lord Derby joined to great ability as a
statesman, and brilliant oratorical powers, a high degree of scholarly
culture and literary ability. Among other works he published a successful
translation of Homer's _Iliad_ in 1864.--Cf. T. E. Kebbel, _English
Statesmen Since the Peace of 1815: Derby_.

DERBY, Edward George Villiers Stanley, seventeenth Earl of, British
politician, born in April, 1865. He served for some years in the Grenadier
Guards, and entered the House of Commons in 1892. In 1895 he became a Lord
of the Treasury, in 1900 Financial Secretary to the War Office, and in 1903
Postmaster-General. He succeeded to the earldom in 1908. Lord Derby became
quite famous as the originator of the _Derby Scheme_, when he was
Director-General of Recruiting in 1915. Under-Secretary for War in 1916, he
succeeded Lloyd George as Secretary when the latter became Premier. In 1918
he was appointed British Ambassador in Paris, but resigned his position in
Sept., 1920, and left Paris in Nov., greatly to the regret of the French
people, to whom he had proved a staunch friend.

DERBY, a municipal, parliamentary, and county borough in England, capital
of Derbyshire, on the Derwent, here crossed by a graceful bridge of three
arches, 115 miles N.N.W. of London. It is pleasantly situated in a wide and
fertile valley open to the south, and is well and regularly built in the
modern quarter. It has some fine public buildings, amongst which are the
churches of All Saints, St. Alkmund, and St. Werburgh, the county hall,
school of arts, and infirmary. There is also a very handsome free library
and museum. The manufactures include silk, cotton, hosiery, lace, articles
in Derbyshire spar, iron castings, and porcelain; and the principal
engineering works of the Midland Railway are here. Derby is one of the
oldest towns in the kingdom, and is supposed to owe its origin to a Roman
station, Derventio. Under the Danes it took the name of Deoraby.
Richardson, the novelist, and Herbert Spencer were natives. It returns two
members to Parliament. Pop. 123,930 (1919).--The county of _Derby_, in the
centre of the kingdom, is about 55 miles long and from 15 to 30 miles
broad; area, 650,369 acres, five-sixths being arable or in permanent
pasture. It exhibits much varied and romantic scenery, the southern and
eastern parts having a fertile soil, while the north-western portion is
bleak, with a rocky and irregular surface. Here is the loftiest range of
the English Midlands, the mountains of the Peak. The Peak itself is 2000
feet high. The principal rivers are the Derwent, the Trent, the Wye, the
Erwash, the Dove, and the Rother. Oats and turnips are important crops, and
dairy-husbandry is carried on to a large extent. Coal is abundant in
various parts of the county, iron-ore is also plentiful, and lead, gypsum,
zinc, fluor-spar, and other minerals are obtained. The manufactures are
very considerable, especially of silk, cotton, and lace, machinery, and
agricultural implements. The county is divided into eight parliamentary
divisions, each with one member. Pop. 683,423.--Cf. J. C. Cox,
_Derbyshire_.

DERBY-DAY, the great annual London holiday, on which is run the horse-race
for the stakes instituted by Lord Derby in 1780. It always takes place on a
Wednesday, being the second day of the grand race-meeting which falls in
the week after Trinity Sunday. The race is run on Epsom Downs, an extensive
Surrey course 15 miles from London. The course is 1-1/2 miles, and the time
usually about 2 minutes, 42 seconds. The entry money of each subscriber is
fifty guineas, and the stakes are run for by three-year-old colts and
fillies entered when yearlings. In the first year of the Derby there were
only thirty-six entries, but they are now very numerous, and the value of
the winner's prize is at least L5000. The race is the most popular of
British sporting events. The Ascot races are patronized by royalty; the
world of fashion is to be found at Goodwood; but Derby-day draws to Epsom a
vast crowd of every class. During the European War the race was suspended,
but a substitute Derby was run at Newmarket from 1915 to 1918. In 1919 the
Derby was again run at Epsom, and was won by Lord Glanely's _Grand Parade_.
In 1920 it was won by Loder's _Spion Kop_, and in 1921 by Joel's
_Humorist_.

DERBY SCHEME, a scheme produced by Lord Derby in 1915 with a view to making
a final effort on behalf of voluntary recruiting. The National Register
(q.v.), taken in August, 1915, of all persons between the ages of fifteen
and sixty-five, had shown that over five million men of military age had
not 'joined up'. As the number of recruits each week fell short of the
number required by Lord Kitchener, Lord Derby, appointed Director of
Recruiting, produced a scheme in which men were divided into 46 groups.
Groups 1 to 23 were for single men, and groups 24 to 46 for married men.
Thus a married man of eighteen was in group 24, whilst a single man of
forty-one was in group 23. The scheme ensured that single men would be
called up first, whilst men who had 'attested' could appeal to a tribunal
and claim temporary or permanent exemption. Two and a half millions offered
themselves in consequence of the Derby Scheme, and two millions were
accepted.

DEREHAM (d[=e]r'am), EAST, a town in England, nearly in the centre of the
county of Norfolk, with manufactures of agricultural implements,
iron-foundries, and a brisk trade. The poet Cowper was buried in the church
there, and George Borrow was born there in 1803. Pop. 5524.

DER'ELICT, a vessel or anything relinquished or abandoned at sea, but most
commonly applied to a ship abandoned by the crew and left floating about.

DERG, LOUGH: (1) a lake, Ireland, county of Donegal, about 3 miles long by
2-1/2 miles broad at the broadest part, and studded with islets, one of
which, called Station Island, is a great resort of Roman Catholic pilgrims;
(2) an expansion of the River Shannon between County Tipperary and Counties
Clare and Galway, about 24 miles long and averaging 2 miles in breadth.

DERHAM, William, English philosopher and divine, born in 1657, died 1735.
He was long rector of Upminster in Essex. In 1696 he published his
_Artificial Clockmaker_. His best-known works are entitled
_Physico-Theology_, _Astro-Theology_, and _Christo-Theology_.

DERMA, or DERMIS, is the true skin lying under the epidermis (cuticle),
which is known in contrast as the scarf-skin.

DERMES'TES, a genus of beetles, one species of which (_D. lardarius_) is
known by the name of bacon-beetle, and is often found in ill-kept ham or
pork shops.

DERMOT MAC MURRAGH, the last Irish King of Leinster, attained the throne in
1140. Having carried off the wife of O'Ruare, Prince of Leitrim, he was
attacked by the latter, and after a contest of some years driven out of
Ireland (1167). He then did homage to the English king, and with the help
of Richard, Earl of Pembroke, recovered his kingdom, but died in the same
year (1170), and was succeeded by Pembroke, who had married his daughter.

DERNBURG, Bernhard, German financier and administrator, born in Darmstadt
in 1865. His father was an editor of the _Berliner Tageblatt_. At the age
of nineteen he came to New York to study banking methods, stayed there for
several years, and on his return to Germany became director of a financial
company. In 1906 he succeeded Prince von Hohenlohe Langenburg as Colonial
Secretary. During his administration the condition of German colonies, and
especially of German East Africa, was greatly improved. From 1914 to 1915
he was a zealous organizer of German propaganda in the United States, but
was subsequently compelled to leave the country.

D['E]ROUL[`E]DE, Paul, French poet, politician, and agitator, born in Paris
in 1846, died there in 1914. Called to the Bar in 1870, he served in the
Franco-Prussian War, and afterwards carried on an active and passionate
agitation for a war of revenge against Germany. He founded the Ligue des
Patriotes, which was suppressed by the Government in 1889, was an ardent
supporter of General Boulanger, and one of the leaders of the reactionary
forces during the Dreyfus case. He sat in the Chamber of Deputies from 1893
to 1895 and from 1898 to 1899. In 1900 he plotted against the Republic, and
sought to bring about a nationalist _coup d'['e]tat_ with a view to
overthrowing the parliamentary constitution. Found guilty, he was sentenced
to ten years' exile, but was allowed to return in 1905, under the law of
amnesty. His works include: _Chants de Soldat_ (1872); _Nouveaux Chants de
Soldat_ (1875); _Chants du paysan_ (1894); _Po['e]sies Militaires_ (1896);
_La Mo[:a]bite_, a religious drama (1880), forbidden by the Censor; and
_L'Helman_, a patriotic play (1877).

DERRICK, a simple kind of crane, chiefly used on board ship, consisting of
a stout pole swung from a mast, and carrying hoisting-tackle at its upper
end. The name is derived from that of a celebrated hangman.

DERRINGER, a small pocket pistol with a short barrel and a large calibre
(usually .41), very effective at short range. It is named after its
inventor, a gun-smith in the United States of America, and would seem to
have been first used in about 1850. It is a single-shot weapon, and so has
largely been superseded by revolvers and automatic pistols.

DER'VISH, or DERVISE (Pers., 'seeking doors' or beggar, and equivalent to
the Ar. _fakir_), a Mohammedan devotee, distinguished by austerity of life
and the observance of strict forms. There are many different orders of
dervishes, the underlying idea of most of them being the revival and
increase of the Moslem faith. Some live in monasteries, others lead an
itinerant life, others devote themselves to menial or arduous occupations.
They are respected by the common people, and the mendicants among them
carry a wooden bowl into which the pious cast alms. One of their forms of
devotion is dancing or whirling about, another is shouting or howling,
uttering the name _Allah_, accompanied by violent motions of the body, till
they work themselves into a frenzy and sometimes fall down foaming at the
mouth. They are credited with miraculous powers, and are consulted for the
interpretation of dreams and the cure of diseases. See
_Mohammedanism._--BIBLIOGRAPHY: E. W. Lane, _Modern Egyptians_; J. P.
Brown, _The Dervishes, or Oriental Spiritualism_; S. M. Zwemer, _Arabia,
the Cradle of Islam_.

DER'WENT, the name of four rivers in England, in Derbyshire, Yorkshire,
Durham, and Cumberland respectively, the last draining Derwentwater Lake.
Also a river in Tasmania.

DERWENTWATER, James Radcliffe, third and last Earl of, one of the leaders
in the rebellion of 1715, born in London 28th June, 1689. The standard of
revolt having been raised in Scotland, Lord Derwentwater commenced the
movement in England on 6th Oct., 1715, but was forced, along with the other
Jacobite nobles, to surrender at discretion on 13th of Nov. He was executed
on Tower Hill 24th Feb., 1716, his estates being confiscated, and in 1735
granted to Greenwich Hospital.

DER'WENTWATER, or KESWICK LAKE, a beautiful lake in Cumberland, England, in
the vale of Keswick. It is about 3 miles in length and 1-1/2 miles in
breadth, and stretches from Skiddaw on the north to the hills of
Borrowdale. Near the south-east corner is the celebrated cascade of Lodore.
Its waters are carried to the sea by the Derwent.

DERZHAVIN (der-zh[:a]'vin), Gabriel Romanovitsh, a Russian lyric poet, born
in 1743, died in 1816. He entered the army as a private soldier,
distinguished himself highly, and was eventually transferred to the Civil
Service, in which he obtained the highest offices. In 1803 he retired from
public life and devoted himself entirely to poetry. One of his most
beautiful poems is _Oda Bog_, or _The Address to the Deity_.

DESAGUADERO (des-[.a]-gw[.a]-d[=a]'r[=o]), a river of Bolivia, in a valley
of the same name, issuing from Lake Titicaca, and carrying its waters into
Lake Aullagas. Also a river in the Argentine Confederation flowing into
Lake Bevedero Grande, and separating the provinces of San Juan and Mendoza.
Desaguadero signifies in Spanish 'a channel of outlet'.

DESAIX DE VEYGOUX (d[.e]-s[=a] d[.e] v[=a]-g[:o]), Louis Charles Antoine, a
distinguished French general, born in 1768 at St. Hilaire d'Ayat, in
Auvergne, died 1800. He was of noble family, and entered the army as a
sub-lieutenant. He distinguished himself greatly in 1794 under Pichegru,
and two years later with the army of the Rhine under Moreau. In 1797 he
accompanied Bonaparte to Egypt, and was very successful in reducing Upper
Egypt. After the Treaty of El Arish he followed Bonaparte to Italy, took
command of the corps of reserve, and, arriving on the field of Marengo at a
critical moment, decided the victory by a brilliant charge, 14th June,
1800. He himself fell, mortally wounded by a musket bullet.

DESAULT (d[.e]-s[:o]), Pierre Joseph, one of the most celebrated surgeons
of France, was born in 1744, and died in 1795. After some experience in the
military hospital at B['e]fort, he went to Paris in 1764, studied under
Petit, and two years afterwards became a lecturer on his own account. His
reputation soon increased, and he became principal surgeon in the Hospital
de la Charit['e], and in 1788 was put at the head of the great H[^o]tel
Dieu in Paris. Here he founded a surgical school, in which many of the most
eminent surgeons of Europe were educated. A digest of his surgical works
was published by Bichat in 1798 (_Oeuvres chirurgicales de Desault_).

DES'CANT, in music, an addition of a part or parts to a subject or melody,
a branch of musical composition which preceded the more modern counterpoint
and harmony, coming into existence at the end of the eleventh or beginning
of the twelfth century.

DESCARTES (d[=a]-k[:a]rt), Ren['e], a great French philosopher and
mathematician, with whom the modern or new philosophy is often considered
as commencing. He was born 31st March, 1596, at La Haye, in Touraine, died
11th Feb., 1650. Educated at the Jesuit College of La Fl[`e]che, where he
showed great talent, he entered the military profession and served in
Holland and in Bavaria. In 1621 he left the army, and after a variety of
travels finally settled in Holland, and devoted himself to philosophical
inquiries. Descartes, seeing the errors and inconsistencies in which other
philosophers had involved themselves, determined to build up a system anew
for himself, divesting himself first of all of the beliefs he had acquired
by education or otherwise, and resolving to accept as true only what could
stand the test of reason. Proceeding in this way, he found (_Meditationes
de Prima Philosophia_) that there was one thing that he could not doubt or
divest himself of the belief of, and that was the existence of himself as a
thinking being, and this ultimate certainty he expressed in the celebrated
phrase "_Cogito, ergo sum_" (I think, therefore I am). Here, then, he
believed he had found the test of truth. Starting from this point Descartes
found the same kind of certainty in such propositions as these: that the
thinking being or soul differs from the body (whose existence consists in
space and extension) by its simplicity and immateriality and by the freedom
that pertains to it; that every perception of the soul is not distinct;
that it is so far an imperfect finite being; that this imperfection of its
own leads it to the idea of an absolutely perfect being; and from this last
idea he deduces all further knowledge of truth. Descartes has been rightly
called the father of modern philosophy, for in him the modern spirit came
into existence. In an age of unrest and ferment his work was that of a
great systematizer. He also contributed greatly to the advancement of
mathematics and physics, the method of co-ordinates, which has
revolutionized geometry, and is of fundamental importance in modern
mathematical physics, being due to him. His system of the universe
attracted great attention in his time. One of his fundamental doctrines was
that the universe is full of matter, there being no such thing as empty
space. On this basis he developed the hypothesis of celestial _vortices_,
immense currents of ethereal matter, by which he accounted for the motion
of the planets (_Principia Philosophiae_, 1644). His works effected a great
revolution in the principles and methods of philosophy. In 1647 the French
court granted him a pension of 3000 livres, and two years later, on the
invitation of Christina of Sweden, he went to Stockholm, where he
died.--BIBLIOGRAPHY: Sir J. P. Mahaffy, _Descartes_; A. Fouill['e]e,
_Descartes_; E. Boutroux, _L'Imagination et les math['e]matiques selon
Descartes_; N. Smith, _Studies in Cartesian Philosophy_; E. S. Haldane,
_Descartes: his Life and Times_.

DESCENT', in law, is the transmission of the right and title to lands to
the heir, on the decease of the proprietor, by the mere operation of law.
The rule determining to whom an estate belongs, on the decease of the
proprietor, is that of consanguinity, or relationship by blood, though with
some exceptions, as in the case of the portion, or the use of a portion, of
a man's property given by the laws of Britain to his widow. The rules of
descent, designating what relations shall inherit, and their respective
shares, will be determined by the genius and policy of the Government and
institutions. Hence the practice of entailments in the feudal system. And
wherever the Government is founded in family privileges, or very intimately
connected with them, as is the case in all Governments where the
hereditarily aristocratical part of the community has a great
preponderance, the sustaining of families will very probably be a
characteristic feature in the code of laws. Thus, in Britain, all the lands
of the father, unless otherwise directed by will, go to the eldest son. (In
England, however, this privilege may shortly be abolished, or the
succession to real estate assimilated to the succession to personal
estate.) In the United States of America this distinction in favour of the
eldest son has been abolished, and the laws there are founded upon the
principle of equal distribution both of real and personal estate among
heirs of the nearest surviving degree. Kindred in blood are divided into
three general classes, viz. 1, descendants; 2, ancestors; 3, collateral
relatives, that is, those who have descended from the same common ancestor.
The civil law computes the degrees by counting the generations up to the
common ancestor, as father, grandfather, great-grandfather; or mother,
grandmother, great-grandmother; and from him or her down to the collateral
relative, as brother, cousin, &c., making the degree of relationship the
sum of these two series of generations. Every person has two sets of
ancestors, the paternal and maternal, and therefore two sets of collateral
relatives. There is also a distinction of collateral kindred, into those of
the whole blood and those of the half blood.--Cf. Pollock and Maitland,
_History of English Law_.

DESCHANEL, Paul Eug[`e]ne Louis, French statesman and tenth President of
the French Republic, born at Brussels on 13th Feb., 1856, where his father
was in exile for opposition to Napoleon III. Educated at the Coll[`e]ge
Sainte Barbe and the Lyc['e]e Condorcet, Paris, he was private secretary
first to De Marc[`e]re, the Home Secretary, in 1876, and then to the
Premier, Jules Simon, in 1877. Sub-prefect at Dreux, Brest, and Meaux, he
was elected to the Chamber of Deputies in Oct., 1885, for Nogent le Rotrou.
In the Chamber of Deputies he soon displayed his power of eloquence, and
eventually became the leader of the Progressive Republicans and exponent of
the separation of Church and State. His authority, which he owed not only
to his eloquence but also to his great tact and correct and dignified
conduct during debates, gradually increased in the Chamber of Deputies, and
even his political enemies admired his courage and his superiority of
intellect. He was consequently elected Vice-President of the Chamber in
1896 and in 1897, and succeeded Henri Brisson as President of the Chamber
in 1898, retaining his office till 1902, when M. L['e]on Bourgeois became
President of the Chamber. Re-elected President of the Chamber in 1912, and
withdrawing his candidature to the presidency of the Republic in favour of
Poincar['e] in 1913, Deschanel retained his post until 1920, when he was
elected President of the Republic by 734 votes. In the meantime, however,
his health had given way, and on 23rd May, 1920, he fell out of a moving
train, an accident resulting in a prolonged illness. A prompt recovery was
at first expected, but this hope soon proved vain. Unable to attend to the
duties of his office, he resigned on 16th Sept., and was succeeded by
Alexandre Millerand. He was elected to the Acad['e]mie Francaise on 18th
May, 1899, and his works include: _La Question du Tonkin_ (1883), _La
Politique Francaise en Oc['e]anie_ (1884), _Orateurs et Hommes d'['E]tat_
(1888), _Figures des Femmes_ (1889), _Figures Litt['e]raires_ (1889), _La
Question Sociale_ (1898), _Quatre ans de Pr['e]sidence_ (1902), _Politique
Int['e]rieure et ['e]trang[`e]re_ (1906), _Paroles Francaises_ (1911), _La
France Victorieuse_ (1919), and _Gambetta_ (1920).

DESEADA (de-se-[:a]'d[.a]), or D['E]SIRADE, one of the Leeward Islands,
belonging to the French, in the Caribbean Sea, about 10 miles long and
hardly 5 miles broad. The soil is in some places black and good, in others
sandy and unproductive. Pop. about 1500.

DESER'TION. In the military sense this implies the act of an officer or
soldier who, either with the intention of not returning at all or of
returning when by reason of his absence it has become impossible for him to
perform a given duty, absents himself from His Majesty's service. The
essence of the offence is intention, and this must be proved to the
satisfaction of the court martial by which the offender is tried. The
distance travelled is no criterion, and a man arrested while leaving the
barracks in disguise may be tried for attempted desertion. In this
connection it should be noted that an attempt to desert, or an attempt to
procure another person to desert, is also an offence, and is punishable
under Section 12 of the Army Act equally with the completed act. As far
back as the middle of the fifteenth century the crime of desertion by a
soldier was made a felony triable by the ordinary law of the land, and with
certain interludes death remained the maximum penalty for desertion for
some 200 years. The present existing Army Act recognizes two degrees of
desertion, i.e. that committed on active service or when under orders for
active service, and that committed under other circumstances. Under the
former heading the maximum punishment is death; under the latter,
imprisonment or penal servitude, according to the number of times the
offence has been committed. A soldier convicted of desertion forfeits the
whole of his service prior to conviction.

DESERTION, in law, the term applied to the act by which a man abandons his
wife or a wife her husband. Such desertion without due cause is, in
England, ground for a judicial separation. Property a wife may have
acquired since desertion is protected against her husband, and he may be
forced to provide for her maintenance. By Scottish law, where either the
husband or wife has deserted and remained separate without due cause for
four years, divorce may be obtained.

DESHOULI[`E]RES (d[=a]-s[:o]l-y[=a]r), Antoinette du Ligier de Lagarde, a
French woman of much literary reputation in the seventeenth century, born
1638, died 1694. She was the centre of attraction in the best circles of
the period, and was elected a member of several learned societies. She
wrote in the _Mercure Galant_ under the name of Amaryllis, and Boileau has
described her in his tenth _Satire_. Among her works are odes, eclogues,
idyls, and a tragedy (_Genseric_).

DESICCATION, a process of dispelling moisture by the use of air, heat, or
chemical agents such as chloride of calcium, quicklime, oil of vitriol, and
fused carbonate of potash.--_Desiccation cracks_, in geology, are the
fissures caused in clayey beds by the sun's heat, and seen in various rock
strata.

DESIGN, thought, arrangement, or grouping, imagination or invention in
works of art. A design is a composition or invention, pictorial,
architectural, or decorative. It may be simply an imperfect sketch, as a
record of a first thought; or it may be a fully matured work, as a cartoon
in preparation for fresco painting, or a drawing to illustrate a book.

DESMIDIA'CEAE, or DESMIDIE'AE, a family of microscopic, fresh-water Green
Algae, group Conjugatae. They are green gelatinous plants composed of
variously formed cells having a bilateral symmetry, which are either free,
or in linear series, or collected into bundles or into star-like groups,
and embedded in a common gelatinous coat. Desmidiaceae differ from
Diatomaceae in their green colour and absence of silica.

DESMO'DIUM, a large genus of leguminous plants, sub-ord. Papilionaceae,
natives of tropical and sub-tropical countries. _D. gyrans_ is the
telegraph plant, so called from the curious movements performed by the two
small lateral leaflets of each leaf, which, at high temperatures, wave up
and down like the arms of a semaphore.

DES MOINES (d[.e] moin), a city of the United States, capital of the state
of Iowa and of Polk County, on the Des Moines River, about 350 miles west
of Chicago. Among its chief buildings are the new State house, the State
arsenal, university, and opera-houses. There are coal-mines in the
vicinity, and the manufactures and other industries are varied and rapidly
increasing. Pop. 104,052 (1917).

DES MOINES, the largest river in the state of Iowa, rises in the S.W. of
Minnesota, and flows in a south-easterly direction till it falls into the
Mississippi about 4 miles below Keokuk, after a course of 300 miles.

DESMONCUS, a genus of tropical American climbing palms, scrambling by means
of stout hooks which are modified leaflets.

DESMOULINS (d[=a]-m[:o]-lan), Beno[^i]t Camille, born in 1760, was
conspicuous during the first period of the French Revolution. He was
amongst the most notable of the pamphleteers and orators who urged the
multitude forward in the path of revolution. He, along with others,
prepared the plan for the taking of the Bastille (July, 1789), was one of
the founders of the club of Cordeliers, and the promoter of the assembly in
the Champ de Mars. In 1789 he began his career as a journalist by the issue
of a weekly publication (_Les R['e]volutions de France et de Brabant_). In
1793 he gave his vote for the death of the king. Having become closely
connected with Danton and the party of opposition to Robespierre, and
inveighing against the reign of blood and terror, he was arrested on the
order of the latter on 30th March, 1794, tried on the 2nd April, and
executed on the 5th. He met his fate in an agony of despair.--Cf. F. A.
Aulard, _Les Orateurs de la L['e]gislative et de la Convention_.

DESNA, a river in the Ukraine, which rises in the government of, and about
50 miles east of the town of Smolensk, flows through the governments of
Orel and Tshernigov till it joins the Dnieper near Kiev. It is 500 miles in
length and navigable nearly throughout.

DE SOTO, Hernando, a Spanish explorer and discoverer of the Mississippi,
born about 1496, died in 1542. He accompanied expeditions to the New World
under Davila and Pizarro, and played a distinguished part in the conquest
of Peru. In 1536 he led an expedition to Florida, whence after many
difficulties he penetrated to the Mississippi, where he was attacked with
fever and died.--The name De Soto has been given to a county in the N.W. of
Mississippi, and to several places in the United States.

DES'POT (Gr. _despot[=e]s_), originally a master, a lord; at a later period
it became an honorary title which the Greek emperors gave to their sons and
sons-in-law when governors of provinces. At present _despot_ means an
absolute ruler, and in a narrower sense a tyrannous one.

DESSALINES (d[=a]-s[.a]-l[=e]n), Jean Jacques, Emperor of Hayti, born in
Africa about 1760. He was a slave in 1791, when the insurrection of the
blacks occurred in that island, but was set free along with the other
slaves in St. Domingo in 1794. His talents for war, his courage, and
unscrupulous conduct raised him to command in the insurrections of the
coloured people, and after the deportation of Toussaint-L'Ouverture, and
the subsequent evacuation of the island by the French, Dessalines was
appointed Governor-General for life with absolute power; and the year
following (1804) was declared Emperor with the title of Jacques I. But his
rule was savage and oppressive, and both the troops and the people, sick of
his atrocities, entered into a conspiracy against him, and on 17th Oct.,
1806, he was slain by one of his soldiers.

DESSAU (des'ou), a town in Germany, capital of the former Duchy of Anhalt,
in a beautiful valley on the left bank of the Mulde, mostly well built,
with fine squares and many handsome buildings. The manufactures consist of
woollens, woollen yarn, carpets, machinery, and tobacco. The former ducal
palace has a picture-gallery and interesting relics and antiquities. Pop.
56,606.

DE STENDHAL. See _Beyle, Marie-Henri_.

DESTER'RO, now FLORIANOPOLIS, a seaport of Brazil, capital of the state of
Santa-Catharina. The harbour, next to Rio de Janeiro, is the best in
Brazil. Pop. 9000.

DESTRUCTORS, REFUSE, the apparatus or plant used in the cremation of house
and factory refuse. Formerly refuse from large towns and populous areas was
either disposed of for manurial purposes or spread over waste land, where
its presence speedily became a nuisance. The consequent danger to the
public health, coupled with the increasing difficulty and cost of its
disposal, led to attempts being made to deal with it by more sanitary
methods. The first attempts to cremate it in a closed furnace on a large
scale, made in London in 1870, were not successful, primarily owing to the
unscientific design of the furnace. In 1877, however, there was built in
Manchester the forerunner of the modern destructor, to the designs of the
late Mr. Alfred Fryer. This consisted of two simple cells, the primary
feature of the design being 'the charging of the refuse into the back of
the furnace, and drawing out the resulting clinker from the front'. With
certain modifications, this design is in general use at the present time.
The basic principles underlying their scientific design may be summed up in
the following points: (_a_) Charging at regular intervals, the refuse being
dumped into a hopper, and fed into the back of the furnace as a charge,
means being taken to prevent undue escape of gases. The moisture having
evaporated, the material may then be raked forward onto the fire-bars,
where combustion takes place. (_b_) To avoid nuisance, the resulting gases
must be inodorous, which requires a temperature of about 2000degF. This is
obtained by passing the products of combustion over the hottest portion of
the fire, prior to their passage into the main flue. (_c_) Removal of the
fine dust and particles in suspension in the flue gases by means of spiral
chambers at the base of chimney. (_d_) Provision of forced draught. A
well-designed plant should show little, if any, suspended matter in the
gases on emission from the chimney. Formerly no use was made of the heat
generated, but modern installations now invariably have steam-raising plant
incorporated in the design. This power is commonly used to generate
electricity. Some portion may be utilized in crushing and screening the
clinker, which is frequently used in making slab-paving, or ground fine and
used as a substitute for sand in mortar. The following data may be found of
service: (_a_) 60 per cent of the average refuse is combustible. (_b_) The
calorific value may be taken as being one-seventh that of good steam-coal.
(_c_) 100 electrical units may be obtained from each ton of refuse
consumed. (_d_) With forced draught, as much as 100 lb. of refuse has been
burnt per square foot of grate area per hour. (_e_) 250 tons of refuse per
annum per 1000 of population may be estimated for.--BIBLIOGRAPHY: W. H.
Maxwell, _Removal and Disposal of Town Refuse_; Kempe, _Engineer's Year
Book_.

DESTUTT DE TRACY, Antoine Louis Claude, French philosophical writer, born
in 1754 of a family of Scottish extraction, died in 1836. As a philosopher
he belonged to the Sensationalist school, and considered all our knowledge
to be derived originally from sensation. He has been called the logician
and metaphysician of the school of Condillac. Among his chief works are:
_Id['e]ologie_ (1801), _Logique_ (1805), and _Trait['e] de la Volont['e]
_(1815).

DETER'MINANT, a mathematical expression which appears in the solution of a
system of equations of the first degree.

The solution of the equations

    a_1x + b_1y = c_1,
    a_2x + b_2y = c_2,

is given by

    x(a_1b_2 - a_2b_1) = c_1b_2 - c_2b_1,
    y(a_1b_2 - a_2b_1) = a_1c_2 - a_2c_1.

Here x and y have the same coefficient a_1b_2 - a_2b_1. This is called a
determinant of the second order, and is written

    |a_1, b_1|
    |a_2, b_2|.

We may now write

     |a_1, b_1|   |c_1, b_1|
    x|        | = |        |
     |a_2, b_2|   |c_2, b_2|.

Similarly with three equations,

    a_1x + b_1y + c_1z = d_1,
    a_2x + b_2y + c_2z = d_2,
    a_3x + b_3y + c_3z = d_3,

we find

    x{a_1(b_2c_3 - b_3c_2) + a_2(b_3c_1 - b_1c_3) + a_3(b_1c_2 - b_2c_1)}
    = d_1(b_2c_3 - b_3c_2) + d_2(b_3c_1 - b_1c_3) + d_3(b_1c_2 - b_2c_1)

The coefficient of x, and the right-hand member, are here determinants of
the third order, and the result is written

     |a_1, b_1, c_1|   |d_1, b_1, c_1|
    x|a_2, b_2, c_2| = |d_2, b_2, c_2|
     |a_3, b_3, c_3|   |d_3, b_3, c_3|.

When the coefficient of x is expanded fully, it consists of six terms, half
of them positive and half negative, each term being the product of three
letters, one from each row and one from each column. Thus in every term,
such as the leading term a_1b_2c_3, the three letters a, b, c, and the
three suffixes 1, 2, 3, all occur once and once only. With regard to the
signs, we note that if the letters a, b, c are always kept in this order,
an interchange of two suffixes changes the sign. Thus, e.g. we may start
from + a_1b_2c_3, interchange the suffixes 2 and 3, and thus find -
a_1b_3c_2. Again, if in the latter term - a_1b_3c_2 we interchange the
suffixes 1 and 3, we find + a_3b_1c_2. It is easy to verify that after any
number of interchanges of this kind a particular term will always come up
with the same sign.

Thus the interchange of two rows (and similarly of two columns) changes the
sign of the determinant. It follows that if two rows (or two columns) are
identical, the determinant is zero. It is now easy to define functions of
n^2 letters, arranged in a square array of n rows and n columns, with
similar properties to those observed above in the case of determinants of
the third order. Determinants are very extensively used in higher algebra,
co-ordinate geometry, and other branches of mathematics. See also
_Elimination_.--BIBLIOGRAPHY: C. Smith, _Algebra_; T. Muir, _Theory of
Determinants_.

DETERMINANTS, in biology, the name applied by Weismann to hypothetical
particles contained in the nuclei of germ-cells, which determine the
existence and nature of the various parts of the body of the embryo. The
theory of determinants is part of an elaborate attempt to explain the facts
of heredity on a mechanical basis. Although it may serve as a working
hypothesis, it is regarded with disfavour by many experts, and may be
regarded as an elaboration of the 'provisional theory of pangenesis'
advanced by Darwin.

DETER'MINISM, a term employed by recent writers, especially since J. Stuart
Mill, to denote a philosophical theory which holds that the will is not
free, but is invincibly determined either--according to the older form of
the theory--by a motive furnished by Providence, or--according to the
modern form--by the aggregation of inherited qualities and tendencies.
Biological determinism maintains that each of our voluntary acts finds its
sufficient and complete cause in the physiological conditions of the
organism. Psychological determinism ascribes efficiency to the psychical
antecedents. Opposed to determinism is the doctrine of indeterminism or
indifferentism. See _Free-will_.

DET'INUE, in law, the form of action whereby a plaintiff seeks to recover a
chattel personal unlawfully detained.

DET'MOLD, a town, Germany, capital of Lippe-Detmold, on the left bank of
the Werra, 50 miles south-west of Hanover, with a new and an old palace (or
castle), good public library, and museum. In the vicinity a colossal statue
has been erected to the Hermann or Arminius who overthrew the Roman general
Varus and his legions in a battle which was fought near this place. The
Senner race of horses is bred near Detmold. Pop. 14,295.

DET'ONATING POWDERS, certain chemical compounds which, on being exposed to
heat or suddenly struck, explode with a loud report, owing to one or more
of the constituent parts suddenly assuming the gaseous state. The chloride
and iodide of nitrogen are very powerful detonating substances. Mercuric
fulminate or fulminating mercury (C_2HgN_2O_2) explodes violently when
forcibly struck or when heated to 180degF. It is used for making percussion
caps, and in detonators for exploding guncotton and nitroglycerin
preparations. Silver fulminate (C_2Ag_2N_2O_2) explodes even more
violently.

DETONATING TUBE, a species of eudiometer, being a stout glass tube used in
chemical analysis for detonating gaseous bodies. It is generally graduated
into centesimal parts, and perforated by two opposed wires for the purpose
of passing an electric spark through the gases which are introduced into
it, and which are confined within it over mercury and water.

DETROIT (de-troit'; Fr. _d['e]troit_, a strait or channel), a flourishing
port and city of the United States, the largest town in Michigan, situated
on the Detroit River, connecting Lakes Erie and St. Clair. The site rises
gradually from the river, and the city is generally well built. Among the
chief edifices are the city hall, the house of correction, post office, and
opera-house. Detroit has increased very rapidly, a fact which is due to its
admirable position for trade, and to its connections with a region into
which a constant tide of emigration is flowing. Among the industrial
establishments are saw-mills, flour-mills, building-yards for ships and
boats, foundries, tanneries, blast-furnaces, pork-packing establishments,
tobacco and cigar manufactories, and locomotive works. The harbour is one
of the finest in the United States, and has a depth of water sufficient for
the largest vessels. Detroit owes its origin to the French, who visited the
site in 1648 and erected the Fort Pontchartrain in 1701. Pop. 688,028
(1919).

DETROIT RIVER, or STRAIT OF ST. CLAIR, a river or strait of North America
which runs from Lake St. Clair to Lake Erie. It is 28 miles long, and of
sufficient depth for the navigation of large vessels. It is about 3/4 mile
wide opposite Detroit and enlarges as it descends.

DETTINGEN (det'ing-en), the name of several places in Germany, amongst
which is a village of Bavaria, on the right bank of the Main, famous for
the victory gained by the English and Austrians under George II of England
over the French in 1743.

DEUCA'LION, in Greek mythology, the son of Prometheus and father of Hellen,
ancestor of the Hellenes. According to tradition he saved himself and his
wife, Pyrrha, from a deluge which Zeus had sent upon the earth, by building
a ship which rested upon Mount Parnassus. To repair the loss of mankind
they were directed by an oracle to throw stones behind them; the stones
thrown by Deucalion became men, those thrown by Pyrrha women.

DEUS EX MACHIN[^A] (mak'i-na; Lat., 'a god out of the machine'), a phrase
used to designate the resorting to supernatural causes to explain phenomena
that one is not able to account for by natural means. The phrase is taken
from the practice on the classical stage of introducing a god from above by
means of some mechanical contrivance in order to effect a speedy
_d['e]nouement_ of the plot.

DEUTERONOMY (Gr. _deuteronomion_, the second law), the name of the fifth
book of the _Pentateuch_ (q.v.). Until the seventeenth century it was
believed to have been written by Moses, but now it is generally held to be
a compilation, the bulk of it having been written in the reign of Manasseh,
or according to other scholars in the reign of Josiah. At any rate the book
was discovered or rediscovered while Josiah was king (_2 Kings_, xxii). It
represents the latest phase in the development of the teaching of Moses.
Its chief aim is to combat idolatry, and to concentrate the religious life
of the country at Jerusalem. It has a lofty moral tone. Of one passage (vi,
4 and 5) Christ said: "On these two commandments hang all the law and the
prophets" (_Matt._ xxii, 40), and all His answers to the Tempter in the
Wilderness are taken from the book of _Deuteronomy_.

DEUTZ (doits), a town in Prussia, on the right bank of the River Rhine,
opposite the city of Cologne, with which it communicates by a bridge. It is
strongly fortified as part of the defences of Cologne, in which it is now
incorporated. There are some manufactories of porcelain and glass, also an
iron-foundry and machine-works. Pop. 17,060.

DEUT'ZIA, a genus of plants, nat. ord. Saxifragaceae, containing seven or
eight species, all of which are interesting from the beauty of their
flowers, some of them favourite garden and greenhouse plants. They are
small shrubs indigenous to China and Japan, and Northern India.

DE VALERA, Eamon, Irish Republican, born at New York in 1883, his father
being a Spaniard, and his mother an Irishwoman. Educated at the Royal
University of Ireland, he early became known for his revolutionary
activities. In 1917 he was elected president of the Gaelic League and was
arrested as an agitator. Elected to Parliament in 1918, while he was in
prison, he refused to take his seat. He was elected 'President' of the
so-called 'Irish Republic' soon afterwards, and in Feb., 1919, escaped from
prison and reached New York, where he started an active propaganda and
began to raise funds for the Irish cause. He returned to Ireland in 1921.

DEV'ENTER, an old town in Holland, province of Overijssel, 8 miles north
from Zutphen, at the confluence of the Schipbeek and Ijssel. Its industries
embrace carpets, cast-iron goods, printed cottons, hosiery, and a kind of
cake called _Deventer Koek_. It has a large export trade in butter. Pop.
32,483 (1918).

DEV'ERON, a river of Scotland belonging to Aberdeenshire and Banffshire, 60
miles long. It flows into the Moray Firth at Banff.

DEVIATION OF THE COMPASS, the deflection of a ship's compass needle from
the magnetic meridian, caused by adjacent iron. Hard iron is very retentive
of a magnetic state, and is specially liable to become magnetized during a
hammering process, as in the building of the ship. Soft iron easily
receives or loses magnetism, and its magnetic state varies with every
shifting of the ship's head. The effect of the former can be counteracted
by magnets suitably placed near the compass, that of the latter by spheres
of soft iron. The ship is swung, and the compass errors found in the
various positions. The effects of the several contributing causes can then
be separated, and the nature of the correctors necessary inferred with
considerable accuracy. When these have been provided, the small residual
errors for different positions of the ship are determined, and a table is
constructed from which the navigator may read the slight correction to
apply to the indication of his compass in steering any desired course.

DEVICE', a name common to all figures, ciphers, characters, rebuses, and
mottoes which are adopted by a person or a family by way of badge or
distinctive emblem, often a representation of some natural body, with a
motto or sentence applied in a figurative sense.

DEVIL (Gr., _diabolos_, a slanderer or accuser), in theology, the name
given to a fallen angel, who is the instigator of evil, and the ruler of
darkness. Most of the old religions of the East acknowledge a host of
devils. The doctrine of Zoroaster, who adopted an evil principle called
Ahriman, opposed to the good principle and served by several orders of
inferior spirits, spread the belief in such spirits among the people. The
Greek mythology did not distinguish with the same precision between good
and bad spirits. With the Mohammedans _Eblis_, or the devil, was an
archangel whom God employed to destroy a pre-Adamite race of _jinns_, or
genii, and who was so filled with pride at his victory that he refused to
obey God. The Satan of the New Testament is also a rebel against God. He
uses his intellect to entangle men in sin and to obtain power over them.
But he is not an independent self-existent principle like the evil
principle of Zoroaster, but a creature subject to omnipotent control. The
doctrine of Scripture on this subject soon became blended with numerous
fictions of human imagination, with the various superstitions of different
countries, and the mythology of the pagans. The excited imaginations of
hermits in their lonely retreats, sunk as they were in ignorance and unable
to account for natural appearances, frequently led them to suppose Satan
visibly present; and innumerable stories were told of his appearance, and
his attributes--the horns, the tail, the cloven foot,--distinctly
described. Theology has always treated the devil from a psychological or
ethical standpoint. From the New Testament we hardly learn more regarding
the devil than that he has a distinct personality; that he is a spirit or
angel who in some way fell; that he is devoid of truth and of all moral
goodness, always warring against the soul of man and leading him towards
evil; that he has demons, spirits, or angels under him who work his will,
and enter into or 'possess' men; but of his or their origin, original
state, or fall, we really learn nothing.--BIBLIOGRAPHY: Mayer, _Historia
Diaboli_; Lecanu, _Histoire de Satan, sa chute, son culte, ses
manifestations, ses oeuvres_; Carus, _History of the Devil_.

DEVIL-FISH, the popular name of various fishes, one of them being the
angler. Among others the name is given to several large species of ray
(especially _Ceratoptera Vampyrus_ which attains the breadth of 20 feet)
occasionally captured on the Atlantic and Pacific coasts of America, and
much dreaded by divers, whom they are said to devour after enveloping them
in their vast wings. During gales of wind or owing to strong currents these
immense fish are driven into shoal water, and, being unable to extricate
themselves, fall an easy prey to the fishermen, who obtain considerable
quantities of oil from their livers. The name is also applied to the larger
eight-armed cephalopod molluscs belonging to _Octopus_ and allied genera. A
combat with one of these is described in Victor Hugo's _Toilers of the
Sea_.

DEVIL'S BIT, the common name of a British species of scabious (_Scabi[=o]sa
succ[=i]sa_), nat. ord. Dipsaceae. It has heads of blue flowers nearly
globular, and a fleshy root, which is, as it were, cut or bitten off
abruptly. It flowers from June to October, and is common in meadows and
pastures.

DEVIL'S BRIDGE, a name for several bridges in wild situations; one being in
Cardiganshire, spanning a gorge of the Mynach; another in Switzerland, over
which the St. Gothard Railway crosses the Reuss.

DEVIL'S PARLIAMENT, the name given to a Parliament convened by Henry VI,
which met at Coventry in 1459 and unjustly accused the Duke of York of high
treason.

DEVIL'S PUNCH-BOWL, a small lake of Ireland, near the Lakes of Killarney,
between 2000 and 3000 feet above the sea, supposed to be the crater of an
ancient volcano. The name is also given to Highcomb Bottom, a glen in
Surrey.

DEVIL'S WALL, in the south of Germany, a structure which was originally a
Roman rampart, intended to protect the Roman settlements on the left bank
of the Danube and on the right bank of the Rhine against the inroads of the
Teutonic and other tribes. Remains of it are found from the Danube, in
Bavaria, to Bonn, on the Rhine.

DEVIL-WORSHIP, the worship paid to the devil, an evil spirit, a malignant
deity, or the personified evil principle in nature, by many of the
primitive tribes of Asia, Africa, and America, under the assumption that
the good deity does not trouble himself about the world; or that the powers
of evil are as mighty as the powers of good, and have in consequence to be
bribed and reconciled. There is a sect called devil-worshippers inhabiting
Armenia and the valley of the Tigris, who pay respect to the devil, to
Christ, and to Allah or the supreme being, and also worship the sun.

DEVISE, in law, usually the disposition of real estate by will, but also
sometimes applied to any gift by will, whether of real or personal estate.

DEVITRIFICATION. Glass which has been kept for a considerable time at a
temperature just below its fusion-point gradually becomes opaque or
crystalline in appearance; this phenomenon is spoken of as
_devitrification_. Poor glass, badly prepared window-glass, and glass which
has been subjected to strain tend to devitrify on exposure to air, some of
the ingredients separating in a crystalline form.

DEVI'ZES, a town in England, county of Wilts, giving name to a
parliamentary division, finely situated on a commanding eminence, 82 miles
west by south of London. The name is derived from the Lat. _divisae_
(_terrae_, divided lands), because the ancient castle of Devizes was built
at the meeting-place of three different manors. Agricultural engines and
implements are made, and malting is carried on. Pop. 6740.

DEVON, or DEVONSHIRE, a maritime county in the s.w. of England, its
northern coast being on the Bristol Channel and its southern on the English
Channel; area, 1,671,364 acres, the county being the third largest of
England. Its principal rivers are the Torridge and the Taw, flowing north
into the Bristol Channel; and the Exe, Axe, Teign, Dart, and Tamar, flowing
into the English Channel. From Exeter to the confines of Cornwall extends
the wide and barren tract called Dartmoor; but the vale of Exeter,
comprising from 120,000 to 130,000 acres, and the south extremity of the
county called _South Hams_, limited by a line drawn from Torbay to Plymouth
Sound, are amongst the most fertile districts of England. Tin, lead, iron,
copper, manganese, granite, and the clay used by potters and pipe-makers
are the chief mineral products. The geological formation of the Old Red
Sandstone is so largely developed that the term Devonian has to some extent
become its synonym. Agriculture is in a somewhat backward state, owing,
probably, to the general preference given to dairy husbandry, for which the
extent and richness of its grass-lands make the county most suitable.
Wheat, barley, beans, pease, and potatoes are the principal crops. About
three-fourths of the county is under crops or in pasture. There is a large
trade in butter, cheese, and live-stock, and the 'clotted' cream and cider
of Devonshire are well known as specialities of the county. There are seven
parliamentary divisions, each with one member. Pop. 699,703.--BIBLIOGRAPHY:
_Victoria County History, Devonshire_; F. J. Snell, _Devonshire,
Historical, Descriptive, and Biographical_.

DEVO'NIAN SYSTEM, in geology, a name originally given to rocks in
Devonshire and Cornwall, intermediate between the Silurian and
Carboniferous strata, and consisting of sandstones, calcareous slates and
limestones, &c. They are divided into lower, middle, and upper series, the
middle most abounding in fossils, including corals, crinoids, brachiopods,
and molluscs. Devonian rocks occupy a large area in Central Europe, as well
as in the United States, Eastern Canada, and Nova Scotia. The terrestrial
and lacustrine equivalents are known as the Old Red Sandstone.

DEV'ONPORT, formerly a county borough and port of England, county of Devon,
contiguous to Plymouth. It is the seat of one of the royal dockyards, and
an important naval and military station. A bastioned wall and fosse defend
the town on the north-east and south sides, while the sea entrance is
protected by heavy batteries on Mount Wise. Connected with the dockyards
and fortifications are the gun wharf, foundries, machine-works, rope-walks,
store-houses, and naval and military barracks. It has no special trade
beyond that connected with the dockyards and Government works. Formerly a
parliamentary borough, returning two members to Parliament, Devonport now
gives its name to a parliamentary division of Plymouth, with which it is
amalgamated since Nov., 1914. Pop. 84,370.

DEVONSHIRE, Spencer Compton Cavendish, eighth Duke of, long known as
Marquess of Hartington, born in 1833, died 1908. He was the eldest
surviving son of the seventh Duke of Devonshire, whom he succeeded in the
dukedom in 1891. He was educated at Trinity College, Cambridge, where he
graduated as M.A. in 1854. He was attached in 1856 to Earl Granville's
Russian mission, and in 1857 was elected as a Liberal one of the members
for North Lancashire. In 1863 he was for a short time a Lord of the
Admiralty, and he then became Under-Secretary for War, being raised to
Cabinet rank as War Secretary in 1866. In 1868 he lost his seat for North
Lancashire, but became Postmaster-General under Gladstone, and was returned
for the Radnor boroughs. In 1871 he was appointed Chief Secretary for
Ireland. He went out with the Gladstone ministry in 1874, and on
Gladstone's retirement he became the leader of the Liberal party. On the
fall of the Conservative Government in 1880 he was elected for North-East
Lancashire, and became Secretary for India under Gladstone, being
transferred to the War Office in 1882. In the general election of 1885 he
was returned for the Rossendale division of Lancashire. He strenuously
opposed Gladstone's Home Rule Scheme of 1886, and became the leader of the
Liberal Unionists, but long declined to take office in the Cabinet. In
1895, however, he became Lord President of the Council, and from 1900 to
1902 he was President of the newly-instituted Board of Education. In 1903
he withdrew from co-operating with Mr. Balfour as Premier, mainly because
he disliked the fiscal changes proposed by Chamberlain. He then accepted
the position of head of the Free-Trade Unionists.

DEW is the name given to the minute drops of water which at certain times
appear by night upon grass, flowers, foliage, and other surfaces which
readily radiate heat. The first attempts at a scientific explanation of dew
were made early in the nineteenth century, when Dr. Wells propounded his
theory on the subject. According to this, the origin is to be found in the
moisture previously contained in a vaporous state in the atmosphere. During
the day the earth both absorbs and emits heat, but by night its supply of
warmth is cut off, while it continues, under favouring circumstances, to
lose heat by radiation into surrounding space. For any given state of the
atmosphere, in respect of the amount of aqueous vapour it contains in a
specified volume, there is a certain temperature at which it can hold just
that amount and no more in suspension. If it be cooled to that temperature,
it begins to deposit its moisture in the liquid form, and if the cooling
proceeds further, more and more is deposited. This particular temperature
is the _dew-point_ appropriate to the given state of humidity of the air.
If the dew-point is below 32degF., the vapour will, when the dew-point is
reached, pass directly into the solid form and be deposited as hoar-frost.
While there is a certain amount of truth in the foregoing theory, it does
not contain the whole facts of the case. Dr. John Aitken, of Falkirk,
Stirlingshire, established by experiments that in most cases probably the
dew found on plants does not come mainly from the atmosphere. To some
extent it exudes from the plants themselves. They derive moisture from the
soil, and in the process of supplying their tissues it passes to their
outer surfaces, whence in the daytime it is evaporated into the air. By
night the fall of temperature checks evaporation of this moisture, and when
it reaches their surfaces, it may remain there in the form of dew-drops.
Also, moisture is condensed out of the atmosphere upon the cooler plant
surfaces, but even this has more often been yielded not long before to the
atmosphere through the medium of the plant tissues, so that upon the whole
the plants play a much more important part in the process than had been
supposed. Dew is most copiously produced when there is a large difference
between the day and night temperatures. Hence it is favoured by the absence
of clouds, which would throw back much of the heat radiated from the earth.
Other favouring circumstances are a still condition of the atmosphere, good
radiating surfaces, and an abundant supply of moisture in the soil.

DEWAR (d[=u]'[.a]r), Sir James, scientist, born at Kincardine-on-Forth,
1842, educated at Dollar Academy, Edinburgh University--where he was
assistant to Lord Playfair when professor of chemistry--and Ghent. In 1873
he was elected Jacksonian professor of experimental philosophy at
Cambridge, an office which he still holds, and in 1879 a professorial
fellow of St. Peter's College. In the latter year he also became Fullerian
professor of chemistry at the Royal Institution, London. He is a fellow of
the Royal Society, has been awarded several medals and prizes for his
scientific researches, including the Rumford medal in 1894 for his
investigations into the properties of matter at its lowest temperatures,
this branch of science, with which the liquefaction of air and gases is
connected, being peculiarly his own. He was the first to reduce hydrogen
gas to the liquid and solid form. Together with Sir F. Abel, he was the
discoverer of cordite. He is an honorary graduate of several universities,
a late president of the Chemical Society and vice-president of the Royal
Society, and was president of the British Association in 1902. He has
contributed numerous papers to the proceedings of the learned societies of
Great Britain, and was knighted in 1904. His collected papers on
spectroscopy appeared in 1915.

DEWAR FLASK, a flask devised by Dewar for the examination of liquefied
gases. It consists of an inner vessel surrounded by a vacuum, which much
reduces loss or gain of heat by the liquid. The principle now finds
practical application in the 'Thermos Flask'.

DEW['A]S, a native state of Central India consisting of two combined states
with two chiefs. Total pop. 250,000. Dew['a]s, the chief town, has a pop.
of 5200.

DEWBERRY (_Rubus coesius_), a European plant belonging to the ord. of the
Rosaceae, and to the same genus as the bramble, from which it is
distinguished by its smaller berries, with fewer grains, and by the bloom,
resembling dew, with which they are covered, and from which the plant
derives its name. It is common in some parts of England. The Canadian
dewberry (_R. procumbens_) yields a much superior fruit.

DE WET, Christian Rudolf, Boer general, born 1854 in the Orange Free State.
His father removing into the Transvaal, he fought as a field-cornet at
Majuba. As member of the Volksraad (1889-97) he helped to draw the two
Dutch republics together, and in the South African War commanded first in
Natal, and then in the west under Cronje, whose rescue at Paardeberg he
attempted, but unsuccessfully. After March, 1900, he distinguished himself
by his attacks on the British lines of communication, and by his skill in
evading capture. He became commander-in-chief of the Free State forces, and
was the only undefeated Boer general at the end of the war, after which he,
with Louis Botha and Delarey, came to Europe to collect funds for his
countrymen. A member of the Legislative Assembly and Minister of
Agriculture, Orange Free State, from 1907 to 1914, he joined the rebellion
at the outbreak of the European War. Captured at Waterburg on 1st Dec., he
was sentenced to a fine of L2000 and six years' imprisonment, but was soon
released. He published _The Three Years' War_ in 1902.

DEWEY, George, American naval officer, born at Montpellier, Vermont, 26th
Dec., 1837, died 16th Jan., 1917. He began active service in the
Mediterranean squadron, and in 1862, under Farragut, he was present at the
passage of Forts Jackson and St. Philip. Lieutenant-commander in 1865,
commander in 1872, he was in command of the Asiatic squadron in 1898, when
he destroyed the Spanish fleet at Manila on 1st May. He was made Admiral of
the Navy and was thanked by Congress. From 1900 till his death he was
President of the General Board of the Navy.

DEWEY, John, American philosopher and psychologist, born at Burlington,
Vermont, 20th Oct., 1859. Educated at the University of Vermont, he
received his Ph.D. degree from Johns Hopkins University. Professor of
philosophy at the Universities of Minnesota, Michigan, and Chicago, where
he was also director of the School of Education, he became professor of
philosophy at Columbia University in 1904. He is one of the two (William
James being the other) American leaders of _pragmatism_, a philosophical
conception according to which questions that have no bearing on experience
and on life have no significance whatever, and are meaningless. (See
_Pragmatism._) His works include: _Outlines of a Critical Theory of Ethics_
(1881), _Study of Ethics_ (1894), _My Pedagogical Creed_ (1897), _The
School and Society_ (1900), _Studies in Logical Theory_ (1903), _How we
Think_ (1909), _Interest and Effort in Education_ (1913), _Democracy and
Education_ (1916), _Letters from China and Japan_ (1920).

DE WINT, Peter, English landscape painter in water-colours, born 1784, died
1849. He studied in the schools of the Royal Academy, where he occasionally
exhibited; but most of his pictures were shown in the exhibitions of the
Water-colour Society. English scenery was his favourite subject. He
occasionally painted in oil with marked success. Several of his pictures
are in the National Gallery and the Victoria and Albert Museum.

DE WITT, Jan, Grand-Pensionary of Holland, celebrated as a statesman and
for his tragical end, was the son of Jacob de Witt, burgomaster of Dort,
and was born in 1625. He became the leader of the political party opposed
to the Prince of Orange, and in 1652, two years after the death of William
II, was made Grand-Pensionary. In 1665 the war with England was renewed,
and conducted by De Witt with great ability till its termination in 1665.
In 1672 Louis XIV invaded the Spanish Netherlands and involved Holland in
war. De Witt's popularity, already on the decline, suffered still further
in the troubles thus occasioned, and he felt it necessary to resign his
office of Grand-Pensionary. At this time his brother Cornelius, who had
been tried and put to torture for conspiring against the life of the young
Prince of Orange, lay in prison. Jan de Witt went to visit him, when a
tumult suddenly arose amongst the people, and both brothers were murdered,
20th Aug., 1672. De Witt was a man of high character, simple and modest in
all his relations.--Cf. Motley, _History of the United Netherlands._

DEW-POINT, the temperature at which the air is saturated with the
water-vapour which it contains. If the temperature of the air falls to the
dew-point, dew is deposited. The dew-point is determined by means of an
instrument called a hygrometer. When the air is 'dry', the dew-point is
low, and evaporation proceeds rapidly, whilst a 'moist' atmosphere is one
whose temperature is near the dew-point, and in which evaporation takes
place slowly.

DEWSBURY, a town, England, in the West Riding of Yorkshire, and 30 miles
south-west of the town of York, chiefly engaged in the manufacture of heavy
woollen cloths, including blankets, carpets, rugs, flannels, and baizes. In
1862 it was made a municipal borough; in 1867 a parliamentary borough,
returning one member. Pop. of municipal borough, 53,351.

[Illustration: A, Dexter chief point.]

DEXTER, a term meaning on the right-hand side, chiefly used in heraldry.
The _dexter chief point_ is a point in the right-hand upper corner of the
shield, being in the dexter extremity of the chief.

DEX'TRINE, or BRITISH GUM, (C_6H_{10}O_5)_x_, a generic name applied to
soluble gummy substances intermediate between starch and glucose. They are
prepared from starch by the aid of dilute mineral acids or of enzymes, and
are usually named according to the colour they give with iodine, e.g.
erythro-dextrine, &c. When heated with dilute acids, they are transformed
into glucose. They are white, odourless substances, and are good
substitutes for gum-arabic. Dextrine is used in calico printing for
thickening colours; for the preparation of gums, and for stiffening cloth.

DEXTRO-COMPOUNDS, bodies which cause the plane of a ray of polarized light
to rotate to the right. Dextrine itself, dextro-glucose, naturally
occurring tartaric acid, malic acid, cinchonine, and many other bodies have
this property; while others, which have the opposite effect, of causing the
plane to rotate to the left, are called _laevo-compounds_.

DEY, an honorary title formerly bestowed by the Turks on elderly men, and
assumed by the rulers (under the Turkish Sultan) of Algiers, Tripoli, and
Tunis.

DHALAK (dh[.a]-l[.a]k'), an archipelago of the Red Sea, belonging to the
Italian territory of Eritrea. It consists of nearly 100 islets, mostly
uninhabited, clustering round the Island of Dhalak-el-Kebir, which is about
35 miles long by 30 miles broad. This island possesses a pearl-fishery.

DHAR (dh[:a]r), a small native state in Central India, with an area of
about 1740 sq. miles. The soil is fertile, and yields wheat, rice, and
opium. Pop. 169,474.--The capital is of the same name, is surrounded by a
mud wall, and has some striking buildings. Pop. 19,000.

DH['A]RANGAON, a town of Hindustan, in Khandesh district, Bombay. Pop.
15,000.

DHARMS['A]LA, a hill station with military cantonments, in Kangra district,
Punjab, India. Pop. 6170.

DHARWAR, the chief town of Dharwar district, in the Bombay Presidency,
Hindustan, a straggling place with some trade. There is a fort well planned
and strongly situated, but now falling into ruins, and military cantonments
at 2 miles' distance. Pop. 32,000.--The Dharwar district has an area of
4535 sq. miles; pop. 1,051,314.

DHAWALA'GIRI, or DHAUL['A]GIRI, one of the highest peaks of the Himalayas,
in Nep['a]l; height, 26,828 feet.

DHOLE (d[=o]l), the Cingalese name for the wild dog of India (_Cyon
dukhunensis_). It is distinguished from the genus Canis or dog proper by
its having one molar fewer in either side of the lower jaw. It is of a
fox-red or rufous-fawn colour, in size between a wolf and a jackal, and
hunts always in packs.

DHOLERA (dh[=o]-l[=a]'r_a_), a town of Hindustan, Bombay Presidency, on a
stream entering the Gulf of Cambay, an important cotton-mart. Pop. 10,190.

DHOLKA, a town of Hindustan, Bombay Presidency, probably one of the oldest
towns in Gujarat. Pop. 16,700.

DHOLPUR, native state of Central India, R['a]jput['a]na; area, 1155 sq.
miles; pop. 263,188.--The capital is also called Dholpur. Pop. 9750.

[Illustration: Arab Dhow]

DHOW (dou), an Arab sea-going vessel, ranging from a comparatively small
size up to 200 tons burden, with one mast and a large triangular (_lateen_)
sail. It is used for merchandise and is often employed in carrying slaves
from the east coast of Africa to Arabia.

DH['U]LI['A], a town of Hindustan, Khandesh district, Bombay Presidency.
Pop. 22,000.

DIABASE, originally an equivalent of diorite; then used for chloritic
igneous rocks of the Intermediate series of various grain; and now usually
for a type of dolerite in which the felspar is embedded in augite.

DIABE'TES is a disease characterized by great thirst, a voracious appetite,
and the passage of large quantities of saccharine urine, while there is
usually marked emaciation and debility. As a rule the skin is dry and the
patient does not perspire. Skin irritations (pruritus) of an intense type
occur frequently and cause much discomfort. Constipation is the rule, but
the digestion usually remains good, and enormous quantities of food are
taken without causing disturbance.

Acute and chronic forms are recognized, but there is no essential
difference, except that in the former the patients are younger, the course
more rapid, and the emaciation more marked. Beyond the large quantity, the
outstanding feature of the urine is the presence of sugar, varying from 2
per cent in mild cases to 10 per cent in severe cases.

The disease is due to disturbance in the carbohydrate metabolism, with the
result that these carbohydrates are not properly assimilated, but passed as
sugar in the urine. Much research has been undertaken to find what organ or
organs of the body cause this defect in metabolism, and recent work in
connection with the pancreas has established a definite relationship
between cells in that organ and the disease.

In treatment the main consideration is to reduce the carbohydrates in the
dietary, and many diets have been produced for this purpose.

Diabetic patients may take:--liquids: clear soups, lemonade, coffee, tea,
cocoa (without sugar), soda-water, and such like waters or milk (in
moderation); animal foods: fish of all sorts, fresh meat, poultry, game,
eggs, butter, cream-cheese; vegetables: lettuce, tomatoes, spinach,
radishes, asparagus, water-cress, cucumbers, chicory, mustard; fruits:
lemons, oranges, and in moderation currants, plums, cherries, pears, apples
(tart), melons, raspberries, strawberries, nuts: bread: gluten bread,
almond or coco-nut biscuits. A substitute for bread is one of the greatest
difficulties, as many gluten foods are very unpalatable.

Further, it is important to observe strict personal hygiene and to take
moderate exercise, lead a regular, quiet life in an equable climate, and
above all to avoid worries of any sort. In acute cases the disease may run
a very rapid course, coma frequently supervening a few days before death,
but chronic cases may live for ten to twenty years.

DIABETIC SUGAR. Sugar is present in normal urine in very small amount--so
small that it cannot be detected by the ordinary tests. In diabetes the
percentage of sugar in the urine may rise, in mild cases, to 1-1/2 to 2 per
cent, and in severe cases it may reach to 10 per cent.

DIABLERETS (d[=e]-[.a]b-l[.e]-r[=a]), LES, a mountain group of the Bernese
Alps, Switzerland, between the cantons Vaud and Valais. The highest peak
has a height of 10,620 feet.

DIACHYLON (d[=i]-ak'i-lon), a substance prepared by heating together oxide
of lead or litharge, olive-oil, and water, until the combination is
complete, and replacing the water as it evaporates. It is used for curing
ulcers, and is the basis of many plasters.

DI'ADEM (Gr. _diadein_, to bind round), an ancient ornament of royalty. It
was originally a head-band or fillet made of silk, linen, or wool, worn
round the temples and forehead, the ends being tied behind and let fall on
the neck, as seen in old representations of the diadem of the Indian
Bacchus. In later times it was usually set with pearls and other precious
stones. The term is also used as equivalent to crown or coronet.

DIAE'RESIS, a separation of one syllable into two, also the mark (") by
which this separation is distinguished, as in _aerial_.

DIAGNO'SIS, in medicine, the recognition of diseases by their distinctive
signs or symptoms; the discovery of the true nature and seat of a disease.

[Illustration: Diagonal Scale]

DIAG'ONAL SCALE, a scale which consists of a set of parallel lines drawn on
a ruler, with lines crossing them at right angles and at equal distances.
One of these equal divisions, namely, that at the extremity of the ruler,
is subdivided into a number of equal parts, and lines are drawn through the
points of division obliquely across the parallels. With the help of the
compasses such a scale facilitates the laying down of lines of any required
length to the 200th part of an inch. The length 1.67 inches, for example,
is given by EF in the figure. Similarly AB = .91 inch, CD = .84 inch.

DIAG'ORAS, ancient Greek poet and philosopher, born in Melos, an island of
the Cyclades, and flourished about 425 B.C. He spent a great part of his
life in Athens. Like his teacher, Democritus, he attacked the prevailing
polytheism, and sought to substitute the active powers of nature for the
divinities of the Greeks. On this account he had to leave Athens.

DI'AGRAM (Gr. _diagraphein_, to describe), a figure or geometrical
delineation applied to the illustration or solution of geometrical
problems, or any illustrative figure in which outlines are chiefly
presented, and the details more or less omitted.

[Illustration: Sun-dial]

DIAL, or SUN-DIAL, an instrument for showing the hour of the day from the
shadow thrown by a _stile_ or _gnomon_ upon a graduated surface while the
sun is shining. This instrument was known from the earliest times amongst
Egyptians, Chaldeans, and Hebrews. From those Eastern nations it came to
the Greeks. It was introduced into Rome during the first Punic War. Dials
are of various construction, horizontal, inclined, or upright, the
principle in every case being to show the sun's distance from the meridian
by means of the shadow cast by the stile or gnomon. The stile is made
parallel with the earth's axis, and may be considered as coinciding with
the axis of the sun's apparent diurnal motion. Consequently, as the sun
moves westwards the shadow of the stile moves round opposite to it, in the
same direction, falling successively on lines drawn to represent the hours
of the day. The dial, of course, gives true solar or _apparent_ time,
which, except on four days of the year, is somewhat different from _mean_
time. Dials are now rather articles of curiosity or ornament than of
use.--BIBLIOGRAPHY: Leybourn, _The Art of Dialling_; Dawbarn, _The
Sun-dial_.

DI'ALECT, the language of a part of a country, or a distant colony,
deviating either in its grammar, vocabulary, or pronunciation, from the
language of that part of the common country whose idiom has been adopted as
the literary language, and the medium of intercourse between well-educated
people. Although the use of provincial dialects becomes inconvenient after
a language has acquired a fixed literary standard, the study of such
dialects is always valuable to the philologist for the light they throw on
the history of the language. The diffusion of education and of printed
books has much relaxed the hold which the provincial dialects of various
countries once had on the people, and in general it may be said that the
educated classes of any country now speak each of them a uniform language.

DIALEC'TICS (Gr. _dialektice_, from _dialektos_, discourse, dialogue), a
philosophic term originally signifying _investigation by dialogue_. It was
first used by Plato to designate the Socratic method. Afterwards it came to
denote the art of inference or argument, and in this sense was synonymous
with _logic_. The term is used in Kant's philosophy to mean the logic of
appearance, or that logic which treats of inevitable tendencies towards
error and illusion in the very nature of reason.

DI'ALLAGE, an altered form of the mineral augite, with a lamellar
structure, and a submetallic lustre on its planes of separation.
Schillerstein, or schiller spar is a similar product of the allied but
rhombic mineral hypersthene. It forms diallage rock, and enters into
serpentine rock.

DIALLING, the art, of making sundials; also the art and practice of
mine-surveying, in which the theodolite and magnetic needle are employed.

DI'ALOGUE, a conversation or discourse between two or more persons. The
word is used more particularly for a formal conversation in theatrical
performances, and for a written conversation or composition, in which two
or more persons carry on a discourse. This form was much in favour amongst
the ancient philosophers as a medium for expressing their thoughts on
subjects. The _Dialogues_ of Plato are the finest example. Many of the
great French and Italian writers have used this form. In the seventeenth
century Fontenelle and F['e]nelon both wrote _Dialogues des Morts_, a title
borrowed from Lucian. Landor's _Imaginary Conversations_ (1821-8) is the
best production of this kind in English.

DIAL'YSIS, the process by means of which a crystalline substance may be
separated from a colloidal body. Certain substances are capable of passing
through parchment, others are not, e.g. a solution containing sugar and
silicic acid may be separated by placing the solution in a parchment-paper
tube suspended in water; the silicic acid remains in the parchment tube,
and the sugar passes through into the surrounding water. The solution is
said to be dialyzed.

DIAMAGNET'IC, a term applied to substances which, when under the influence
of magnetism and freely suspended, take a position at right angles to the
lines of magnetic force. From the experiments of Faraday it appears that
all matter is subject to the magnetic force as universally as it is to the
gravitating force, arranging itself into three divisions, the
_ferromagnetic_, _paramagnetic_, and _diamagnetic_. Among the former are
iron, nickel, cobalt, magnetic oxide of iron, and Heusler's alloy. The more
feebly magnetic bodies are classed as paramagnetics, and those which behave
as described above are called diamagnetic substances. Among the latter are
bismuth, antimony, cadmium, copper, gold, lead, mercury, silver, tin, zinc,
and most solid, liquid, and gaseous substances. A diamagnetic body is one
which is not so magnetic as the medium in which it is suspended. The action
of bismuth, the strongest diamagnetic substance, is weak when compared with
the magnetic action of iron.

DIAMANTI'NA, a town, Brazil, in the diamond-mining district in the state of
Minas Geraes, the inhabitants of which are almost all engaged in the gold
and diamond trade. Pop. about 14,000.

[Illustration: Diameter]

DIAM'ETER (Gr. _dia_, through, and _metron_, measure), the straight line
drawn through the centre of a circle and terminated by the circumference.
It thus divides the circle into two equal parts, and is the greatest chord.
The length of the diameter is to the length of the circumference of the
circle as 1 to 3.14159265..., the latter number being an interminable
decimal. The name is also given to any chord of a conic which passes
through its centre.

[Illustration: Diamonds, rough and variously cut]

DI'AMOND, the hardest and one of the most valuable of gems, and the purest
form in which the element carbon is found. (See _Carbon_.) It crystallizes
in forms belonging to the regular or cubic system, the most common being
the regular octahedron and rhombic dodecahedron (twelve faces). The finest
diamonds are colourless, perfectly clear, and pellucid. Such are said to be
of the finest _water_. But diamonds are often blue, pink, green, or yellow,
and such are highly prized if of a decided and equal tint throughout. The
hardness of the diamond is such that nothing will scratch it, nor can it be
cut but by itself. The value of a diamond is much enhanced by cutting
facets upon it inclined at certain angles to each other so as to produce
the greatest possible play of colour and lustre. What is called the
_brilliant_ cut best brings out the beauty of the stone. Its upper or
principal face is octagonal, surrounded by many facets. But this form of
cutting requires an originally well-shaped stone. For other diamonds the
_rose_ cut is used. In this form six triangles are cut on the top so that
their apices meet in a point called the summit. Round this are disposed
other facets. Stones which are too thin to cut as rose-diamonds are cut as
_table_-diamonds, which have a very slight play of colour. In the cut, fig.
1 is the diamond in its rough state; fig. 2 is the vertical, and fig. 3 the
lateral appearance of a brilliant; fig. 4 the vertical, and fig. 5 the
lateral appearance of a rose-cut diamond; in fig. 6 the flat portion _a_ in
a cut stone is called the _table_; the part _a b b_, which projects from
the setting, is the _front_, the part _b b c_, sunk in the setting, is the
_back_ or _culasse_, while the line _b b_ is the _girdle_. The art of
cutting and polishing the diamond was unknown in Europe till the fifteenth
century, and the stone itself was not nearly so highly valued in the Middle
Ages as the ruby. Diamonds are valuable for many purposes. Their powder is
the best for the lapidary, and they are used for jewelling watches, and in
the cutting of window- and plate-glass. When used as a glazier's tool the
diamond must be uncut. Inferior kinds of diamonds are also extensively used
by engineers in rock-boring, and by copperplate engravers as
etching-points. Diamonds are obtained from deposits of various kinds,
mostly alluvial (sands, clays, &c.), being separated by washing. They have
been found in India, Borneo, and other parts of the East; sometimes in N.
America and Australia; Brazil has produced large numbers; but the chief
diamond-field of to-day is in Cape Province, the centre being Kimberley.
Diamonds were discovered here in 1867, and since then the output has
amounted to over L183,000,000 in value. The diamonds are no longer obtained
by mere surface workings, but the excavations have been carried down to a
depth of 2000 feet. 'River diggings' are also carried on on the banks of
some of the rivers. Some of the S. African diamonds are very large. One of
them, the Cullinan diamond, discovered in 1905, is a monster of 3025
carats, of very good colour, being by far the largest diamond known. A
celebrated diamond is the Koh-i-noor (Mountain of Light), an Indian stone
belonging to the British crown. Its history extends over five or six
centuries. It weighed at one time 280 carats, but by cutting has been
reduced to about 106 carats. The Orlov diamond, which belonged to the
Emperor of Russia, weighed 194 carats; the Pitt diamond, among the French
crown jewels, weighs 136-1/2 carats.--BIBLIOGRAPHY: A. Jeffries, _A
Treatise on Diamonds and Pearls_; H. Emanuel, _Diamonds and Precious
Stones_; E. W. Streeter, _Precious Stones and Gems_; _idem_, _The Great
Diamonds of the World_; G. F. H. Smith, _Gem-Stones_; P. A. Wagner, _The
Diamond Fields of Southern Africa_.

[Illustration]

DIAMOND-BEETLE, _Entimus imperialis_, a handsome South American insect
belonging to the family Curculionidae or weevils. It is spangled with
golden-green on a black background.

DIAMOND HARBOUR, a port on the left bank of the Hugli River, about 38 miles
by the railway from Calcutta, formerly much used as an anchorage for ships
waiting for the tide.

[Illustration: Diana. From a statue in the British Museum]

DIAMOND LORE. In Hellenic, Arabian, Chinese, and other literature the
diamond is connected with the eagle and snakes. Diamonds, according to
ancient belief, lie in deep valleys infested by snakes, or entirely
surrounded by straight, high cliffs. Pieces of flesh are thrown down and
eagles seize them. The birds are followed to their nests, where the
diamonds that adhered to the flesh are found. Mixed with this legend is the
older one regarding the 'eagle stone', which assists parturition. It was
believed a woman was easily delivered if the 'eagle stone' were placed on
her abdomen. The Chinese legend was imported with the diamond from Fu-lin
(Syria). Indian diamond lore is mixed with pearl lore. According to the
Buddha birth stories, diamonds are found in the sea. The ancients asserted
that the diamond could not be injured by iron, fire, or smoke. Before it
could be broken it had to be steeped in ram's blood. The alchemists used
lead as a substitute for ram's blood. In Chinese lore diamonds are rulers
of gold and have their origin in gold. A similar belief prevailed in
mediaeval Europe, adamantine gold being credited with the same virtues as
the diamond. Both gold and the diamond were sacred. The diamond is a
mediaeval symbol of Christ; in the Far East it is connected with Buddha.
The association of the diamond with snakes gave origin to the belief that
it was poisonous, the saliva of the snakes clinging to it. Diamond dust is
regarded in India as a deadly poison. Like the sacred pearl, the diamond
has been credited with nocturnal luminosity. Certain varieties of diamonds
when heated, rubbed, or exposed in bright sunshine emit slight rays of
light for a short time in darkness. The belief in 'night shining gems',
however, had origin in pearl lore, the pearl having been connected with the
moon ('the pearl of heaven'). Coral, rhinoceros-horn, fern seed, the
mandrake, &c., were likewise connected with the moon-goddess and credited
with nocturnal luminosity.

DIAMOND NECKLACE, an affair of some note in French history immediately
preceding the Revolution. See _Marie Antoinette_; _La Motte_; and _Rohan,
Louis_.

DIAN'A, in Roman mythology, an ancient Italian goddess, in later times
identified with the Greek Art[)e]mis, with whom she had various attributes
in common, being the virgin goddess of the moon, and of the chase, and
having as attributes the crescent moon, bow, arrows, and quiver. The name
is a feminine form of Janus. She seems to have been originally the patron
divinity of the Sabines and Latins. She was worshipped especially by women,
as presiding over births, no man being allowed to enter her temple.

DIANA-MONKEY (_Cercopith[=e]cus Diana_), a species of monkey found in West
Africa, and so named from the crescent-shaped band on the forehead
resembling the crescent moon, which was the symbol of Diana. Another
characteristic feature is the possession of a pointed white beard.

DIANA OF POITIERS, Duchess of Valentinois, born in 1499. She was the
mistress of King Henry II of France, and descended from the noble family of
Poitiers, in Dauphiny. At an early age she married the Grand-Seneschal of
Normandy, Louis de Br['e]z['e], became a widow at thirty-one, and some time
after the mistress of the young Duke of Orleans. On his accession to the
throne in 1547, as Henry II, Diana continued to exercise an absolute empire
over him till his death in 1559. After that event she retired to her castle
of Anet, where she died in 1566.--Cf. Capefigue, _Diane de Poitiers_.

DIAPA'SON, in music, the concord of the first and last notes of an octave.
The word is also used for the most important foundation-stops of an organ.
They are of several kinds, as _open diapason_, _stopped diapason_, _double
diapason_. The French use the term as equivalent to pitch in music.

[Illustration: Diaper Ornamentation. Westminster Abbey]

DI'APER, a kind of textile fabric much used for towels and napkins, and
formed either of linen or cotton, or a mixture of the two, upon the surface
of which a flowered or figured pattern is produced by a peculiar mode of
twilling.--As a term in ornamentation diaper is applied to a surface
covered with a flowered pattern sculptured in low relief, or to a similar
pattern in painting or gilding covering a panel or flat surface.

DIAPHANOSCOPE, (1) an apparatus by means of which transparent positive
photographs may be viewed. The name is also given to (2) an instrument
employed in obstetrical surgery; electric light, contained in a glass tube
or bulb, is introduced into the female internal organs, and, thus
illumined, their condition can be examined through the translucent walls of
the abdomen.

DIAPHORET'ICS (Gr. _diaphorein_, to carry through) are agents used in
medical practice to produce perspiration. The Turkish bath, hydropathic
treatment, diluent drinks, &c., are employed for this purpose. The degree
of perspiration produced is more than normal, but less than in sweating.
See _Sudorifics_.

DIAPHRAGM (d[=i]'a-fram), in anatomy, a muscular membrane placed
transversely in the trunk, and dividing the chest from the abdominal
cavity. In its natural situation the diaphragm is convex on the upper side
and concave on its lower, but when the lungs are filled with air it becomes
almost flat. It is the principal agent in respiration, particularly in
inspiration. A complete diaphragm is found only in Mammalia.

DIARBEK'IR, a town in Armenia, formerly in Asiatic Turkey, capital of the
vilayet of same name, on a high bank overlooking the Tigris, and surrounded
by a lofty massive wall. It has manufactures of iron- and copper-ware,
leather, silk, woollen, and cotton goods, and a considerable trade. Pop.
about 38,000.--The province of Diarbekir has an area of 14,480 sq. miles,
and a pop. of 471,500.

DIARRHOE'A is morbidly frequent evacuation of the bowels. Several forms are
recognized. _Choleraic diarrhoea_; this form is acute, and is marked by
great frequency, with serous stools, and accompanied by vomiting and
collapse. _Critical diarrhoea_ occurs at the crisis of a disease.
_Lienteric diarrhoea_ is marked by the passage of fluid stools containing
scraps of undigested food. _Mucous diarrhoea_ is marked by the presence of
mucous in the stools. _Summer diarrhoea_ occurs chiefly among young
children and infants, most frequently in late summer. It is usually acute
in type and associated with marked prostration. In epidemic form it may
give rise to a high mortality in crowded districts and in institutions.
_Nervous diarrhoea_ is produced by some emotional cause. The treatment,
whatever the type, is to get rid of the cause of the irritation, and to
avoid further irritation in the intestinal tract. For this purpose
purgatives are given, and all solid food forbidden. This is followed by
gastro-intestinal sedatives and a gradual return to normal diet--substances
causing least digestive difficulty being first given.

DIASTASE is an unorganized ferment or enzyme produced in the germination of
barley, oats, &c. It is soluble in water, and the solution has the property
of inducing fermentation or hydrolysis of starch into dextrine and glucose.
To prepare diastase, barley is allowed to germinate; germination is then
interrupted by raising the temperature, and the grain is treated with a
mixture of water and alcohol under pressure, and filtered. Diastase, being
soluble, is obtained in the filtrate.

DIATHER'MANCY, the property that is possessed in various degrees by
different substances, of transmitting radiant heat. Bodies that are equally
transparent, that is, bodies which have equal power of transmitting rays of
light, are very different in their power of transmitting heat-rays. Thus a
thin plate of glass and a thin plate of rock-salt may be nearly equally
transparent, but the plate of rock-salt has far superior power of
transmitting rays of heat. The latter, it has been found, allows 92 per
cent of the total heat from most sources to pass; glass and other
substances transmit a much smaller proportion, and the amount varies with
the source. Rock-salt is diathermanous to heat from nearly all sources. It
has been shown that rock-salt is extremely opaque or athermanous to the
radiations from a piece of heated rock-salt. The diathermancy of the plates
in every case decreases very rapidly as their thickness is increased. See
_Radiation_.

DIATH'ESIS is the term given in medicine to a constitutional predisposition
to a disease; thus uratic diathesis is a tendency to gout; aneurysmal
diathesis is an inherent predisposition to aneurysms.

DIATOMA'CEAE, a family of Algae, consisting of microscopic unicellular
plants with brown chromatophores found in fresh, brackish, and salt water,
and on damp ground. The cell wall contains a very large quantity of silica,
and is formed in each cell into three portions, viz. two generally
symmetrical valves and a connecting hoop. The species consist of single
free cells, or the cells remain connected so as to form usually linear
colonies, sometimes enclosed in a transparent gelatinous sheath. The
ordinary method of increase is by cell division. A sexual process
resembling that of the conjugatae also occurs. Diatoms constitute an
important source of food for the lower marine animals, and thus indirectly
for the food-fishes. Diatomaceae are found fossil, forming considerable
deposits of tertiary age, as at Bilin, Richmond in the United States, &c.
Fossil polishing-powders, as tripoli and bergmehl, are composed of them;
also kieselguhr, which, impregnated with nitroglycerine, forms dynamite.
They are abundant in guano.

DIAT'OMITE (Ger. _kieselguhr_), a diatomaceous earth (see _Diatomaceae_)
generally found underlying peat. In Skye, at Loch Quire, it is found about
18 inches below the surface, and extends downward for about 7 feet, and in
some places to a much greater depth. Another important area is north of
Toome Bridge in the county of Antrim. Diatomite is principally used for the
manufacture of dynamite on account of its value as an absorbent. It is
described also as extremely well adapted for the manufacture of silicate
paints, siliceous glazings, porcelain, boiler-coatings, and for isolating
felt and bricks for cold-storage buildings.

DIATON'IC, a term originally applied by the Greeks to one of their three
genera of music. In modern music it is applied to the natural scale, and to
the intervals, chords, melodies, or harmony characteristic of it. A
diatonic chord is a chord having no note chromatically altered. A diatonic
interval is an interval formed by two notes of the diatonic scale unaltered
by accidentals. A diatonic melody is a melody composed of notes belonging
to one scale only.

DIAZ, Bartolommeo, a celebrated Portuguese navigator of the fifteenth
century, named in 1486 commander of one of that long succession of
exploratory expeditions which the Portuguese court had during this century
become distinguished for promoting. The two vessels composing the
expedition sailed along the African coast till they reached Cape Negro
(lat. 15deg 50' S.), where Diego Cam, a previous explorer, had stopped. At
29deg S. they anchored at a point to which they gave the name of Angra das
Voltas (Bay of Detours). In sailing south from this point they doubled the
Cape of Good Hope without knowing it, and landed at a bay on the east
coast. Diaz now wished to continue his voyage in order to discover the
country of Prester John, but the sailors refused to accompany him. In again
doubling the Cape he gave it the name of Cabo Tormentoso (Cape of Storms),
which the king changed to its present designation. In 1500 Diaz had command
of a vessel in the expedition of Cabral which discovered Brazil. In
returning home the vessel which he commanded was lost, 29th May, 1500.

DIAZO COMPOUNDS, or DIAZONIUM COMPOUNDS, a name given to substances
containing the chemical group - N:N -; thus diazo-benzene chloride, C_6H_5
- N:N.Cl, or diazo-toluene sulphate, C_6H_4(CH_3) - N:NH.SO_4, &c.

These substances are formed from the aromatic amines by treatment with
nitrous acid at low temperatures. Primary amines all react with nitrous
acid at moderate temperatures when the amino group (NH_2) is replaced by a
hydroxyl group (OH); thus ethylamine (C_2H_5NH_2) reacts with nitrous acid
(HNO_2), yielding alcohol (C_2H_5OH), C_2H_5NH_2 + HNO_2 - C_2H_5OH + N_2 +
H_2O. The aromatic amines, however, if treated below 0deg C. with nitrous
acid, yield diazo compounds, and not hydroxy compounds, e.g. aniline
treated with nitrous acid in hydrochloric acid solution yields
diazo-benzene chloride, C_6H_5NH_2.HCl + HONO = C_6H_5 - N:N.Cl + 2(H_2O).
Diazo salts are crystalline compounds soluble in water, sparingly soluble
in alcohol, and are unstable, decomposing explosively if struck or suddenly
heated. In solution in water they decompose as the temperature rises,
liberating nitrogen, and forming hydroxy compounds, C_6H_5N:NCl + H_2O =
C_6H_5OH + N_2 + HCl. Diazo salts are valuable in the synthesis of
different classes of compounds, as the - N:N - group reacts readily with
other groups. For this purpose it is usually only necessary to prepare a
solution containing the diazo compound. In the preparation of the azo dyes
the starting-point is a primary amine; the amino group is 'diazotized',
i.e. treated with a solution of sodium nitrite and dilute mineral acid at
low temperature. A diazo salt is formed, and is then made to react in
solution with a hydroxy compound or an amino compound, &c., with the
formation of a highly coloured azo compound. The diazo compound is then
said to be coupled. Diazo compounds are therefore important intermediate
substances in the manufacture of azo dyes.

The diazo group may also be exchanged for the hydroxyl group by warming the
solution with water, or for the cyanogen group by warming with a solution
of potassium cyanide, e.g. diazo-benzene chloride warmed with potassium
cyanide solution is converted into the nitrile of benzoic acid, C_6H_5 -
N:NCl + KCN = C_6H_5CN + KCl + N_2; or transformed into halogen derivatives
of hydrocarbons by warming with cuprous chloride, e.g. diazo-benzene
chloride is transformed into chlorobenzene, C_6H_5 - N:NCl + Cu_2Cl_2 =
C_6H_5Cl + N_2 + Cu_2Cl_2. These reactions, where nitrogen is eliminated
from the compound, and a group or element replaces the two atoms of
nitrogen, afford a means of synthesizing a variety of compounds.

DIB'DIN, Charles, an English dramatic manager and poet, composer and actor,
born in 1745, died in 1814. At the age of fifteen he made his appearance on
the stage, and was early distinguished as a composer. He invented a new
kind of entertainment, consisting of music, songs, and public declamations,
which he wrote, sang, composed, and performed himself, and by this means
succeeded in amusing the public for twenty years. In 1769 he composed some
of the music for the Shakespeare jubilee at Stratford-on-Avon. His
patriotic songs were very popular, and his sea-songs, amongst which are
_Tom Bowling_, _Poor Jack_, and _The Trim-built Wherry_, are still
favourites in the British navy. He also wrote a _History of the Stage_, and
the novels _The Devil_ and _Hannah Hewitt_.--His son, Charles Dibdin,
composed and wrote many small pieces and occasional songs.--Another son,
Thomas, early displayed the same dramatic tastes as his father, was
connected with various theatres, and wrote a great many songs and a number
of dramas.

DIBDIN, Thomas Frognall, an English bibliographer, born in 1776, died in
1847, was the son of the elder brother of Charles Dibdin the celebrated
naval song-writer. After studying law and practising as a provincial
counsel, he took orders and became a popular preacher in London. Here his
bibliographical tastes developed themselves, and the Roxburghe Club being
established in 1812, he became its first vice-president. Among his numerous
writings may be noted: _Bibliomania_, _Bibliographical Decameron_,
_Typographical Antiquities of Great Britain_, and _The Library Companion_.

DIBRANCHIA'TA. See _Cephalopoda_.

DICE, cubical pieces of bone or ivory, marked with dots on each of their
six faces, from one to six, according to the number of faces. They are
shaken in a small box and then thrown on the table. Dice are often loaded
or falsified in some way so as to make the high or the low sides turn down.
The origin of dice is ascribed to Palamedes of Greece (1244 B.C.), although
Herodotus attributes the invention of knuckle-bones and of dice to the
Lydians. Dice were well known amongst the ancient Egyptians and Greeks, and
are still very popular in Japan, China, India, and other Asiatic countries.

DICEN'TRA. See _Dielytra_.

DICHASIUM. See _Cyme_.

DICHLAMYDEOUS (d[=i]-klam-id'i-us), in botany, said of plants that have
both calyx and corolla.

DICHOGAMY, in flowers, the condition in which anthers and stigmas ripen at
different times, whereby self-pollination is effectually prevented. If the
anthers ripen first, as in borage, columbine, crocus, Caryophyllaceae,
Compositae, Labiatae, &c., the flower is said to be protandrous;
protogynous flowers, with stigmas ripening and withering before the pollen
is shed, occur, e.g. in Christmas rose, Colchicum, horse-chestnut, and in
the majority of wind-pollinated plants.

DICHOTOMY (d[=i]-kot'o-mi), a cutting in two; a division by pairs. Hence,
in botany, a mode of branching by constant forking, each branch dividing
into two others. See _Branching_.

DICHROIC, or more generally PLEOCHROIC, CRYSTALS (d[=i]-kr[=o]'ik),
crystals that have the property of exhibiting different colours, according
to the direction in which they are traversed by rays of light. When
polarized light is passed through a transparent plate of a pleochroic
mineral, the colour will vary with the direction in which the
light-vibrations take place. Hence, _face-pleochroism_, the colour of the
plate, may be distinguished from the colours given by _axis-pleochroism_,
the colours given by light vibrating parallel with certain optical
directions in the crystal.

DICHROITE (d[=i]'kro-[=i]t), or IOLITE, a mineral, a silicate of magnesium,
iron, and aluminium, which readily undergoes modifications and passes into
hydrous silicate. It exhibits marked pleochroism, whence the name.

DICK, Thomas, LL.D., a Scottish author of popular scientific works, born at
Dundee in 1774, died 29th July, 1857. He was for many years a teacher at
Perth, but subsequently resided at Broughty-Ferry, where he devoted himself
to astronomical science, especially in its relations to religion. Some
years before his death a small pension was granted to him by the
Government. Amongst his works are: _The Christian Philosopher_ (1823), _The
Philosophy of Religion_ (1825), _The Philosophy of a Future State (1828)_,
and _Celestial Scenery_ (1838).

DICKENS, Charles, one of the greatest English novelists, born 7th Feb.,
1812, at Landport, Portsmouth, died 9th June, 1870. His father, John
Dickens, was then in the employment of the Navy Pay Department, but
subsequently became a newspaper reporter in London. Young Dickens received
a somewhat scanty education, was for a time a mere drudge in a blacking
warehouse, and subsequently a clerk in an attorney's office. Having
perfected himself in shorthand, however, he became a newspaper critic and
reporter, was engaged on _The Mirror of Parliament_, and _The True Sun_,
and in 1835 on _The Morning Chronicle_. For some time previously he had
been contributing humorous pieces to _The Monthly Magazine_; but at length,
in 1835, appeared in _The Morning Chronicle_ the first of that series of
_Sketches by Boz_ which brought Dickens into fame. It was followed in quick
succession by a pamphlet entitled _Sunday under Three Heads, by Timothy
Spark_ (1836); _The Tuggs at Ramsgate_ (1836); _The Village Coquette_, a
comic opera (1836); and a farce called _The Strange Gentleman_ (1836). In
the same year Chapman & Hall engaged the new writer to prepare the
letterpress for a series of comic sketches on sporting subjects by Seymour,
an artist who had already achieved fame, and suggested as a subject the
adventures of an eccentric club. Seymour committed suicide soon after, and
H. K. Browne joined Dickens as illustrator, the result being the immortal
_Pickwick Papers_. The great characteristics of Dickens's genius were now
fully apparent, and his fame rose at once to the highest point it was
possible for a writer of fiction to reach. A new class of characters,
eccentric indeed, but vital representations of the humours and oddities of
life, such as Mr. Pickwick, Sam Weller and his father, Mr. Winkle, and
others, was made familiar to the public. Under the name of _The Posthumous
Papers of the Pickwick Club_ this work was published in 2 vols. 8vo, in
1837. In the same year Dickens was engaged as editor of _Bentley's
Magazine_, to which he contributed _Oliver Twist_, a work which opened up
that vein of philanthropic pathos and indignant satire upon institutions
which became a distinguishing feature of his works. Before the completion
of _Oliver Twist_, _Nicholas Nickleby_ was begun, being issued complete in
1839. As the special object of _Oliver Twist_ was to expose the conduct of
workhouses, that of _Nicholas Nickleby_ was to denounce the management of
cheap boarding-schools. _Master Humphrey's Clock_, issued in weekly
numbers, contained among other matter two other leading tales, _The Old
Curiosity Shop_ and _Barnaby Rudge_, the latter a historical tale, going
back to the times of the Gordon riots. It was published complete between
1840 and 1841. In 1841 Dickens visited America, and on his return he wrote
_American Notes for General Circulation_ (1842). His next novel, _Martin
Chuzzlewit_ (1844), dwelt again on his American experiences. This work also
added a number of typical figures--Mr. Pecksniff, Mark Tapley, Sarah Gamp,
and others--to English literature. The series of _Christmas Tales_, in
which a new element of his genius, the power of handling the weird
machinery of ghostly legend in subordination to his own peculiar humour,
excited a new sensation of wonder and delight. These, enumerated
consecutively, were: _A Christmas Carol_ (1843), _The Chimes_ (1844), _The
Cricket on the Hearth_ (1845), _The Battle of Life_ (1846), _The Haunted
Man_ and _The Ghost's Bargain_ (1847). The extraordinary popularity of
these tales created for a time a new department in literature, that of the
sensational tale for the Christmas season. In 1845 Dickens went to Italy,
and on his return _The Daily News_, started on 1st Jan., 1846, was
entrusted to his editorial management; but, despite his early training,
this was an occupation uncongenial to his mind, and in a few months the
experiment was abandoned. His _Pictures from Italy_ were published the same
year. Next followed his novel of _Dombey and Son_ (1848), and _David
Copperfield_, a work which has a strong autobiographical element in it
(1849-50). In 1850 Dickens became editor of the weekly serial _Household
Words_, in which various original contributions from his own pen appeared.
In 1853 his _Bleak House_ came out. _A Child's History of England_,
commenced in _Household Words_, was published between 1852 and 1854. _Hard
Times_ appeared in _Household Words_, and was published in 1854. _Little
Dorrit_, commenced in 1856, dealt with imprisonment for debt, the contrasts
of character developed by wealth and poverty, and executive imbecility,
idealized in the Circumlocution Office. In 1859, in consequence of a
disagreement with his publishers, _All the Year Round_ superseded
_Household Words_; and in the first number of this periodical, 28th May,
was begun _A Tale of Two Cities_. _Great Expectations_ followed in the same
paper, on 1st Dec., 1860. In _All the Year Round_ also appeared a series of
disconnected sketches called _The Uncommercial Traveller_, published in
1868. _Our Mutual Friend_, completed in 1865, and published in the usual
monthly numbers, with illustrations by Marcus Stone, was the last great
serial work which Dickens lived to finish. It contained some studies of
characters of a breadth and depth unusual with Dickens, and is
distinguished among his works by its elaborate plot. The first number of
his last work, _The Mystery of Edwin Drood_, was issued on 1st April, 1870,
and only three numbers had appeared when he died somewhat suddenly, at his
residence, Gad's Hill Place, near Rochester, on 9th June. He had
considerably overtaxed his strength during his later years, more especially
by his successive series of public readings from his own works, one series
being delivered in America between 1867 and 1868. He was buried in
Westminster Abbey. Dickens's work as a novelist is firmly based upon a wide
and keen observation of men. The essence of his art was caricature, and for
comic effect he, therefore, often exaggerated the abuses he attacked. His
characters exhibit little more than one trait or quality, but the single
trait or quality which they embody is truly conceived, and exhibited with
great vitality and humour. His creative power was immense, and his great
humour is admitted by all, even by those who consider his pathos as
overdrawn. In spite, therefore, of all that is grotesque and overstrained
in his work, he has been rightly placed amongst the great
artists.--BIBLIOGRAPHY: J. Forster, _Life of Charles Dickens_; George
Gissing, _Charles Dickens: a Critical Study_; G. K. Chesterton, _Charles
Dickens_; R. H. Shepherd, _The Bibliography of Dickens_; Sir F. T.
Marzials, _Life of Charles Dickens_; E. Pugh, _The Charles Dickens
Originals_; P. H. Fitzgerald, _Memoirs of Charles Dickens_.

DICKSONIA, a genus of Leptosporangiate ferns, section Gradatae, mostly
large tree-ferns, such as _D. antarctica_, a native of Australia and New
Zealand, often grown in greenhouses.

[Illustration: Portion of a Four-year-old Dicotyledonous Woody Stem cut in
Winter

B, Bast. B.K., Bark external to the first periderm layer, corresponding to
the primary cortex. C, Cambium ring. E, Early wood. J, J, J, Junction of
the wood of successive years. L, Late wood. M, Medulla. M.R., Medullary
rays, various views. P, Protoxylem. 1, 2, 3, 4, The four successive annual
rings.]

DICOTYLEDON (d[=i]-kot-i-le'don), a plant whose seeds are readily
recognized by the embryo containing a pair of cotyledons or seed-leaves,
which are always opposite to each other. Dicotyledons are further
characterized by their netted-veined leaves and their 'open' vascular
bundles containing a cambium; the parts of the flower are commonly in fours
or fives. In Bentham and Hooker's system the class is divided into four
subclasses--Thalamiflorae, Calyciflorae, Corolliflorae, and Monochlamydeae.
Engler's system recognizes only two subclasses, viz. Archichlamydeae and
Sympetalae.

DICTAPHONE, an adaptation of the gramophone, in which the principle of that
invention is applied to the requirements of modern business. Letters or
memoranda are spoken into the machine, which 'records' them on waxen
cylinders. The machine is then passed on to a shorthand writer or typist
(or the cylinder may be transferred to a duplicate machine), and the
recorded matter is dictated. The motive power is electricity; the speed of
dictation is capable of adjustment to that of the writer; and by means of
an accessory machine the records can be scraped and re-used.

DICTA'TOR, an extraordinary magistrate of the Roman Republic, first
instituted B.C. 501. The power of naming a dictator, when an emergency
arose requiring a concentration of the powers of the State in a single
superior officer, was vested by a resolution of the Senate in one of the
Consuls. The dictatorship was limited to six months, and the person who
held it could not go out of Italy. This rule was laid aside during the
first Punic War. The dictator was also forbidden to appear in Rome on
horseback without the permission of the people, and he had no control over
the public funds without the permission of the Senate. He had the power of
life and death, and could punish without appeal to the Senate or people.
All the other magistrates were under his orders. Originally the dictator
was a patrician, but in 356 B.C. the plebeian Marcius Rutilus was called
upon to fill the office of dictator. The term is now often applied to
rulers enjoying or exercising extra-constitutional power.--Cf. A. H. J.
Greenidge, _Roman Public Life_.

DICTIONARY (from the Lat., _dictio_, a saying, expression, word), a book
containing the words, or subjects, which it treats, arranged in
alphabetical order. It may be either a vocabulary, or collection of the
words in a language, with their definitions; or a special work on one or
more branches of science or art prepared on the principle of alphabetical
arrangement, such as dictionaries of biography, law, music, medicine,
history, or philosophy. Amongst dictionaries of the English language, the
earliest seem to have been those of Bullokar (1616) and Cockeram (1623).
That of Dr. Johnson, published in 1755, made an epoch in this department of
literature. Previous to this the chief English dictionary was that of
Bailey, a useful work in its way. An enlarged edition of Johnson's
dictionary, by the Rev. H. J. Todd, appeared in 1818; and this, again
enlarged and modified, was issued under the editorship of Dr. R. G. Latham
(1864-72). The best-known American dictionary of the English language is
that by Noah Webster, published in 1828, and since entirely recast.
Richardson's dictionary, published during 1836 and 1837, was valuable
chiefly for its quotations. Ogilvie's _Imperial English Dictionary_, based
on Webster, and first published between 1847 and 1850, has been issued in a
remodelled and greatly enlarged form (4 vols. 1881-2 and subsequently,
Charles Annandale, LL.D., editor). It is one of the encyclopaedic
dictionaries. Cassell's _Encyclopaedic Dictionary_ is another extensive
work (1879-88). The largest completed English dictionary is the _Century
Dictionary_ (New York, 1889-91, 6 vols. quarto). _The Standard Dictionary_
is another American work. A new English dictionary 'on historical
principles', first edited by Sir J. A. H. Murray, LL.D., with the
assistance of many scholars, and now edited by Dr. Henry Bradley, is being
published at the Clarendon Press since 1884. Among foreign dictionaries are
the polyglot dictionary of Calepino (1502), the Latin and Greek _Thesaurus_
of Robert and Henry Stephanus, the Italian _Vocabulario della Crusca_
(1612), &c. The chief etymological dictionary of English words is that by
Professor Skeat (1882). Among French dictionaries (for French people) the
chief is that of Littr['e]; among German, the dictionary begun by the
brothers Grimm.

DICTYOTACEAE, a family of Brown Algae, section Cyclosporeae. _Dictyota
dichotoma_, with a delicate, flattened, repeatedly forked thallus, is not
uncommon in sandy pools on our coasts. The plants are of three kinds, viz.
[male], bearing antheridia; [female], bearing oogonia; and neuter,
producing tetraspores. The oospores give rise to neuter plants, the
tetraspores to [male] or [female] plants. This is one of the best instances
of 'homologous' alternation of generations, i.e. that type in which the
different generations are identical in form, differing only in their
reproductive organs and in the number of chromosomes in their nuclei.
Another genus is Padina.

DIDACTIC POETRY, that kind of poetry which professes to give a kind of
systematized instruction on a definite subject or range of subjects. Thus
the _Georgics_ of Virgil and the _De Rerum Natura_ of Lucretius profess to
give, the one a complete account of agriculture and kindred arts, the other
a philosophical explanation of the world. Other examples of purely didactic
poetry are Horace's _Ars Poetica_, and Pope's _Essay on Criticism_. In a
larger sense of the word most great poems might be called didactic, since
they contain a didactic element in the shape of history or moral teaching,
Dante's _Divina Commedia_, Milton's _Paradise Lost_, or Goethe's _Faust_,
for example. The difference may be said to be this, that in the one case
the materials are limited and controlled by nothing but the creative fancy
of the poet, while in the other they are much more determined by the actual
nature of the subject treated of.

DIDEL'PHIA, one of the three subclasses of the Mammalia (the others being
Monodelphia and Ornithodelphia), comprising only one order, that of
Marsupials or pouched mammals.

DIDEROT (d[=e]d-r[=o]), Denis, a French writer and philosopher, born in
1713, at Langres, in Champagne, died in 1784. He was educated in the school
of the Jesuits, and afterwards at Paris, at the College of Harcourt, but
declined to study law, preferring to earn his living by teaching
mathematics. His first works were the _Essai sur le M['e]rite et la Vertu_
(1745); and the _Pens['e]es Philosophiques_ (1746), a pamphlet against the
Christian religion. His _Lettre sur les Aveugles [`a] l'Usage de Ceux qui
Voyent_ is in the same strain. These heterodox publications cost him an
imprisonment for some time at Vincennes. Diderot now tried writing for the
stage, but his pieces were failures. In 1749 he had begun, along with
D'Alembert and some others, the _Encyclopaedia_. At first it was intended
to be mainly a translation of one already published in English by Chambers.
Diderot and D'Alembert, however, enlarged upon this project, and made the
new _Encyclopaedia_ a magnificently comprehensive and bold account of all
the thought and science of the time. Diderot, besides revising the whole,
undertook at first the mechanical arts, and subsequently made contributions
in history, philosophy, and art criticism. But the profits of all his
labour were small, and it was only the liberality of the Empress Catherine,
who purchased his library for 50,000 livres and made him a yearly allowance
of 1000 livres, that saved Diderot from indigence. In 1773 he visited St.
Petersburg to thank his benefactress and was received with great honour. On
his return to France he lived in retirement, passing the last ten years of
his life in writing and conversations, wherein, as Marmontel said, he was
at his best. Besides his articles in the _Encyclopaedia_ he wrote numerous
works, some of which were published after his death. Among the best known
are _Le Neveu de Rameau_, a kind of philosophical dialogue which Goethe
thought worthy of translation; _Essai sur la Peinture_, and _Paradoxe sur
le Com['e]dien_, suggestive essays on the principles of painting and
acting; two lively tales, _La Religieuse_ and _Jacques le Fataliste_. On
account of his great interest in almost every branch of human knowledge,
Voltaire nicknamed him 'Pantophile Diderot'.--BIBLIOGRAPHY: T. Carlyle,
_Essay on Diderot_; F. Bruneti[`e]re, _['E]tudes Critiques_; R. L. Cru,
_Diderot as a Disciple of English Thought_.

DIDO, or ELISSA, the reputed founder of Carthage. She was the daughter of a
king of Tyre, called by some Belus, by others Metten or Matgenus. After her
father's death, her brother Pygmalion murdered her husband Sicharbas, or as
Virgil calls him Sychaeus, with the view of obtaining his wealth. But Dido,
accompanied by many Tyrians of her party, fled with all the treasure over
sea, and, landing on the coast of Africa, founded Carthage about 860 B.C.
The story is told by Virgil, with many inventions of his own, in the
_Aeneid_ (Books i and ii).

DIDOT (d[=e]-d[=o]), a famous house of printers, booksellers, and
typefounders at Paris. The founder was _Francois Didot_, born in 1689, died
1757. Of his sons _Francois-Ambroise_ (born 1720, died 1804) and
_Pierre-Francois_ (born 1732, died 1795) the first distinguished himself in
the type-founding art as an inventor of new processes and machines, the
second was equally eminent for his bibliographical knowledge, and
contributed much also to the advancement of printing.--_Pierre_ (born 1761,
died 1853) succeeded his father Francois-Ambroise in the printing business.
He made himself famous by his magnificent editions of classic authors in
folio, amongst which his Virgil (1798) and his Racine (1801) may be
particularly mentioned. He did much also for the improvement of types. He
is known also as an author.--_Firmin_ (born 1764, died 1836), the brother
of Pierre, took charge of the type-founding, was the inventor of a new sort
of script, and an improver of the stereotype process.--_Ambroise-Firmin_
(born 1790, died 1876), and _Hyacinthe-Firmin_ (born 1794, died 1880)
occupied a distinguished position amongst the publishers of Paris. The
former left a collection of MSS. which was worth, at the time of his death,
about two million francs. The house has now extended its trade into
everything connected with bookselling, paper-making, and bookbinding.

DIDSBURY, a district of Manchester, on the Midland Railway, 4 miles south
by east of Manchester, a place of residence of many Manchester business
men. There is an important Wesleyan Training College there. Pop. 9234.

[Illustration: Didunculus strigirostris]

DIDUN'CULUS, a genus of birds allied to the pigeons, and comprising only
the one species, _D. strigirostris_, native to some of the Samoan Islands.
This bird is of special interest as being the nearest living ally of the
extinct dodo. It has a length of about 14 inches, with a glossy plumage
verging from a velvety black on the back to greenish black on the head,
breast, and abdomen. The large beak, which is nearly as long as the head,
is greatly arched on the upper half, while the lower is furnished with two
or three tooth-like indentations.

DIDYM'IUM, a rare metallic element, occurring along with _lanthanum_ in the
mineral cerite as discovered by Mosander in 1842. It has been resolved into
two new elements: _Praseodymium_ (Pr, 140.9) and _Neodymium_ (Nd, 144.3).

DIE, a metallic stamp for impressing a design or figure upon coins or other
metallic objects. See _Dies_ and _Die-sinking_.

DIE (d[=e]), an ancient town, France, department of Dr[^o]me, 26 miles
south-east of Valence; with an ancient cathedral and Roman remains. Pop.
4000.

DI['E] (di-[=a]), ST., a town, France, department of Vosges, on the
Meurthe, 25 miles E.N.E. of Epinal. Both iron and copper are worked; there
are marble quarries; and numerous manufactures are carried on. Pop. 19,029.

DIEBITSCH-SABALKANSKI, Hans Karl, a Russian general, born at Grossleippe,
in Silesia, in 1785, died 9th June, 1831. He was educated at the military
school of Berlin, but in 1801 quitted the Prussian service for that of
Russia. He was present at the battles of Austerlitz and Friedland, served
with distinction in the campaign of 1812, took part in the battles of
Dresden and Leipzig, and was made lieutenant-general at the age of
twenty-eight. He had the chief command in the Turkish War of 1828-9,
stormed Varna, and made the famous passage of the Balkans, for which the
surname of Sabalkanski was conferred on him. In 1830 he commanded the army
sent against the revolted Poles, but did not distinguish himself in this
service.--Cf. Bantych-Kamenski, _Biographies of Russian Field-marshals_.

DIEFFENBACH (d[=e]'fen-b[.a]_h_), Johann Friedrich, German surgeon, born at
K[:o]nigsberg in 1792, died in 1847. After having studied at Bonn and
Paris, he settled in Berlin, where his talent as an operator soon attracted
notice. Surgery is particularly indebted to him for new methods of forming
artificial noses, eyelids, and lips, and curing squinting and stammering.

DIEGO GARCIA. See _Chagos_.

DI'ELECTRIC, in electricity, a name applied by Faraday to any medium
through or across which electrostatic induction can take place. See
_Electricity_ (Electrostatics). Faraday first showed that electrostatic
induction was not action at a distance, but took place by means of the
insulating medium separating the two conductors. The medium he named a
_dielectric_, and measured its specific inductive capacity by taking that
of common air as unity.

DIELY'TRA, or DICENTRA, a genus of plants, of the nat. ord. Fumariaceae or
Fumitories. The best known is _D. spectabilis_, a native of Northern China
and Siberia, now common in European and other gardens. It blossoms in April
and May, and its long drooping racemes of purplish-red blossoms present a
very graceful appearance. It grows freely in the open air. It is sometimes
called bleeding heart or virgin's heart from the shape of the blossoms.

DIEMEN (d[=e]'men), Anton van, Dutch administrator, was born in 1593, died
in 1645. Having gone to India, he speedily rose to the highest dignities,
and was at length, in 1636, made Governor-General. He administered the
government with much ability, and contributed much to the establishment of
the Dutch commerce in India. Abel Tasman, whom he sent with a vessel to the
South Seas in 1642, gave the name of _Van Diemen's Land_ to the island now
called Tasmania.

DIEPPE (d[=e]-ep'), a seaport town, France, department of
Seine-Inf['e]rieure, on the English Channel, at the embouchure of the
Arques, 93 miles N.N.W. of Paris. Almost the only public edifices worth
special notice are the two Gothic churches, St. Jacques, begun in the
thirteenth century, and St. R['e]mi, founded in 1522, and the old castle
(1433), now a barracks. To the west of Dieppe proper is the suburb La
Barre; and on the opposite side of the harbour Le Pollet, inhabited chiefly
by sailors and fishermen. The old port is spacious, but a new channel with
its own harbour system has been added, and vessels of 20-foot draft can now
enter. Dieppe is one of the chief watering-places of France, and is much
frequented by visitors in summer and autumn. The great bathing
establishment forms a luxurious retreat for bathers and invalids, and
includes a ballroom. The manufactures include works in ivory, horn, and
bone, lace-making, sugar-refining, and shipbuilding. There is a busy
fishery, and the foreign trade is still considerable. There is constant
steam intercourse between this port and Newhaven. In early times Dieppe was
the chief port of France, but its prosperity diminished after the
revocation of the Edict of Nantes (1685). During the European War Dieppe
was an important Allied base. Pop. 23,973.

DIERX, L['E]ON, French poet, born in the Island of R['e]union in 1838.
Educated in Paris, he became one of the foremost of the Parnassians. His
works include: _Aspirations_, _Po[`e]mes et Po['e]sies_, _La rencontre_,
and _Les Amants_. His collected poems (1889-90) were crowned by the
Acad['e]mie. He died in Paris, 11th June, 1912.

DIES AND DIE-SINKING. Die-sinking is the art of preparing dies, a die being
a plate or block, usually of metal, so cut or shaped as to be capable, by
means of stamping or pressure, of transferring a given design to some
article which is to be manufactured in quantity. The pressure may be
applied by any sort of power, from hand to hydraulic.

The steel for the manufacture of steel dies is carefully selected, forged
at a high heat into the rough die, softened by careful annealing, and then
handed over to the engraver. After the engraver has worked out the design
in intaglio, the die is put through the operation of hardening, after
which, being cleaned and polished, it is called a _matrix_. This is not,
however, generally employed in multiplying impressions, but is used for
making a _punch_ or steel impression for relief. For this purpose another
block of steel of the same quality is selected, and, being carefully
annealed or softened, is compressed by proper machinery upon the matrix
till it receives the impression. When this process is complete, the
impression is retouched by the engraver, and hardened and collared like the
matrix. Any number of dies may now be made from this punch by impressing
upon it plugs of soft steel.

There is hardly any article which does not in the course of its manufacture
require the use of a die of some kind. For all sorts of metal-work, seals,
rings, silverware, moulds and shapes of sheet steel or tin, dies are
employed. For this class of work they are usually of steel. For embossing
articles of leather, wood, celluloid, rubber, cloth, or clay, dies of brass
and phosphor-bronze are commonly used, these being easier media to work in
and yet sufficiently strong. The dies for letter headings and company seals
are cut, in reverse to the design required, in steel; those for sealing-wax
seals in steel or brass; the lettering being usually punched in by hand by
separate letter punches, which themselves have been cut in relief on steel.
Designs which are unusually ornate may be engraved by hand. Dies for
embossing designs on leather, catalogue covers, cardboard articles, cards,
and soft materials are usually modelled in brass. The design in reverse is
cut out to a depth corresponding to the relief wanted. These dies are
usually worked up by hand by the engraver. Dies for the reproduction of
rubber stamps for printing on clay are cut in phosphor-bronze or hard brass
in relief and reverse, and with an extreme bevel. The dies or blocks are
then struck deeply into lead, and melted rubber is poured into the moulds
so formed. When set, the rubber is removed and mounted as a hand-stamp
ready to impress the clay in ink. Dies for wallpapers are cut on rollers.
Steel dies for flower-shapes have a cutting edge, so that they can stamp
out and emboss in one action. Of late years machinery has come much into
use for relieving the engraver of some of his labour, but the designs are
generally kept secret. One machine, called the pantograph or engraving
machine, reproduces engravings in all metals and many shapes from patterns.
Many of the stamp-duty steel dies made and issued by the Royal Mint are
reproduced from this machine in reductions from brass
patterns.--BIBLIOGRAPHY: Lucas, _Dies and Die-making_; J. V. Woodworth,
_Dies: their Construction and Use_.

DIESEL, Rudolph, German inventor, born in Paris in 1858, died in 1913.
Educated in England and at Munich, he proposed in 1893 to utilize directly
the energy created by the combustion of fuel, a proposal which led to his
invention of the Diesel engine. (See _Internal Combustion Engines_.) In
1913 he was called to England to consult with the Admiralty on the
application of his motor, but was drowned in crossing the Channel. In 1894
he published a monograph entitled _Theory and Construction of a Rational
Heat Motor_.

DIES FASTI ET NEFASTI, a Roman division of days, with reference to judicial
business, into working-days and holidays. A _dies fastus_ was a day on
which courts and assemblies could be held and judgments pronounced; a _dies
nefastus_, a day on which courts could not be held nor judgments
pronounced.

DIES IRAE (d[=i]'es [=i]'r[=e]), one of the great Latin hymns of the
Mediaeval Church, generally used as part of the requiem or mass for the
souls of the dead. It describes, as its name ('the day of wrath') denotes,
the Last Judgment of the world, and seems to have been suggested by the
description in _Zephaniah_, i, 15 and 16. It is supposed to have been
written by Thomas da Celano, a Franciscan friar of the thirteenth century.
It was translated by Crashaw and Dryden in the seventeenth century, and by
Macaulay and others in the nineteenth, but none of these translations
conveys the solemn force of the original.

DIEST (d[=e]st), a town, Belgium, province of Brabant, 32 miles E.N.E. of
Brussels. It has some manufactures, but the chief products of the place are
beer and gin, the former being largely exported. The town was occupied by
the Germans in 1914, and re-entered by the Belgians in 1918. Pop. 8800.

DIESTERWEG, Friedrich Adolf Wilhelm, German educator, born in 1790, died in
1866. In 1820 he became director of the new Teachers' Seminary at M[:o]rs,
and soon gained a reputation as teacher and educator. He was a follower of
Pestalozzi, and aimed at making every subject of instruction a means of
education. In 1827 he founded the _Rheinische Bl[:a]tter f[:u]r Erziehung
und Unterricht_, wherein he advocated his pedagogical views.

DI'ET, a meeting of some body of men held for deliberation or other
purposes; a term especially applied to the legislative or administrative
assemblies of Austria, Germany, and Poland.

DIETET'ICS (Gr. _diaita_, daily regimen), that part of medicine which
relates to the regulation of diet. The ideal diet is clearly that which,
without burdening the viscera uselessly, furnishes all necessary nutritive
elements, with due consideration for special physiological conditions in
any given case. Under the head of _Aliment_ the physiological properties of
various foods have already been considered theoretically in respect of
their capacity to supply physical waste in nitrogenous and non-nitrogenous
matter. (See _Aliment_.) No single substance contains the elements needed
to replace this waste in their requisite proportions, and a mixed diet is
therefore necessary. For instance, to secure the required amount of carbon
a man would need to eat about 4 lb. of lean beef, while 1 lb. would yield
all the nitrogen required; thus, apart from the labour of digesting 4 lb.
of beef, the body would be compelled to get rid of the excess of nitrogen.
Bread, on the other hand, has carbon in abundance, but is deficient in
nitrogen; so that by uniting 2 lb. of bread with 3/4 lb. of lean meat, the
due proportion of carbon and nitrogen is satisfactorily supplied. Milk and
oatmeal taken together also contain nitrogenous and non-nitrogenous
substances in nearly the required proportions. A certain proportion of
saline matter is also necessary. The nature of the food most suitable for a
healthy man is dependent in part upon general conditions, such as climate
and season, and in part upon special conditions of individual habit. The
inhabitants of the Arctic regions need large quantities of oleaginous food;
those of the Tropics live chiefly on starchy products. With increased
activity and exertion, as in training, an increase in the nitrogenous foods
becomes necessary. In a state of health we need not draw hairbreadth
distinctions as to the superior salubrity of the several sorts of diet, the
quantity rather than the quality of food being the main consideration.
Those persons who have been most remarkable for health and long life have
generally been contented with two moderate meals a day, which are certainly
quite sufficient during a state of health. In various countries the
breakfast generally consists of tea, coffee, or cocoa, with a certain
proportion of bread and butter; persons with delicate digestive powers, or
who lead a sedentary life, cannot with safety or comfort eat animal food
_constantly_ to breakfast. At dinner all made-dishes highly spiced, such as
curries, turtle-soup, &c., as provoking appetite, are hurtful; and the
custom of late dining is not to be commended. Stewed and boiled meats are
more difficult to digest than meat cooked by fire alone. The flesh of young
animals seems to be more difficult of digestion than that of old; and the
flesh of tame than that of wild animals. All sorts of fat meat must be
taken in smaller quantities. Hence, also, ham, bacon, and salted meats
cannot be eaten in such quantities as the tender flesh of poultry. Fish has
the advantage of being easily soluble. All boiled vegetables are in general
easy of digestion; raw vegetables and salads are rather more difficult.
Fruit should be taken in the forenoon rather than after a hearty meal. The
moderate use of fermented liquors is far from being invariably an evil, but
the smaller the quantity habitually used the better in the majority of
cases.

In all diseases attended with much fever or quickness of pulse the stomach
loathes animal food, and there is generally a great increase of thirst, to
quench which water, either quite cold, or iced, or tepid, or rendered acid,
may be freely indulged. Infusions, too, of barley, sage, balm, &c., may be
taken. In chronic diseases attended with hectic fever, milk is the most
proper diet. The best food for infants is, of course, their mother's milk;
but whenever they begin to cut teeth a little animal food, such as
soft-boiled eggs, beef-tea, and even chicken minced very fine, may be
given. Many infants suffer from having too much sugar given them in their
food.--BIBLIOGRAPHY: R. H. Chittenden, _Physiological Economy in
Nutrition_, and _Nutrition of Man_; Hutchison, _Food and Dietetics_; Lusk,
_The Science of Nutrition_.

DIETRICH (d[=e]'tri_h_), Christian Wilhelm Ernst, a German painter and
engraver, born in 1712, died in 1774. He studied under his father, and
afterwards under Alexander Thiele at Dresden, where he became court-painter
and professor in the academy. He adopted several different manners,
successfully imitating Raphael and Mieris, Correggio, and Ostade.

DIETRICH OF BERN (d[=e]'tri_h_), the name under which Theodoric the Great,
King of the Ostrogoths, appears in the old German legends. Bern stands for
Verona, his capital.

DIEU, or D'YEU (dy_eu_; ancient INSULA DEI), an island off the west coast
of France, department of Vend['e]e. It is inaccessible on the west side,
but on the east has a tolerable harbour defended by batteries. The chief
industry is fishing. There are four lighthouses on the island. Pop. 3809.

DIEU ET MON DROIT (dy_eu_ e mo[n.] drw[:a]; 'God and my right'), the
battle-cry of Richard I at the battle of Gisors (1198), signifying that he
was not subject to France, but owed his power to God alone. The battle-cry
was then adopted as the motto of the arms of England, and revived by Edward
III in 1340, when he claimed the crown of France. Except during the reigns
of Elizabeth and Anne, who used the motto _Semper eadem_, and of William
III, who personally used _Je maintiendray_, it has ever since been the
royal motto of England.

DIEZ (d[=e]ts), Friedrich Christian, German philologist of the Romance
languages, born in 1794, died in 1876. Having qualified himself as a
lecturer at Bonn, he was appointed professor of the Romance languages there
in 1830. His work stands in much the same relation to the Romance dialects
which the researches of Grimm occupy with respect to German dialects. In
addition to various works on the poetry of the Troubadours, he published a
very valuable _Grammatik der Romanischen Sprachen_ (1836-42, translated
into English by Cayley in 1863), and an _Etymologisches W[:o]rterbuch der
Romanischen Sprachen_ (1853).

DIFFERENCE, a stock-exchange term. When stock is bought or sold merely as a
speculation for the rise or fall, with no intention of the buyer to 'take
up' the stock, or of the seller to deliver it, the 'difference' is the
movement in price which may take place between the date of the transaction
and the following 'settling-day'. If the price falls, the buyer has to pay
the difference upon 'carrying over' his purchase to the next account; if it
rises, the seller is at the loss. Since the first weeks of the European War
all stock-exchange transactions have been made, in theory at least, for
cash, and speculative business of this nature has been consequently much
reduced.

DIFFERENCES, FINITE, a calculus much used in actuarial work, which deals
with a series of numbers by considering the differences of the successive
terms.

If u_1, u_2, u_3, ... are the terms of the series, then u_2 - u_1, u_3 -
u_2, u_4 - u_3,... form another series called the series of first
differences. The notation used is u_2 - u_1 = [Delta]u_1, u_3 - u_2 =
[Delta]u_2,...

These first differences may themselves be differenced, giving the second
differences [Delta]u_2 - [Delta]u_1, [Delta]u_3 - [Delta]u_2, ..., which
are written [Delta]^2u_1, [Delta]^2u_2,...

Similarly, we form the third differences [Delta]^3u_1 = [Delta]^2u_2 -
[Delta]^2u_1, and so on.

As an example, let the original series be the cubes of the natural numbers.

     1   8  27  64  125   216  /  343  512
     7  19  37  61   91  /  127   169
    12  18  24  30  /  36   42
     6   6   6  /  6    6
     0   0  /  0   0

Here we begin by writing down the series of cubes as far, say, as 216;
beneath these we write the first differences 8 - 1 = 7, 27 - 8 = 19, &c. We
thus obtain the part of the table to the left of the diagonal line.

We observe that the third differences are constant, each being 6. (It is
easy to prove generally that the nth differences of the series, 1^n, 2^n,
3^n,..., are constant.) Knowing the third differences, we can now extend
the table as far as we wish to the right of the diagonal line. We get first
6 + 30 = 36, 36 + 91 = 127, 127 + 216 = 343. We infer that 7^3 = 343.

Since u_1 - u_0 = [Delta]u_0, we have u_1 = u_0 + [Delta]u_0 = (1 +
[Delta])u_0.

Similarly, u_2 = (1 + [Delta])u_1 = (1 + [Delta])^2u_0; and, generally,

  u^x = (1 + [Delta])^xu_0
           = {1 + x[Delta] + (x(x-1)/(1x2)) x [Delta]^2 + ...}u_0
           = u_0 + x[Delta]u_0 + (x(x-1)/(1x2)) x [Delta]^2)u_0 + ...

a formula much used by calculators, and known as Newton's interpolation
formula.

The above symbolic method of proof only applies when x is a positive
integer, but the result is used in practice even for fractional values of
x, as in most cases the high differences become negligible.

If n is a positive integer, it is easy to prove that

  [Delta]^nu_x = u_{x+n} - nu_{x+n-1} + ((n(n-1))/(1x2))u_{x+n-2} - ...

If the nth differences vanish, or are negligible, this gives

  0 = u_{x+n} - nu_{x+n-1} + ((n(n-1))/(1x2))u_{x+n-2} -... +(-1)^nu_x,

another useful interpolation formula, by which we can calculate any missing
term of a series.--BIBLIOGRAPHY: G. Boole, _Finite Differences; Textbook of
the Institute of Actuaries_.

DIFFERENTIAL EQUATION, an algebraical relation involving derivatives or
differentials. Examples:

  d^2z/dt^2 = g:  ydx + xdy + zdz = 0.

An _ordinary_ differential equation involves only one independent variable,
a _partial_ differential equation involves more than one. Examples of
ordinary equations:

  d^2y/dx^2 + (1/x)dy/dx + y = 0;  d^2x/dt^2 + a(dy/dt) + px + qy = 0.

Examples of partial differential equations:

  x(dz/dx) + y(dz/dy) = nz;  d^2u/dx^2 + d^2u/dy^2 + d^2u/dz^2 = 0.

Equations, whether ordinary or partial, can also be classified as _linear_
or _non-linear_. A linear equation is a rational integral equation of the
first degree in the dependent variable or variables and their derivatives.
The equation

  x^2 d^2y/dx^2 + x dy/dx + (x^4 + 1)y = 0

is linear, but

  (dy/dx)^2 = xy and y dy/dx = x^2

are non-linear. The _order_ of an equation is the order of the highest
derivative or differential which it contains. Of the three equations last
written, the first is _linear of the second order_, the other two are of
the _first order and second degree_. To _integrate_ a differential equation
or system of equations is to find a relation or relations among the
variables, equivalent to the given equation or equations. Thus the integral
of

  d^2z/dt^2 = g is z =  1/2gt^2 + At + B,

where A and B are _arbitrary constants_. An ordinary equation of the _n_th
order with one dependent variable has exactly _n_ arbitrary constants in
its complete integral, or solution. In a practical problem the arbitrary
constants are determined by the _initial_, or _boundary_, _conditions_. The
solution of d^2z/dt^2 = g, e.g. is completely determinate if the values of
z and dz/dt when t = 0 are given. The solution of _partial_ equations may
involve arbitrary _functions_, which become definite when proper initial or
boundary conditions are assigned. Thus the equation du/dx = du/dt has for
its complete solution u = [phi](x + t), where [phi] may be a function of
any form whatever; if now we are given that, when t = 0, u = a given
function f(x), we obtain f(x) = [phi](x), so that the solution required is
u = f(x + t). Certain ordinary linear equations of the second order are
specially important, both from the beauty of their theory and from their
usefulness in Mathematical Physics. Some of these equations are: Bessel's
equation, Legendre's equation, the hypergeometric equation, Mathieu's
equation, Lam['e]'s equation. Linear partial equations of the second order
are fundamental in Physics. Such are: Laplace's equation,

  d^2V/dx^2 + d^2V/dy^2 + d^2V/dz^2= 0;

the wave equation,

  d^2V/dt^2 = c^2(d^2V/dx^2 + d^2V/dy^2 + d^2V/dz^2);

the equation of conduction of heat,

  dV/dt = k(d^2V/dx^2 + d^2V/dy^2 + d^2V/dz^2).

These involve one dependent variable only. Equations with several dependent
variables occur in Elasticity, Electrodynamics, and Hydrodynamics. A
notable feature of the hydrodynamical equations is that they are not
linear.

No general rules exist enabling us to deal with a differential equation
taken at random, and only a few types have been completely solved. Of
soluble equations, the most important are those which are _linear with
constant coefficients_.

_Example 1._ d^2x/dt^2 - 7dx/dt + 12 = 0. To solve this, try x = e^{mt}. We
find e^{mt}(m^2 - 7m + 12) = 0. Thus m = 3 or 4. It is now easy to show
that x = Ae^{3t} + Be^{4t} is a solution, where A and B are arbitrary
constants. This is the general solution. We can determine A and B if the
values of x and dx/dt are given for a definite value of t, say t = 0.

_Example 2._ d^2y/dt^2 = c^2 d^2y/dx^2. Try y = e^{lx + mt}. We find m^2 =
c^2l^2, or m = +/-cl. Hence y = Ae^{l(x + ct)} + Be^{l(x - ct)} is a
solution for all values of A, B, l; so, also, is the sum of any number of
terms of similar forms. We may infer that the general solution is

  y = f(x + ct) + F(x - ct),

where f and F are arbitrary functions. It is only in exceptional cases that
an equation can be solved, as in these two examples, by an analytical
formula; indeed, differential equations are the most fertile source of new
functions in analysis. But, as in the analogous cases of algebraic
equations and definite integrals, it may be quite possible to find, by
methods of approximation, an arithmetical solution which is sufficient for
the purpose in hand.--BIBLIOGRAPHY: H. T. H. Piaggio, _Differential
Equations_; J. M. Page, _Ordinary Differential Equations_; A. R. Forsyth,
_A Treatise on Differential Equations_; E. T. Whittaker and G. N. Watson,
_Modern Analysis_.

DIFFRAC'TION, a term applied to the bending that rays of light undergo in
passing close to the edge of an opaque body. Thus when a beam of direct
sunlight is admitted into a dark room through a narrow slit, and falls upon
a screen placed to receive it, there appears a line of white light bordered
by coloured fringes; these fringes are produced by diffraction, and in the
case given it may be seen that the red or long-wave rays are diffracted
more than the blue rays. See _Interference_.

DIFFU'SION, the gradual mixing of gases, liquids, or solids when brought
into direct contact. When a block of lead is placed on a block of gold,
with their smooth surfaces in close contact, it is found that, after
several weeks, gold has diffused into the lead, and lead into the gold. In
the case of gases, when a jar of oxygen and a jar of hydrogen are connected
together by a tube or opening of any kind, they rapidly become mixed; and
their mixture does not depend on gravity, but takes place in opposition to
that force, as may be shown by placing the jar of hydrogen gas above the
other. Oxygen is sixteen times heavier than hydrogen, bulk for bulk, but
the heavier gas moves upwards and the lighter downwards, and the process of
intermixture, or _diffusion_, goes on till the two gases are apparently
equably distributed throughout the whole space. After that they have no
tendency whatever to separate. Similarly, if two vessels, one containing
oxygen and the other hydrogen, be connected by a tube which is stuffed with
a plug of porous material, such as plaster of Paris, the gases gradually
diffuse one into the other through the porous plug. The two gases, however,
do not pass through the porous separator at equal rates, but in _inverse
proportion to the square roots of the densities of the gases_. Thus in the
case of two vessels, one containing hydrogen and the other oxygen, which is
sixteen times as heavy as hydrogen, the hydrogen will pass towards the
oxygen jar four times as quickly as the oxygen will pass towards the
hydrogen jar. Kindred phenomena occur when two liquids that are capable of
mixing, such as alcohol and water, are put in contact, the two gradually
diffusing one into the other in spite of the action of gravity. In some
cases, however, as where ether and water are employed, the diffusion is
only partial, this result arising from the fact that these two liquids are
not miscible in all proportions. When solutions of various solid bodies are
placed in contact, interdiffusion also takes place. On the results of his
examination of the phenomena of diffusion of liquids and salts across
porous membranes or _septa_, Graham founded a method of separating
_colloid_ from _crystalloid_ bodies, which he called _dialysis_.

DIGAM'MA, a letter which once belonged to the Greek alphabet, and which
remained longest in use among the Aeolians. It resembled our letter F, and
hence was called _digamma_, that is, double [Gamma]. It appears to have had
the force of _f_ or _v_. Its existence was first pointed out by Richard
Bentley.

DIGBY, Sir Everard, an English gentleman, born of a Roman Catholic family
in 1578. He enjoyed some consideration at the court of Elizabeth and James
I, by whom he was knighted. Having contributed money to the Guy Fawkes
conspiracy, he was tried and hanged in 1606.

DIGBY, Sir Kenelm, eldest son of the preceding, born in 1603, died in 1665.
He studied at Oxford, was knighted in 1623, and on the accession of Charles
I was created a gentleman of the bedchamber, a Commissioner of the Navy,
and a governor of Trinity House. He soon after fitted out at his own
expense a small but successful squadron against the French and Venetians.
In 1636 he became a Roman Catholic, and was imprisoned as a Royalist during
1642-3, when he was allowed to retire to the Continent. At the Restoration
he returned to England, became a member of the Royal Society, and was much
visited by men of science. He wrote numerous works: a _Treatise on the
Nature of Bodies_, a _Treatise on the Nature and Operation of the Soul_,
and _Of the Cure of Wounds by the Powder of Sympathy_.

DI'GEST, a name originally given to a collection or body of Roman laws,
digested or arranged under proper titles by order of the Emperor Justinian.
Hence applied to any somewhat similar collection.

DIGES'TER, a strong vessel of copper or iron, on which is screwed an
air-tight cover with a safety-valve, the object being to prevent loss of
heat by evaporation, and to enable boiling to take place at a high
pressure. Water may be thus heated to 400degF.; at which temperature its
solvent power is so greatly increased that bones are converted into a
jelly.

DIGES'TION is that process in the animal body by which the aliments are so
acted upon that the nutritive parts are prepared to enter the circulation,
and separated from those which cannot afford nourishment to the body. The
organs effecting this process are called the _digestive_ organs, and
consist of the stomach, the great and small intestines, &c. (see
_Intestine_, _Stomach_), the liver, and pancreas. When the aliments, after
being properly prepared and mixed with saliva by mastication, have reached
the stomach, they are intimately united with a liquid substance called the
_gastric juice_, by the motion of the stomach. By this motion the aliments
are mechanically separated into their smallest parts, penetrated by the
gastric juice, and transformed into a uniform pulpy or fluid mass. The
gastric juice acts upon the albuminous parts of the food, converting them
into peptones, which can pass through organic membranes and thus enter the
blood. This action is aided by the warmth of the stomach. The pulpy mass,
called _chyme_, proceeds from the stomach, through the pylorus, into that
part of the intestinal canal called the small intestine, where it is mixed
with the pancreatic juice, bile, and intestinal juice. The pancreatic juice
converts starch into sugar, albumins into peptones, and emulsionizes fats,
so that all these kinds of food are rendered capable of absorption. The
process is aided by the intestinal juice. The bile also acts upon fats, and
thus the food is formed into the _chyle_, which is absorbed into the system
by the capillary vessels called _lacteals_ (see _Chyle_; _Chyme_), while
the non-nutritious matters pass down the intestinal canal and are carried
off.--BIBLIOGRAPHY: F. Hare, _Food Factor in Disease_; Taylor, _Digestion
and Metabolism_.

DIGIT (dij'it; Lat. _digitus_, a finger), in arithmetic, any one of the ten
numerals, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0. Digit is also a measure of a
finger's breadth, equal to 3/4 inch.

DIGIT, in astronomy, is the measure by which we estimate the quantity of an
eclipse. The diameter of the sun or moon's disk is conceived to be divided
into twelve equal parts, called _digits_; and according to the number of
those parts or digits which are obscured, so many digits are said to be
eclipsed.

DIGITALIN (dij-i-t[=a]'lin), a vegetable alkaloid, the active principle of
the _Digit[=a]lis purpur[)e]a_ or foxglove. It has a bitter taste, and is a
strong poison, but is used medicinally, especially for the heart. See next
article.

DIGITA'LIS (dij-), a genus of plants, nat. ord. Scrophulariaceae,
containing about twenty species of tall herbs, natives of Europe and
Western Asia. The purple foxglove (_D. purpur[)e]a_) is a common wild
flower in Britain, and several species are grown in gardens. Various
preparations from the foxglove receive this name, and are used in medicine,
principally in cases of heart disease.

DIGITIGRA'DA (_digitus_, finger, toe, and _gradi_, to walk), a section of
the Carnivora, so called from their walking on the ends of their toes; as
the dog, cat, and their allies. See _Plantigrade_.

DIGITO'RIUM, a small portable dumb instrument having a short keyboard with
five keys like those of a piano, used by piano-players for practice, to
give strength and flexibility to the fingers.

DIGNE (d[=e]ny), a town, France, capital of the department of Basses-Alpes,
picturesquely situated on a mountain slope, 60 miles north-east of
Marseilles. In 1629 a plague reduced the population from 20,000 to 1500.
Pop. 7317.

DIJON (d[=e]-zh[=o]n; Lat. _Castrum Divonense_), a town in Eastern France,
capital of the department of C[^o]te-d'Or, in a fertile plain, at the foot
of a range of vine-clad slopes, formerly surrounded by ramparts, which now
furnish beautiful promenades. At some distance it is surrounded by a series
of forts. Some of the buildings belong to the period when Dijon was capital
of the dukedom of Burgundy, the chief being the cathedral of St.
B['e]nigne, a building of vast extent with a lofty wooden spire above 300
feet high; the churches of N[^o]tre Dame and St. Michael; the ancient
palace of the Dukes of Burgundy, now used as the h[^o]tel de ville and
museum; and the _palais de justice_, formerly the Parliament House of
Burgundy. Dijon is the birth-place of Bossuet. It has important educational
institutions and a valuable library. Industries: woollens, hosiery,
candles, mustard, vinegar, chemicals, paper-hangings, tanneries, foundries,
machine factories, cotton- and oil-mills. The trade is considerable,
particularly in the wines of Burgundy. Pop. 76,847.

DIKE, or DYKE (connected with the Gr. _teichos_, wall), a word variously
used in different localities to represent a ditch or trench, and also an
embankment, rampart, or wall. It is specially applied to an embankment
raised to oppose the incursions of the sea or of a river, the dikes of
Holland being notable examples of work of this kind. These are often raised
40 feet above the high-water mark, and are wide enough at the top for a
common roadway or canal, sometimes for both. The Helder Dike, one of the
largest, is about 6 miles in length and costly in upkeep. See _Embankment_.

DIKE, or DYKE, in geology, a term applied to intrusive igneous masses, such
as basalt, which fill up veins and fissures in the other rocks, and
sometimes project on the surface like walls through their superior
resistance to weathering.

DILAPIDATION, in English ecclesiastical law, is where an incumbent of a
church living suffers the parsonage-house or outhouses to fall down, or be
in decay for want of necessary repairs; or it is the pulling down or
destroying any of the houses or buildings belonging to a spiritual living,
or destroying of the woods, trees, &c., appertaining to the same. An
outgoing incumbent (or his heirs) is liable for dilapidation to his
successor. In general, the term is applied to the act of allowing or
causing any lands, houses, &c., to become waste or to decay.

DILEM'MA (from Gr. _di-_, double, and _l[=e]mma_, proposition, assumption),
in logic, a form of argument used to prove the falsehood or absurdity of
some assertion, as in the following instance: If he did so he must be
either foolish or wicked; but we know he is neither foolish nor wicked;
therefore he cannot have done so. The two suppositions, which are equally
untenable, are called the 'horns' of the dilemma.

DILETTANTE (di-let-t[.a]n't[=a]), an Italian expression, signifying a lover
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_.

DIONYSIUS THE AREOPAGITE, that is, one of the judges of the Areopagus, at
Athens, a convert to Christianity by the Apostle Paul about the middle of
the first century, and the first Bishop of Athens, where he suffered
martyrdom. Certain writings formerly ascribed to him consist of obscurely
written treatises on mystical subjects. Scotus Erigena translated them into
Latin. In France, where a certain Dionysius (see _Denis, St._) established
the first Christian community at Paris in the third century, they were
readily received, this Dionysius being without further inquiry taken for
the Areopagite, because the origin of the Gallican Church could thus be
carried back to the first century; and France gained a patron who was a
martyr and the immediate disciple of an apostle.--Cf. article in Smith's
_Dictionary of Christian Biography_.

DIONYSIUS THE ELDER, in Greek history, tyrant or absolute ruler of
Syracuse, born about 430 B.C. of obscure parentage. He obtained the rank of
general, and afterwards of commander-in-chief; and, gaining the support of
the army, he seized the supreme power in Syracuse, though only twenty-five
years of age. He extended his rule over other cities in Sicily; and after
some successes and reverses in the struggle with the Carthaginians, he
gained a complete victory over them under the walls of Syracuse. In his
expeditions into Lower Italy he reduced the city of Rhegium by famine
(387). After another short war with Carthage he lived some time in peace,
occupied with writing poems and tragedies, with which he contended for the
Olympian prize. In 368 he commenced a new war against the Carthaginians,
but failed to drive them entirely out of Sicily. He is said to have died
from a potion administered at the instigation of his son Dionysius the
Younger (367 B.C.).

DIONYSIUS THE LITTLE (so called on account of his short stature), a
Scythian monk who was abbot of a monastery at Rome in the beginning of the
sixth century, and died about the year A.D. 530, according to others about
545, celebrated as the first to introduce the computation of time from the
Christian era. This mode of computation, however, was not publicly used
until the eighth century.

DIONYSIUS THE YOUNGER, a tyrant of Syracuse, who succeeded his father,
Dionysius the Elder, in 367 B.C. For the purpose of recalling him from the
excesses to which he was addicted, his kinsman Dion persuaded him to invite
Plato to his court, but the influence of the philosopher effected no
permanent change. Becoming suspicious of Dion, the tyrant banished him and
confiscated his property, but in 357 B.C. Dion made himself master of
Syracuse. Dionysius fled to Locri, but after the murder of Dion recovered
his power in Syracuse. His misfortunes, however, had rendered him more
cruel, and Timoleon, who came to Syracuse with aid from Corinth against the
Carthaginians, deposed him in 344 B.C. He was carried to Corinth, where he
is said to have gained a living by giving lessons in grammar, or as one of
the attendants on the rites of Cybele.

DIONY'SUS, the original Greek name of the god of wine, the name Bacchus, by
which he was also called both by the Greeks and the Romans, being at first
a mere epithet or surname.--Cf. R. Brown, _The Great Dionysiak Myth_.

DIOON, a genus of Cycads, natives of Mexico, where meal is prepared from
the starchy seeds.

DIOPHAN'TUS OF ALEXANDRIA, the first Greek writer on algebra, flourished,
according to some authorities, about the middle of the fourth century after
Christ. He is called the Father of Algebra, and left behind him thirteen
books of _Arithmetical Questions_, of which only six are extant; and a work
on _Polygonal Numbers_.

DIOP'SIDE, a calcium magnesium silicate, of the pyroxene series, occurring
in igneous rocks and altered limestones, with a vitreous lustre, and of a
pale-green, or a greenish- or yellowish-white colour.

DIOP'SIS, a genus of two-winged flies of which the species are native to
India and Africa. Each side of the head is drawn out into a long lateral
horn, which bears the eye and antenna at its extremity.

DI'OPTASE, emerald copper ore, hydrated silicate of copper, a translucent
mineral, occurring crystallized in six-sided prisms. It occurs in Siberia,
Hungary, and Chile. It has been used as a gem-stone, notably in Persia and
Russia.

DIOPTER, the unit in terms of which the power of a lens or curved mirror
can be expressed. It is obtained by taking the reciprocal of the focal
length of the lens or mirror in metres. Thus, a lens with focal length 1
metre has a power of 1 diopter. If the focal length is 2 metres, the power
is 1/2 diopter. The power may also be obtained by dividing 39.37 by the
focal length in inches. The unit is employed in classifying spectacle
lenses.

DI'ORITE, a coarsely crystalline igneous rock, sometimes of a whitish
colour speckled with black or greenish-black, sometimes very dark in
colour, consisting of hornblende and calcium sodium felspar. Dark mica
sometimes takes the place of hornblende (mica-diorite). The 'greenstones'
of older authors are mostly diorites.

DIOSCOREACEAE, a nat. ord. of monocotyledons, with alternate
reticulate-veined leaves, tuberous root-stocks, and twining stems. The
flowers are small and unisexual. There are 6 genera, with about 100
species. The typical genus is Dioscorea, which includes the yam. Black
bryony is the only British representative.

DIOSCOR'IDES, Pedanius, a Greek physician, born in Cilicia in the first
century of the Christian era. He was the author of a celebrated work on
_materia medica_, in five books, particularly valuable in regard to botany.

DIOSCU'RI. See _Castor and Pollux_.

DIOS'PYROS, a large genus of trees or shrubs, natives of the warmer regions
of the world, nat. ord. Ebenaceae. The trees of this genus supply ebony
wood. That from Ceylon is the wood of _D. Eb[)e]num_; from India, of _D.
melanoxylon_ and other species; and that from Mauritius, _D. tesselaria_.
The Chinese date-plum (_D. kaki_) is an apple-like tree which produces
large red fruits resembling tomatoes. In China and Japan this tree is as
important as the apple is in Northern Europe.

DIP, of the horizon, the angle of depression of the visible horizon at sea
below the true horizontal direction, due to the height of the eye above the
level of the sea. The dip in minutes of arc is approximat

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