Chapter IV: Part 4

_Diazomethane_, CH2N2, was first obtained in 1894 by H. v. Pechmann
(_Ber._, 1894, 27, p. 1888; 1895, 28, p. 855). It is prepared by the
action of aqueous or alcoholic solutions of the caustic alkalis on the
nitroso-acidyl derivatives of methylamine (such, for example, as
_nitrosomethyl urethane_, NO.N(CH3).CO2C2H5, which is formed on
passing nitrous fumes into an ethereal solution of methyl urethane).
E. Bamberger (_Ber._, 1895, 28, p. 1682) regards it as the anhydride
of iso-diazomethane, CH3.N:N.OH, and has prepared it by a method
similar to that used for the preparation of iso-diazobenzene. By the
action of bleaching powder on methylamine hydrochloride, there is
obtained a volatile liquid (_methyldichloramine_, CH3.N.Cl2), boiling
at 58-60 deg. C., which explodes violently when heated with water,
yielding hydrocyanic acid (CH3NCl2 = HCN + 2HCl). Well-dried
hydroxylamine hydrochloride is dissolved in methyl alcohol and mixed
with sodium methylate; a solution of methyldichloramine in absolute
ether is then added and an ethereal solution of diazomethane distils
over. Diazomethane is a yellow inodorous gas, very poisonous and
corrosive. It may be condensed to a liquid, which boils at about 0
deg. C. It is a powerful methylating agent, reacting with water to
form methyl alcohol, and converting acetic acid into methylacetate,
hydrochloric acid into methyl chloride, hydrocyanic acid into
acetonitrile, and phenol into anisol, nitrogen being eliminated in
each case. It is reduced by sodium amalgam (in alcoholic solution) to
_methylhydrazine_, CH3.NH.NH2. It unites directly with acetylene to
form pyrazole (H. v. Pechmann, _Ber._, 1898, 31, p. 2950) and with
fumaric methyl ester it forms pyrazolin dicarboxylic ester.
(F. G. P.*)

See G. T. Morgan, _B.A. Rep._, 1902; J. Cain, _Diazo Compounds_,
1908.

DIAZOMATA (Gr. [Greek: diazoma], a girdle), in architecture, the landing places and passages which were carried round the semicircle and separated the upper and lower tiers in a Greek theatre.

DIBDIN, CHARLES (1745-1814), British musician, dramatist, novelist, actor and song-writer, the son of a parish clerk, was born at Southampton on or before the 4th of March 1745, and was the youngest of a family of eighteen. His parents designing him for the church, he was sent to Winchester; but his love of music early diverted his thoughts from the clerical profession. After receiving some instruction from the organist of Winchester cathedral, where he was a chorister from 1756 to 1759, he went to London at the age of fifteen. Here he was placed in a music warehouse in Cheapside, but he soon abandoned this employment to become a singing actor at Covent Garden. On the 21st of May 1762 his first work, an operetta entitled _The Shepherd's Artifice_, with words and music by himself, was produced at this theatre. Other works followed, his reputation being firmly established by the music to the play of _The Padlock_, produced at Drury Lane under Garrick's management in 1768, the composer himself taking the part of Mungo with conspicuous success. He continued for some years to be connected with Drury Lane, both as composer and as actor, and produced during this period two of his best known works, _The Waterman_ (1774) and _The Quaker_ (1775). A quarrel with Garrick led to the termination of his engagement. In _The Comic Mirror_ he ridiculed prominent contemporary figures through the medium of a puppet show. In 1782 he became joint manager of the Royal circus, afterwards known as the Surrey theatre. In three years he lost this position owing to a quarrel with his partner. His opera _Liberty Hall_, containing the successful songs "Jock Ratlin," "The Highmettled Racer," and "The Bells of Aberdovey," was produced at Drury Lane theatre on the 8th of February 1785. In 1788 he sailed for the East Indies, but the vessel having put in to Torbay in stress of weather, he changed his mind and returned to London. In a musical variety entertainment called _The Oddities_, he succeeded in winning marked popularity with a number of songs that included "'Twas in the good ship 'Rover'," "Saturday Night at Sea," "I sailed from the Downs in the 'Nancy,'" and the immortal "Tom Bowling," written on the death of his eldest brother, Captain Thomas Dibdin, at whose invitation he had planned his visit to India. A series of monodramatic entertainments which he gave at his theatre, Sans Souci, in Leicester Square, brought his songs, music and recitations more prominently into notice, and permanently established his fame as a lyric poet. It was at these entertainments that he first introduced many of those sea-songs which so powerfully influenced the national spirit. The words breathe the simple loyalty and dauntless courage that are the cardinal virtues of the British sailor, and the music was appropriate and naturally melodious. Their effect in stimulating and ennobling the spirit of the navy during the war with France was so marked as to call for special acknowledgment. In 1803 Dibdin was rewarded by government with a pension of L200 a year, of which he was only for a time deprived under the administration of Lord Grenville. During this period he opened a music shop in the Strand, but the venture was a failure. Dibdin died of paralysis in London on the 25th of July 1814. Besides his _Musical Tour through England_ (1788), his _Professional Life_, an autobiography published in 1803, a _History of the Stage_ (1795), and several smaller works, he wrote upwards of 1400 songs and about thirty dramatic pieces. He also wrote the following novels:--_The Devil_ (1785); _Hannah Hewitt_ (1792); _The Younger Brother_ (1793). An edition of his songs by G. Hogarth (1843) contains a memoir of his life. His two sons, Charles and Thomas John Dibdin (q.v.), whose works are often confused with those of their father, were also popular dramatists in their day.

DIBDIN, THOMAS FROGNALL (1776-1847), English bibliographer, born at Calcutta in 1776, was the son of Thomas Dibdin, the sailor brother of Charles Dibdin. His father and mother both died on the way home to England in 1780, and Thomas was brought up by a maternal uncle. He was educated at St John's College, Oxford, and studied for a time at Lincoln's Inn. After an unsuccessful attempt to obtain practice as a provincial counsel at Worcester, he was ordained a clergyman at the close of 1804, being appointed to a curacy at Kensington. It was not until 1823 that he received the living of Exning in Sussex. Soon afterwards he was appointed by Lord Liverpool to the rectory of St Mary's, Bryanston Square, which he held until his death on the 18th of November 1847. The first of his numerous bibliographical works was his _Introduction to the Knowledge of Editions of the Classics_ (1802), which brought him under the notice of the third Earl Spencer, to whom he owed much important aid in his bibliographical pursuits. The rich library at Althorp was thrown open to him; he spent much of his time in it, and in 1814-1815 published his _Bibliotheca Spenceriana_. As the library was not open to the general public, the information given in the _Bibliotheca_ was found very useful, but since its author was unable even to read the characters in which the books he described were written, the work was marred by the errors which more or less characterize all his productions. This fault of inaccuracy however was less obtrusive in his series of playful, discursive works in the form of dialogues on his favourite subject, the first of which, _Bibliomania_ (1809), was republished with large additions in 1811, and was very popular, passing through numerous editions. To the same class belonged the _Bibliographical Decameron_, a larger work, which appeared in 1817. In 1810 he began the publication of a new and much extended edition of Ames's _Typographical Antiquities_. The first volume was a great success, but the publication was checked by the failure of the fourth volume, and was never completed. In 1818 Dibdin was commissioned by Earl Spencer to purchase books for him on the continent, an expedition described in his sumptuous _Bibliographical, Antiquarian and Picturesque Tour in France and Germany_ (1821). In 1824 he made an ambitious venture in his _Library Companion, or the Young Man's Guide and Old Man's Comfort in the Choice of a Library_, intended to point out the best works in all departments of literature. His culture was not broad enough, however, to render him competent for the task, and the work was severely criticized. For some years Dibdin gave himself up chiefly to religious literature. He returned to bibliography in his _Bibliophobia, or Remarks on the Present Depression in the State of Literature and the Book Trade_ (1832), and the same subject furnishes the main interest of his _Reminiscences of a Literary Life_ (1836), and his _Bibliographical, Antiquarian and Picturesque Tour in the Northern Counties of England and Scotland_ (1838). Dibdin was the originator and vice-president, Lord Spencer being the president, of the Roxburghe Club, founded in 1812,--the first of the numerous book clubs which have done such service to literature.

DIBDIN, THOMAS JOHN (1771-1841), English dramatist and song-writer, son of Charles Dibdin, the song-writer, and of Mrs Davenet, an actress whose real name was Harriet Pitt, was born on the 21st of March 1771. He was apprenticed to his maternal uncle, a London upholsterer, and later to William Rawlins, afterwards sheriff of London. He summoned his second master unsuccessfully for rough treatment; and after a few years of service he ran away to join a company of country players. From 1789 to 1795 he played in all sorts of parts; he acted as scene painter at Liverpool in 1791; and during this period he composed more than 1000 songs. He made his first attempt as a dramatic writer in _Something New_, followed by _The Mad Guardian_ in 1795. He returned to London in 1795, having married two years before; and in the winter of 1798-1799 his _Jew and the Doctor_ was produced at Covent Garden. From this time he contributed a very large number of comedies, operas, farces, &c., to the public entertainment. Some of these brought immense popularity to the writer and immense profits to the theatres. It is stated that the pantomime of _Mother Goose_ (1807) produced more than L20,000 for the management at Covent Garden theatre, and the _High-mettled Racer_, adapted as a pantomime from his father's play, L18,000 at Astley's. Dibdin was prompter and pantomime writer at Drury Lane until 1816, when he took the Surrey theatre. This venture proved disastrous and he became bankrupt. After this he was manager of the Haymarket, but without his old success, and his last years were passed in comparative poverty. In 1827 he published two volumes of _Reminiscences_; and at the time of his death he was preparing an edition of his father's sea songs, for which a small sum was allowed him weekly by the lords of the admiralty. Of his own songs "The Oak Table" and "The Snug Little Island" are well-known examples. He died in London on the 16th of September 1841.

DIBRA (Slav. _Debra_), the capital of a sanjak bearing the same name, in the vilayet of Monastir, eastern Albania, Turkey. Pop. (1900) about 15,000. Dibra occupies a valley enclosed by mountains, and watered by the Tsrni Drin and Radika rivers, which meet 3 m. S. It is a fortified city, and the only episcopal see of the Bulgarian exarchate in Albania; most of the inhabitants are Albanians, but there is a strong Bulgarian colony. The local trade is almost entirely agricultural.

DIBRUGARH, a town of British India, in the Lakhimpur district of eastern Bengal and Assam, of which it is the headquarters, situated on the Dibru river about 4 m. above its confluence with the Brahmaputra. Pop. (1901) 11,227. It is the terminus of steamer navigation on the Brahmaputra, and also of a railway running to important coal-mines and petroleum wells, which connects with the Assam-Bengal system. Large quantities of coal and tea are exported. There are a military cantonment, the headquarters of the volunteer corps known as the Assam Valley Light Horse; a government high school, a training school for masters; and an aided school for girls. In 1900 a medical school for the province was established, out of a bequest left by Brigade-Surgeon J. Berry-White, which is maintained by the government, to train hospital assistants for the tea gardens. The Williamson artisan school is entirely supported by an endowment.

DICAEARCHUS, of Messene in Sicily, Peripatetic philosopher and pupil of Aristotle, historian, and geographer, flourished about 320 B.C. He was a friend of Theophrastus, to whom he dedicated the majority of his works. Of his writings, which comprised treatises on a great variety of subjects, only the titles and a few fragments survive. The most important of them was his [Greek: bios tes Hellados] (_Life in Greece_), in which the moral, political and social condition of the people was very fully discussed. In his _Tripoliticos_ he described the best form of government as a mixture of monarchy, aristocracy and democracy, and illustrated it by the example of Sparta. Among the philosophical works of Dicaearchus may be mentioned the _Lesbiaci_, a dialogue in three books, in which the author endeavours to prove that the soul is mortal, to which he added a supplement called _Corinthiaci_. He also wrote a _Description of the World_ illustrated by maps, in which was probably included his _Measurements of Mountains_. A description of Greece (150 iambics, in C. Muller, _Frag. hist. Graec_. i. 238-243) was formerly attributed to him, but, as the initial letters of the first twenty-three lines show, was really the work of Dionysius, son of Calliphon. Three considerable fragments of a prose description of Greece (Muller, i. 97-110) are now assigned to an unknown author named Heracleides. The _De re publica_ of Cicero is supposed to be founded on one of Dicaearchus's works.

The best edition of the fragments is by M. Fuhr (1841), a work of
great learning; see also a dissertation by F. G. Osann, _Beitrage zur
rom. und griech. Litteratur_, ii. pp. 1-117 (1839); Pauly-Wissowa,
_Realencyclopadie der klass. Altertumswiss_. v. pt. 1 (1905).

DICE (plural of die, O. Fr. _de_, derived from Lat. _dare_, to give), small cubes of ivory, bone, wood or metal, used in gaming. The six sides of a die are each marked with a different number of incised dots in such a manner that the sum of the dots on any two opposite sides shall be 7. Dice seem always to have been employed, as is the case to-day, for gambling purposes, and they are also used in such games as backgammon. There are many methods of playing, from one to five dice being used, although two or three are the ordinary numbers employed in Great Britain and America. The dice are thrown upon a table or other smooth surface either from the hand or from a receptacle called a dice-box, the latter method having been in common use in Greece, Rome and the Orient in ancient times. Dice-boxes have been made in many shapes and of various materials, such as wood, leather, agate, crystal, metal or paper. Many contain bars within to ensure a proper agitation of the dice, and thus defeat trickery. Some, formerly used in England, were employed with unmarked dice, and allowed the cubes to fall through a kind of funnel upon a board marked off into six equal parts numbered from 1 to 6. It is a remarkable fact, that, wherever dice have been found, whether in the tombs of ancient Egypt, of classic Greece, or of the far East, they differ in no material respect from those in use to-day, the elongated ones with rounded ends found in Roman graves having been, not dice but _tali_, or knucklebones. Eight-sided dice have comparatively lately been introduced in France as aids to children in learning the multiplication table. The teetotum, or spinning die, used in many modern games, was known in ancient times in China and Japan. The increased popularity of the more elaborate forms of gaming has resulted in the decline of dicing. The usual method is to throw three times with three dice. If one or more sixes or fives are thrown the first time they may be reserved, the other throws being made with the dice that are left. The object is to throw three sixes = 18 or as near that number as possible, the highest throw winning, or, when drinks are to be paid for, the lowest throw losing. (For other methods of throwing consult the _Encyclopaedia of Indoor Games_, by R. F. Foster, 1903.) The most popular form of pure gambling with dice at the present day, particularly with the lower classes in America, is _Craps_, or _Crap-Shooting_, a simple form of _Hazard_, of French origin. Two dice are used. Each player puts up a stake and the first caster may cover any or all of the bets. He then _shoots_, i.e. throws the dice from his open hand upon the table. If the sum of the dice is 7 or 11 the throw is a _nick_, or _natural_, and the caster wins all stakes. If the throw is either 2, 3 or 12 it is a _crap_, and the caster loses all. If any other number is thrown it is a _point_, and the caster continues until he throws the same number again, in which case he wins, or a 7, in which case he loses. The now practically obsolete game of Hazard was much more complicated than _Craps_. (Consult _The Game of Hazard Investigated_, by George Lowbut.) _Poker dice_ are marked with ace, king, queen, jack and ten-spot. Five are used and the object is, in three throws, to make pairs, triplets, full hands or fours and fives of a kind, five aces being the highest hand. Straights do not count. In throwing to decide the payment of drinks the usual method is called _horse and horse_, in which the highest throws retire, leaving the two lowest to decide the loser by the best two in three throws. Should each player win one throw both are said to be _horse and horse_, and the next throw determines the loser. The two last casters may also agree to _sudden death_, i.e. a single throw. _Loaded dice_, i.e. dice weighted slightly on the side of the lowest number, have been used by swindlers from the very earliest times to the present day, a fact proved by countless literary allusions. Modern dice are often rounded at the corners, which are otherwise apt to wear off irregularly.

_History._--Dice were probably evolved from knucklebones. The antiquary Thomas Hyde, in his _Syntagma_, records his opinion that the game of "odd or even," played with pebbles, is nearly coeval with the creation of man. It is almost impossible to trace clearly the development of dice as distinguished from knucklebones, on account of the confusing of the two games by the ancient writers. It is certain, however, that both were played in times antecedent to those of which we possess any written records. Sophocles, in a fragment, ascribed their invention to Palamedes, a Greek, who taught them to his countrymen during the siege of Troy, and who, according to Pausanias (on Corinth, xx.), made an offering of them on the altar of the temple of Fortune. Herodotus (_Clio_) relates that the Lydians, during a period of famine in the days of King Atys, invented dice, knucklebones and indeed all other games except chess. The fact that dice have been used throughout the Orient from time immemorial, as has been proved by excavations from ancient tombs, seems to point clearly to an Asiatic origin. Dicing is mentioned as an Indian game in the _Rig-veda_. In its primitive form knucklebones was essentially a game of skill, played by women and children, while dice were used for gambling, and it was doubtless the gambling spirit of the age which was responsible for the derivative form of knucklebones, in which four sides of the bones received different values, which were then counted, like dice. Gambling with three, sometimes two, dice ([Greek: kuboi]) was a very popular form of amusement in Greece, especially with the upper classes, and was an almost invariable accompaniment to the symposium, or drinking banquet. The dice were cast from conical beakers, and the highest throw was three sixes, called _Aphrodite_, while the lowest, three aces, was called the _dog_. Both in Greece and Rome different modes of counting were in vogue. Roman dice were called _tesserae_ from the Greek word for four, indicative of the four sides. The Romans were passionate gamblers, especially in the luxurious days of the Empire, and dicing was a favourite form, though it was forbidden except during the Saturnalia. The emperor Augustus wrote in a letter to Suetonius concerning a game that he had played with his friends: "Whoever threw a _dog_ or a six paid a _denarius_ to the bank for every die, and whoever threw a _Venus_ (the highest) won everything." In the houses of the rich the dice-beakers were of carved ivory and the dice of crystal inlaid with gold. Mark Antony wasted his time at Alexandria with dicing, while, according to Suetonius, the emperors Augustus, Nero and Claudius were passionately fond of it, the last named having written a book on the game. Caligula notoriously cheated at the game; Domitian played it, and Commodus set apart special rooms in his palace for it. The emperor Verus, adopted son of Antonine, is known to have thrown dice whole nights together. Fashionable society followed the lead of its emperors, and, in spite of the severity of the laws, fortunes were squandered at the dicing table. Horace derided the youth of the period, who wasted his time amid the dangers of dicing instead of taming his charger and giving himself up to the hardships of the chase. Throwing dice for money was the cause of many special laws in Rome, according to one of which no suit could be brought by a person who allowed gambling in his house, even if he had been cheated or assaulted. Professional gamblers were common, and some of their loaded dice are preserved in museums. The common public-houses were the resorts of gamblers, and a fresco is extant showing two quarrelling dicers being ejected by the indignant host. Virgil, in the _Copa_ generally ascribed to him, characterizes the spirit of that age in verse, which has been Englished as follows:--

"What ho! Bring dice and good wine!
Who cares for the morrow?
Live--so calls grinning Death--
Live, for I come to you soon!"

That the barbarians were also given to gaming, whether or not they learned it from their Roman conquerors, is proved by Tacitus, who states that the Germans were passionately fond of dicing, so much so, indeed, that, having lost everything, they would even stake their personal liberty. Centuries later, during the middle ages, dicing became the favourite pastime of the knights, and both dicing schools (_scholae deciorum_) and gilds of dicers existed. After the downfall of feudalism the famous German mercenaries called _landsknechts_ established a reputation as the most notorious dicing gamblers of their time. Many of the dice of the period were curiously carved in the images of men and beasts. In France both knights and ladies were given to dicing, which repeated legislation, including interdictions on the part of St Louis in 1254 and 1256, did not abolish. In Japan, China, Korea, India and other Asiatic countries dice have always been popular and are so still.

See Foster's _Encyclopaedia of Indoor Games_ (1903); Raymond's
_Illustriertes Knobelbrevier_ (Oranienburg, 1888); _Les Jeux des
Anciens_, by L. Becq de Fouquieres (Paris, 1869); _Das Knochelspiel
der Alten_, by Bolle (Wismar, 1886); _Die Spiele der Griechen und
Romer_, by W. Richter (Leipzig, 1887); Raymond's _Alte und neue
Wurfelspiele_; _Chinese Games with Dice_, by Stewart Culin
(Philadelphia, 1889); _Korean Games_, by Stewart Culin (Philadelphia,
1895).

DICETO, RALPH DE (d. c. 1202), dean of St Paul's, London, and chronicler, is first mentioned in 1152, when he received the archdeaconry of Middlesex. He was probably born between 1120 and 1130; of his parentage and nationality we know nothing. The common statement that he derived his surname from Diss in Norfolk is a mere conjecture; Dicetum may equally well be a Latinized form of Dissai, or Dicy, or Dizy, place names which are found in Maine, Picardy, Burgundy and Champagne. In 1152 Diceto was already a master of arts; presumably he had studied at Paris. His reputation for learning and integrity stood high; he was regarded with respect and favour by Arnulf of Lisieux and Gilbert Foliot of Hereford (afterwards of London), two of the most eminent bishops of their time. Quite naturally, the archdeacon took in the Becket question the same side as his friends. Although his narrative is colourless, and although he was one of those who showed some sympathy for Becket at the council of Northampton (1164), the correspondence of Diceto shows that he regarded the archbishop's conduct as ill-considered, and that he gave advice to those whom Becket regarded as his chief enemies. Diceto was selected, in 1166, as the envoy of the English bishops when they protested against the excommunications launched by Becket. But, apart from this episode, which he characteristically omits to record, he remained in the background. The natural impartiality of his intellect was accentuated by a certain timidity, which is apparent in his writings no less than in his life. About 1180 he became dean of St Paul's. In this office he distinguished himself by careful management of the estates, by restoring the discipline of the chapter, and by building at his own expense a deanery-house. A scholar and a man of considerable erudition, he showed a strong preference for historical studies; and about the time when he was preferred to the deanery he began to collect materials for the history of his own times. His friendships with Richard Fitz Nigel, who succeeded Foliot in the see of London, with William Longchamp, the chancellor of Richard I., and with Walter of Coutances, the archbishop of Rouen, gave him excellent opportunities of collecting information. His two chief works, the _Abbreviationes Chronicorum_ and the _Ymagines Historiarum_, cover the history of the world from the birth of Christ to the year 1202. The former, which ends in 1147, is a work of learning and industry, but almost entirely based upon extant sources. The latter, beginning as a compilation from Robert de Monte and the letters of Foliot, becomes an original authority about 1172, and a contemporary record about 1181. In precision and fulness of detail the _Ymagines_ are inferior to the chronicles of the so-called Benedict and of Hoveden. Though an annalist, Diceto is careless in his chronology; and the documents which he incorporates, while often important, are selected on no principle. He has little sense of style; but displays considerable insight when he ventures to discuss a political situation. For this reason, and on account of the details with which they supplement the more important chronicles of the period, the _Ymagines_ are a valuable though a secondary source.

See W. Stubbs' edition of the _Historical Works_ of Diceto (Rolls ed.
1876, 2 vols.), and especially the introduction. The second volume
contains minor works which are the barest compendia of facts taken
from well-known sources. Diceto's fragmentary Domesday of the
capitular estates has been edited by Archdeacon Hale in _The Domesday
of St Paul's_, pp. 109 ff. (Camden Society, 1858).

DICEY, EDWARD (1832- ), English writer, son of T. E. Dicey of Claybrook Hall, Leicestershire, was born in 1832. Educated at Trinity College, Cambridge, where he took mathematical and classical honours, he became an active journalist, contributing largely to the principal reviews. He was called to the bar in 1875, became a bencher of Gray's Inn in 1896, and was treasurer in 1903-1904. He was connected with the _Daily Telegraph_ as leader writer and then as special correspondent, and after a short spell in 1870 as editor of the _Daily News_ he became editor of the _Observer_, a position which he held until 1889. Of his many books on foreign affairs perhaps the most important are his _England and Egypt_ (1884), _Bulgaria, the Peasant State_ (1895), _The Story of the Khedivate_ (1902), and _The Egypt of the Future_ (1907). He was created C.B. in 1886.

His brother ALBERT VENN DICEY (b. 1835), English jurist, was educated at Balliol College, Oxford, where he took a first class in the classical schools in 1858. He was called to the bar at the Inner Temple in 1863. He held fellowships successively at Balliol, Trinity and All Souls', and from 1882 to 1909 was Vinerian professor of law. He became Q.C. in 1890. His chief works are the _Introduction to the Study of the Law of the Constitution_ (1885, 6th ed. 1902), which ranks as a standard work on the subject; _England's Case against Home Rule_ (1886); _A Digest of the Law of England with Reference to the Conflict of Laws_ (1896), and _Lectures on the Relation between Law and Public Opinion in England during the 19th century_ (1905).

DICHOTOMY (Gr. [Greek: dicha], apart, [Greek: temnein], to cut), literally a cutting asunder, the technical term for a form of logical division, consisting in the separation of a genus into two species, one of which has and the other has not, a certain quality or attribute. Thus men may be thus divided into white men, and men who are not white; each of these may be subdivided similarly. On the principle of contradiction this division is both exhaustive and exclusive; there can be no overlapping, and no members of the original genus or the lower groups are omitted. This method of classification, though formally accurate, has slight value in the exact sciences, partly because at every step one of the two groups is merely negatively characterized and therefore incapable of real subdivision; it is useful, however, in setting forth clearly the gradual descent from the most inclusive genus (_summum genus_) through species to the lowest class (_infima species_), which is divisible only into individual persons or things. (See further DIVISION.) In astronomy the term is used for the aspect of the moon or of a planet when apparently half illuminated, so that its disk has the form of a semicircle.

DICK, ROBERT (1811-1866), Scottish geologist and botanist, was born at Tullibody, in Clackmannanshire, in January 1811. His father was an officer of excise. At the age of thirteen, after receiving a good elementary education at the parish school, Robert Dick was apprenticed to a baker, and served for three years. In these early days he became interested in wild flowers--he made a collection of plants and gradually acquired some knowledge of their names from an old encyclopaedia. When his time was out he left Tullibody and gained employment as a journeyman baker at Leith, Glasgow and Greenock. Meanwhile his father, who in 1826 had been removed to Thurso, as supervisor of excise, advised his son to set up a baker's shop in that town. Thither Robert Dick went in 1830, he started in business as a baker and worked laboriously until he died on the 24th of December 1866. Throughout this period he zealously devoted himself to studying and collecting the plants, mollusca and insects of a wide area of Caithness, and his attention was directed soon after he settled in Thurso to the rocks and fossils. In 1835 he first found remains of fossil fishes; but it was not till some years later that his interest became greatly stirred. Then he obtained a copy of Hugh Miller's _Old Red Sandstone_ (published in 1841), and he began systematically to collect with hammer and chisel the fossils from the Caithness flags. In 1845 he found remains of _Holoptychius_ and forwarded specimens to Hugh Miller, and he continued to send the best of his fossil fishes to that geologist, and to others after the death of Miller. In this way he largely contributed to the progress of geological knowledge, although he himself published nothing and was ever averse from publicity. His herbarium, which consisted of about 200 folios of mosses, ferns and flowering plants "almost unique in its completeness," is now stored, with many of his fossils, in the museum at Thurso. Dick had a hard struggle for existence, especially through competition during his late years, when he was reduced almost to beggary: but of this few, if any, of his friends were aware until it was too late. A monument erected in the new cemetery at Thurso testifies to the respect which his life-work created, when the merits of this enthusiastic naturalist came to be appreciated.

See _Robert Dick, Baker of Thurso, Geologist and Botanist_, by Samuel
Smiles (1878).

DICK, THOMAS (1774-1857), Scottish writer on astronomy, was born at Dundee on the 24th of November 1774. The appearance of a brilliant meteor inspired him, when in his ninth year, with a passion for astronomy; and at the age of sixteen he forsook the loom, and supported himself by teaching. In 1794 he entered the university of Edinburgh, and set up a school on the termination of his course; then, in 1801, took out a licence to preach, and officiated for some years as probationer in the United Presbyterian church. From about 1807 to 1817 he taught in the secession school at Methven in Perthshire, and during the ensuing decade in that of Perth, where he composed his first substantive book, _The Christian Philosopher_ (1823, 8th ed. 1842). Its success determined his vocation as an author; he built himself, in 1827, a cottage at Broughty Ferry, near Dundee, and devoted himself wholly to literary and scientific pursuits. They proved, however, owing to his unpractical turn of mind, but slightly remunerative, and he was in 1847 relieved from actual poverty by a crown pension of L50 a year, eked out by a local subscription. He died on the 29th of July 1857. His best-known works are: _Celestial Scenery_ (1837), _The Sidereal Heavens_ (1840), and _The Practical Astronomer_ (1845), in which is contained (p. 204) a remarkable forecast of the powers and uses of celestial photography. Written with competent knowledge, and in an agreeable style, they obtained deserved and widespread popularity.

See R. Chambers's _Eminent Scotsmen_ (ed. 1868); _Monthly Notices Roy.
Astr. Society_, xviii. 98; _Athenaeum_ (1857), p. 1008. (A. M. C.)

DICKENS, CHARLES JOHN HUFFAM (1812-1870), English novelist, was born on the 7th of February 1812 at a house in the Mile End Terrace, Commercial Road, Landport (Portsea)--a house which was opened as a Dickens Museum on 22nd July 1904. His father John Dickens (d. 1851), a clerk in the navy-pay office on a salary of L80 a year, and stationed for the time being at Portsmouth, had married in 1809 Elizabeth, daughter of Thomas Barrow, and she bore him a family of eight children, Charles being the second. In the winter of 1814 the family moved from Portsea in the snow, as he remembered, to London, and lodged for a time near the Middlesex hospital. The country of the novelist's childhood, however, was the kingdom of Kent, where the family was established in proximity to the dockyard at Chatham from 1816 to 1821. He looked upon himself in later years as a man of Kent, and his capital abode as that in Ordnance Terrace, or 18 St Mary's Place, Chatham, amid surroundings classified in Mr Pickwick's notes as "appearing" to be soldiers, sailors, Jews, chalk, shrimps, officers and dockyard men. He fell into a family the general tendency of which was to go down in the world, during one of its easier periods (John Dickens was now fifth clerk on L250 a year), and he always regarded himself as belonging by right to a comfortable, genteel, lower middle-class stratum of society. His mother taught him to read; to his father he appeared very early in the light of a young prodigy, and by him Charles was made to sit on a tall chair and warble popular ballads, or even to tell stories and anecdotes for the benefit of fellow-clerks in the office. John Dickens, however, had a small collection of books which were kept in a little room upstairs that led out of Charles's own, and in this attic the boy found his true literary instructors in _Roderick Random_, _Peregrine Pickle_, _Humphry Clinker_, _Tom Jones_, _The Vicar of Wakefield_, _Don Quixote_, _Gil Blas_ and _Robinson Crusoe_. The story of how he played at the characters in these books and sustained his idea of Roderick Random for a month at a stretch is picturesquely told in _David Copperfield_. Here as well as in his first and last books and in what many regard as his best, _Great Expectations_, Dickens returns with unabated fondness and mastery to the surroundings of his childhood. From seven to nine years he was at a school kept in Clover Lane, Chatham, by a Baptist minister named William Giles, who gave him Goldsmith's _Bee_ as a keepsake when the call to Somerset House necessitated the removal of the family from Rochester to a shabby house in Bayham Street, Camden Town. At the very moment when a consciousness of capacity was beginning to plump his youthful ambitions, the whole flattering dream vanished and left not a rack behind. Happiness and Chatham had been left behind together, and Charles was about to enter a school far sterner and also far more instructive than that in Clover Lane. The family income had been first decreased and then mortgaged; the creditors of the "prodigal father" would not give him time; John Dickens was consigned to the Marshalsea; Mrs Dickens started an "Educational Establishment" as a forlorn hope in Upper Gower Street; and Charles, who had helped his mother with the children, blacked the boots, carried things to the pawnshop and done other menial work, was now sent out to earn his own living as a young hand in a blacking warehouse, at Old Hungerford Stairs, on a salary of six shillings a week. He tied, trimmed and labelled blacking pots for over a year, dining off a saveloy and a slice of pudding, consorting with two very rough boys, Bob Fagin and Pol Green, and sleeping in an attic in Little College Street, Camden Town, in the house of Mrs Roylance (Pipchin), while on Sunday he spent the day with his parents in their comfortable prison, where they had the services of a "marchioness" imported from the Chatham workhouse.

Already consumed by ambition, proud, sensitive and on his dignity to an extent not uncommon among boys of talent, he felt his position keenly, and in later years worked himself up into a passion of self-pity in connexion with the "degradation" and "humiliation" of this episode. The two years of childish hardship which ate like iron into his soul were obviously of supreme importance in the growth of the novelist. Recollections of the streets and the prison and its purlieus supplied him with a store of literary material upon which he drew through all the years of his best activity. And the bitterness of such an experience was not prolonged sufficiently to become sour. From 1824 to 1826, having been rescued by a family quarrel and by a windfall in the shape of a legacy to his father, from the warehouse, he spent two years at an academy known as Wellington House, at the corner of Granby Street and the Hampstead Road (the lighter traits of which are reproduced in Salem House), and was there known as a merry and rather mischievous boy. Fortunately he learned nothing there to compromise the results of previous instruction. His father had now emerged from the Marshalsea and was seeking employment as a parliamentary reporter. A Gray's Inn solicitor with whom he had had dealings was attracted by the bright, clever look of Charles, and took him into his office as a boy at a salary of thirteen and sixpence (rising to fifteen shillings) a week. He remained in Mr Blackmore's office from May 1827 to November 1828, but he had lost none of his eager thirst for distinction, and spent all his spare time mastering Gurney's shorthand and reading early and late at the British Museum. A more industrious apprentice in the lower grades of the literary profession has never been known, and the consciousness of opportunities used to the most splendid advantage can hardly have been absent from the man who was shortly to take his place at the head of it as if to the manner born. Lowten and Guppy, and Swiveller had been observed from this office lad's stool; he was now greatly to widen his area of study as a reporter in Doctors' Commons and various police courts, including Bow Street, working all day at law and much of the night at shorthand. Some one asked John Dickens, during the first eager period of curiosity as to the man behind "Pickwick," where his son Charles was educated. "Well really," said the prodigal father, "he may be said--haw--haw--to have educated himself." He was one of the most rapid and accurate reporters in London when, at nineteen years of age, in 1831, he realized his immediate ambition and "entered the gallery" as parliamentary reporter to the _True Sun_. Later he was reporter to the _Mirror of Parliament_ and then to the _Morning Chronicle_. Several of his earliest letters are concerned with his exploits as a reporter, and allude to the experiences he had, travelling fifteen miles an hour and being upset in almost every description of known vehicle in various parts of Britain between 1831 and 1836. The family was now living in Bentwick Street, Manchester Square, but John Dickens was still no infrequent inmate of the sponging-houses. With all the accessories of these places of entertainment his son had grown to be excessively familiar. Writing about 1832 to his school friend Tom Mitton, Dickens tells him that his father has been arrested at the suit of a wine firm, and begs him go over to Cursitor Street and see what can be done. On another occasion of a paternal disappearance he observes: "I own that his absence does not give me any great uneasiness, knowing how apt he is to get out of the way when anything goes wrong." In yet another letter he asks for a loan of four shillings.

In the meanwhile, however, he had commenced author in a more creative sense by penning some sketches of contemporary London life, such as he had attempted in his school days in imitation of the sketches published in the _London_ and other magazines of that day. The first of these appeared in the December number of the _Old Monthly Magazine_ for 1833. By the following August, when the signature "Boz" was first given, five of these sketches had appeared. By the end of 1834 we find him settled in rooms in Furnival's Inn, and a little later his salary on the _Morning Chronicle_ was raised, owing to the intervention of one of its chiefs, George Hogarth, the father of (in addition to six sons) eight charming daughters, to one of whom, Catherine, Charles was engaged to be married before the year was out. Clearly as his career now seemed designated, he was at this time or a little before it coquetting very seriously with the stage: but circumstances were rapidly to determine another stage in his career. A year before Queen Victoria's accession appeared in two volumes _Sketches by Boz_, _Illustrative of Everyday Life and Everyday People_. The book came from a prentice hand, but like the little tract on the Puritan abuse of the Sabbath entitled "Sunday under three Heads" which appeared a few months later, it contains in germ all, or almost all, the future Dickens. Glance at the headings of the pages. Here we have the Beadle and all connected with him, London streets, theatres, shows, the pawnshop, Doctors' Commons, Christmas, Newgate, coaching, the river. Here comes a satirical picture of parliament, fun made of cheap snobbery, a rap on the knuckles of sectarianism. And what could be more prophetic than the title of the opening chapter--Our Parish? With the Parish--a large one indeed--Dickens to the end concerned himself; he began with a rapid survey of his whole field, hinting at all he might accomplish, indicating the limits he was not to pass. This year was to be still more momentous to Dickens, for, on the 2nd of April 1836, he was married to George Hogarth's eldest daughter Catherine. He seems to have fallen in love with the daughters collectively, and, judging by subsequent events, it has been suggested that perhaps he married the wrong one. His wife's sister Mary was the romance of his early married life, and another sister, Georgina, was the dearest friend of his last ten years.

A few days before the marriage, just two months after the appearance of the _Sketches_, the first part of _The Posthumous Papers of the Pickwick Club_ was announced. One of the chief vogues of the day was the issue of humorous, sporting or anecdotal novels in parts, with plates, and some of the best talent of the day, represented by Ainsworth, Bulwer, Marryat, Maxwell, Egan, Hook and Surtees, had been pressed into this kind of enterprise. The publishers of the day had not been slow to perceive Dickens's aptitude for this species of "letterpress." A member of the firm of Chapman & Hall called upon him at Furnival's Inn in December 1835 with a proposal that he should write about a Nimrod Club of amateur sportsmen, foredoomed to perpetual ignominies, while the comic illustrations were to be etched by Seymour, a well-known rival of Cruikshank (the illustrator of _Boz_). The offer was too tempting for Dickens to refuse, but he changed the idea from a club of Cockney sportsmen to that of a club of eccentric peripatetics, on the sensible grounds, first that sporting sketches were stale, and, secondly, that he knew nothing worth speaking of about sport. The first seven pictures appeared with the signature of Seymour and the letterpress of Dickens. Before the eighth picture appeared Seymour had blown his brains out. After a brief interval of Buss, Dickens obtained the services of Hablot K. Browne, known to all as "Phiz." Author and illustrator were as well suited to one another and to the common creation of a unique thing as Gilbert and Sullivan. Having early got rid of the sporting element, Dickens found himself at once. The subject exactly suited his knowledge, his skill in arranging incidents--nay, his very limitations too. No modern book is so incalculable. We commence laughing heartily at Pickwick and his troupe. The laugh becomes kindlier. We are led on through a tangle of adventure, never dreaming what is before us. The landscape changes: Pickwick becomes the symbol of kindheartedness, simplicity and innocent levity. Suddenly in the Fleet Prison a deeper note is struck. The medley of human relationships, the loneliness, the mystery and sadness of human destinies are fathomed. The tragedy of human life is revealed to us amid its most farcical elements. The droll and laughable figure of the hero is transfigured by the kindliness of human sympathy into a beneficent and bespectacled angel in shorts and gaiters. By defying accepted rules, Dickens had transcended the limited sphere hitherto allotted to his art: he had produced a book to be enshrined henceforth in the inmost hearts of all sorts and conditions of his countrymen, and had definitely enlarged the boundaries of English humour and English fiction. As for Mr Pickwick, he is a fairy like Puck or Santa Claus, while his creator is "the last of the mythologists and perhaps the greatest."

When _The Pickwick Papers_ appeared in book form at the close of 1837 Dickens's popular reputation was made. From the appearance of Sam Weller in part v. the universal hunger for the monthly parts had risen to a furore. The book was promptly translated into French and German. The author had received little assistance from press or critics, he had no influential connexions, his class of subjects was such as to "expose him at the outset to the fatal objections of vulgarity," yet in less than six months from the appearance of the first number, as the _Quarterly Review_ almost ruefully admits, the whole reading world was talking about the Pickwickians. The names of Winkle, Wardle, Weller, Jingle, Snodgrass, Dodson & Fogg, were as familiar as household words. Pickwick chintzes figured in the linendrapers' windows, and Pickwick cigars in every tobacconist's; Weller corduroys became the stock-in-trade of every breeches-maker; Boz cabs might be seen rattling through the streets, and the portrait of the author of _Pelham_ and _Crichton_ was scraped down to make way for that of the new popular favourite on the omnibuses. A new and original genius had suddenly sprung up, there was no denying it, even though, as the _Quarterly_ concluded, "it required no gift of prophecy to foretell his fate--he has risen like a rocket and he will come down like the stick." It would have needed a very emphatic gift of prophecy indeed to foretell that Dickens's reputation would have gone on rising until at the present day (after one sharp fall, which reached an extreme about 1887) it stands higher than it has ever stood before.

Dickens's assumption of the literary purple was as amazing as anything else about him. Accepting the homage of the luminaries of the literary, artistic and polite worlds as if it had been his natural due, he arranges for the settlement of his family, decrees, like another Edmund Kean, that his son is to go to Eton, carries on the most complicated negotiations with his publishers and editors, presides and orates with incomparable force at innumerable banquets, public and private, arranges elaborate villegiatures in the country, at the seaside, in France or in Italy, arbitrates in public on every topic, political, ethical, artistic, social or literary, entertains and legislates for an increasingly large domestic circle, both juvenile and adult, rules himself and his time-table with a rod of iron. In his letter-writing alone, Dickens did a life's literary work. Nowadays no one thinks of writing such letters; that is to say, letters of such length and detail, for the quality is Dickens's own. He evidently enjoyed this use of the pen. Page after page of Forster's _Life_ (750 pages in the _Letters_ edited by his daughter and sister-in-law) is occupied with transcription from private correspondence, and never a line of this but is thoroughly worthy of print and preservation. If he makes a tour in any part of the British Isles, he writes a full description of all he sees, of everything that happens, and writes it with such gusto, such mirth, such strokes of fine picturing, as appear in no other private letters ever given to the public. Naturally buoyant in all circumstances, a holiday gave him the exhilaration of a schoolboy. See how he writes from Cornwall, when on a trip with two or three friends, in 1843. "Heavens! if you could have seen the necks of bottles, distracting in their immense variety of shape, peering out of the carriage pockets! If you could have witnessed the deep devotion of the post-boys, the maniac glee of the waiters! If you could have followed us into the earthy old churches we visited, and into the strange caverns on the gloomy seashore, and down into the depths of mines, and up to the tops of giddy heights, where the unspeakably green water was roaring, I don't know how many hundred feet below.... I never laughed in my life as I did on this journey. It would have done you good to hear me. I was choking and gasping and bursting the buckles off the back of my stock, all the way. And Stanfield"--the painter--"got into such apoplectic entanglements that we were obliged to beat him on the back with portmanteaus before we could recover him."