I L I I L L 703 See Baer and Helmersen, Beitrdge zur Kenntniss dcs Russ. Rcichcs, xx. ; Seinenow in Petermann s Mittheilungen, 1858 ; Slovar Ross. Imp.; lludlolf, " Das Ili-Thal und_ seine Bewohner," in Petermann s Erfi " On the Valley of the Hi," in Proc. Roy. Geoy. Soc., 18/4. ILIOS, or ILIUM. See TROY. ILKESTOX, a market-town of Derbyshire, is situated on a hill commanding fine views of the Ere wash valley, and on the Erewash branch line of the Midland Railway, 8 miles west by north of Nottingham, and 9 east-north east of Derby. The town is under the government of a local board of health, and has a county court. The prin cipal buildings are the parish church of St Mary s in the Norman and Early English style, with lofty pinnacled tower ; the town-hall erected in 1868 ; and the mechanic s institute. National schools have been recently erected. The manufactures of the town are principally hosiery and lace, and various kinds of stoneware. Coal and iron are wrought in the neighbourhood. An alkaline mineral spring, resembling the seltzer water of Germany, was discovered in 1830, and baths were then erected, which were after wards extended. The waters are used both externally and internally, and are efficacious in rheumatism, gout, spinal affections, liver complaints, and kindred ailments. The principal constituents of the water are carbonic acid, sulphuric acid, muriatic acrl, lime, magnesia, and soda, The town, which is very ancient, obtained a grant for a market and fair in 1251. It was formerly the seat of the assizes, which were transferred to Nottingham on account of the plague. The population of the parish in 1861 was 8374, and of the town 3330, and the popu lation of the parish and local board district in 1871 was 9662. ILLE-ET-VILATNE, a maritime department of France, formed out of part of the old province of Brittany, is situated on the north-west coast, between 47 38 and 48 37 N. lat. and 1 and 2 14 W. long. It is bounded on the N. by the sea and the department of Manche, on the E. by Mayenne, on the S. by Loire-Inf6rieure, and on the W. by Morbihan and Cotes-du-Nord. It takes its name from its two principal rivers, the Ille and the Vilaine. The former joins the Vilaine at Rennes after a course of 18 miles through the department, and the latter, which rises in Mayenne, flows past the towns of Vitre , Rennes, and lledon. The stream is tidal up to the port of Redon, and is navigable for barges as far as Rennes. The Vilaine receives the Men and the Seiche, which are both navigable. There are two other navigable streams, the Airon and the Ranee. The Ille-et-Rance canal connects the town of Rennes with those of Dinan and St Malo. The depart ment forms one vast plateau, broken by ranges of low hills, which decline on the one side to the English Channel and on the other to the Bay of Biscay. The sea-coast line is partly rocky and partly marshy, the marshy portions being in many places defended against the encroachments of the sea by artificial dams. There are also morasses in many parts of the interior, with a number of stagnant lakes, a circumstance which renders the atmosphere very humid. The sky is seldom bright, for the south-west winds, while they keep the temperature mild, also bring frequent showers, and in spring and autumn thick fogs prevail. The soil is thin and not very fertile, but lately has been improved by the use of artificial manure. The only truly fruitful portion is that round Dol. About two-thirds of the soil is under culture, one-ninth in meadows, one-fifteenth in wood, and one-sixth waste. Cereals of all kinds are grown, but the principal are wheat, rye, and barley. Potatoes, flour, and hemp are also largely grown, and tobacco is cultivated to some extent. Apples and pears are the principal fruit, and the cider of the canton of Dol has a high reputation. The vine is cultivated in the southern districts. Cheese, said to equal Gruyere, is made in considerable quantities, and the butter of Rennes has a reputation equal to that of the best in France. Large numbers of horses and cattle are raised. The horses belong to the small hardy Breton breed, and are much in demand as post and artillery horses. Notwithstanding the extent of heath land very few sheep are kept. The principal manufactures are leather, sea-salt, glass, paper, and linen. Iron ore is obtained in considerable quantities, and there are also lead and zinc mines, as well as slate quarries. The population is of Celtic origin, and the dialect is a mixture of Celtic and French. Ille-et-Vilaine is divided into the arrondissements of Fougeres, St Malo, Montfort, Redon, Rennes, and Vitre, with 43 cantons and 350 communes. The chief town is Rennes, and the principal seaport St Malo. The department has an area of 2597 square miles. The population in 1872 was 589,532, and in 1876 it had reached 602,712. ILLINOIS Copyright, 1880, by diaries Scribner s Som. ILLINOIS, the twenty-first in the order of admission Plate ^ and the fourth in rank of population of the States of the American Union, is one of the group of States formed out of the " North- West Territory." Its boundaries, begin ning at the point where the Wabash river joins the Ohio, pass thence north by that river, by the west line of Indiana, and by Lake Michigan to 42 30 N. lat., thence west to the Mississippi river, thence south by that river to its con fluence with the Ohio river, and thence, by that, north easterly to the mouth of the Wabash. It has an area of 55,414 square miles, extending with varying width from 42 30 to 36 59 N. lat. Surface and Soil. Illinois is a great plain, with its highest section in the north, on Lake Michigan ; thence it imperceptibly declines to the south-west, in which direction its principal rivers flow to the Mississippi. A small tract in the north-west, which includes the lead mines, is hilly and broken, and there are bluffs along the Mississippi, some of which rise 300 to 400 feet. A ridge extends across the south end of the State, constituting the fruit district of the region, called " Egypt " on account of its never-failing fertility. On this ridge or swell of clay land are grown all the varieties of berries, grapes, plums, peaches, apples, and all kinds of vegetables in great profusion, which find prompt sale in Chicago and the northern counties by reason of reaching market at early dates in the season. Excepting along the rivers, and where there has been extensive tree planting, the greater part of the State consists of a vast level or slightly undulating treeless prairies. Much of this has been reclaimed from swamp land by systematic drainage, and is found to be the strongest and most productive soil of the State. To the eye the surface of the. State is as level as that of an ocean in calm. The general slope from the watershed rarely exceeds 1 foot to the mile, and the fall of the Illinois river in a course of 300 miles to the south-west, is, for most of the distance, but 1 inch to the mile. The origin of the prairies is still a matter of speculation, but there is an opinion that in a former geological age the whole State was the bed of a vast shallow freshwater lake. The prairie soil is a black fine humus mould, formed of the decayed vegetation, and underlain at varying depths by clay. The soil is of great fertility, and much of it seemingly inexhaustible. Over these prairies for hundreds of miles the plough never touches stone, pebble, or even sand. A luxuriant native grass formerly sustained herds of buffalo,
and from the still unbroken prairie surface are annually
