IRENE IRENE, a Byzantine empress, born of obscure parentage in Athens about 752, died on the isle of Lesbos, Aug. 15, 803. She was an or- phan, and 17 years old when her beauty and genius attracted the attention of the emperor Constantino V. Copronymus, who destined her to bo the wife of his son and heir Leo. Their nuptials were celebrated with royal splendor at Constantinople in 769. Her. husband com- pelled her to abandon the worship of images, but she gained his love and confidence, and was appointed in his testament (780) to ad- minister the government during the minority of their son Oonstantine VI., then nine years old. In 780 she assembled at Constantinople a council to restore images in the churches; but it was interrupted by the garrison of the capital. In the following year she called an- other council at Nicsea, in which the veneration of images was declared agreeable to Scripture and reason, and to the fathers and councils of the church. Constantino was encouraged by his favorites to throw off the maternal yoke, and planned the perpetual banishment of Irene to Sicily. Her vigilance disconcerted the pro- ject, but, while the two factions divided the court, the Armenian guards refused to take the oath of fidelity which she exacted to herself alone, and Constantino became lawful emperor. Irene was dismissed to a life of solitude in one of the imperial palaces, but her intrigues led to several conspiracies for her restoration. On the return of Constantino from an expedi- tion against the Arabs in 797, he was assailed in the hippodrome by assassins, but escaped, and fled to Phrygia. Irene joined her son and persuaded him to return to the capital. There he was surprised by her emissaries, and stab- bed in the eyes, but, according to Gibbon, survived many years. Irene ruled the empire for five years with prudence and energy. In- tercourse was renewed between the Byzantine court and that of Charlemagne, and she is said to have sent ambassadors (about 800) to nego- tiate a marriage between that emperor and her- self, thus to unite the empires of the East and West; but there is reason to doubt that this was the object of the embassy. As her golden chariot moved through the streets of Constan- tinople, the reins of the four white steeds were held by as many patricians marching on foot. Most of these patricians were eunuchs; and one of them, the great treasurer Nicephorus, having been secretly invested with the purple, immediately caused her arrest, and, after treach- erously obtaining possession of her treasures, banished her to the isle of Lesbos (802). There, deprived of all means of subsistence, she gained a scanty livelihood by spinning, and died of grief within a year. Her protection of image worship has caused her to be enrolled among the saints in the Greek calendar. IRETON, Henry, an English soldier, son-in-law of Oliver Cromwell, born in Nottinghamshire in 1610, died in the camp before Limerick, Nov. 15, 1651. He graduated at Trinity col- IRIS 363 !ege, Oxford, and commenced reading for the .aw ; but his studies were interrupted by the civil war, and he joined the parliamentary army. At the battle of Naseby he was taken prisoner, but escaped. Having married Brid- get Cromwell, Oliver's eldest daughter, in 1646, he was appointed captain of horse, and soon afterward colonel. Ireton was one of the most active in compassing the death of the king, and signed the death warrant. Under the protectorate Cromwell made him president of Munster and afterward lord deputy of Ire- land, in which capacity he acted with much administrative vigor, and the greater part of the island submitted to him without resistance. He died of the plague. His body was carried to London, and buried in the chapel of Henry VII. in Westminster abbey. On the restora- tion his remains were exhumed, exposed on a
- ibbet, and burned by the hangman at Tyburn.
['he royalists admitted his ability, but de- nounced him as treacherous and hypocritical ; his friends eulogized his sanctity and talents. From his skill in drawing up ordinances, peti- tions, and declarations, he was called "the scribe." A pension of 2,000 from the con- fiscated estates of the duke of Buckingham, re- fused by him, was settled on his family. IRIARTE. See YRIAKTE. IRIDIUM (Lat. iris, rainbow), a metal so named from the colors exhibited by its solu- tions; symbol, Ir; chemical equivalent, 98 - 56. It was discovered by Desootils in 1803, and by Smithson Tennant in 1804. It occurs native and nearly pure, also associated with osmium, platinum, and rhodium, and in alloys of various proportions of these metals. An alloy of one fifth platinum and four fifths iridium has been met with in octahedral crystals whiter than platinum, and of specific gravity 22-66. When native platinum is dissolved in nitro-hydro- chloric acid, black scales remain behind, which are composed of iridium and osmium. These metals may then be separated by one of the methods in use, and the iridium is obtained in a gray metallic powder, resembling spongy platinum. It is very hard, white, and brittle, and may be melted on lime by the oxyhydrogen blowpipe, or by the heat of the voltaic cur- rent. When thus fused it has the specific gravity of 21-15. None of the acids attack the pure metal, but when alloyed with plati- num it is readily dissolved by aqua regia. Iridium black, similar to platinum black, may be obtained by decomposing a solution of its sulphate by alcohol. If heated in a finely di- vided sta,te in the open air, iridium absorbs oxygen ; it is also oxidized by nitre and caustic potash. Small grains of iridium containing a little platinum are picked out from the grains of the latter metal, and from their extreme hardness make excellent nibs for gold pens. IRIS, in Greek mythology, a daughter of the sea god Thaumas and of the oceanide Electra, and sister of the Harpies. According to some writers she was a virgin ; others make her the
