Part 28

DUTCH EAST INDIES, forming a large and important colonial possession of the Netherlands Government, lie between 6deg N. and 11deg S., and 95deg E. and 141deg E. The colony includes Java and Madura, with the 'Outposts', which comprise Sumatra, the south-east and west portions of Borneo, Banca, Billiton, Celebes, the Timor and Riau-Lingga Archipelagos, the smaller Sunda Islands, and the north and west of New Guinea. The total area is about 735,000 sq. miles; the population of about 47,000,000 is composed of 46,000,000 natives of Malay race, 832,000 Arabs, Chinese, and other Orientals, and some 80,000 whites. The origin of the colony may be traced to the treaty made by the Dutch with the Sultan of Bantam in Sumatra (1595), which was followed by the formation of the Dutch East India Company (1602), the establishment of Batavia (1619) on the ruins of the native town of Jacatra, and the settlement in Sumatra (1677). The Dutch East India Company was dissolved in 1798, since which date the colony has been administered from the Netherlands by a Governor-General, who, assisted by a Council of five members nominated by the queen, has the power to pass laws, subject to the general regulations adopted in 1854. Some of the outlying islands are, however, administered by their native princes under the 'advice' of a Netherlands Resident. Batavia (population about 234,000), a town in the province of the same name on the north-west coast of Java, is the administrative capital and an important centre of trade. Java and Sumatra, containing about three-fourths of the total population of the colony, are self-supporting as regards food, besides producing for European consumption large quantities of tobacco, tea, coffee, sugar, cinchona, tin, rubber, and copra. The colonial army numbers some 1200 officers and 40,000 men; compulsory service for white men within certain age-limits was adopted in 1918. There is also a small naval force.--BIBLIOGRAPHY: Bemmelen and Hooyer, _Guide to the Dutch East Indies_; W. Cool, _With the Dutch in the East_; J. M. Brown, _The Dutch East_.

DUTCH METAL, an alloy containing 84.5-84.7 per cent of copper and 15.5-15.3 per cent of zinc, with a fine golden-yellow colour, ductile, malleable, and tenacious. When beaten out by a process analogous to that for gold-leaf, until the sheets are less than 1/50,000th part of an inch thick, it constitutes Dutch leaf or Dutch foil, and is used as a cheap substitute for gold-leaf for ornamental purposes.

DUTCH PINK, a bright yellow colour used in distemper, for staining paper-hangings, and for other ordinary purposes. It is composed of chalk or whiting coloured with a decoction of birch leaves, French berries, and alum.

DUTCH RUSH, _Equis[=e]tum hyem[=a]le_, one of the plants known as horse-tails, with a firm texture and so large an amount of silica in the cuticle that it is employed as a fine sand-paper for polishing delicate woodwork. The plant is found in marshes and woods in Britain, but for economic use it is imported from Holland, whence its popular name.

DUTROCHET (d[.u]-tro-sh[=a]), Ren['e] Joachim Henri, a French physiologist, born in Poitou in 1776, died at Paris in 1847. He served for some time as medical attendant to Joseph Bonaparte during the Spanish campaign 1808-9; but afterwards returned to France, and retired to the estate of Ch[^a]teaurenault, where he devoted himself exclusively to physical and physiological studies. His chief works have been published in a collective form with the title _M['e]moires pour servir [`a] l'Histoire Anatomique et Physiologique des V['e]g['e]taux et des Animaux_ (1837, 2 vols.).

DVINA, NORTHERN, a Russian river formed by the union of two small streams in the government of Vologda. It flows in a north-westerly direction, and falls by four mouths into the White Sea. At Archangel, before it divides, it is 4 miles broad. It is navigable as far as Suchona, and is connected with the Volga and Neva by canal.

DVO[VR]['A]K (dvor-sh[:a]k'), Anton, a Bohemian musical composer, born in 1841, died in 1904. He studied at the Prague Conservatoire, and composed several operas on national Bohemian subjects, songs, orchestral arrangements of Bohemian dances, several symphonies, a _Stabat_ _Mater_, a cantata (_The Spectre Bride_), and an oratorio (_St. Ludmila_). In 1892 he was director of the New York National Conservatory, and after 1895 he lived in Prague, where he wrote, in 1889, the opera _Der Teufel und die wilde K[:a]tze_.

DWARF, a term applied to any animal or plant greatly below the usual size of its kind, particularly to a human being of small dimensions. Strictly speaking, the term should be used with reference to individuals and not to races. When a whole population consists of people of small stature, the proper term to apply to them is pigmies, not dwarfs. Accounts of pigmy tribes have been common from early times, such tribes being located especially in Africa; and it would appear from the accounts of Du Chaillu, Schweinfurth, and other travellers that there are several pigmy tribes throughout this continent. The Obongo, a race of dwarfs, are described as living in woods near the Okanda River, in wretched huts made of branches. Other races are the Mabongo, and the Akka dwarfs of Central Africa (see _Akkas_); and a race exists in the Congo State, not as a distinct community, however, but mixed with other tribes. Individual dwarfs occur in all races, and were formerly a fashionable appendage to the courts of princes and the families of nobles. Jeffery Hudson, the favourite dwarf of Charles I, at the age of thirty is said to have been only 18 inches high, though he afterwards grew to 3 feet 9 inches. B['e]b['e], the celebrated dwarf of Stanislas of Poland, was 33 inches; Wybrand Lolkes, a Dutch dwarf, when sixty years of age was only 27 inches; Charles H. Stratton, 'General Tom Thumb', was 31 inches high at the age of twenty-five; Francis Flynn, 'General Mite', was only 21 inches at sixteen. In most of the extreme cases the dwarfing is the result of some defect in the ductless glands which regulate the normal growth of the body. Stories of dwarfs and brownies are to be found in the folk-lore of many tribes on earth.--BIBLIOGRAPHY: E. J. Wood, _Giants and Dwarfs_; E. Tyson, _Philological Essay concerning Pygmies of the Ancients_.

DWARFING, the process of training up trees or shrubs for ornament in houses so as to cause them never to reach more than a very small size, by keeping them in poor soil, giving them little water, pinching off strong shoots, &c. It is much practised among the Chinese and Japanese.

DWIGHT (dw[=i]t), Timothy, American divine, born in Massachusetts 1752, died 1817. His father was Colonel Timothy Dwight, and his mother was a daughter of Jonathan Edwards. He served as chaplain in the revolutionary army, and ultimately became president of Yale College. His _Theology Explained and Defended_ (1818) was for long a standard work both in Britain and in America.

DY'AKS, the aborigines of Borneo, chiefly inhabiting the interior of the island. They are a finely formed race, of a yellow complexion, and are described as docile, industrious, and superior to the Malays. The more advanced of them practise agriculture and dwell in neatly-constructed and tolerably comfortable houses. In Sarawak they have made considerable advances in civilization. The practice of head-hunting (hunting their enemies to make trophies of their heads) is practised among them, but has been abolished where European influence prevails.--Cf. Hose and McDougall, _The Pagan Tribes of Borneo_ (2 vols.).

DYAUS (dyous), the god of the sky in the older mythology of the Hindus. His name is etymologically connected with that of the Greek Zeus.

DYCE (d[=i]s), Alexander, Shakespearean editor, born at Edinburgh 30th June, 1798, died 15th May, 1869. He was educated at Edinburgh and Oxford, but in 1827 settled in London, where most of his life was passed. He first became known by his editions of Collins, Peele, Webster, Marlowe, and Skelton, accompanied by notes and biographies of the authors. His chief work was an edition of Shakespeare in six volumes, with notes (1853-8).

DYCE, William, painter, born at Aberdeen in 1806, died near London, 1864. He studied in London and Rome, and practised his art in Edinburgh. In 1840 he became director of the School of Design in London, and in 1844 was appointed professor of fine art in King's College, London. He was elected a Royal Academician in 1848. Amongst his chief works are: _Francesca da Rimini_ (1837): _Joash shooting the Arrow of Deliverance_ (1844); _King Lear in the Storm_ (1851); _Christabel_ (1855); _The Good Shepherd_ (1856); _The Baptism of Ethelbert_, a large fresco for the Houses of Parliament, and a series of frescoes illustrative of the legends relating to King Arthur, for the same. He also executed for the Prince Consort, at Osborne, the fresco _Neptune giving the Empire of the Sea to Britannia_.

DYEING is the art of colouring textile and other materials in such a way that the colours are not readily removed by the action of light, washing, &c. Like spinning and weaving, it was originally a home industry, as it still is in many places. The natural dyes formerly employed are now largely displaced by dyes derived from coal-tar products, the first discovery of which was made by Perkin in 1856; a few mineral colours are employed in cotton dyeing. Before dyeing, the materials have generally to be cleansed or bleached to get rid of undesirable colouring matters or impurities; and frequently a textile material is subjected to some subsidiary treatment in order to obtain special effects. For example, cotton yarn may be subjected to the action of strong caustic soda ('mercerizing' process) while in a state of great tension, in order to give it a permanent silky lustre. Dyeing is not only an art, it is also a branch of applied chemistry. One fundamental principle is, that the colouring matter and other necessary substances must be applied in a state of solution, and while in direct contact with the fibre they must be rendered insoluble, so that they are precipitated within or upon the fibre and fixed permanently. The method of effecting this varies greatly, according to the fibre and the colouring matter employed. As a rule, the vegetable and the animal fibres are dyed by very different methods. The affinity of the animal fibres for certain colouring matters is often so great that they are readily dyed by simple immersion in hot colour solutions; but this simple process is not generally sufficient. According to the method of their application in dyeing, the following groups of dye-stuffs may be distinguished: _Acid Dyes_, _Basic Dyes_, _Direct Dyes_, _Developed Dyes_, _Mordant Dyes_, _Vat Dyes_. A dye is _substantive_ to a particular fibre when it dyes that fibre directly, and _adjective_ when the presence of a third substance known as a _mordant_ is necessary.

The _acid dyes_ are so called because they are of an acid character and are applied in an acid dye-bath. As a rule, they are only suitable for dyeing the animal fibres, e.g. wool and silk, also leather, horn, feathers, &c., and they are substantive to these materials. The purple vegetable dyestuff _orchil_ belongs to this class. The acid dyes derived from coal-tar are very numerous, and yield a great variety of hues--red, orange, yellow, green, blue, violet, brown, and black. The _basic dyes_ are so called because their essential constituents, to which they owe their dyeing power, are organic bases. The bases themselves are colourless and too insoluble in water to be of use, hence they are employed in the form of their soluble coloured salts, usually the hydrochlorides of the colour-bases. Their solutions are precipitated by tannic acid, because it combines with the colour-bases to form insoluble tannates. Wool, silk, and animal substances generally have a direct attraction for colour-bases, and hence these fibres are readily dyed by simple immersion in hot aqueous solutions of the basic dyes. Cotton and linen, on the other hand, are not dyed so readily; they need first to be mordanted or impregnated with the _mordant_ tannic acid. Most of the colours of this class are fugitive to light, and all but one, viz. _barberry root_, are derived from coal-tar products.

The _direct dyes_ are so called because they dye cotton without the aid of any mordanting process. The first of this class derived from coal-tar was _congo red_, discovered in 1884; at present this group includes a very great variety of fast colours, and forms, indeed, one of the most important and valuable series of dye-stuffs employed. Cotton, linen, and the vegetable fibres generally are dyed in the simplest possible manner by merely boiling them in a solution of the dye-stuff, with or without the addition of a little soap, carbonate or sulphate of soda, &c. Wool and silk are frequently dyed in the same manner as cotton. Very few vegetable dye-stuffs belong to the direct colours, e.g. _Safflower_, _Turmeric_, _Saffron_, _Annatto_ (see the articles). They are all fugitive, and are now of little or no importance to the dyer. The coal-tar colours of this class, on the other hand, are extremely numerous. The _developed dyes_ are formed _in situ_ upon the fibre by the successive application of two or more substances. They include _aniline black_, a permanent black produced by the oxidation of aniline, and the _ice colours_, which are _azo dyes_ derived from certain coal-tar products containing nitrogen.

The _mordant dyes_ form one of the most important classes of colouring matters, for they include not only most of the vegetable dye-stuffs, e.g. madder, logwood, fustic, &c., but also many valuable fast coal-tar colours, commonly known as the _alizarin dyes_, after their typical representative, alizarin. These mordant dyes have by themselves very little colouring power, as a rule, and if employed alone in dyeing give little or no result. If applied, however, in conjunction with metallic salts, notably those of chromium, aluminium, iron, tin, and copper, they each yield a variety of colours, according to the metallic salt employed. In employing them two distinct operations are usually involved: first, that of applying the metallic salt or _mordant_, called the _mordanting process_; and second, that of _dyeing_ proper, in which the mordanted material is boiled in a solution or decoction of the dye-stuff. During the dyeing operation the colouring principle of the dye-stuff combines with the metallic salt already upon the material, and the colour is thus produced and fixed upon the fibre. The method of mordanting varies with the fibre and the metallic salt employed. The vegetable dye-stuffs of this class include _Madder_, _Sapanwood_, _Camwood_, _Barwood_, _Old Fustic_, _Young Fustic_, _Quercitron Bark_, _Persian Berries_, _Weld_, _Logwood_ (see these separate articles). _Madder_ was formerly the most important and highly valued of the dye-stuffs of this class, being especially employed to produce the fine 'Turkey-red' dye; but it is now entirely superseded by the coal-tar colour alizarin. Similarly, the employment of _cochineal_ (an insect dye) has also greatly diminished through the introduction of the cheaper colours. _Camwood_ and _barwood_ are almost entirely used in wool-dyeing, either in conjunction with the indigo-vat or for the purpose of dyeing various shades of brown. _Old fustic_ is the most important of the yellow mordant dye-stuffs, and the colours are fast although not very brilliant. _Quercitron bark_ is an excellent dye-stuff employed by wool-dyers for the production of bright orange and yellow colours. _Persian berries_ and _weld_, a species of wild mignonette, are both excellent dye-stuffs, but their employment is now limited. _Logwood_ is largely employed by wool, silk, and cotton dyers for dyeing black and dark-blues, which, although fast to washing, are only moderately so towards light. The important vegetable dye _catechu_ (q.v.) is used in dyeing cotton and wool brown. On wool, catechu yields _khaki_ browns in single bath by using copper sulphate as the mordant. On silk, it is largely employed for weighting purposes in the process of dyeing black. Although dyewoods are still much employed, they are being steadily replaced by coal-tar colours. The _vat dyes_ are insoluble in water, but yield reduction products which are soluble in aqueous alkali, and can be readily reoxidized to the dye-stuff. In this class may be included the _sulphur dyes_, substances of uncertain composition obtained by fusing certain compounds containing nitrogen with sulphur and sodium sulphide, which are now extensively and increasingly employed, especially as direct dyes for cotton. _Indigo_, a typical vat dye, is prepared both artificially and from natural sources. It is a dark-blue powder quite insoluble in water, but when reduced it yields _indigo-white_ which dissolves in aqueous alkali, the solution thus obtained being called an _indigo-vat_. Cotton, wool, or silk steeped for some time in the clear yellow solution of such a vat, and then exposed to the oxidizing influence of the air, is dyed a permanent blue. The indigo-white absorbed by the fibre loses its acquired hydrogen, and thus insoluble indigo-blue is regenerated within and upon the fibre.

In the classification adopted above, the following _mineral colours_ employed in cotton dyeing belong to the group of developed dyes, since they are formed on the fibre: _chrome yellow_, obtained by immersing cotton successively in solutions of acetate of lead and bichromate of potash; _iron buff_ (oxide of iron), produced by the successive application of sulphate of iron and carbonate of soda; _Prussian blue_, developed by passing the buff-dyed cotton through an acidified solution of potassium ferrocyanide; _manganese brown_ (oxide of manganese), deposited similarly to iron buff. The mineral colours are very useful for certain purposes, and are very fast to light.--BIBLIOGRAPHY: Crookes, _A Practical Handbook of Dyeing and Calico-printing_; W. P. Dreaper, _Chemistry and Physics of Dyeing_; Knecht, Rawson, and Loewenthal, _Manual of Dyeing_; Rawson, Gardner, and Laycock, _A Dictionary of Dyes, Mordants, &c._

DYER, John, English poet, born in Carmarthenshire about 1700, died in 1758. Educated at Westminster School, he became a painter, but, not succeeding in that vocation, took orders and was appointed to a small living. In 1727 he published his poem of _Grongar Hill_, in 1740 _The Ruins of Rome_, and in 1757 _The Fleece_, a didactic poem in five books.

DYER'S-BROOM, a European and now also N. American shrub (_Genista tinctoria_), formerly used with woad for dyeing green.

DYER'S-WEED, _Res[=e]da Lute[)o]la_, a British plant of the same genus as mignonette, otherwise called _Yellow-weed_, _Weld_, or _Woad_, nat. ord. Resedaceae. This plant grows in waste ground; it affords a beautiful yellow dye, and is cultivated for that purpose.--_Dyer's Greenweed_ is _Genista tinctoria_.

DYING DECLARATION, a deposition made by one who is in prospect of death. Such declarations are as a general rule admissible as evidence only in criminal and not in civil cases, and must be made, according to English, though not Scottish law, in the full consciousness of the danger of death.

DYNAM'ICS is the science which deals with the laws of force in their relation to matter at rest or in motion, and as such it is differentiated from _kinematics_, which considers motion mathematically, and apart from the forces producing it. Dynamics is divided into two great branches: _statics_, which treats of solid bodies at rest under the action of forces; and _kinetics_, which treats of the action of forces in producing motion in solid bodies. Formerly the latter alone was called dynamics, and to this, in conjunction with statics, the general name _mechanics_ was given. In the wide sense dynamics includes also hydrodynamics. It is to Newton that we owe the clear statement of the three primary laws of force on which the science of dynamics is based. These are: (1) that every body remains in a state of rest, or of uniform motion along a straight line, unless it is compelled by force to change that state; (2) that rate of change of momentum is in proportion to the force employed, and occurs along the straight line in which the force acts; (3) that, as the result of every

## action, there is always an equal and opposite reaction. These laws, which

were formulated from experiment, involve the conception of force as a primary influence or action expressed in terms of space, time, and matter. Now, in dealing with the laws of force, a standard of measurement is required which shall be applicable to all forces at all times, and we therefore require to begin by establishing units of space, time, and mass. There are two systems of units in use, the one British, the other French. In the British system the foot is taken as the unit of length, and the second as the unit of time. In the French the centimetre is the unit of length, the second the unit of time; the unit velocity in the one case being that of one foot per second, in the other one centimetre per second. The British unit of mass is the pound (the mass of a certain lump of platinum deposited in the Exchequer Office, London); the French the gramme; and accordingly the French units of space, mass, and time are commonly known as the C.G.S. (centimetre, gramme, second) units. As the weight of a pound (or a gramme) is not the same at all parts of the earth's surface, it cannot give us of itself an absolute or dynamical unit of force, that is, an invariable unit; but taking it in conjunction with unit time and unit velocity, we do obtain such a unit. Two absolute units of force are in common use in dynamics, the _poundal_ and the _dyne_, the latter being the absolute unit in the C.G.S. system. The former is _that force which, acting on the mass of one pound for one second, generates in that mass a velocity of one foot per second_. The latter is _that force which, acting on the mass of one gramme for one second, generates in that mass a velocity of one centimetre per second_. It is important in dynamics to distinguish between _mass_ and _weight_. The _mass_ of one pound is the quantity of matter equal to a certain standard quantity (a certain lump of metal) and is quite independent of force. The _weight_ of one pound is the force with which the mass of one pound is attracted to the earth's surface by the force of gravity. Another important term is _momentum_: the momentum of a body in motion at any instant is the product of the mass of the body and the velocity at that instant. See _Couple_; _Elasticity_; _Energy_; _Force_; _Hydrodynamics_; _Kinematics_; _Kinetics_; _Statics_; _Thermodynamics_; _Waves_.--BIBLIOGRAPHY: Kelvin and Tait, _Natural Philosophy_; A. Gray, _Dynamics_; P. G. Tait, _Dynamics_; S. L. Loney, _Mechanics and Hydrostatics for Beginners_.

DYN'AMITE. See _Explosives_.

DY'NAMO. See _Generator_.

DYNAMOM'ETER, an apparatus for measuring the power or rate of working of a machine. There are two types, the transmission dynamometer, which measures the power of the machine without sensibly diminishing it; and the absorption dynamometer, which measures the power by using it all. The instrument is generally employed to determine the horse-power transmitted by a shaft or by belting.--Cf. Aspinall Parr's _Electrical Engineering Testing_.

DYRRHACHIUM. See _Durazzo_.

DY'SART, a royal and municipal burgh of Scotland, in Fife, on the Firth of Forth. It is an old place, and is a member of the Kirkcaldy district of parliamentary burghs. Pop. of royal burgh, 4197.