Chapter IX: Act 1890 (3)

One of the earliest red-hot tube syntheses of importance was the
formation of naphthalene from a mixture of alcohol and ether vapours.
Such condensations were especially studied by M. P. E. Berthelot, and
shown to be very fruitful in forming hydrocarbons. Sometimes reagents
are placed in the combustion tube, for example lead oxide (litharge),
which takes up bromine and sulphur. In its simplest form the apparatus
consists of a straight tube, made of glass, porcelain or iron
according to the temperature required and the nature of the reacting
substances, heated in an ordinary combustion furnace, the mixture
entering at one end and the vapours being condensed at the other.
Apparatus can also be constructed in which the unchanged vapours are
continually circulated through the tube. Operating in a current of
carbon dioxide facilitates the process by preventing overheating.

7. _Distillation in Chemical Technology._--In laboratory practice use
is made of a fairly constant type of apparatus, only trifling
modifications being generally necessary to adapt the apparatus for any
distillation or fractionation; in technology, on the other hand, many
questions have to be considered which generally demand the adoption of
special constructions for the economic distillation of different
substances. The modes of distillation enumerated above all occur in
manufacturing practice. Distillation in a vacuum is practised in two
forms:--if the pump draws off steam as well as air it is termed a
"wet" air-pump; if it only draws off air, it is a "dry" air-pump. In
the glycerin industry the lyes obtained by saponifying the fats are
first evaporated with "wet vacuum" and finally distilled with closed
and live steam and a "dry vacuum." Two forms of steam distillation may
be distinguished:--in one the still is simply heated by a steam coil
wound inside or outside the still--this is termed heating by dry
steam; in the other steam is injected into the mass within the
still--this is the distillation with live steam of laboratory
practice. The details of the plant--the material and fittings of the
still, the manner of heating, the form of the condensing plant,
receivers, &c.--have to be determined for each substance to be
distilled in order to work with the maximum economy.

For the distillation of liquids the retort is usually a cylindrical
pot placed vertically; cast iron is generally employed, in which case
the bottom is frequently incurved and thicker than the sides in order
to take up the additional wear and tear. Sometimes linings of
enamelled iron or other material are employed, which when worn can be
replaced at a far lower cost than that of a new still. Glass stills
heated by a sand bath are sometimes employed in the final distillation
of sulphuric acid; platinum, and an alloy of platinum and iridium with
a lining of gold rolled on (a discovery due to Heraeus), are used for
the same purpose. Cast iron stills are provided with a hemispherical
head or dome, generally attached to the body of the still by bolts,
and of sufficient size to allow for any frothing. It is invariably
provided with an opening to carry off the vapours produced. In its
more complete form a still has in addition the following
fittings:--The dome is provided with openings to admit (1) the axis of
the stirring gear (in some stills the stirring gear rotates on a
horizontal axis which traverses the side and not the head of the
still), (2) the inlet and outlet tubes of a closed steam coil, (3) a
tube reaching to nearly the bottom of the still to carry live steam,
(4) a tube to carry a thermometer, (5) one or more manholes for
charging purposes, (6) sight-holes through which the operation can be
watched, and (7) a safety valve. The body of the still is provided
with one or more openings at different heights to serve for the
discharge of the residue in the still, and sometimes with a glass
gauge to record the quantity of matter in the still. For dry
distillations the retorts are generally horizontal cylinders, the
bottom or lower surface being sometimes flattened. Iron and fireclay
are the materials commonly employed; wrought iron is used in the
manufacture of wood-spirit, fireclay for coal-gas (see GAS:
_Manufacture_), phosphorus, zinc, &c. The vertical type, however, is
employed in the manufacture of acetone and of iodine.

Several modes of heating are adopted. In some cases, especially in dry
distillations, the furnace flames play directly on the retorts, in
others, such as in the case of nitric acid, the whole still comes
under the action of the furnace gases to prevent condensation on the
upper part of the still, while in others the furnace gases do not play
directly on the base or upper portion of the still but are conducted
around it by a system of flues (see COAL-TAR). Steam heating, dry or
live, is employed alone and also as an auxiliary to direct firing.

The condensing plant varies with the volatility of the distillate. Air
cooling is adopted whenever possible. For example, in the less modern
methods for manufacturing nitric acid the vapours were conducted
directly into double-necked bottles (_bombonnes_) immersed in water. A
more efficient arrangement consists of a stack of vertical pipes
standing up from a main or collecting trough and connected at the top
in consecutive pairs by a cross tube. By an arrangement of diaphragms
in the lower trough the vapours are circulated through the system. As
an auxiliary to air cooling the stack may be cooled by a slow stream
of water trickling down the outside of the pipes, or, in certain
cases, cold water may be injected into the condenser in the form of a
spray, where it meets the ascending vapours. Horizontal air-cooling
arrangements are also employed. A common type of condenser consists of
a copper worm placed in a water bath; but more generally straight
tubes of copper or cast iron which cross and recross a rectangular
tank are employed, since this form is more readily repaired and
cleansed. Wood-spirit, petroleum and coal-tar distillates are
condensed in plant of the latter type. In cases where the condenser is
likely to become plugged there is a pipe by means of which live steam
can be injected into the condenser. The supply of water to the
condenser is regulated according to the volatility of the condensate.
When the vapours readily condense to a solid form the condensing plant
may take the form of large chambers; such conditions prevail in the
manufacture of arsenic, sulphur and lampblack: in the latter case
(which, however, is not properly one of distillation) the chamber is
hung with sheets on which the pigment collects. Large chambers are
also used in the condensation of mercury.

Dephlegmation of the vapours arising from such mixtures as coal-tar
fractions, petroleum and the "wash" of the spirit industry, is very
important, and many types of apparatus are employed in order to effect
a separation of the vapours. The earliest form, invented by C. B.
Mansfield to facilitate the fractionation of paraffin and coal-tar
distillates, consisted in having a pipe leading from the inclined
delivery tube of the still to the still again, so that any vapour
which condensed in the delivery tube was returned to the still. Of
really effective columns Coupier's was one of the earliest. The
vapours rising from the still traverse a tall vertical column, and are
then conveyed through a series of bulbs placed in a bath kept at the
boiling-point of the most volatile constituent. The more volatile
vapours pass over to the condensing plant, while the less volatile
ones condense in the bulbs and are returned to the column at varying
heights by means of connecting tubes. The French column is similar in
action. The Coffey still is one of the most effective and is employed
in the spirit, ammonia, coal-tar and other industries. It consists of
a vertical column divided into a number of sections by horizontal
plates, which are perforated so that the ascending vapours have to
traverse a layer of liquid. Above this "separator" is a reflux
condenser, termed the "cooler," maintained at the correct temperature
so that only the more volatile component passes to the receiver. The
success of the operation chiefly depends upon the proper management of
the cooler.

8. _Commercial Distillation of Water._--Distilled water, i.e. water
free from salts and to some extent of the dissolved gases which are
always present in natural waters, is of indispensable value in many
operations both of scientific and industrial chemistry. The apparatus
and process for distilling ordinary water are very simple. The body of
the still is made of copper, with a head and worm, or condensing
apparatus, either of copper or tin. The still is usually fed
continuously by the heated water from the condenser. The first portion
of the distillate brings over the gases dissolved in the water,
ammonia and other volatile impurities, and is consequently rejected;
scarcely two-fifths of the entire quantity of water can be safely used
as pure distilled water.

Apparatus for the economic production of a potable water from
sea-water is of vital importance in the equipment of ships. The simple
distillation of sea-water, and the production thereby of a certain
proportion of chemically fresh water, is a very simple problem; but it
is found that water which is merely evaporated and recondensed has a
very disagreeable flat taste, and it is only after long exposure to
pure atmospheric air, with continued agitation, or repeated pouring
from one vessel to another, that it becomes sufficiently aerated to
lose its unpleasant taste and smell and become drinkable. The water,
moreover, till it is saturated with gases, readily absorbs noxious
vapours to which it may be exposed. For the successful preparation of
potable water from sea-water, the following conditions are
essential:--1st, aeration of the distilled product so that it may be
immediately available for drinking purposes; 2nd, economy of coal to
obtain the maximum of water with the minimum expenditure of fuel; and
3rd, simplicity of working parts, to secure the apparatus from
breaking down, and enable unskilled attendants to work it with safety.
The problem is a comparatively old one, for we find that R. Fitzgerald
patented a process in 1683 having for its purpose the "sweetening of
sea-water." A history of early attempts is given in S. Hales's
_Philosophical Experiments_, published in 1739. Among the earlier of
the modern forms of apparatus which came into practical adoption are
the inventions of Dr Normandy and of Chaplin of Glasgow, the apparatus
of Rocher of Nantes, and that patented by Galle and Mazeline of Havre.
Normandy's apparatus, although economical and producing water of good
quality, is very complex in its structure, consisting of very numerous
working parts, with elaborate arrangements of pipes, cocks and other
fittings. It is consequently expensive and requires careful attention
for its working. It was extensively adopted in the British navy, the
Cunard line and many other important emigrant and mercantile lines.
Chaplin's apparatus, which was invented and patented later, has also
since 1865 been sanctioned for use on emigrant, troop and passenger
vessels. The apparatus possesses the great merit of simplicity and
compactness, in consequence of which it is comparatively cheap and not
liable to derangement. It was adopted by many important British and
continental shipping companies, among others by the Peninsular &
Oriental, the Inman, the North German Lloyd and the Hamburg American
companies.

The modern distilling plant consists of two main parts termed the
evaporator and condenser; in addition there must be a boiler
(sometimes steam is run off the main boilers, but this practice has
several disadvantages), pumps for circulating cold water in the
condenser and for supplying salt water to the evaporator, and a filter
through which the aerated water passes. The evaporator consists of a
cylindrical vessel having in its lower half a horizontal copper coil
connected to the steam supply. The cylindrical vessel is filled to a
certain level with salt water and the steam turned on. The water
vaporizes and is led from the dome of the evaporator to the head of
the condenser. The water level is maintained in the evaporator until
it contains a certain amount of salt. It is then run off, and replaced
by fresh sea-water. The condenser consists of a vertical cylinder
having manifolds at the head and foot and through which a number of
tubes pass. In some types, e.g. the Weir, the condensing water
circulates upwards through the tubes; in others, e.g. the Quiggins,
the water circulates around the tubes. Various forms of the tubes have
been adopted. In the Pape-Henneberg condenser, which has been adopted
in the German navy, they are oval in section and tend to become
circular under the pressure of the steam; this alteration in shape
makes the tubes self-scaling. In the Quiggins condenser, which has
been widely adopted, e.g. in the "Lusitania," the steam traverses
vertical copper coils tinned inside and outside; the coils are
crescent-shaped, a form which gives a greater condensing surface and
makes the coils self-scaling. The aeration of the water is effected by
blowing air into the steam before it is condensed; as an auxiliary,
the storage tanks have a false bottom perforated by fine holes so that
if air be injected below it, the water is efficiently aerated by the
air which traverses it in fine streams. After condensation the water
is filtered through charcoal. The filter is either a separate piece of
plant, or, as in the Quiggins form, it may be placed below the coils
in the same outer vessel. In this plant the aeration is conducted by
blowing in air at the base of the condenser. After filtration the
water is pumped to the storage tanks. Many types of distilling plant
are in use in addition to those mentioned above, for example the
Rayner, Kirkaldy, Merlees, Normand; the United States navy has adopted
a form designed by the Bureau of Engineering.

BIBLIOGRAPHY.--The general practice of laboratory distillation is
discussed in all treatises on practical organic chemistry; reference
may be made to Lassar-Cohn, _Manual of Organic Chemistry_ (1896), and
_Arbeitsmethoden fur organisch-chemische Laboratorien_ (1901); Hans
Meyer, _Analyse und Konstitutionermittlung organischer Verbindungen_
(1909). The theory of distillation finds a place in all treatises on
physical chemistry. Of especial importance is Sidney Young,
_Fractional Distillation_ (1903). The history of distillation is to be
studied in E. Gildemeister and F. Hoffmann, _Die atherischen Ole_
(Berlin, 1899; Eng. tr. by E. Kremers, Milwaukee Press, 1900). The
technology of distillation is best studied in relation to the several
industries in which it is employed; reference should be made to the
articles COAL-TAR, GAS, PETROLEUM, SPIRITS, NITRIC ACID, &c.
(C. E.*)

DISTRACTION (from Lat. _distrahere_, to pull asunder), a drawing away or apart; a word now used generally of a state of mind, to mean a diversion of attention, or a violent emotion amounting almost to madness.

DISTRESS (from the O. Fr. _destrece_, _destresse_, from the past participle of the Lat. _distringere_, to pull apart, used in Late Lat. in the sense of to punish, hence to distrain), pressure, especially of sorrow, pain or ill-fortune. As a legal term, the action of distraining or distraint, the right which a landlord has of seizing the personal chattels of his tenant for non-payment of rent. Cattle _damage feasant_ (doing damage or trespassing upon a neighbour's land) may also be _distrained_, i.e. may be detained until satisfaction be rendered for injury they have done. The cattle or other animals thus distrained are a mere pledge in the hands of the injured person, who has only power to retain them until the owner appear to make satisfaction for the mischief they have done. "Distress damage feasant" is also applicable to inanimate things on the land if doing damage thereto or to its produce; things in actual use, however, are exempt. Such distress must be made during the actual trespass, and by whoever is aggrieved by the damage. Distress for rent was also at one time regarded as a mere pledge or security; but the remedy, having been found to be speedy and efficacious, was rendered more perfect by enactments allowing the thing taken to be sold. Blackstone notes that the law of distresses in this respect "has been greatly altered within a few years last past." The legislature, in fact, converted an ancient right of personal redress into a powerful remedy for the exclusive benefit of a single class of creditors, viz. landlords. Now that the relation of landlord and tenant in England has come to be regarded as purely a matter of contract, the language of the law-books seems to be singularly inappropriate. The defaulting tenant is a "wrong-doer," the landlord is the "injured party,"; any attempt to defeat the landlord's remedy by carrying off distrainable goods is denounced as "fraudulent and knavish." The operation of the law has, as we shall point out, been mitigated in some important respects, but it still remains an almost unique specimen of one-sided legislation.

At common law distress was said to be incident to _rent service_, and by particular reservation to rent charges; but by 4 Geo. II. c. 28 it was extended to _rent seck_, _rents of assize_ and chief rents (see RENT). It is therefore a general remedy for rent certain in arrear. All personal chattels are distrainable with the following exceptions:--(1) things in which there can be no property, as animals _ferae naturae_; (2) ledgers, daybooks, title-deeds, &c.; (3) things delivered to a person following a public trade, as a horse sent to be shod, &c.; (4) things already in the custody of the law; (5) things which cannot be restored in as good a plight as when distrained, that is, perishable articles; (6) fixtures; (7) beasts of the plough and instruments of husbandry while there is other sufficient distress to be found; (8) instruments of a man's trade or profession in actual use at the time the distress is made. If not in actual use they are only privileged in case there is other sufficient distress upon the premises. These exceptions, it will be seen, imply that the thing distrained is to be held as a pledge merely--not to be sold. They also imply that in general any chattels found on the land in question are to be available for the benefit of the landlord, whether they belong to the tenant or not. This principle worked with peculiar harshness in the case of lodgers, whose goods might be seized and sold for the payment of the rent due by their landlord to his superior landlord. By the Lodgers' Goods Protection Act 1871, however, where a lodger's goods have been seized by the superior landlord the lodger may serve him with a notice stating that the intermediate landlord has no interest in the property seized, but that it is the property or in the lawful possession of the lodger, and setting forth the amount of the rent due by the lodger to his immediate landlord. On payment or tender of such rent the landlord cannot proceed with the distress against the goods in question. By the Law of Distress Amendment Act 1908 this protection was extended to under tenants liable to pay rent by equal quarterly instalments, as well as to any person whatsoever who is not a tenant of the premises or any part thereof nor has any beneficial interest therein. The act, however, excludes certain goods, particularly goods belonging to the husband or wife of the tenant whose rent is in arrear, goods comprised in any bill of sale, hire purchase agreement or settlement made by the tenant, goods in the possession or disposition of a tenant by the consent and permission of the true owner under such circumstances as to make the tenant reputed owner, goods of the partner of an immediate tenant, and goods (not being goods of a lodger) upon premises where any trade or business is carried on in which both the immediate tenant and the under tenant have an interest. The act does not apply where an under tenancy has been created in breach of a covenant or agreement between the landlord and his immediate tenant. The Law of Distress Amendment Act 1888 also absolutely exempted from distress the tools and implements of trade and wearing apparel and bedding of a tenant and his family to the value of five pounds, and the Law of Distress Amendment Act 1895 gave power to a court of summary jurisdiction to direct that such goods, when distrained upon, should be restored if not sold, or, if sold, to order their value to be paid by the persons who levied the distress or directed it to be levied. Originally the landlord could only seize things actually on the premises, so that the remedy might be defeated by the things being taken away. But by an act of 1710, and by the Distress for Rent Act 1737, he may follow things fraudulently or clandestinely removed off the premises within thirty days after their removal, unless they have been in the meantime bona fide sold for a valuable consideration. The sixth exception mentioned above was held to extend to sheaves of corn; but by an act of 1690 corn, when reaped, as well as hay, was made subject to distress. That act was modified by the Landlord and Tenant Act 1851, under which growing crops seized by the sheriff and sold under an execution are liable to distress for rent which becomes due after the seizure and sale, if there is no other sufficient distress on the premises.

Excessive or disproportionate distress exposes the distrainer to an action, and any irregularity formerly made the proceedings void _ab initio_, so that the remedy was attended with considerable risk. The Distress for Rent Act 1737, before alluded to, in the interests of landlords, protected distresses for _rent_ from the consequences of irregularity. In all cases of distress for rent, if the owner do not within five days (by the Law of Distress Amendment Act 1888, fifteen days, if the tenant make a request in writing to the person levying the distress and also give security for any additional cost that may be occasioned by such extension of time) replevy the same with sufficient security, the thing distrained may be sold towards satisfaction of the rent and charges, and the surplus, if any, must be returned to the owner. To "replevy" is when the person distrained upon applies to the proper authority (the registrar of the county court) to have the thing returned to his own possession, on giving security to try the right of taking it in an action of replevin.

Duties and penalties imposed by act of parliament (e.g. payment of rates and taxes) are sometimes enforced by distress.

DISTRIBUTION (Lat, _distribuere_, to deal out), a term used in various connexions with the general meaning of spreading out. In law, the word is used for the division of the personal estate of an intestate among the next-of-kin (see INTESTACY). The important scientific question as to the distribution of plants and animals on the earth is treated under PLANTS: _Distribution_, and ZOOLOGICAL DISTRIBUTION. In economics the word is used generally for the transference of commodities from person to person or from place to place, or the dividing up of large quantities of commodities into smaller quantities; and in a more technical sense, for the division of the product of industry amongst the various members or classes of the community. The theory of economic distribution, i.e. the causes which determine rent, wages, profits and interest, forms an important subject-matter in all text-books. Among recent works, see E. Cannan's _History of Theories of Production and Distribution, 1776-1848_ (1893), J. R. Common's _Distribution of Wealth_ (1893), and H. J. Davenport's _Value and Distribution_ (Chicago, 1908).

DISTRICT, a word denoting in its more general sense, a tract or extent of a country, town, &c., marked off for administrative or other purposes, or having some special and distinguishing characteristics. The medieval Latin _districtus_ (from _distringere_, to distrain) is defined by Du Cange as _Territorium feudi, seu tractus, in quo Dominus vassallos et tenentes suos distringere potest_; and as _justitiae exercendae in eo tractu facultas_. It was also used of the territory over which the feudal lord exercised his jurisdiction generally. It may be noted that _distringere_ had a wider significance than "to distrain" in the English legal sense (see DISTRESS). It is defined by Du Cange as _compellere ad aliquid faciendum per mulctam, poenam, vel capto pignore_. In English usage, apart from its general application in such forms as postal district, registration district and the like, "district" has specific usages for ecclesiastical and local government purposes. It is thus applied to a division of a parish under the Church Building Acts, originally called a "perpetual curacy," and the church serving such a division is properly a "district chapel." Under the Local Government Act of 1894 counties are divided for the purposes of the act into urban and rural districts. In British India the word is used to represent the _zillah_, an administrative subdivision of a province or presidency. In the United States of America the word has many administrative, judicial and other applications. In South Carolina it was used instead of "county" for the chief division of the state other than in the coast region. In the Virginias, Tennessee, Georgia, Kentucky and Maryland it answers to "township" or precinct, elsewhere the principal subdivision of a county. It is used for an electoral "division," each state being divided into Congressional and senatorial districts; and also for a political subdivision ranking between an unorganized and an organized Territory--e.g., the District of Columbia and Alaska.

DISTYLE (from Gr. [Greek: di-], two, and [Greek: stylos], column), the architectural term given to a portico which has two columns between antae, known as _distyle-in-antis_ (see TEMPLE).

DITHMARSCHEN, or DITMARSH (in the oldest form of the name _Thiatmaresgaho_, Dietmar's Gau), a territory between the Eider, the Elbe and the North Sea, forming the western part of the old duchy of Holstein, and now included in the Prussian province of Schleswig-Holstein. It contains about 550 sq. m. with 90,000 inhabitants. The territory consists to the extent of one half of good pasture land, which is preserved from inroads of the sea by banks and dams, the other half being mostly waste. It was originally colonized mainly from Friesland and Saxony. The district was subjugated and Christianized by Charlemagne in 804, and ranked as a separate _Gau_, included perhaps in the countship of Stade, or _Comitalus utriusque ripae_. From the same century, according to one opinion, or from the year 1182, when the countship was incorporated with their see, according to another, the archbishops of Bremen claimed supremacy over the land; but the inhabitants, who had developed and consolidated a systematic organism for self-government, made obstinate resistance, and rather attached themselves to the bishop of Schleswig. Ditmarsken, to use the Scandinavian form of the name, continued part of the Danish dominions till the disastrous battle of Bornhoved in 1227, when its former independence was regained. The claims of the archbishop of Bremen were now so far recognized that he exercised the royal rights of _Heerbann_ and _Blutbann_,[1] enjoyed the consequent emoluments, and was represented first by a single _advocatus_, or _Vogt_, and afterwards by one for each of the five Doffts, or marks, into which the land was divided after the establishment of Meldorf. The community was governed by a _Landrath_ of forty-eight elective consuls, or twelve from each of the four marks; and even in the 14th century the power of the episcopal _advocati_ was so slight that a chronicler quoted by Conrad von Maurer says, _De Ditmarschen leven sunder Heren und Hovedt unde dohn wadt se willen_, "the Ditmarschen live without lord and head, and do what they will." In 1319 and in 1404 they succeeded in defeating the invasions of the Holstein nobles; and though in 1474 the land was nominally incorporated with the duchy by the emperor Frederick III., the attempt of the Danish king Hans and the duke of Gottorp to enforce the decree in 1500 resulted only in their complete rout in the marshes of the Dussend-Duwels-Warf. During the early part of the century which began with such prestige for Ditmarsh, it was the scene of violent internal conflict in regard to the religious questions of the time; and, thus weakened, it was obliged in 1559 to submit to partition among its three conquerors--King Frederick II. of Denmark and Dukes John and Adolphus. A new division took place on Duke John's death in 1581, by which Frederick obtained South Ditmarsh, with its chief town of Meldorf, and Adolphus obtained North Ditmarsh, with its chief town of Heide; and this arrangement continued till 1773, when all the Gottorp possessions were incorporated with the Danish crown.

See Dahlmann's edition of Neocorus, _Chronik von Dithmarschen_ (Kiel,
1827), and _Geschichte Danemarks_ (1840-1844); Michelsen,
_Urkundenbuch zur Geschichte des Landes Dithmarschen_ (1834),
_Sammlung altdithmarscher Rechtsquellen_ (1842), and _Dithmarschen im
Verhaltniss zum bremischen Erzstift_; Kolster, _Geschichte
Dithmarschens, nach F. R. Dahlmanns Vorlesungen_ (1873).

FOOTNOTE:

[1] That is, the right of claiming military service, and the right of
bringing capital offenders to justice.

DITHYRAMBIC POETRY, the description of poetry in which the character of the dithyramb is preserved. It remains quite uncertain what the derivation or even the primitive meaning of the Greek word [Greek: dithyrambos] is, although many conjectures have been attempted. It was, however, connected from earliest times with the choral worship of Dionysus. A dithyramb is defined by Grote as a round choric dance and song in honour of the wine-god. The earliest dithyrambic poetry was probably improvised by priests of Bacchus at solemn feasts, and expressed, in disordered numbers, the excitement and frenzy felt by the worshippers. This element of unrestrained and intoxicated vehemence is prominent in all poetry of this class. The dithyramb was traditionally first practised in Naxos; it spread to other islands, to Boeotia and finally to Athens. Arion is said to have introduced it at Corinth, and to have allied it to the worship of Pan. It was thus "merged," as Professor G. G. Murray says, "into the Satyr-choir of wild mountain-goats" out of which sprang the earliest form of tragedy. But when tragic drama had so far developed as to be quite independent, the dithyramb did not, on that account, disappear. It flourished in Athens until after the age of Aristotle. So far as we can distinguish the form of the ancient Greek dithyramb, it must have been a kind of irregular wild poetry, not divided into strophes or constructed with any evolution of the theme, but imitative of the enthusiasm created by the use of wine, by what passed as the Dionysiac delirium. It was accompanied on some occasions by flutes, on others by the lyre, but we do not know enough to conjecture the reasons of the choice of instrument. Pindar, in whose hands the ode took such magnificent completeness, is said to have been trained in the elements of dithyrambic poetry by a certain Lasus of Hermione. Ion, having carried off the prize in a dithyrambic contest, distributed to every Athenian citizen a cup of Chian wine. In the opinion of antiquity, pure dithyrambic poetry reached its climax in a lost poem. _The Cyclops_, by Philoxenus of Cythera, a poet of the 4th century B.C. After this time, the composition of dithyrambs, although not abandoned, rapidly declined in merit. It was essentially a Greek form, and was little cultivated, and always without success, by the Latins. The dithyramb had a spectacular character, combining verse with music. In modern literature, although the adjective "dithyrambic" is often used to describe an enthusiastic movement in lyric language, and particularly in the ode, pure dithyrambs have been extremely rare. There are, however, some very notable examples. The _Baccho in Toscana_ of Francesco Redi (1626-1698), which was translated from the Italian, with admirable skill, by Leigh Hunt, is a piece of genuine dithyrambic poetry. _Alexander's Feast_ (1698), by Dryden, is the best example in English. But perhaps more remarkable, and more genuinely dithyrambic than either, are the astonishing improvisations of Karl Mikael Bellman (1740-1795), whose Bacchic songs were collected in 1791 and form one of the most remarkable bodies of lyrical poetry in the literature of Sweden. (E. G.)

DITTERSBACH, a town of Germany, in the Prussian province of Silesia, 3 m. by rail S.E. from Waldenburg and 50 m. S. W. from Breslau. It has coal-mines, bleach-fields and match factories. Population (1905) 9371.

DITTERSDORF, KARL DITTERS VON (1739-1799), Austrian composer and violinist, was born in Vienna on the 2nd of November 1739, his father's name being Ditters. Having shown as a child marked talent for the violin, he was allowed to play in the orchestras of St Stephen's and the _Schottenkirche_, where he attracted the attention of a notable patron of music, Prince Joseph Frederick of Hildburghausen (1702-1787), who is also remembered as a soldier for his disastrous leading of the forces of the Empire at Rossbach. The prince gave the boy, now eleven years old, a place in his private orchestra--the first of the kind established in Vienna,--and also saw to it that he received an excellent general education. The Seven Years' War proved disastrous to both music and morals; and young Ditters, who had fallen into evil ways, fled from Hildburghausen, whither he had gone with the prince, to avoid the payment of his gambling debts. His patron generously forgave and recalled him, but soon afterwards gave up his orchestra at Vienna. Ditters now obtained a place in the Vienna opera; but he was not satisfied, and in 1761 eagerly accepted an invitation to accompany Gluck, whose acquaintance, as well as that of Haydn, he had made while in the service of the prince, on a professional journey to Italy. His success as a violinist on this occasion was equal to that of Gluck as composer; and on his return to Vienna he was recognized as the superior of Antonio Lolli, who as virtuoso had hitherto held the palm. In 1764 he was again associated with Gluck in the musical part of the ceremonies at Frankfort, attending the coronation of the archduke Joseph as King of the Romans. His next appointment was that of conductor of the orchestra of the bishop of Grosswardein, a Hungarian magnate, at Pressburg. He set up a private stage in the episcopal palace, and wrote for it his first "opera buffa," _Amore in musica_. His first oratorio, _Isacco figura del Redentore_, was also written during this time; but the scandal of performances of light opera by the bishop's company, even on fast days and during Advent, outweighed this pious effort; the empress Maria Theresa sharply called the worldly prelate to order; and he, in a huff, dismissed his orchestra (1769). After a short interlude, Ditters was again in the service of an ecclesiastical patron, count von Schafgotsch, prince bishop of Breslau, at his estate of Johannesberg in Silesia. Here he displayed so much skill as a sportsman, that the bishop procured for him the office of forester (_Forstmeister_) of the principality of Neisse. He had already, by the same influence, been made knight of the Golden Spur (1770). At Johannesberg Ditters also produced a comic opera, _Il Viaggiatore americano_, and an oratorio, _Davide_. The title role of the latter was taken by a pretty Italian singer, Signora Nicolini, whom Ditters married. In 1773 he was ennobled as Karl von Dittersdorf, and at the same time was appointed administrator (_Amtshauptmann_) of Freyenwaldau, an office which he performed by deputy. In the same year his oratorio _Ester_ was produced in Vienna. During the War of Bavarian Succession the prince bishop's orchestra was dissolved, and Dittersdorf employed himself in his office at Freyenwaldau; but after the peace of Tetschen (1779) he again became conductor of the reconstituted orchestra. From this time forward his output was enormous. In 1780 ten months sufficed for the production of his _Giobbe_ (Job) and four operas, three of which were successful; and besides these he wrote a large number of "characterized symphonies," founded on the _Metamorphoses_ of Ovid. He was now at the height of his fame, and spent the fortune which it brought him in much luxury. But after a time his patron fell on evil days, the famous orchestra had to be reduced, and when the bishop died in 1795 his successor dismissed the composer with a small money gift. Poor and broken in health, he accepted the asylum offered to him by Ignaz Freiherr von Stillfried, on his estate near Neuhaus in Bohemia, where he spent what strength was left him in a feverish effort to make money by the composition of operas, symphonies and pianoforte pieces. He died on the 1st of October 1799, praying "God's reward" for whoever should save his family from starvation. On his death-bed he dictated to his son his _Lebensbeschreibung_ (autobiography).

Dittersdorf's chief talent was for comic opera and instrumental music in the sonata forms. In both of these branches his work still shows signs of life, and it is of great historical interest, since he was not only an excellent musician and a friend of Haydn but also a thoroughly popular writer, with a lively enough musical wit and sense of effect to embody in an amusing and fairly artistic form exactly what the best popular intelligence of the times saw in the new artistic developments of Haydn. Thus, while in the amiable monotony and diffuseness of Boccherini we may trace Haydn as a force tending to disintegrate the polyphonic suite-forms of instrumental music, in Dittersdorf on the other hand we see the popular conception of the modern sonata and dramatic style. Yet, with all his popularity, the reality of his progressive outlook may be gauged from the fact that, though he was at least as famous a violinist as Boccherini was a violoncellist, there is in his string quartets no trace of that tendency to sacrifice the ensemble to an exhibition of his own playing which in Boccherini's chamber music puts the violoncello into the same position as the first violin in the chamber music of Spohr. In Dittersdorf's quartets (at least six of which are worthy of their survival at the present day) the first violin leads indeed, but not more than is inevitable in such unsophisticated music where the normal place for melody is at the top. The appearance of greater vitality in the texture of Boccherini's quintets is produced merely by the fact that, his special instrument being the violoncello, his displays of brilliance inevitably occur in the inner parts. Six of Dittersdorf's symphonies on the _Metamorphoses_ of Ovid were republished in 1899, the centenary of his death. In them we have an amusing and sometimes charming illustration of the way in which at transitional periods music, as at the present day, is ready to make crutches of literature. The end of the representation of the conversion of the Lycian peasants into frogs is prophetically and ridiculously Wagnerian in its ingenious expansion of rhythm and eminently expert orchestration. Every external feature of Dittersdorf's style seems admirably apt for success in German comic opera on a small scale; and an occasional experimental performance at the present day of his _Doktor und Apotheker_ is not less his due than the survival of his best quartets.

See his _Lebensbeschreibung_, published at Leipzig, 1801 (English
translation by A. D. Coleridge, 1896); an article in the _Rivista
musicale_, vi. 727; and the article "Dittersdorf" in Grove's
_Dictionary of Music and Musicians_.

DITTO (from the Lat. _dictum_, something said, Ital. _detto_, aforesaid), that which has been said before, the same thing. The word is frequently abbreviated into "do." In accounts, "ditto" is indicated by two dots or a dash under the word or figure that would otherwise be repeated. A "suit of dittos," a trade or slang phrase, is a suit in which coat, trousers and waistcoat are all of the same material.

DITTON, HUMPHRY (1675-1715), English mathematician, was born at Salisbury on the 29th of May 1675. He studied theology, and was for some years a dissenting minister at Tonbridge, but on the death of his father he devoted himself to the congenial study of mathematics. Through the influence of Sir Isaac Newton he was elected mathematical master in Christ's hospital. He was author of the following memoirs and treatises:--"Of the Tangents of Curves, &c.," _Phil. Trans._ vol. xxiii.; "A Treatise on Spherical Catoptrics," published in the _Phil. Trans._ vol. xxiv., from which it was copied and reprinted in the _Acta Eruditorum_ (1707), and also in the Memoirs of the Academy of Sciences at Paris; _General Laws of Nature and Motion_ (1705), a work which is commended by Wolfius as illustrating and rendering easy the writings of Galileo and Huygens, and the _Principia_ of Newton; _An Institution of Fluxions, containing the First Principles, Operations, and Applications of that admirable Method, as invented by Sir Isaac Newton_ (1706). In 1709 he published the _Synopsis Algebraica_ of John Alexander, with many additions and corrections. In his _Treatise on Perspective_ (1712) he explained the mathematical principles of that art; and anticipated the method afterwards elaborated by Brook Taylor. In 1714 Ditton published his _Discourse on the Resurrection of Jesus Christ;_ and _The New Law of Fluids, or a Discourse concerning the Ascent of Liquids in exact Geometrical Figures, between two nearly contiguous Surfaces_. To this was annexed a tract ("Matter not a Cogitative Substance") to demonstrate the impossibility of thinking or perception being the result of any combination of the parts of matter and motion. There was also added an advertisement from him and William Whiston concerning a method for discovering the longitude, which it seems they had published about half a year before. Although the method had been approved by Sir Isaac Newton before being presented to the Board of Longitude, and successfully practised in finding the longitude between Paris and Vienna, the board determined against it. This disappointment, aggravated as it was by certain lines written by Dean Swift, affected Ditton's health to such a degree that he died in the following year, on the 15th of October 1715.

DIU, an island and town of India, belonging to Portugal, and situated at the southern extremity of the peninsula of Kathiawar. Area of district, 20 sq. m. Pop. (1900) 14,614. The anchorage is fairly protected from the sea, but the depth of water is only 3 to 4 fathoms. The channel between the island on Diu and the mainland is navigable only by fishing boats and small craft. The town is well fortified on the old system, being surrounded by a wall with towers at regular intervals. Many of the inhabitants are the well-known Banyan merchants of the east coast of Africa and Arabia. Native spirits are distilled from the palm, salt is made and fish caught. The trade of the town, however, is decayed. There are remains of several fine ancient buildings. The cathedral or Se Matriz, dating from 1601, was formerly a Jesuit college. The mint, the arsenal and several convents (now ruined or converted to other uses) are also noteworthy. The Portuguese, under treaty with Bahadur Shah of Gujarat, built a fort here in 1535, but soon quarrelled with the natives and were besieged in 1538 and 1545. The second siege is one of the most famous in Indo-Portuguese history, and is the subject of an epic by Jeronymo Corte Real (q.v.).

See R. S. Whiteway, _Rise of the Portuguese Power in India_ (1898).

DIURETICS (from Gr. [Greek: dia], through, and [Greek: ourein], pass urine), the name given to remedies which, under certain conditions, stimulate an increased flow of urine. Their mode of action is various. Some are absorbed into the blood, carried to the secretory organs (the kidneys), and stimulate them directly, causing an increased flow of blood; others act as stimulants through the nervous system. A second class act in congested conditions of the kidneys by diminishing the congestion. Another class, such as the saline diuretics, are effectual by virtue of their osmotic action. A fourth class are diuretic by increasing the blood pressure within the vessels in general, and the Malpighian tufts in particular,--some, as digitalis, by increasing the strength of the heart's contractions, and others, as water, by increasing the amount of fluid circulating in the vessels. Some remedies, as mercury, although not diuretic themselves, when prescribed along with those which have this action, increase their effect. The same remedy may act in more than one way, e.g. alcohol, besides stimulating the secretory organs directly, is a stimulant to the circulation, and thus increases the pressure within the vessels. Diuretics are prescribed when the quantity of urine is much diminished, or when, although the quantity may be normal, it is wished to relieve some other organ or set of organs of part of their ordinary work, or to aid in carrying off some morbid product circulating in the blood, or to hasten the removal of inflammatory serous exudations, or of dropsical collections of fluid. Caffeine, which is far the best true diuretic, acts in nearly every way mentioned above. Together with digitalis it is the most efficient remedy for cardiac dropsy. A famous diuretic pill, known as Guy's pill, consists of a grain each of mercurial pill, digitalis leaves and squill, made up with extract of henbane. Digitalis, producing its diuretic effect by its combined action on heart, vessels and kidneys, is much used in the oedema of mitral disease, but must be avoided in chronic Bright's disease, as it increases the tension of the pulse, already often dangerously high. Turpentine and cantharides are not now recommended as diuretics, as they are too irritating to the kidneys.

DIURNAL MOTION, the relative motion of the earth and the heavens, which results from the rotation of our globe on its axis in a direction from west toward east. The actual motion consists in this rotation. But the term is commonly applied to the resultant apparent revolution of the heavens from east to west, the axis of which passes through the celestial poles, and is coincident in direction with the axis of the earth.

DIVAN (Arabic _d[=i]w[=a]n_), a Persian word, derived probably from Aramaic, meaning a "counting-house, office, bureau, tribunal"; thence, on one side, the "account-books and registers" of such an office, and, on another, the "room where the office or tribunal sits"; thence, again, from "account-book, register," a "book containing the poems of an author," arranged in a definite order (alphabetical according to the rhyme-words), perhaps because of the saying, "Poetry is the register (_d[=i]w[=a]n_) of the Arabs," and from "bureau, tribunal," "a long seat, formed of a mattress laid against the side of the room, upon the floor or upon a raised structure or frame, with cushions to lean against" (Lane, _Lexicon_, 930 f.). All these meanings existed and exist, especially "bureau, tribunal," "book of poems" and "seat"[1]; but the order of derivation may have been slightly different. The word first appears under the caliphate of Omar (A.D. 634-644). Great wealth, gained from the Moslem conquests, was pouring into Medina, and a system of business management and administration became necessary. This was copied from the Persians and given the Persian name, "divan." Later, as the state became more complicated, the term was extended over all the government bureaus. The divan of the Sublime Porte was for long the council of the empire, presided over by the grand vizier.

See Von Kremer, _Culturgeschichte des Orients_, i. 64, 198.
(D. B. MA.)

FOOTNOTE:

[1] The divan in this sense has been known in Europe certainly since
about the middle of the 18th century. It was fashionable, roughly
speaking, from 1820 to 1850, wherever the romantic movement in
literature penetrated. All the boudoirs of that generation were
garnished with divans; they even spread to coffee-houses, which were
sometimes known as "divans" or "Turkish divans"; and a "cigar divan"
remains a familiar expression.

DIVER, a name that when applied to a bird is commonly used in a sense even more vague than that of loom, several of the sea ducks or _Fuligulinae_ and mergansers being frequently so called, to say nothing of certain of the auks or _Alcidae_ and grebes; but in English ornithological works the term diver is generally restricted to the Family known as _Colymbidae_, a very well-marked group of aquatic birds, possessing great, though not exceptional, powers of submergence, and consisting of a single genus _Colymbus_ which is composed of three, or at most four, species, all confined to the northern hemisphere. This Family belongs to the _Cecomorphae_ of T. H. Huxley, and is usually supposed to occupy a place between the _Alcidae_ and _Podicipedidae_; but to which of these groups it is most closely related is undecided. Professor Brandt in 1837 (_Beitr. Naturgesch. Vogel_, pp. 124-132) pointed out the osteological differences of the grebes and the divers, urging the affinity of the latter to the auks; while, thirty years later, Professor Alph. Milne-Edwards (_Ois. foss. France_, i. pp. 279-283) inclined to the opposite view, chiefly relying on the similarity of a peculiar formation of the tibia in the grebes and divers,[1] which indeed is very remarkable, and, in the latter group, attracted the attention of Willughby more than 230 years ago. On the other hand Professor Brandt, and Rudolph Wagner shortly after (Naumann's _Vogel Deutschlands_, ix. p. 683, xii. p. 395), had already shown that the structure of the knee-joint in the grebes and divers differs in that the former have a distinct and singularly formed _patella_ (which is undeveloped in the latter) in addition to the prolonged, pyramidally formed, procnemial process--which last may, from its exaggeration, be regarded as a character almost peculiar to these two groups.[2] The evidence furnished by oology and the newly-hatched young seems to favour Brandt's views. The abortion of the _rectrices_ in the gerbes, while these feathers are fairly developed in the divers, is another point that helps to separate the two Families.

The commonest species of _Colymbus_ is _C. septentrionalis_, known as the red-throated diver from an elongated patch of dark bay which distinguishes the throat of the adult in summer dress. Immature birds want the bay patch, and have the back so much more spotted that they are commonly known as "speckled divers." Next in size is the black-throated diver, _C. arcticus_, having a light grey head and a gular patch of purplish-black, above which is a semicollar of white striped vertically with black. Still bigger is the great northern diver, _C. glacialis_ or _torquatus_, with a glossy black head and neck, two semicollars of white and black vertical stripes, and nearly the whole of the black back and upper surface of the wings beautifully marked with white spots, varying in size and arranged in belts.[3] Closely resembling this bird, so as to be most easily distinguished from it by its yellow bill, is _C. adamsi_. The divers live chiefly on fish, and are of eminently marine habit, though invariably resorting for the purpose of breeding to freshwater lakes, where they lay two dark brown eggs on the very brink; but they are not unfrequently found far from the sea, being either driven inland by stress of weather, or exhausted in their migrations. Like most birds of their build, they chiefly trust to swimming, whether submerged or on the surface, as a means of progress, but once on the wing their flight is strong and they can mount to a great height. In winter their range is too extensive and varied to be here defined, though it is believed never to pass, and in few directions to approach, the northern tropic; but the geographical distribution of the several forms in summer requires mention. While _C. septentrionalis_ inhabits the north temperate zone of both hemispheres, _C. arcticus_ breeds in suitable places from the Hebrides to Scandinavia, and across the Russian empire, it would seem, to Japan, reappearing in the north-west of North America,[4] though its eastern limit on that continent cannot be definitely laid down; but it is not found in Greenland, Iceland, Shetland or Orkney. _C. glacialis_, on the contrary, breeds throughout the north-eastern part of Canada, in Greenland and in Iceland. It has been said to do so in Scotland as well as in Norway, but the assertion seems to lack positive proof, and it may be doubted whether, with the exception of Iceland, it is indigenous to the Old World,[5] since the form observed in North-eastern Asia is evidently that which has been called _C. adamsi_, and is also found in North-western America; but it may be remarked that one example of this form has been taken in England (_Proc. Zool. Society_, 1859, p. 206) and at least one in Norway (_Nyt Mag. for Naturvidenskaberne_, 1877, p. 134). (A. N.)

FOOTNOTES:

[1] The remains of _Colymboides minutus_, from the Miocene of Langy,
described by this naturalist in the work just cited, seem to show it
to have been a generalized form. Unfortunately its tibia is unknown.

[2] A. H. Garrod, in his tentative and chiefly myological arrangement
of Birds (_Proc Zool. Society_, 1874, p. 117), placed the
_Colymbidae_ and _Podicipedidae_ in one order (_Anseriformes_) and
the _Alcidae_ in another (_Charadriiformes_); but the artificial
nature of this assignment may be realized by the fact of his
considering the other families of the former order to be _Anatidae_
and _Spheniscidae_.

[3] The osteology and myology of this species are described by Dr
Coues (_Mem. Boston Soc. Nat. History_, i. pp. 131-172, pl. 5).

[4] Lawrence's _C. pacificus_ seems hardly to deserve specific
recognition.