especially in cases of syphilitic origin. See Eye, Diseases of the.
IRKUTSK, ē̇r-ko͞otsk′. A governor-generalship and a government of Eastern Siberia. The former comprises the governments of Irkutsk and Yeniseisk (q.v.), and the Territory of Yakutsk (q.v.), with a total area of nearly 2,800,000 square miles, and a population in 1897 of 1,328,150 (Map: Asia, K 3). The Government of Irkutsk is bounded by the Territory of Yakutsk on the north, the territories of Yakutsk and Trans-Baikalia on the east, the Chinese Empire on the south, and the Siberian Government of Yeniseisk on the west. Area, nearly 280,000 square miles. Its surface is generally mountainous. The Sayan Mountains run along the southern boundary; the Baikal Mountains along the western shore of Lake Baikal. The chief rivers are the Lena, which rises in the Baikal Mountains, and the Angara, with its numerous mountain tributaries. Irkutsk takes in a large portion of Lake Baikal. The mountains of Irkutsk are rich in minerals, containing deposits of iron, coal, graphite, and salt. The climate is raw and severe, the annual average temperature at the capital being about 32°. Only an insignificant portion of the cultivable land has been cleared, by far the larger part of the country being covered with forests, filled with fur-bearing animals. The land wherever cultivated is fertile and yields ample crops of rye, wheat, oats, barley, buckwheat, and potatoes. The raising of domestic animals is confined mostly to the natives. The manufacturing as well as the mining industries are as yet only slightly developed, the former being concentrated mostly in the town of Irkutsk. The population (500,500 in 1897) consists mostly of Russians, Buriats, Tunguses, and Jews. Capital, Irkutsk (q.v.).
IRKUTSK. The capital of the Governor-Generalship and of the Government of Irkutsk, and the finest city of Siberia, situated at the confluence of the Irkut with the Angara, 40 miles north of the southern extremity of Lake Baikal and 3385 miles by rail from Moscow (Map: Asia, K 3). It was almost entirely rebuilt after the destructive fire of 1879, and is now a handsome, well laid out city, with well-paved, wide streets, and all the essential features of a modern city. The climate is healthful, owing to the high altitude of the city; the winters, however, are severe. There are in Irkutsk a theatre, a library, a museum, a meteorological station, and a branch of the Imperial Geographical Society. The manufactures are unimportant, and go mostly to satisfy domestic demands. The commerce is of great importance. Irkutsk being one of the chief centres of the Russian tea trade, as well as one of the principal stations on the Trans-Siberian Railway. Population, in 1897, 51,400, including 4500 exiles. Irkutsk was founded by Cossacks in 1653, created a town in 1686, and soon became the centre of the Russo-Chinese tea trade.
IRMINUS (AS., exalted). The divine ancestor of the Germanic Hermiones, probably identical with Tiw or Tyr. The Saxons erected in his honor great tree-trunks, the so-called Irminsûli, e.g. at Scheidungen, after the defeat of the Thuringians, and at Eresburg, Westphalia. The latter, which was looked upon as the national shrine, was destroyed by Charles the Great in 772.
IRNERIUS, ēr-nē′rĭ-ŭs, or GUARNE′RIUS (c.1050-c.1130). An eminent Italian jurist, founder of the so-called School of Glossators. He was born at Bologna. When quite young he taught in his native city dialectics and rhetoric, but soon devoted himself entirely to the study of the Justinian Code, probably in Rome, where he also seems to have lectured on law. In or about 1084 he returned to Bologna, and there established a new law school. His most important work is the Summa Codicis (first ed. by Fitting, 1894), formerly attributed to Placentin. Consult Fitting, Die Anfänge der Rechtsschule in Bologna (1888).
IRON (AS. īren, īsern, Goth. eisarn, OHG. īsarn, īsan, Ger. Eisen, from OIr. iarn, Welsh haiarn, Corn. hoern, Bret. hoiarn, iron; possibly connected ultimately with Lat. æs, Goth. aiz, OHG. ēr, Ger. Erz, bronze, AS. ār, Eng. ore, Skt. ayas, metal). The most abundant and useful of the metals. Unlike many of the common metals, iron is found only rarely in the native state, its occurrence being limited to meteorites which fall upon the earth from extra-terrestrial regions. Combined with oxygen and other elements, however, it is widely distributed as a constituent of rocks, and forms extensive deposits in many parts of the world.
Early History. Articles of stone, bronze, and iron have been found together on the site of the Swiss lake dwellings, but the most ancient specimens of iron at present known come from Egyptian and Assyrian ruins. There is in the British Museum a piece of iron taken from the Pyramid of Gizeh, which is believed to date from about B.C. 4000, and also an axe-head of Egyptian manufacture dating from B.C. 1370. Though the earliest pieces of iron now known came from Egypt, it is thought that probably the Assyrians were the first to use the metal freely in the manufacture of tools, weapons, and ornaments. Numerous samples of iron implements dating from B.C. 800, and including the fragment of a saw 44 inches long, were obtained from the ruins of Nimrud. In India, the famous iron pillar at Kutub, near Delhi, standing 22 feet above ground and weighing about 6 tons, dates from B.C. 400. It was made by welding disks of metal together, indicating a remarkable degree of skill on the part of those early iron-workers.
The Greeks were familiar with the uses of iron at least six hundred years before the Christian Era, although the metal was very scarce. It was not until the Roman Empire was fairly established that the use of iron became general over civilized Europe. The Romans made both wrought iron and steel, using the latter metal for swords and other edged implements. The ancient Britons, at the time of the invasion of Britain by Julius Cæsar, B.C. 55, were found to use swords, spears, hooks, and scythes of iron, indicating a familiarity with the metal for a considerable period previous. During the Roman occupation iron manufacture was vigorously developed, and in the succeeding Saxon age it seems also to have flourished. After the Norman Conquest little attention was paid to iron manufacture in England. In Germany, however, the art flourished vigorously, iron implements being exported to other countries in considerable quantities. Until about the middle of the fourteenth century all iron was produced by the direct pro-
