108 



IOLAUS IONIAN DIALECT. 



with the iilkali to which it is united, in the condition 

 of hydriodic acid; and peroxide of manganese is also 

 added, in order to facilitate the decomposition of the 

 liydriodic acid. 



Iodine forms acids also by uniting with oxygen and 

 wait chlorine. When it is brought into contact with 

 protoxide of chlorine, immediate action ensues ; the 

 chlorine of the protoxide unites with one portion of 

 incline, and its oxygen with another, forming two 

 compounds, a volatile .orange-coloured matter, the 

 chloriodic acid, and a white solid substance, which is 

 iodic acid. lodic acid acts powerfully on inflammable 

 substances. With charcoal, sulphur, sugar, and 

 similar combustibles, it forms mixtures which deto- 

 nate when heated. It enters into combination with 

 metallic oxides, giving rise to salts called iodates. 

 These compounds, like the chlorates, yield pure oxy- 

 :; fi\ by heat, and deflagrate when thrown on burning 

 charcoal. Iodic acid is decomposed by sulphurous, 

 phosphorous, and hydriodic acids, and by sulphureted 

 hydrogen. Iodine, in each case, is set at liberty, and 

 may be detected, as usual, by starch. Chloriodic 

 acid, which is also formed by simply immersing dry 

 iodine in chlorine eas, deliquesces in the open air, 

 and dissolves very freely in water. Its solution is 

 very sour to the taste ; and it reddens vegetable 

 blues, but afterwards destroys them. It does not 

 unite with alkaline bases ; in which respect it wants 

 one of the characteristics of an acid, and has hence 

 been called by Gay-Lussac a chloride of iodine. 

 Iodine unites with nitrogen, forming a dark powder, 

 which is characterized, like chloride of nitrogen, by 

 its explosive property. In order to form it, iodine is 

 put into a solution of ammonia ; the alkali is decom- 

 posed ; its elements unite with different portions of 

 iodine, and thus cause the formation of hydriodic acid 

 and iodide of nitrogen. Iodine forms, with sulphur, 

 a feeble compound, of a grayish-black colour. With 

 phosphorus, also, it combines with great rapidity at 

 common temperatures, attended with the emergence 

 of heat. It manifests little disposition to combine 

 with metallic oxides ; but it has a strong attraction 

 for the pure metals, producing compounds which are 

 called iodurets, or iodides. The iodides of lead, 

 copper, bismuth, silver, and mercury, are insoluble 

 in water, while the iodides of the very oxidizable 

 metals are soluble in that liquid. If we mix a hydri- 

 odate with the metallic solutions, all the metals which 

 do not decompose water will give precipitates, while 

 those which decompose that liquid will give none. 

 Iodine, besides being employed for philosophical 

 illustration, is used in the arts, for pigments, dyes, 

 and medicine. The proto-ioduret of mercury is used 

 in England as a substitute for vermilion, in the pre- 

 paration of paper-hangings ; and a compound of 

 hydriodate of potassa 65, iodate of potassa 2, and 

 ioduret of mercury 33, is employed in printing calico. 

 The tincture of iodine, 48 grs. to 1 oz. of alcohol, is 

 a powerful remedy in the goitre and other glandular 

 diseases ; but it is so violent in its action on the sys- 

 tem as to require great caution in its administration. 

 The hydriodate of potash, or of soda, is also applied 

 to medical uses ; and it is inferred, that the efficacy 

 of many mineral springs, in certain diseases, is owing 

 to the presence of one or the other of these salts. 



IOLAUS. See Protesilaus. 



IOLE. S.ee Hercules. 



IOLITE, CORDIERITE, or DICHROITE, is an 

 earthy mineral, commonly massive, though sometimes 

 crystallized in six or twelve-sided prisms, with indis- 

 tinct cleavages, parallel to the sides of a six-sided 

 prism, which is considered as its primary form ; lus- 

 tre, vitreous ; colour, various shades of blue, gene- 

 rally inclining to black ; streak, white ; transparent 

 or translucent ; blue, if viewed in the direction of 



the axis ; yellowish gray, perpendicular to it ; hard 

 ness, the same as that of quartz ; specific gravity, 

 2.583. It consists, according to Stromeyer, of 



Silica, 48.538 



Alumine, 31.730 



Magnesia, 11.305 



Oxide of Iron, 5.686 



Oxide of manganese, 0.702 



Water, or loss, 1.648 



Before the blowpipe, it melts in a good heat, but 

 with difficulty, and only on its edges, into a glass not 

 inferior to the mineral, either in colour or transpa- 

 rency. It occurs in aggregated crystals, with garnet, 

 Suartz, &c., at Cabo de Gata in Spain. A variety 

 )und in Bavaria, at Bodenmais, which is generally 

 massive, resembling quartz, and imbedded in iron 

 pyrites, has been called peliom. Handsome blue 

 crystals of this species, found at Orijerfvi in Finland, 

 have been called steinheilite , in honour of count 

 Steinheil. The sapphire d'eau of jewellers is a trans- 

 parent variety of the present species from Ceylon. 



ION ; 1. a son of Xuthus and Creusa, daughter of 

 Erechtheus, who married Helice, the daughter of 

 Selinus, king of JEgiale. He succeeded to the 

 throne of his father-in-law, and built a city, which he 

 called Helice, on account of his wife. His subjects, 

 from him, received the name of lonians, and the 

 country that of Ionia. (See lonians) 2. A tragic 

 poet of Chios, who flourished about the eighty-second 

 Olympiad. His tragedies were represented at Athens, 

 where they met with universal applause. He is 

 mentioned and greatly commended by Aristophanes 

 and Athenafius, &c. 3. A native of Ephesus, intro- 

 duced in Plato's dialogues as reasoning with Socrates. 



IONA. See Icolmkill. 



IONIA ; the ancient name of Achaia (hence the 

 Ionian sea and Ionian islands). By Ionia is generally 

 understood that district of Asia Minor, where the 

 lonians from Attica settled, about 1050 B. C . This 

 beautiful and fertile country extended from the river 

 Hennus to the Maeander, along the shore of the 

 ^Egean sea, opposite the islands of Samos and Chios, 

 and was bounded by Caria, jEolia, and Lydia. Com- 

 merce, navigation, and agriculture early rendered it 

 wealthy and flourishing, as is proved by the great 

 number of populous cities it contained, among which 

 the most important were Ephesus (the chief place), 

 Smyrna, Clazomenae, Erythra, Colophon, and Miletus. 

 These free cities formed the Ionian league, but 

 Croesus, and afterwards Cyrus, made them tributaries. 

 They remained subject to the Persians until they re- 

 covered their independence by the assistance of the 

 Athenians and Lacedemonians, after having previous- 

 ly made an unsuccessful attempt, during the reign of 

 Darius Hystaspes. They were again subjected, and 

 again delivered by Alexander the Great. Ionia, at 

 a later period, became a Roman province, and was 

 totally devastated by the Saracens, so that few ves- 

 tiges of its ancient civilization remain. The lonians 

 were considered effeminate and voluptuous, but, at 

 the same time, highly amiable. Their dialect par- 

 took of their character. (See Ionian Dialect.) The 

 arts and sciences flourished in this happy country, 

 particularly those which contribute to embellish 

 life. The Asiatic Greeks became the teachers and 

 examples of the European Greeks. Homer the 

 poet, Apelles and Parrhasius the painters, were 

 lonians. The Ionic column proves the delicacy of 

 their taste. See Architecture, Ionian Philosophy, 

 and lonians. 



IONIAN DIALECT; one of the Greek dialects, 

 the softest of all, on account of the large proportion 

 of the vowels to the consonants (see the article Con- 



