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This Plants, Pcinf-id, xwNalural Hijlory. In Dr. Grew's 

 Catalogue of the Rarities of Grediam College, p. 274, he 

 Oieiitions a petrified iris-root ; a iloiie fomewhat flat, but ra- 

 diated frop.i the central pitli, the polilhed end of which, when 

 wetted, (hewed thcfe radiations very fine : this extraneous 

 foffil probably belonged to the coralline tribe, ir.ftead of being 

 a rcoi. In Dr. Leigh's account of tiie fodil plants, found 

 in the coal-pits at Burnley in Lancalhire, he mentions iris : 

 long narrow leaves, refembliiig thofe of flags, and fo called 

 in geuer«l, are common in coal ftrata ; thcfe kinds of leaves 

 in the grit-ftone quairics in DerbyOiire are often called 

 fwords, iVom the rcfemblance of their impreflions in the ilone 

 to the fiieatli of a iword. 



IRISH Sea, in Geography, the name of that part of 

 the Atlantic ocean, which is between the coalls of Ireland 

 and Great Britain. 



Irish Terms. See Terms. 



IRKINEEVA, in Geography, a town of Ruffia, in the 

 government of Toboiflv ; 160 miles E.N.E. of Enifeilk. 

 N. lat. 5S 50'. E. long. 96 . 



IRKUTSK, a town of Ruffia, and capital of a go- 

 vernment, to which it gives name, on the Angara, near the 

 lake Baikal, the fee of a Greek archbiiliop, and a place of 

 confiderable commerce ; the caravans which trade to China 

 paffing through it. N. lat. ^t/ 4'. E. long. 95°. 



IRKUrSKOT, a governmeMt of Ruffia, containing all 

 that pa;t of Siberia which lies beyond the 107th degree of 

 eaft longitude ; bounded on the N. by the Frozen fea, 

 on the E. by the N. Pacific ocean, on the S. by Chiiiefe 

 Tartary, and on the W. by the governments of Kolivan and 

 Toboidv. It is the mod extenfive, but lead populous of a'l 

 the Ruffian governments, and is divided into the four pro- 

 vinces of Irkutflt, Nertchinft:, Yakutlk, and Ochotfe, fo 

 called from the four principal towns. 



IRMA-HiSSAR, a town of A.latic Turkey, in Nato- 

 lia ; 40 miles S.E. of Callamena. 



IRNEE, a town of Hiudooflan, in the circar of Mahur ; 

 38 ir.iles N. of Mahur. 



IRNERIUS, in Biography, fometimes called Wernerius, 

 a celebrated jurid of the twelfth century, was probably born 

 at Bologn;;. Ke firft taught philofophy in that city, and 

 acquired much diflintlion by being the firft who opened a 

 fchool for leisures in the Roman law in Italy, after is in- 

 terruption by the invafionsof the barbarous nations. He alfo 

 com.pofed gloffes upon the Roman law, not only upon the 

 Code and Inftitutions, but upon the Digeft. lie obtained 

 great reputation by his labours ; and the nam.e of Werne- 

 rius, in a plea of the couiuefs Matilda, in 1113, itands 

 before that of any other of the lawyers. The fame cir- 

 cumlance is found in the pleas of the emperor Henry IV. 

 from the year II 16 to 1118, which proves that he attend- 

 ed the court of that monarch m his profeflional capaci- 

 ty. In 1 118 he accompa ied Henry to Rome, where 

 he was em^^loycd to perfuade the Romans to the ekftion 

 of the anti-pope Burdin. He died about the year IT50; 

 and is faid to have introduced the degree of dodlor into 

 the univerfities. Bayle. 



IROM, E'if-n, Germ. Fer, Fr. Farum, Lat. Fcrro, 

 Ital. Jcren, Swvd Jernet, Dan. Vas, Hur'g. Hierro, Span. 

 Ja!az9, Rufl". Firro, Port Z^n^o, Gr. 7nD (Bharzel, 

 or Varxel), Heb. Mars, Alchem. 



The ufe of this metal is of very hijh antiquity, though 

 no* fo remote, there is reafon to believe, as that of either 

 ■god, filver, or copper. The inferior brilliancy of its colour 

 may, perhaps, inlomc degree, account for this circumllancc ; 



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as well as the gre.iter /kill required to obtain it from its ores,, 

 and convert it to the purpofes of art. It is mentioned fre- 

 quently in the pcntateuch ; and was, in the time of the cele- 

 brated writer of that hiilory, employed for the fabricatioa 

 of fwords, knives, and various other (harp-edged iullru- 

 ments. We may form fomc eflimate of the value that was 

 then attached to it, from an exprefiion in the eighth chapter 

 of Deuteronomy, where Mofcs tells the Ifraclitcs, in his 

 dcfcriplive eulogy oftl'.c Land of Promife, that it is "aland 

 whofe itones are iron, and out of whofe hills" they in-ay 

 " dig brafs." A circrmilance, illuftrative of the fame faft, 

 at a later date, is furniilied about 400 years fubfequeiit to 

 that period, when Aciiilles propofed a ball of iron as one of 

 the prizes to be diilrJbuted to the vidors at the games infti- 

 tuted in honour of Patroclus. [Vtuc'>:, t.) The art of 

 working it appears, in the courfe of a few fucceeding cen- 

 turies, to have arrived at confiderable perfection ; for, accord- 

 ing to the information of Herodotus (Clioxxv.), a faucer 

 of the metal, very curioufly iiilayed, was prefeuted by 

 Aly attes, king of Lydia, to the Delphic oracle, which, he 

 fays, " is of furprifing workmanlhip, and as worthy of ob- 

 fervation as any of the offerings preferved at Delphi." The 

 durability of iron, and its ii^cil'penfible affillance in the pre- 

 paration of every other metal, make it one of the moil va- 

 luable polFeffions that has been beq:eathed to the ufe of civi- 

 lized man. " Without it," obferves Fourcroy, "agricul- 

 ture could uQt have exiiled, nor could the plough have 

 rendered the earth fertile. The philofopher, while he 

 iludies the progreis of the human underilanding, and com- 

 pares the fortune and Rate of the difl^^rent nations edabliflied 

 en various portions of tlie Curface of the globe, will remark, 

 that their iron-works feem, iii fome meafure, to be propor- 

 tioned to their intelligence, to the advancement of reafon 

 amongft them, and the degree of perfeftion to wliieh the 

 arts have arrived. When we ccnfider it in this point of view, 

 as the agent by which men, in the variety of its ufes, and the 

 numerous wants it fuppl,c;s, acxpure enjoyments whicli would 

 be unknown to them if tliey did not polieis thefc produds of 

 their induftry, iron mull fingularly contribute to extend their 

 ideas, to multiply their knowledge, and to conduft their 

 fpirit towards that perfeftibility, which nature has given no 

 lefs, as the charaiter of the human fpecies, than as the 

 fource of all the adv.-mtages it can enjoy." Syft. vol. 6. 



Iron is a malleable and dudliie metal, of a blueifli-white to- 

 lour ; is fufceptible of a very high polifli, and of the fpcci- 

 fic gravity, according to the tables of Mufchenbroeck, Swe- 

 denburg, and Bridon, of from 7.600 to 7.895, and even 

 3.166. It is foluble in moll acids, and precipitable from its 

 combination with them, by various re-agents, which will be 

 hereafter pointed out. With tiic Pruflic acid it forms that 

 beautiful pigment known in commerce, and the arts, by the 

 name of PruJJlan blue ; and in a variety of other ways, con- 

 ftitutes tiie bafisof many valuable preparations. The conv 

 biiiations under which it is exhibited to us in nature are de- 

 tailed in the foilowmg leClion. 



§ I. Ores of Ir or... 



Sp. 1. Natiwe iron. Gcdiegcn-eifai. Fernallf. Ferrum 71a- 

 tivum. 



Its colour is fteel-grey, paffing to filver-white. Occurs 

 only in a ramofe form ; the mattes alluded to by Brochant 

 and others being now confidered of meteoric trigin. Surface 

 glillening. Internally it is intermcd ate between glitlening 

 and glimmering ; and its liillre mctalli c. Frailurc hackly. 

 It is rather foft, is completely malleable, and flexible with- 

 out being elaiUc. Sp. gr. 7.8, 



A fpe. 



