INVESTITURE (Late Lat. _investitura_), the formal installation into an

office or estate, which constituted in the middle ages one of the acts

that betokened the feudal relation between suzerain and vassal. The

suzerain, after receiving the vassal's homage and oath of fealty,

invested him with his land or office by presenting some symbol, such as

a clod, a banner, a branch, or some other object according to the custom

of the fief. Otto of Freising says: "It is customary when a kingdom is

delivered over to any one that a sword be given to represent it, and

when a province is transferred a standard is given." As feudal customs

grew more stereotyped, the sword and sceptre, emblematic respectively of

service and military command and of judicial prerogatives, became the

usual emblems of investiture of laymen. The word investiture (from

_vestire_, to put in possession) is later than the 9th century; the

thing itself was an outcome of feudal society.

It is in connexion with the Church that investiture has its greatest

historical interest. The Church quite naturally shared in feudal

land-holding; in addition to the tithes she possessed immense estates

which had been given her by the faithful from early times, and for the

defence of which she resorted to secular means. The bishops and abbots,

by confiding their domains to laymen on condition of assistance with the

sword in case of need, became temporal lords and suzerains with vassals

to fight for them, with courts of justice, and in short with all the

rights and privileges exercised by lay lords. On the other hand there

were bishop-dukes, bishop-counts, &c., themselves vassals of other

lords, and especially of the king, from whom they received the

investiture of their temporalities. Many of the faithful founded abbeys

and churches on condition that the right of patronage, that is the

choice of beneficiaries, should be reserved to them and their heirs.

Thus in various ways ecclesiastical benefices were gradually transformed

into fiefs, and lay suzerains claimed the same rights over ecclesiastics

as over other vassals from whom they received homage, and whom they

invested with lands. This ecclesiastical investiture by lay princes

dates at least from the time of Charlemagne. It did not seem fitting at

first to confer ecclesiastical investiture by such military and worldly

emblems as the sword and sceptre, nor to exact an oath of fealty. The

emperor Henry I. invested bishops with a glove; Otto II. presented the

pastoral staff; Conrad II., according to Wipo, went farther and required

from the archbishop of Milan an oath of fealty. By the time of Henry

III. investiture with ring and crozier had become the general practice:

it probably had been customary in some places since Otto II.

Investiture of ecclesiastics by laymen had certain serious effects which

were bound to bring on a conflict between the temporal and spiritual

authorities. In the first place the lay authorities often rendered

elections uncanonical by interfering in behalf of some favourite,

thereby impairing the freedom of the electors. Again, benefices were

kept vacant for long periods in order to ensure to the lord as long as

possible the exercise of his regalian rights. And, finally, control by

temporal princes of investiture, and indirectly of election, greatly

increased simony. Otto II. is charged with having practised simony in

this connexion, and under Conrad II. the abuse grew prevalent. At a

synod at Reims in 1049, the bishops of Nevers and Coutances affirmed

that they had bought their bishoprics, and the bishop of Nantes stated

that his father had been a bishop and that on his decease he himself had

purchased the see. At a synod at Toulouse in 1056, Berengar of Narbonne

accused the bishop of having purchased his see for 100,000 _solidi_, and

of having plundered his church and sold relics and crucifixes to Spanish

Jews in order to secure another 100,000 _solidi_ with which to buy for

his brother the bishopric of Urgel. Innumerable similar cases appear in

acts of synods and in chronicles during the 11th century. Ecclesiastical

investiture was further complicated by the considerable practice of

concubinage. There was always the tendency for clerics in such cases to

invest their sons with the temporalities of the Church; and the synod

convened by Benedict VIII. at Pavia in 1018 (or 1022 according to some

authorities) was mainly concerned with the issue of decrees against

clerics who lived with wives or concubines and bestowed Church goods on

their children. In time the Church came to perceive how closely lay

investiture was bound up with simony. The sixth decree of the Lateran

synod of 1059 forbade any cleric to accept Church office from a layman.

In the following year this decree was reaffirmed by synods held at

Vienne and Toulouse under the presidency of a legate of Nicholas II. The

main investiture struggle with the empire did not take place, however,

until Hildebrand became Pope Gregory VII. To Gregory it was intolerable

that a layman, whether emperor, king or baron, should invest a churchman

with the emblems of spiritual office; ecclesiastical investiture should

come only from ecclesiastics. To the emperor Henry IV. it was highly

undesirable that the advantages and revenues accruing from lay

investiture should be surrendered; it was reasonable that ecclesiastics

should receive investiture of temporalities from their temporal

protectors and suzerains.

Although the full text of the decrees of the famous Lenten synod of 1075

has not been preserved, it is known that Gregory on that occasion

denounced the marriage of the clergy, excommunicated five of Henry IV.'s

councillors on the ground that they had gained church offices through

simony, and forbade the emperor and all laymen to grant investiture of

bishopric or inferior dignity. The pope immediately summoned Henry to

appear at Rome in order to justify his private misconduct, and Henry

replied by causing the partisan synod of Worms (1076) to pronounce

Gregory's deposition. The pope excommunicated the emperor and stirred up

civil war against him in Saxony with such success that he brought about

Henry's bitter humiliation at Canossa in the following year. The papal

prohibition of lay investiture was renewed at synods in 1078 and 1080,

and although Gregory's death in exile (1085) prevented him from

realizing his aim in the matter, his policy was steadfastly maintained

by his successors. Victor III. condemned lay investiture at the synod of

Benevento in 1087, and Urban II. at that of Melfi in 1089. At the

celebrated council of Clermont (1095), at which the first crusade was

preached, Urban strengthened the former prohibitions by declaring that

no one might accept any spiritual office from a layman, or take an oath

of fealty to any layman. Urban's immediate successor, Paschal II.,

stirred up the rebellion of the emperor's son, but soon found Henry V.

even more persistent in the claim of investiture than Henry IV. had

been. Several attempts at settlement failed. In February 1111 legates of

Paschal II. met Henry V. at Sutri and declared that the pope was ready

to surrender all the temporalities that had been bestowed on the clergy

since the days of Charlemagne in return for freedom of election and the

abolition of lay investiture. Henry, having agreed to the proposal,

entered Rome to receive his crown. The bishops and clergy who were

present at the coronation protested against this surrender, and a tumult

arising, the ceremony had to be abandoned. The king then seized pope and

curia and left the city. After two months of close confinement Paschal

consented to an unqualified renunciation on his part of the right of

investiture. In the following year, however, a Lateran council

repudiated this compact as due to violence, and a synod held at Vienne

with papal approval declared lay investiture to be heresy and placed

Henry under the ban. The struggle was complicated throughout its course

by political and other considerations; there were repeated rebellions of

German nobles, constant strife between rival imperial and papal factions

in the Lombard cities and at Rome, and creation of several anti-popes,

of whom Guibert of Ravenna (Clement III.) and Gregory VIII. were the

most important. Final settlement of the struggle was retarded, moreover,

by the question of the succession to the lands of the great Countess

Matilda, who had bequeathed all her property to the Holy See, Henry

claiming the estates as suzerain of the fiefs and as heir of the

allodial lands. The efforts of Gelasius II. to settle the strife by a

general council were rendered fruitless by his death (1119).

At length in 1122 the struggle was brought to an end by the concordat of

Worms, the provisions of which were incorporated in the eighth and ninth

canons of the general Lateran council of 1123. The settlement was a

compromise. The emperor, on the one hand, preserved feudal suzerainty

over ecclesiastical benefices; but, on the other, he ceased to confer

ring and crozier, and thereby not only lost the right of refusing the

elect on the grounds of unworthiness, but also was deprived of an

efficacious means of maintaining vacancies in ecclesiastical offices.

Few efforts were made to undo the compromise. King Lothair the Saxon

demanded of Innocent II. the renewal of lay investiture as reward for

driving the antipope Anacletus from Rome, but the opposition of St

Bernard and the German prelates was so potent that the king dropped his

demand, and Innocent in 1133 confirmed the concordat. In fact, the

imperial control over the election of bishops in Germany came later to

be much curtailed in practice, partly by the tacitly changed relations

between the empire and its feudatories, partly by explicit concessions

wrung at various times from individual emperors, such as Otto IV. in

1209 and Frederick II. in 1213; but the principles of the concordat of

Worms continued theoretically to regulate the tenure of bishoprics and

abbacies until the dissolution of the empire on 1806.

In France the course of the struggle was somewhat different. As in the

empire, the king and the nobles, each within his own sphere of

influence, claimed the right of investing with ring and crozier and of

exacting homage and oaths of fealty. The struggle, however, was less

bitter chiefly because France was not a united country, and it was

eventually terminated without formal treaty. The king voluntarily

abandoned lay investiture and the claim to homage during the pontificate

of Paschal II., but continued to interfere with elections, to

appropriate the revenues of vacant benefices, and to exact an oath of

fealty before admitting the elect to the enjoyment of his temporalities.

Most of the great feudal lords followed the king's example, but their

concessions varied considerably, and in the south of France some of the

bishops were still doing homage for their sees until the closing years

of the 13th century; but long before then the right of investing with

ring and crozier had disappeared from every part of France.

England was the scene of an investiture contest in which the chief

actors were Henry I. and Anselm. The archbishop, in obedience to the

decrees of Gregory VII. and Urban II., not only refused to perform

homage to the king (1100), but also refused to consecrate newly-chosen

bishops who had received investiture from Henry. The dispute was bitter,

but was carried on without any of the violence which characterized the

conflict between papacy and empire; and it ended in a compromise which

closely foreshadowed the provisions of the concordat of Worms and

received the confirmation of Paschal II. in 1106. Freedom of election,

somewhat similar in form to that which still exists, was formally

conceded under Stephen, and confirmed by John in Magna Carta.

Many documents relating to the investiture struggle have been edited

by E. Dummler in _Monumenta Germaniae historica, Libelli de lite

imperatorum et pontificum saeculis xi. et xii._ (3 vols., 1891-1897),

See Ducange, _Glossarium_, s.v. "Investitura."

On investiture in the empire consult C. Mirbt, _Die Publizistik im

Zeitalter Gregors VII._ (Leipzig, 1894); E. Bernheim, _Das Wormser

Konkordat_ (Breslau, 1906); R. Boerger, _Die Belehnungen der deutschen

geistlichen Fursten_ (Leipzig, 1901); K. E. Benz, _Die Stellung der

Bischofe von Meissen, Merseburg und Naumburg im Investiturstreite

unter Heinrich IV. und Heinrich V._ (Dresden, 1899); W. Martens,

_Gregor VII., sein Leben und Wirken_ (2 vols., Leipzig, 1894); P.

Fisher, _The Medieval Empire_, c. 10 (London, 1898). For France, see

P. Imbart de la Tour, _Les Elections episcopales dans l'eglise de

France du XI^e au XII^e siecle_ (Paris, 1891); A. Luchaire,

_Histoire des institutions monarchiques de la France sous les premiers

Capetiens 987-1180_ (2nd ed., Paris, 1891); P. Viollet, _Histoire des

institutions politiques et administratives de la France_ (Paris,

1898); Ibach, _Der Kampf zwischen Papsttum und Konigtum von Gregor

VII. bis Calixto II._ (Frankfort, 1884). For England, see J. F.

Bohmer, _Kirche und Staat in England und in der Normandie in XI. und

XII. Jahrhundert_ (Leipzig, 1899); E. A. Freeman, _The Reign of

William II. Rufus and the Accession of Henry I._ (London, 1882); H. W.

C. Davis, _England under the Normans and Angevins_ (London, 1905).

INVOICE (originally a plural, _Invoyes_ or _Invoys_, of _Invoy_, a

variant of "envoy," from the French _envoyer_, to send), a statement

giving full particulars of goods sent or shipped by a trader to a

customer, with the quantity, quality and prices, and the charges upon

them. Consular invoices, i.e. invoices signed at the port of shipment by

a consul of the country to which the goods are being consigned, are

generally demanded by those countries which impose _ad valorem_ duties.

INVOLUTION (Lat. _involvere_, to roll up), a rolling up or complication.

In arithmetic, involution is the operation of raising a quantity to any

power; it is the converse of evolution, which is the operation of

extracting any root of a quantity (see ARITHMETIC; ALGEBRA). In

geometry, an involution is a one-to-one correspondence between two

ranges of points or between two pencils (see GEOMETRY: _Projective_).

The "involute" of a curve may be regarded as the locus of the extremity

of a string when it is unwrapped from the curve (see INFINITESIMAL

CALCULUS).

IO, in Greek mythology, daughter of Inachus, the river-god of Argos and

its first king. As associated with the oldest worship of Hera she is

called the daughter of Peiren, who made the first image of that goddess

out of a pear-tree at Tiryns; and under the name of Callithyia Io was

regarded as the first priestess of Hera. Zeus fell in love with her,

and, to protect her from the wrath of Hera, changed her into a white

heifer (Apollodorus ii. 1; Hyginus, _Fab._ 145; Ovid, _Metam._ i.

568-733); according to Aeschylus (_Supplices_, 299) the metamorphosis

was the work of Hera herself. Hera, having persuaded Zeus to give her

the heifer, set Argus Panoptes to watch her. Zeus thereupon sent Hermes,

who lulled Argus to sleep and cut off his head with the sword with which

Perseus afterwards slew the Gorgon. In another account Argus is killed

by a stone thrown by Hermes. But the wrath of Hera still pursued Io.

Maddened by a gadfly sent by the goddess she wandered all over the

earth, swam the strait known on this account as the Bosporus (Ox-ford),

and crossed the Ionian sea (traditionally called after her) until at

last she reached Egypt, where she was restored to her original form and

became the mother of Epaphus. Accounts of her wanderings (differing

considerably in detail) are given in the _Supplices_ and _Prometheus

Vinctus_ of Aeschylus. Various interpretations are given of the latter

part of her story, which dates from the 7th century B.C., when

intercourse was frequent between Greece and Egypt, and when much

influence was exerted on Greek thought by Egyptian religion. According

to the rationalistic explanation of Herodotus (i. 1) Io was an Argive

princess who was carried off to Egypt by the Phoenicians. Epaphus, the

son of Io, the supposed founder of Memphis, was identified with Apis. He

was said to have been carried off by order of Hera to Byblus in Syria,

where he was found again by Io. On returning to Egypt, Io, afterwards

identified with Isis, married Telegonus and founded the royal families

of Egypt, Phoenicia, Argos and Thebes. The journey to Syria in search of

Epaphus was invented to explain the fact that the Phoenician goddess

Astarte, who was sometimes represented as horned, was confounded with

Io.

Io herself is variously interpreted. She is usually understood to be the

moon in the midst of the mighty heaven, studded with stars, represented

by Argus. According to others, she is the annual rising of the Nile; the

personification of the Ionian race; the mist; the earth. It seems

probable that she was a duplicate of Hera (Io [Greek: Boukeros] is Hera

[Greek: Boopis]), or a deity in primitive times worshipped under the

symbol of a cow, whose worship was superseded by that of Hera; the

recollection of this early identity would account for Io being regarded

as the priestess of the goddess in later times. Amongst the Romans she

was sometimes identified with Anna Perenna. The legend of Io spread

beyond Argos, especially in Byzantium and Euboea, where it was

associated with the town of Argura. It was a favourite subject among

Greek painters, and many representations of it are preserved on vases

and wall paintings; Io herself appears as a horned maiden or as the

heifer watched by Argus.

See R. Engelmann, _De Ione_ (1868), with notes containing references

to authorities, and his article in Roscher's _Lexikon der Mythologie_;

J. Overbeck, _De Ione, telluris, non lunae, Dea_ (1872); P. W.

Forchhammer, _Die Wanderungen der Inachostochter Io_ (1881), with map

and special reference to Aeschylus's account of Io's wanderings; F.

Durrbach in Daremberg and Saglio's _Dictionnaire des antiquites_; G.

Mellen, _De Ius fabula_ (1901); Wernicke _s.v._ "Argos" in

Pauly-Wissowa's _Realencyclopadie_, ii. pt. i. (1896); J. E. Harrison

in _Classical Review_ (1893, p. 76); Bacchylides xviii. (xix.), with

Jebb's notes.

IODINE (symbol I, atomic weight 126.92), a chemical element, belonging

to the halogen group. Its name is derived from Gr. [Greek: ioeides]

(violet-coloured), in allusion to the colour of its vapour. It was

discovered in 1812 by B. Courtois when investigating the products

obtained from the mother-liquors prepared by lixiviating kelp or burnt

seaweed, and in 1815 L. J. Gay-Lussac showed that it was an element.

Iodine does not occur in nature in the uncombined condition, but is

found very widely but sparingly distributed in the form of iodides and

iodates, chiefly of sodium and potassium. It is also found in small

quantities in sea-water, in some seaweeds, and in various mineral and

medicinal springs. Deep-sea weeds as a rule contain more iodine than

those which are found in the shallow waters.

Iodine is obtained either from kelp (the ashes of burnt seaweed) or from

the mother-liquors obtained in the purification of Chile saltpetre. In

the former case the seaweed is burnt in large heaps, care being taken

that too high a temperature is not reached, for if the ash be allowed to

fuse much iodine is lost by volatilization. The product obtained after

burning is known either as _kelp_ or _varec_. Another method of

obtaining kelp is to heat the seaweed in large retorts, whereby tarry

and ammoniacal liquors pass over and a very porous residue of kelp

remains. A later method consists in boiling the weed with sodium

carbonate; the liquid is filtered and hydrochloric acid added to the

filtrate, when _alginic acid_ is precipitated; this is also filtered

off, the filtrate neutralized by caustic soda, and the whole evaporated

to dryness and carbonized, the residue obtained being known as _kelp

substitute_. The kelp obtained by any of these methods is then

lixiviated with water, which extracts the soluble salts, and the liquid

is concentrated, when the less soluble salts, which are chiefly alkaline

chlorides, sulphates and carbonates, crystallize out and are removed.

Sulphuric acid is now added to the liquid, and any alkaline sulphides

and sulphites present are decomposed, while iodides and bromides are

converted into sulphates, and hydriodic and hydrobromic acids are

liberated and remain dissolved in the solution. The liquid is run into

the iodine still and gently warmed, manganese dioxide in small

quantities being added from time to time, when the iodine distils over

and is collected. In the second method it is found that the

mother-liquors obtained from Chile saltpetre contain small quantities of

sodium iodate NaIO3; this liquor is mixed with the calculated quantity

of sodium bisulphite in large vats, and iodine is precipitated:--

2NaIO3 + 5NaHSO3 = 3NaHSO4 + 2Na2SO4 + H2O + I2.

The precipitate is washed and then distilled from iron retorts. Iodine

may also be prepared by the decomposition of an iodide with chlorine, or

by heating a mixture of an iodide and manganese dioxide with

concentrated sulphuric acid. Commercial iodine may be purified by mixing

it with a little potassium iodide and then subliming the mixture; in

this way any traces of bromine or chlorine are removed. J. S. Stas

recommends solution of the iodine in potassium iodide and subsequent

precipitation by the addition of a large excess of water, the

precipitate being washed, distilled in steam, and dried _in vacuo_ over

solid calcium nitrate, and then over solid caustic baryta.

Iodine is a greyish-black shining solid, possessing a metallic lustre

and having somewhat the appearance of graphite. Its specific gravity is

4.948 (17 deg./4 deg.). It melts at 114.2 deg. C. and boils at 184.35

deg. C. under atmospheric pressure (W. Ramsay and S. Young). The

specific heat of solid iodine is 0.0541 (H. Kopp). Its latent heat of

fusion is 11.7 calories, and its latent heat of vaporization is 23.95

calories (P. A. Favre and J. T. Silbermann). The specific heat of iodine

vapour at constant pressure is 0.03489, and at constant volume 0.02697.

It volatilizes slowly at ordinary temperatures, but rapidly on heating.

Iodine vapour on heating passes from a violet colour to a deep indigo

blue; this behaviour was investigated by V. Meyer (_Ber._, 1880, 13, p.

394), who found that the change of colour was accompanied by a change of

vapour density. Thus, the density of air being taken as unity, Victor

Meyer found the following values for the density of iodine vapour at

different temperatures:--

T deg. C. 253 450 506 842 1027 1570

Density 8.89 8.84 8.73 6.08 5.75 5.67

This shows that the iodine molecule becomes less complex in structure at

higher temperatures.

Iodine possesses a characteristic penetrating smell, not so pungent,

however, as that of chlorine or bromine. It is only very sparingly

soluble in water, but dissolves readily in solutions of the alkaline

iodides and in alcohol, ether, carbon bisulphide, chloroform, and many

liquid hydrocarbons. Its solutions in the alkaline iodides and in

alcohol and ether are brown in colour, whilst in chloroform and carbon

bisulphide the solution is violet. It appears to combine with the

solvent (P. Waentig, _Zeit. phys. Chem._, 1909, p. 513). Its chemical

properties closely resemble those of chlorine and bromine; its affinity

for other elements, however, is as a rule less than that of either. It

will only combine with hydrogen in the presence of a catalyst, but

combines with many other elements directly; for example, phosphorus

melts and then inflames, antimony burns in the vapour, and mercury when

heated with iodine combines with it rapidly. It is completely oxidized

to iodic acid when boiled with fuming nitric acid. It is soluble in a

solution of caustic potash, a dilute solution most probably containing

the hypoiodite, which, however, changes slowly into iodate, the change

taking place rapidly on warming. When alkali is added to aqueous iodine,

followed immediately by either soda water or sodium bicarbonate, most of

the original iodine is precipitated (R. L. Taylor, _Jour. Chem. Soc._,

1897, 71, p. 725, and K. J. P. Orton, _ibid._ p. 830). Iodine can be

readily detected by the characteristic blue coloration that it

immediately gives with starch paste; the colour is destroyed on heating,

but returns on cooling provided the heating has not been too prolonged.

Iodine in the presence of water frequently acts as an oxidizing agent;

thus arsenious acid and the arsenites, on the addition of iodine

solution, are converted into arsenic acid and arsenates. A dilute

solution of iodine prevents the decomposition of hydrogen peroxide by

colloidal platinum (G. Bredig, _Zeit. phys. Chem._, 1899, 31, p. 258;

1901, 37, p. 323).

Iodine finds application in organic chemistry, forming addition products

with unsaturated compounds, the combination, however, being more slow

than in the case of chlorine or bromine. It rarely substitutes directly,

because the hydriodic acid produced reverses the reaction; this can be

avoided by the presence of precipitated mercuric oxide or iodic acid,

which react with the hydriodic acid as fast as it is formed, and

consequently remove it from the reacting system. As a rule it is

preferable to use iodine in the presence of a carrier, such as amorphous

phosphorus or ferrous iodide or to use it with a solvent. It is found

that most organic compounds containing the grouping CH3.CO.C--or

CH3.CH(OH).C--in the presence of iodine and alkali give iodoform CHI3.

Hydriodic acid, HI, is formed by the direct union of its components in

the presence of a catalytic agent; for this purpose platinum black is

used, and the hydrogen and iodine vapour are passed over the heated

substance. On shaking up iodine with a solution of sulphuretted

hydrogen in water, a solution of hydriodic acid is obtained, sulphur

being at the same time precipitated. The acid cannot be prepared by

the action of concentrated sulphuric acid on an iodide on account of

secondary reactions taking place, which result in the formation of

free iodine and sulphur dioxide. The usual method is to make a mixture

of amorphous phosphorus and a large excess of iodine and then to allow

water to drop slowly upon it; the reaction starts readily, and the gas

obtained can be freed from any admixed iodine vapour by passing it

through a tube containing some amorphous phosphorus. It is a

colourless sharp-smelling gas which fumes strongly on exposure to air.

It readily liquefies at 0 deg. C. under a pressure of four

atmospheres, the liquefied acid boiling at -34.14 deg. C. (730.4 mm.);

it can also be obtained as a solid melting at -50.8 deg. C. It is

readily soluble in water, one volume of water at 10 deg. C. dissolving

425 volumes of the acid. The saturated aqueous solution is colourless

and fumes strongly on exposure to air; after a time it darkens in

colour owing to liberation of iodine. The gas is readily decomposed by

heat into its constituent elements. It is a powerful reducing agent,

and is frequently employed for this purpose in organic chemistry; thus

hydroxy acids are readily reduced on heating with the concentrated

acid, and nitro compounds are reduced to amino compounds, &c. It is

preferable to use the acid in the presence of amorphous phosphorus,

for the iodine liberated during the reduction is then utilized in

forming more hydriodic acid, and consequently the original amount of

acid goes much further. It forms addition compounds with unsaturated

compounds.

It has all the characteristics of an acid, dissolving many metals with

evolution of hydrogen and formation of salts, called _iodides_. The

iodides can be prepared either by direct union of iodine with a metal,

from hydriodic acid and a metal, oxide, hydroxide or carbonate, or by

action of iodine on some metallic hydroxides or carbonates (such as

those of potassium, sodium, barium, &c.; other products, however, are

formed at the same time). The iodides as a class resemble the

chlorides and bromides, but are less fusible and volatile. Silver

iodide, mercurous iodide, and mercuric iodide are insoluble in water;

lead iodide is sparingly soluble, whilst most of the other metallic

iodides are soluble. Strong heating decomposes the majority of the

iodides. Nitrous acid and chlorine readily decompose them with

liberation of iodine; the same effect being produced when they are

heated with concentrated sulphuric acid and manganese dioxide. The

soluble iodides, on the addition of silver nitrate to their nitric

acid solution, give a yellow precipitate of silver iodide, which is

insoluble in ammonia solution. Hydriodic acid and the iodides may be

estimated by conversion into silver iodide.

Iodine combines with chlorine to form _iodine monochloride_, ICl,

which may be obtained by passing dry chlorine over dry iodine until

the iodine is completely liquefied, or according to R. Bunsen by

boiling iodine with _aqua regia_ and extracting with ether. It exists

in two different crystalline forms, the more stable or [alpha] form

melting at 27.2 deg. C., and the less stable or [beta] form melting at

13.9 deg. C. It is readily decomposed by water. The _trichloride_,

ICl3, results from the action of excess of chlorine on iodine, or from

iodic acid and hydrochloric acid, or by heating iodine pentoxide with

phosphorus pentachloride. It crystallizes in long yellow needles and

decomposes readily on heating into the monochloride and chlorine. It

is readily soluble in water, but excess of water decomposes it. (See

W. Stortenbeker, _Zeit. phys. Chem._, 1889, 3, p. 11.) Iodine

monochloride in glacial acetic acid solution was used by A. Michael

and T. H. Norton (_Ber._, 1876, 9, p. 1752) for the preparation of

paraiodo-acetanilide.

_Iodine Pentoxide_, I2O5, the best-known oxide, is obtained as a white

crystalline solid by heating iodic acid to 170 deg. C.; it is easily

soluble in water, combining with the water to regenerate iodic acid;

and when heated to 300 deg. C. it breaks up into its constituent

elements, (see M. Guichard, _Compt. rend._, 1909, 148, p. 925.) Iodine

dioxide, I2O4, obtained by Millon, and reinvestigated by M. M. P. Muir

(_Jour. Chem. Soc._, 1909, 95, p. 656), is a lemon-yellow solid

obtained by acting on iodic acid with sulphuric acid, oxygen being

evolved. By acting with ozone on a chloroform solution of iodine, F.

Fichter and F. Rohner (_Ber._, 1909, 42, p. 4093) obtained a yellowish

white oxide, of the formula I4O9, which they regard as an iodate of

tervalent iodine, Millon's oxide being considered a basic iodate.

Although _hypoiodous acid_ is not known, it is extremely probable that

on adding iodine or iodine monochloride to a dilute solution of a

caustic alkali, hypoiodites are formed, the solution obtained having a

characteristic smell of iodoform, and being of a pale yellow colour.

It oxidizes arsenites, sulphites and thiosulphates immediately. The

solution is readily decomposed on the addition of sodium or potassium

bicarbonates, with liberation of iodine. The hypoiodite disappears

gradually on standing, and rapidly on warming, being converted into

iodate (see R. L. Taylor, _Jour. Chem. Soc._, 1897, 71, p. 725, and K.

J. P. Orton, _ibid._ p. 830). The peculiar nature of the action

between iodine and chlorine in aqueous solution has led to the

suggestion that the product is a base, i.e. iodine hydroxide.

Tri-iodine hydroxide, I3.OH, is obtained by oxidizing potassium iodide

with sulphuric acid and potassium permanganate (A. Skrabal and F.

Buchter, _Chem. Zeit._, 1909, 33, pp. 1184, 1193).

_Iodic Acid_, HIO3, can be prepared by dissolving iodine pentoxide in

water; by boiling iodine with fuming nitric acid, 6I + 10HNO3 = 6HIO3

+ 10NO + 2H2O; by decomposing barium iodate with the calculated

quantity of sulphuric acid, previously diluted with water, or by

suspending iodine in water and passing in chlorine, I2 + 5Cl2 + 6H2O =

2HIO3+10HCl. It is a white crystalline solid, easily soluble in water,

the solution showing a strongly acid reaction with litmus; the colour,

however, is ultimately discharged by the bleaching power of the

compound. It is a most powerful oxidizing agent, phosphorus being

readily oxidized to phosphoric acid, arsenic to arsenic acid, silicon

at 250 deg. C. to silica, and hydrochloric acid to chlorine and water.

It is readily reduced, with separation of iodine, by sulphur dioxide,

hydriodic acid or sulphuretted hydrogen, thus:--

HIO3 + 5HI = 3H2O + 3I2; 2HIO3+5SO2 + 4H2O = 5H2SO4 + I2;

2HIO3 + 5H2S = I2 + 5S + 6H2O.

The salts, known as the _iodates_, can be prepared by the action of

the acid on a base, or sometimes by the oxidation of iodine in the

presence of a base. They are mostly insoluble or only very slightly

soluble in water. The iodates of the alkali metals are, however,

readily soluble in water (except potassium iodate). They are more

easily reduced than the corresponding chlorates; an aqueous solution

of hydriodic acid giving free iodine and a metallic oxide, whilst

aqueous hydrochloric acid gives iodine trichloride, chlorine, water

and a chloride. They are decomposed on heating, with liberation of

oxygen, in some cases leaving a residue of iodide and in others a

residue of oxide of the metal, with liberation of iodine as well as of

oxygen.

_Periodic Acid_, HIO4.2H2O, is only known in the hydrated form. It can

be prepared by the action of iodine on perchloric acid, or by boiling

normal silver periodate with water: 2AgIO4 + 4H2O = Ag2H3IO6 +

HIO4.2H2O. It is a colourless, crystalline, deliquescent solid which

melts at 135 deg. C., and at 140 deg. C. is completely decomposed into

iodine pentoxide, water and oxygen. The periodates are a very complex

class of salts, and may be divided into four classes, namely,

meta-periodates derived from the acid HIO4; meso-periodates from

HIO4.H2O, para-periodates from HIO4.2H2O and the diperiodates from

2HIO4.H2O (see C. Kimmins, _Jour. Chem. Soc._, 1887, 51, p. 356).

Iodine has extensive applications in volumetric analysis, being used

more especially for the determination of copper.

The atomic weight of iodine was determined by J. S. Stas, from the

analysis of pure silver iodate, and by C. Marignac from the

determinations of the ratios of silver to iodine, and of silver iodide

to iodine; the mean value obtained for the atomic weight being 126.53.

G. P. Baxter (_Jour. Amer. Chem. Soc._, 1904, 26, p. 1577; 1905, 27,

p. 876; 1909, 31, p. 201), using the method of Marignac, obtained the

value 126.985 (O = 16). P. Kothner and E. Aeuer (_Ber._, 1904, 37, p.

2536; _Ann._, 1904, 337, p. 362), who converted pure ethyl iodide into

hydriodic acid and subsequently into silver iodide, which they then

analysed, obtained the value 126.026 (H = 1); a discussion of this and

other values gave as a mean 126.97 (O = 16).

In _medicine_ iodine is frequently applied externally as a

counter-irritant, having powerful antiseptic properties. In the form of

certain salts iodine is very widely used, for internal administration in

medicine and in the treatment of many conditions usually classed as

surgical, such as the bone manifestations of tertiary syphilis. The most

commonly used salt is the iodide of potassium; the iodides of sodium and

ammonium are almost as frequently employed, and those of calcium and

strontium are in occasional use. The usual doses of these salts are from

five to thirty grains or more. Their pharmacological action is as

obscure as their effects in certain diseased conditions are consistently

brilliant and unexampled. Our ignorance of their mode of action is

cloaked by the term _deobstruent_, which implies that they possess the

power of driving out impurities from the blood and tissues. Most notably

is this the case with the poisonous products of syphilis. In its

tertiary stages--and also earlier--this disease yields in the most rapid

and unmistakable fashion to iodides; so much so that the administration

of these salts is at present the best means of determining whether, for

instance, a cranial tumour be syphilitic or not. No surgeon would think

of operating on such a case until iodides had been freely administered

and, by failing to cure, had proved the disease to be non-syphilitic.

Another instance of this deobstruent power--"alterative," it was

formerly termed--is seen in the case of chronic lead poisoning. The

essential part of the medicinal treatment of this condition is the

administration of iodides, which are able to decompose the insoluble

albuminates of lead which have become locked up in the tissues, rapidly

causing their degeneration, and to cause the excretion of the poisonous

metal by means of the intestine and the kidneys. The following is a list

of the principal conditions in which iodides are recognized to be of

definite value: metallic poisonings, as by lead and mercury, asthma,

aneurism, arteriosclerosis, angina pectoris, gout, goitre, syphilis,

haemophilia, Bright's disease (nephritis) and bronchitis.

Small quantities of the iodate (KIO3) are a frequent impurity in

iodide of potassium, and cause the congeries of symptoms known as

_iodism_. These comprise dyspepsia, skin eruption and the

manifestations which are usually identified with a "cold in the head."

In many cases, as in syphilis, aneurism, lead poisoning, &c., the life

of the patient depends on the free and continued use of the iodide,

and this is best to be accomplished by securing an absolutely pure

supply of the salt. Another often successful method of preventing the

onset of symptoms of poisoning is to administer small doses of

ammonium carbonate with the drug, thereby neutralizing the iodic acid

which is liberated in the stomach.

IODOFORM, CHI3, a valuable antiseptic discovered by G. S. Serullas in

1822; in 1834 J. B. Dumas showed that it contained hydrogen. It is

formed by the action of iodine and aqueous potash on ethyl alcohol,

acetone, acetaldehyde and from most compounds containing the grouping

CH3.CO.C-. Its formation from alcohol may be represented thus: C2H5OH +

4I2 + 6KHO = CHI3 + KHCO2 + 5KI + 5H2O. It crystallizes in yellow

hexagonal plates, melting at 119-120 deg. C., and is readily soluble in

alcohol and ether, but is insoluble in water. It has a characteristic

odour and is volatile in steam. On reduction with hydriodic acid, it

yields methylene iodide, CH2I2.

More recently, iodoform has been prepared by the electrolysis of a

solution of potassium iodide in the presence of alcohol or acetone,

the electrolytic cell being fitted with a diaphragm, in order to

prevent the hydrogen which is formed at the same time from reducing

the iodoform, or from combining with the iodine to form hydriodic

acid. K. Elbs uses a solution of potassium iodide and sodium carbonate

in water, which with the necessary alcohol is contained in a porous

cell fitted with a lead anode, whilst the cathode compartment contains

a solution of caustic soda and a nickel electrode. The electrolysis is

carried out at a temperature of 70 deg. C., and a current density of

one ampere per square decimetre is used. At the end of three hours a

yield of 70% of the theoretical quantity is obtained.

IOLA, a city and the county-seat of Allen county, Kansas, U.S.A., on the

Neosho river, about 100 m. S. by W. of Kansas City. Pop. (1890) 1706;

(1900) 5791, of whom 237 were foreign-born and 207 were negroes; (1905)

10,287; (1910) 9032. It is served by the Atchison, Topeka & Santa Fe,

the Missouri Pacific and the Missouri, Kansas & Texas railways. It is

pleasantly situated in a level valley where there is a great abundance

of natural gas and some fine building stone. The city has large zinc

smelters and zinc rolling-mills, a foundry, machine shops, and

manufactories of cement, sulphuric acid and brick. The municipality owns

and operates its waterworks, gas plant and electric-lighting plant. Iola

was founded in 1859 by a company whose members were dissatisfied with

the location of the county-seat at Humboldt. It became the county-seat

in 1865, was chartered as a city of the third class in 1870 and became a

city of the second class in 1898. The rapid growth of the city dates

from the discovery of natural gas here, on Christmas Day 1893.

IOLITE, a mineral occasionally cut as a gem-stone, and named from the

violet colour which it sometimes presents ([Greek: ion], "violet";

[Greek: lithos], "stone"). It is generally called by petrographers

cordierite, a name given by R. J. Hauy in honour of the French

mineralogist, P. L. Cordier, who discovered its remarkable dichroism,

and suggested for it the name dichroite, still sometimes used. The

difference of colour which it shows in different directions is so marked

as to be well seen without the dichroscope. The typical colours are deep

blue, pale blue and yellowish grey. While the crystal as a whole shows

these three colours, each face is dichroic.

Iolite is a hydrous magnesium and aluminium silicate, with ferrous iron

partially replacing magnesium. It crystallizes in the orthorhombic

system. In hardness and specific gravity it much resembles quartz. The

transparent blue or violet variety used as a gem occurs as pebbles in

the gravels of Ceylon, and bears in many cases a resemblance to

sapphire. The paler kinds are often called water-sapphire (_saphir

d'eau_ of French jewellers) and the darker kinds lynx-sapphire; the

shade of colour varying with the direction in which the stone is cut.

From sapphire the iolite is readily distinguished by its stronger

pleochroism, its lower density (about 2.6) and its inferior hardness

(about 7).

Iolite occurs in granite and in true eruptive rocks, but is most

characteristically developed as a product of contact metamorphism in

gneiss and altered slates. A variety occurring at the contact of

clay-slate and granite on the border of the provinces of Shimotsuke and

Kodzuke in Japan has been called cerasite. It readily suffers chemical

change, and gives rise to a number of alteration-products, of which

pinite is a characteristic example.

Although iolite, or cordierite, is rather widely distributed as a

constituent of certain rocks, fine crystals of the mineral are of very

limited occurrence. One of the best-known localities is Bodenmais, in

Bavaria, where it occurs with pyrrhotite in a granite matrix. It is

found also in Norway, Sweden and Finland, in Saxony and in Switzerland.

Large crystals are developed in veins of granite running through gneiss

at Haddam, Connecticut; and it is known at many other localities in the

United States. (F. W. R.*)

ION, of Chios, Greek poet, lived in the age of Pericles. At an early age

he went to Athens, where he made the acquaintance of Aeschylus. He was a

great admirer of Cimon and an opponent of Pericles. He subsequently met

Sophocles in his native island at the time of the Samian war. From

Aristophanes (_Peace_, 830 ff.) it is concluded that he died before the

production of that play (421). His first tragedy was produced between

452-449 B.C.; and he was third to Euripides and Iophon in the tragic

contest of 429. In a subsequent year he gained both the tragic and

dithyrambic prizes, and in honour of his victory gave a jar of Chian

wine to every Athenian citizen (Athenaeus p. 3). He is further credited

by the scholiast on Aristophanes (loc. cit.) with having composed

comedies, dithyrambs, epigrams, paeans, hymns, scolia, encomia and

elegies; and he is the reputed author of a philosophical treatise on the

mystic number three. His historical or biographical works were five in

number, and included an account of the antiquities of Chios and of

[Greek: epidemiai], recollections of visitors to the island.

See C. Nieberding, _De Ionis Chii vita_ (1836, containing the

fragments); F. Allegre, _De Ione Chio_ (1890), an exhaustive

monograph; and Bentley, _Epistola ad Millium_.

IONA, or ICOLMKILL, an island of the Inner Hebrides, Argyllshire,

Scotland, 6(1/2) m. S. of Staffa and 1(1/4) m. W. of the Ross of Mull,

from which it is separated by the shallow Sound of Iona. Pop. (1901)

213. It is about 3(1/2) m. long and 1(1/2) m. broad; its area being some

2200 acres, of which about one-third is under cultivation, oats,

potatoes and barley being grown. In the rest of the island grassy

hollows, yielding pasturage for a few hundred cattle and sheep and some

horses, alternate with rocky elevations, which culminate on the northern

coast in Duni (332 ft.), from the base of which a dazzling stretch of

white shell sand, partly covered with grass, stretches to the sea. To

the south-west the island is fringed with precipitous cliffs. Iona is

composed entirely of ancient gneisses and schists of Lewisian age; these

include bands of quartzite, slate, marble and serpentine. The strike of

the rocks is S.W.-N.E. and they are tilted to very high angles. Fronting

the Sound is the village of Iona, or Buile Mor, which has two churches

and a school. The inhabitants depend partly on agriculture and partly on

fishing.

The original form of the name Iona was Hy, Hii or I, the Irish for

Island. By Adamnan in his _Life_ of St Columba it is called _Ioua

insula_, and the present name Iona is said to have originated in some

transcriber mistaking the _u_ in Ioua for _n_. It also received the name

of Hii-colum-kill (Icolmkill), that is, "the island of Columba of the

Cell," while by the Highlanders it has been known as Innis nan

Druidhneah ("the island of the Druids"). This last name seems to imply

that Iona was a sacred spot before St Columba landed there in 563 and

laid the foundations of his monastery. After this date it quickly

developed into the most famous centre of Celtic Christianity, the mother

community of numerous monastic houses, whence missionaries were

despatched for the conversion of Scotland and northern England, and to

which for centuries students flocked from all parts of the north. After

St Columba's death the soil of the island was esteemed peculiarly

sanctified by the presence of his relics, which rested here until they

were removed to Ireland early in the 9th century. Pilgrims came from far

and near to die in the island, in order that they might lie in its holy

ground; and from all parts of northern Europe the bodies of the

illustrious dead were brought here for burial. The fame and wealth of

the monastery, however, sometimes attracted less welcome visitors.

Several times it was plundered and burnt and the monks massacred by the

heathen Norse sea-rovers. Late in the 11th century the desecrated

monastery was restored by the saintly Queen Margaret, wife of Malcolm

Canmore, king of Scotland; and in 1203 a new monastery and a nunnery

were founded by Benedictine monks who either expelled or absorbed the

Celtic community. In 838 the Western Isles, then under the rule of the

kings of Man, were erected into a bishopric of which Iona was the seat.

When in 1098 Magnus III., "Barefoot," king of Norway, ousted the jarls

of Orkney from the isles, he united the see of the Isles (Sudreyar, "the

southern islands," Lat. _Sodorenses insulae_) with that of Man, and

placed both under the jurisdiction of the archbishopric of Trondhjem.

About 1507 the island again became the seat of the bishopric of the

Isles; but with the victory of the Protestant party in Scotland its

ancient religious glory was finally eclipsed, and in 1561 the monastic

buildings were dismantled by order of the Convention of Estates. (For

the political fortunes of Iona see HEBRIDES.)

The existing ancient remains include part of the cathedral church of St

Mary, of the nunnery of St Mary, St Oran's chapel, and a number of tombs

and crosses. The cathedral dates from the 13th century; a great portion

of the walls with the tower, about 75 ft. high, are still standing. The

choir and nave have been roofed, and the cathedral has in other respects

been restored, the ruins having been conveyed in 1899 to a body of

trustees by the eighth duke of Argyll. The remains of the conventual

buildings still extant, to judge by the portion of a Norman arcade, are

of earlier date than the cathedral. The small chapel of St Oran, or

Odhrain, was built by Queen Margaret on the supposed site of Columba's

cell, and its ruins are the oldest in Iona. Its round-arched western

doorway has the characteristic Norman beak-head ornamentation. Of the

nunnery only the chancel and nave of the Norman chapel remain, the last

prioress, Anna (d. 1543), being buried within its walls. The cemetery,

called in Gaelic _Reilig Oiran_ ("the burial-place of kings"), is said

to contain the remains of forty-eight Scottish, four Irish and eight

Danish and Norwegian monarchs, and possesses a large number of

monumental stones. At the time of the Reformation it is said to have had

360 crosses, of which most were thrown into the sea by order of the

synod of Argyll. Many, however, still remain, the finest being Maclean's

cross and St Martin's. Both are still almost perfect, and are richly

carved with Runic inscriptions, emblematic devices and fanciful scroll

work. Of Columba's monastery, which was built of wood about 1/4 m. from

the present ruins, nothing remains.

IONIA, in ancient geography, the name given to a portion of the W. coast

of Asia Minor, adjoining the Aegean Sea and bounded on the E. by Lydia.

It consisted of a narrow strip of land near the coast, which together

with the adjacent islands was occupied by immigrant Greeks of the Ionic

race, and thus distinguished from the interior district, inhabited by

the Lydians. According to the universal Greek tradition, the cities of

Ionia were founded by emigrants from the other side of the Aegean (see

IONIANS), and their settlement was connected with the legendary history

of the Ionic race in Attica, by the statement that the colonists were

led by Neleus and Androclus, sons of Codrus, the last king of Athens. In

accordance with this view the "Ionic migration," as it was called by

later chronologers, was dated by them one hundred and forty years after

the Trojan war, or sixty years after the return of the Heraclidae into

the Peloponnese. Without assigning any definite date, we may say that

recent research has tended to support the popular Greek idea that Ionia

received its main Greek element rather late--after the descent of the

Dorians, and, therefore, after any part of the Aegean period. The only

Aegean objects yet found (1910) in or near Ionia are some sherds of the

very latest Minoan age at Miletus. It is not probable that all the Greek

colonists were of the not numerous Ionian race. Herodotus tells us (i.

146) that they comprised settlers from many different tribes and cities

of Greece (a fact indicated also by the local traditions of the cities),

and that they intermarried with the native races. A striking proof of

this was the fact that so late as the time of the historian distinct

dialects were spoken by the inhabitants of different cities within the

limits of so restricted an area. E. Curtius supposed that the population

of this part of Asia was aboriginally of Ionic race and that the

settlers from Greece found the country in the possession of a kindred

people. The last contention is probably true; but the kinship was

certainly more distant than that between two branches of one Ionian

stock.

The cities called Ionian in historical times were twelve in number,--an

arrangement copied as it was supposed from the constitution of the

Ionian cities in Greece which had originally occupied the territory in

the north of the Peloponnese subsequently held by the Achaeans. These

were (from south to north)--Miletus, Myus, Priene, Ephesus, Colophon,

Lebedus, Teos, Erythrae, Clazomenae and Phocaea, together with Samos and

Chios. Smyrna (q.v.), originally an Aeolic colony, was afterwards

occupied by Ionians from Colophon, and became an Ionian city,--an event

which had taken place before the time of Herodotus. But at what period

it was admitted as a member of the league we have no information. The

cities above enumerated unquestionably formed a kind of league, of which

participation in the Pan-Ionic festival was the distinguishing

characteristic. This festival took place on the north slope of Mt.

Mycale in a shrine called the Panionium. But like the Amphictyonic

league in Greece, the Ionic was rather of a sacred than a political

character; every city enjoyed absolute autonomy, and, though common

interests often united them for a common political object, they never

formed a real confederacy like that of the Achaeans or Boeotians. The

advice of Thales of Miletus to combine in a political union was

rejected.

Ionia was of small extent, not exceeding 90 geographical miles in length

from N. to S., with a breadth varying from 20 to 30 m., but to this must

be added the peninsula of Mimas, together with the two large islands. So

intricate is the coastline that the voyage along its shores was

estimated at nearly four times the direct distance. A great part of this

area was, moreover, occupied by mountains. Of these the most lofty and

striking were Mimas and Corycus, in the peninsula which stands out to

the west, facing the island of Chios; Sipylus, to the north of Smyrna;

Corax, extending to the south-west from the Gulf of Smyrna, and

descending to the sea between Lebedus and Teos; and the strongly marked

range of Mycale, a continuation of Messogis in the interior, which forms

the bold headland of Trogilium or Mycale, opposite Samos. None of these

mountains attains a height of more than 4000 ft. The district comprised

three extremely fertile valleys formed by the outflow of three rivers,

among the most considerable in Asia Minor: the Hermus in the north,

flowing into the Gulf of Smyrna, though at some distance from the city

of that name; the Cayster, which flowed under the walls of Ephesus; and

the Maeander, which in ancient times discharged its waters into the deep

gulf that once bathed the walls of Miletus, but which has been gradually

filled up by this river's deposits. With the advantage of a peculiarly

fine climate, for which this part of Asia Minor has been famous in all

ages, Ionia enjoyed the reputation in ancient times of being the most

fertile of all the rich provinces of Asia Minor; and even in modern

times, though very imperfectly cultivated, it produces abundance of

fruit of all kinds, and the raisins and figs of Smyrna supply almost all

the markets of Europe.

The colonies naturally became prosperous. Miletus especially was at an

early period one of the most important commercial cities of Greece; and

in its turn became the parent of numerous other colonies, which extended

all around the shores of the Euxine and the Propontis from Abydus and

Cyzicus to Trapezus and Panticapaeum. Phocaea was one of the first Greek

cities whose mariners explored the shores of the western Mediterranean.

Ephesus, though it did not send out any colonies of importance, from an

early period became a flourishing city and attained to a position

corresponding in some measure to that of Smyrna at the present day.

_History._--The first event in the history of Ionia of which we have

any trustworthy account is the inroad of the Cimmerii (see SCYTHIA),

who ravaged a great part of Asia Minor, including Lydia, and sacked

Magnesia on the Maeander, but were foiled in their attack upon

Ephesus. This event may be referred to the middle of the 7th century

B.C. About 700 B.C. Gyges, first Mermnad king of Lydia, invaded the

territories of Smyrna and Miletus, and is said to have taken Colophon

as his son Ardys did Priene. But it was not till the reign of Croesus

(560-545 B.C.) that the cities of Ionia successively fell under Lydian

rule. The defeat of Croesus by Cyrus was followed by the conquest of

all the Ionian cities. These became subject to the Persian monarchy

with the other Greek cities of Asia. In this position they enjoyed a

considerable amount of autonomy, but were for the most part subject to

local despots, most of whom were creatures of the Persian king. It was

at the instigation of one of these despots, Histiaeus (q.v.) of

Miletus, that in about 500 B.C. the principal cities broke out into

insurrection against Persia. They were at first assisted by the

Athenians, with whose aid they penetrated into the interior and burnt

Sardis, an event which ultimately led to the Persian invasion of

Greece. But the fleet of the Ionians was defeated off the island of

Lade, and the destruction of Miletus after a protracted siege was

followed by the reconquest of all the Asiatic Greeks, insular as well

as continental.

The victories of the Greeks during the great Persian war had the

effect of enfranchizing their kinsmen on the other side of the Aegean;

and the battle of Mycale (479 B.C.), in which the defeat of the

Persians was in great measure owing to the Ionians, secured their

emancipation. They henceforth became the dependent allies of Athens

(see DELIAN LEAGUE), though still retaining their autonomy, which they

preserved until the peace of Antalcidas in 387 B.C. once more placed

them as well as the other Greek cities in Asia under the nominal

dominion of Persia. They appear, however, to have retained a

considerable amount of freedom until the invasion of Asia Minor by

Alexander the Great. After the battle of the Granicus most of the

Ionian cities submitted to the conqueror. Miletus, which alone held

out, was reduced after a long siege (334 B.C.). From this time they

passed under the dominion of the successive Macedonian rulers of Asia,

but continued, with the exception of Miletus (q.v.), to enjoy great

prosperity both under these Greek dynasties and after they became part

of the Roman province of Asia.

Ionia has laid the world under its debt not only by giving birth to a

long roll of distinguished men of letters and science (see IONIAN SCHOOL

OF PHILOSOPHY), but by originating the distinct school of art which

prepared the way for the brilliant artistic development of Athens in the

5th century. This school flourished in the 8th, 7th and 6th centuries,

and is distinguished by the fineness of workmanship and minuteness of

detail with which it treated subjects, inspired always to some extent by

non-Greek models. Naturalism is progressively obvious in its treatment,

e.g. of the human figure, but to the end it is still subservient to

convention. It has been thought that the Ionian migration from Greece

carried with it some part of a population which retained the artistic

traditions of the "Mycenaean" civilization, and so caused the birth of

the Ionic school; but whether this was so or not, it is certain that

from the 8th century onwards we find the true spirit of Hellenic art,

stimulated by commercial intercourse with eastern civilizations, working

out its development chiefly in Ionia and its neighbouring isles. The

great names of this school are Theodorus and Rhoecus of Samos; Bathycles

of Magnesia on the Maeander; Glaucus, Melas, Micciades, Archermus,

Bupalus and Athenis of Chios. Notable works of the school still extant

are the famous archaic female statues found on the Athenian Acropolis in

1885-1887, the seated statues of Branchidae, the Nike of Archermus found

at Delos, and the objects in ivory and electrum found by D. G. Hogarth

in the lower strata of the Artemision at Ephesus in 1904-1905 (see GREEK

ART).

BIBLIOGRAPHY.--Beside general authorities under ASIA MINOR see

especially F. Beaufort, _Ionian Antiquities_ (1811); R. Chandler, &c.,

_Ionian Antiquities_ (1769 ff.); Histories of Greek Sculpture by A. S.

Murray, M. Collignon and E. A. Gardner, and special works cited under

particular cities; E. Curtius, _Die Ionier vor der ionischen

Wanderung_ (1855); D. G. Hogarth, _Ionia and the East_ (1909), with

map. (E. H. B.; D. G. H.)

IONIA, a city and the county-seat of Ionia county, Michigan, U.S.A., on

the Grand river, about 34 m. E. of Grand Rapids. Pop. (1904) 5222;

(1910) 5030. It is served by the Grand Trunk and the Pere Marquette

railways. The greater part of the city is built on the bottom-lands of

the valley within an area 2 m. in length and 1 m. in width, but some of

the finest residences stand on the hills, which form an irregular

semicircle behind the city, and command extensive views of the valley.

Much of the building material is a brown sandstone obtained from

quarries only 3 m. distant; white clay, also, is found in the vicinity.

The city is a trade centre for a rich farming district, has car-shops

(of the Pere Marquette railway) and iron foundries, and manufactures

wagons, pottery, furniture and clothing. The waterworks are owned and

operated by the municipality. Ionia was settled in 1833 by immigrants

from German Flats, near Herkimer, New York. It was incorporated as a

village in 1857, but the charter was allowed to lapse; it was again

incorporated as a village in 1865, and was chartered as a city in 1873.

IONIAN ISLANDS, the collective name for the Greek islands of Corfu,

Cephalonia, Zante, Santa Maura, Ithaca, Cythera (Cerigo) and Paxo, with

their minor dependencies. These seven islands (for details of which see

their separate headings) are often described also as the _Heptanesus_

("Seven Islands"), but they have no real geographical unity. The history

of the name "Ionian" in this connexion is obscure, but it is probably

due to ancient settlements of Ionian colonists on the coasts and

islands. The political unity of the seven islands is of comparatively

modern date; their independence as a separate state lasted only seven

years (1800-1807). To a certain extent they have passed under the same

succession of influences; they have been subjected to the same

invasions, and have received accessions to their populations from the

same currents of migration or conquest. But even what may be considered

as common experiences have affected the individual islands in different

ways; in the matter of population, for instance, Corfu has undergone

much more important modifications than Ithaca.

The Ionian islands consist almost entirely of Cretaceous and Tertiary

beds, but in Corfu Jurassic deposits belonging to various horizons

have also been found. The oldest beds which have yet been recognized

are shales and hornstones with Liassic fossils. These are overlaid

conformably by a thick series of platy limestones, known as the Viglas

limestone, which appears to represent the rest of the Jurassic system

and also the lower part of the Cretaceous. Then follows a mass of

dolomite and unbedded limestones containing _Hippurites_ and evidently

of Upper Cretaceous age. The Eocene beds are folded with the

Cretaceous, and in many places the two formations have not yet been

separately distinguished. Both occasionally assume the form of Flysch.

Miocene beds are found in Corfu and Zante, and Pliocene deposits cover

much of the low-lying ground.

_History._--The beginning of Heptanesian history may be said to date

from the 9th century. Leo the Philosopher (about A.D. 890) formed all or

most of the islands into a distinct province under the title of the

Thema of Cephallenia, and in this condition they belonged to the

Eastern empire after Italy had been divided into various states, but

this political or administrative unity could not last long in the case

of islands exposed by their situation to opposite currents of conquest.

Robert Guiscard, having captured Corfu (1081) and Cephalonia, might have

become the founder of a Norman dynasty in the islands but for his early

death at Cassopo. Amid the struggles between Greek emperors and Western

crusaders during the 12th century, Corfu, Cephalonia, Zante, &c., emerge

from time to time; but it was not till the Latin empire was established

at Constantinople in 1204 that the Venetians, who were destined to give

the Ionian Islands their place in history, obtained possession of Corfu.

They were afterwards robbed of the island by Leon Vetrano, a famous

Genoese corsair; but he was soon defeated and put to death, and the

senate, to secure their position, granted fiefs in Corfu to ten noble

families in order that they might colonize it (1206). The conquest of

Cephalonia and Zante followed, and we find five counts of the family of

Tocco holding Cephalonia, and probably Zante as well as Santa Maura, as

tributary to the republic. But the footing thus gained by the Venetians

was not maintained, and through the closing part of the 13th and most of

the 14th century the islands were a prey by turns to corsairs and to

Greek and Neapolitan claimants. In 1386, however, the people of Corfu

made voluntary submission to the Venetian republic which had now risen

to be the first maritime power in the Mediterranean. In 1485 Zante was

purchased from the Turks in a very depopulated condition; and in 1499

Cephalonia was captured from the same masters; but Santa Maura, though

frequently occupied for a time, was not finally attached to Venice till

1684, and Cerigo was not taken till 1717.

Venetian and French rule.

The Venetians, who exacted heavy contributions from the islands, won the

adherence of the principal native families by the bestowal of titles and

appointments; the Roman Catholic Church was established, and the Italian

and Greek races were largely assimilated by intermarriage; Greek ceased

to be spoken except by the lower classes, which remained faithful to the

Orthodox communion. On the fall of the Venetian republic in 1797 the

treaty of Campo Formio, which gave Venice to Austria, annexed the Ionian

Islands to France; but a Russo-Turkish force drove out the French at the

close of 1798; and in the spring of 1799 Corfu capitulated. By treaty

with the Porte in 1800, the emperor Paul erected the "Septinsular

Republic," but anarchy and confusion followed till a secret article in

the treaty of Tilsit, in 1807, declared the Islands an integral part of

the French empire. They were incorporated with the province of Illyria,

and in this condition they remained till the decline of the French

power. The British forces, under General Oswald, took Zante, Cephalonia

and Cerigo in 1809, and Santa Maura in 1810; Colonel (afterwards Sir

Richard) Church (q.v.), reduced Paxo in 1814; and after the abdication

of Napoleon, Corfu, which had been well defended by General Donzelot,

was, by order of Louis XVIII., surrendered to Sir James Campbell. By the

treaty of Paris (9th November 1815) the contracting powers--Great

Britain, Russia, Austria and Prussia--agreed to place the "United States

of the Ionian Islands" under the exclusive protection of Great Britain,

and to give Austria the right of equal commercial advantage with the

protecting country, a plan strongly approved by Count Capo d'Istria, the

famous Corfiot noble who afterwards became president of the new republic

of Greece.

British Protectorate.

The terms of the treaty of Paris were not only of indefinite import but

were susceptible of contradictory interpretations. And instead of

interpreting the other articles in harmony with the first, which

declared the islands one "sole free and independent state," the

protecting Power availed itself of every ambiguity to extend its

authority. The first lord high commissioner, Sir Thomas Maitland, who as

governor of Malta had acquired the sobriquet of "King Tom," was not the

man to foster the constitutional liberty of an infant state. The treaty

required, with questionable wisdom, that a constitution should be

established, and this was accordingly done; but its practical value was

trifling. The constitution, voted by a constituent assembly in 1817 and

applied in the following year, placed the administration in the hands of

a senate of six members and a legislative assembly of forty members; but

the real authority was vested in the high commissioner, who was able

directly to prevent anything, and indirectly to effect almost anything.

Sir Thomas Maitland was not slow to exercise the control thus permitted

him, though on the whole he did so for the benefit of the islands. The

construction of roads, the abolition of direct taxes and of the system

of farming the church lands, the securing of impartial administration of

justice, and the establishment of educational institutions are among the

services ascribed to his efforts. These, however, made less impression

on the Heptanesians than his despotic character and the measures which

he took to prevent them giving assistance in the Greek war of

independence in 1821. He was succeeded in 1823 by General Sir Frederick

Adam, who in the main carried out the same policy. Under his government

the new fortifications of Corfu and some of the most important public

works which still do honour to the English protectorate were undertaken.

Lord Nugent, who became high commissioner in 1832, was followed by Sir

Howard Douglas (1835-1841), who ruled with a firm, too often with a high

hand; and he was met by continual intrigues, the principal exponent of

the opposition being the famous Andreas Mustoxidi (d. 1861). A complete

change of policy was inaugurated by Mr Mackenzie (1841-1843), and his

successor Lord Seaton (1843-1849) was induced by the European

disturbances of 1848 to initiate a number of important reforms. But the

party which wished for union with Greece was rapidly growing in vigour

and voice. Serious insurrections of the peasantry, especially in

Cephalonia, had to be put down by military force, and the parliament

passed a resolution in favour of immediate union with Greece. The hopes

of the unionists were roused by the appointment of W. E. Gladstone as

high commissioner extraordinary to investigate the condition of the

islands. From his known sympathy with Greek independence, it was their

expectation that he would support their pretensions. But after a tour

through the principal islands Gladstone came to the conclusion that the

abolition of the protectorate was not the wish of the mass of the

people. For a few days in 1859 he held office as lord high commissioner,

and in that capacity he proposed for the consideration of the assembly a

series of reforms. These reforms were, however, declared inadmissible by

the assembly; and Sir Henry Storks, who succeeded Gladstone in February

1859, began his rule by a prorogation. The contest continued between the

assembly and the protectorate. The British government was slow to

realize the true position of affairs: as late as May 1861 Gladstone

spoke of the cession of the islands as "a crime against the safety of

Europe," and Sir Henry Storks continued to report of tranquillity and

contentment. The assembly of 1862 accused the high commissioner of

violation of the constitution and of the treaty of Paris, and complained

that England remained in ignorance of what took place in the islands.

Cession to Greece.

On the abdication of King Otho of Greece in 1862 the Greek people by

universal suffrage voted Prince Alfred of England to the throne, and

when he declined to accept the crown England was asked to name a

successor. The candidate proposed was Prince William George of

Glucksburg, brother of the princess of Wales; and the British government

declared to the provisional government of Greece that his selection

would be followed by the long-refused cession of the Ionian Islands.

After the prince's election by the national assembly in 1863 the high

commissioner laid before the Ionian parliament the conditions on which

the cession would be carried out. The rejection of one of those

conditions--the demolition of the fortifications of Corfu--led to a new

prorogation; but none the less (on March 29, 1864) the plenipotentiaries

of the five great powers signed the treaty by which the protectorate was

brought to a close. The neutrality which they attributed to the whole of

the islands was (January 1864) confined to Corfu and Paxo. On May 31st

of that year Sir Henry Storks left Corfu with the English troops and

men-of-war. King George made his entry into Corfu on the 6th of June.

Since their annexation to Greece the history of the Ionian islands has

been uneventful; owing to various causes their prosperity has somewhat

declined. Corfu (Corcyra) with Paxo; Cephalonia; Santa Maura (Levkas)

with Thiaki (Ithaca) and Zante (Zacynthos) each form separate nomarchies

or departments; Cerigo (Cythera) forms part of the nomarchy of Laconia.

The islands retain the exemption from direct taxation which they enjoyed

under the British protectorate; in lieu of this there is an _ad valorem_

tax of 20(1/2)% on exported oil and a tax of 6% on wine exported to Greek

ports; these commodities are further liable to an export duty of 1(1/2)%

which is levied on all agricultural produce and articles of local

manufacture for the maintenance and construction of roads. The excellent

roads, which date from the British administration, are kept in fair

repair.

See Mustoxidi, _Delle cose Corciresi_ (Corfu, 1848). Lunzi, [Greek:

Peri tes politikes katastaseos tes Heptanesou epi Heneton] (Athens,

1856): Ansted, _The I. I._ (London, 1863); Viscount Kirkwall, _Four

Years in the I. I._ (London, 1864) vol. i. containing a chronological

history of the British protectorate; F Lenormant, _La Grece et les

iles ioniennes_ (Paris, 1865); P. Chiotis, _Hist. des iles ioniennes_

(Zante, 1815-1864); Mardo, _Saggio di una descrizione

geografico-storica delle Isole_ (Corfu, 1865) (mainly geographical);

De Bosset, _Description des monnaies d'Ithaque et de Cephalonie_

(London, 1815); Postolakas, [Greek: Katalogos ton archaion nomismaton

ton neson Kerkyras, Leukados], &c. (Athens, 1868), Wiebel, _Die Insel

Kephalonia und die Meermuhlen von Argostoli_ (Hamburg, 1873);

Tsitselis, [Greek: Glossarion Kephallenias], (Athens, 1876); [Greek:

Onomata theseon en Kephallenia] in the "Parnassus" i. 9-12 (Athens,

1877); Riemann, "Recherches archeologiques sur les Iles ioniennes" in

_Bibliotheque des Ecoles francaises d'Athenes et de Rome_ (Paris,

1879-1880); Gregorovius, _Corfu: eine ionische Idylle_ (Leipzig,

1882); J. Partsch, _Die Insel Corfu: eine geographische Monographie_

(Gotha, 1887); _Die Insel Levkas_ (Gotha, 1889); _Kephallenia und

Ithaka_ (Gotha, 1890); _Die Insel Zante_ (Gotha, 1891). (J. D. B.)

IONIANS, the name given by the Greeks to one of the principal divisions

of the Hellenic peoples. In historic times it was applied to the

inhabitants of (1) Attica, where some believed the Ionians to have

originated; (2) parts of Euboea; (3) the Cycladic islands, except Melos

and Thera; (4) a section of the west coast of Asia Minor, from the gulf

of Smyrna to that of Iasus (see IONIA); (5) colonies from any of the

foregoing, notably in Thrace, Propontis and Pontus in the west, and in

Egypt (Naucratis, Daphnae); some authorities have found traces of an

ancient Ionian population in (6) north-eastern Peloponnese. The meaning

and derivation of the name are not known. It occurs in two forms,

[Greek: Iawones] and [Greek: Iones] (compare [Greek: Chaones] and

[Greek: Chones] in Epirus)--not counting the name [Greek: Ionios]

applied to the open sea west of Greece. In the traditional genealogy of

the Hellenes, Ion, the ancestor of the Ionians, is brother of Achaeus

and son of Xuthus (who held Peloponnese after the dispersal of the

children of Hellen). But this genealogy, though it is attributed to

Hesiod, is apparently post-Homeric; and it is clear that the Ionian name

had independent and varied uses and meanings in very early times. In

Homer the word [Greek: Iawones] occurs as a name of inhabitants of

Attica, with the epithet [Greek: elkechitones] (Il. xiii. 685 =

"trail-vest"), describing some point of costume, and later regarded as

imputing effeminacy. The Homeric _Hymn to Apollo of Delos_ (7th century)

describes an Ionian population in the Cyclades with a loose religious

league about the Delian sanctuary.

The same word [Greek: Iawon] (_Javan_) appears in Hebrew literature of

the 8th and 7th centuries, to denote one group of the "Japhetic" peoples

of Asia Minor, Cyprus and perhaps Rhodes: "by these were the isles of

the nations divided, in their lands, every one after his tongue, after

their families, in their nations," a comprehensive expression for the

island-strewn regions farther west (Gen. x. 10). In Ezek. xxvii. 13, 19,

_Javan_ trades with Tyre in slaves, bronze-work, iron and drugs. Later

allusions show that on Semitic lips _Javan_ meant western traders in

general. In Persian _Yauna_ was the generic term for Greeks.[1]

The earliest explicit Greek account of the Ionians is given in the 5th

century by Herodotus (i. 45, 56, 143-145, v. 66, vii. 94, viii. 44-46).

The "children of Ion" originated in north-eastern Peloponnese; and

traces of them remained in Troezen and Cynuria. Expelled by the Achaeans

(who seem to have entered Peloponnese about four generations before the

Dorian Invasion) they invaded and dominated Attica; and about the time

of the Dorian Invasion took the lead under the Attic branch of the

Neleids of Pylus (Hdt. i. 147, v. 65) in the colonization of the

Cyclades and of Asiatic Ionia, which in Homer is still "Carian." Many of

the colonists, however, were not Ionians, but refugees from other parts

of Greece, between Euboea and Argolis (Hdt. i. 146); others looked on

Attica as their first home, though the true Ionians were intruders

there. The Pan-Ionian sanctuary of Poseidon on the Asiatic promontory of

Mycale was regarded as perpetuating a cult from Peloponnesian Achaea,

and the league of twelve cities which maintained it, as imitated from an

Achaean dodecapolis, and as claiming (absurdly, according to Herodotus

i. 143) purer descent than other Ionians.

In Herodotus's account of the first Greek intercourse with Egypt (about

664 B C.) he describes "Ionian and Carian" adventurers and mercenaries

in the Delta. Later the commoner antithesis is between Ionian and

Dorian, first (probably) in the colonial regions of Asia Minor, and

later more universally.

In the 5th century the name "Ionian" was already falling into discredit.

Causes of this were (1) the peace-loving luxury (born of commercial

wealth and contact with Oriental life) of the great Ionian cities of

Asia; (2) the tameness with which they submitted first to Lydia and to

Persia, then to Athenian pretensions, then to Sparta, and finally to

Persia again; (3) the decadence and downfall of Athens, which still

counted as Ionian and had claimed (since Solon's time) seniority among

"Ionian" states. In the later 4th century the name survives only (a) as

a geographical expression for part of the coast of Asia Minor, (b) in

European Greece as the name of that section of the Northern Amphictyony

in which Athens and its colonies were reckoned.

The traditional history of Asiatic Ionia is generally accepted, and in

its broad outlines is probably well founded. Common to all groups of

Ionians in the Aegean is a dialect of Greek which has [eta] for [alpha]

(in Attic only partially) and (in Asiatic Ionian especially) [kappa] for

[pi] in certain words. Herodotus states that there were four distinct

dialects in Asiatic Ionia itself (i. 142) and the dialect of Attica

differed widely from all other forms of Ionic. Earlier phases of Ionic

forms are dominant in the language of Homer. Most Ionian states exhibit

also traces of the fourfold tribal divisions named after the "children

of Ion"; but additional tribes occur locally. (Hdt. v. 66, 69.) All

reputed colonies from Attica (except Ephesus and Colophon) kept also the

feast of Apaturia; and many worshipped Apollo Patrous as the reputed

father of Ion. The few observations hitherto made on the sites of Ionian

cities indicate continuity of settlement and culture as far back as the

latest phases of the Mycenaean (Late Minoan III.) Age and not farther,

supporting thus far the traditional foundation dates.

The theory of E. Curtius (1856-1890) that the Ionians originated in Asia

Minor and spread thence through the Cyclades to Euboea and Attica

deserts ancient tradition on linguistic and ethnological grounds of

doubtful value. Ad. Holm supports it (_Gesch. Gr._, Berlin, 1886, i.

86), but A. von Gutschmid (_Beitr. z. Gesch. d. alten Orients_, Leipzig,

1856, 124 ff.) and E. Meyer (_Philologus_ NF. 2, 1889, p. 268 ff.; NF.

3, 1890, p. 479 ff.) follow Herodotus with qualifications. J. B. Bury

(_Eng. Hist. Rev._ xv. 228), though he regards the Ionian peoples as of

European origin, thinks that they may have got their name from some part

of the Asiatic coast. Ionian culture and art, though little known in

their earlier phases, derive their inspiration on the one side from

those of the old Aegean (Minoan) civilization, on the other from the

Oriental (mainly Assyrian) models which penetrated to the coast through

the Hittite civilization of Asia Minor. Egyptian influence is almost

absent until the time of Psammetichus, but then becomes predominant for

a while. Local and regional peculiarities, however, disappear almost

wholly in the 5th and 4th centuries, under the overpowering influence of

Athens.

AUTHORITIES.--Besides the sections on _Ionians_ in the general

histories of Greece and the references given in G. Busolt,

_Griechische Geschichte_, i. (2nd ed., Gotha, 1893), pp. 262, 277 ff.,

see E. Curtius, _Die Ionier vor der ionischen Wanderung_ (Berlin,

1855), and papers in _Gott. Gel. Anz._ (1856), p. 1152 f. and (1859),

p. 2021 f.; _Jahrb. f. kl. Philol._ 83 (1860), p. 449 f.; _Hermes_ 25

(1890), p. 141 f.; A. von Gutschmid, _Beitrage z. Gesch. d. alten

Orients_ (Leipzig, 1856), p. 124 ff.; E. Meyer, _Philologus_ 47 (NF.

2, 1889), p. 268 ff. and 49 (NF. 3, 1890), p. 479 ff.; V. Boehlau,

_Aus ionischen und aolischen Necropolen_ (Cassel, 1897); H. W. Smyth,

_The Ionic Dialect_ (1889). P. Cauer, "De dialecto attica vetustiore

quaestiones epigraphicae," in G. Curtius, _Studien z. gr. u. lat.

Gramm._ 8 (1875), p. 223, 399; Karsten, _De titulorum Ionicorum

dialecto_ (Halle, 1882); F. Bechtel, _Die Inschriften des ion.

Dialekts_ (Gottingen, 1877). For the political history of the Ionian

Greeks see GREECE: _History_, and IONIA; for the special history and

characteristics of individual Ionian cities, the respective names.

(J. L. M.)