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more oxygen, we are enabled to account for iron-moulds 

 being eaiier to remove, as they are more recent. The ftain 

 foon acquires an orange-red colour, by abforbing oxygen, 

 and is with more difficulty extrafted. Various means are 

 employed by the laundrcflcs for removing flains of iron, the 

 moll general of which is the citric acid, commonly called 

 fait of lemons. The muriatic acid is frequently employed 

 by the bleachers, and it is by far the molt rapid and effec- 

 tual procefs ; but the great caution nccefi'ary, in fuddenly 

 wafhing the fpot after the ftain has difappeared, leffens its 

 utility fordomellic ufe. When the fpot is dipped into the 

 clear muriatic acid, the iron almoft inllantly disappears, and 

 it is at that inllantthe part fliould be plunged into a quantity 

 of clean water, and walhed as quick as polTible ; the wafli- 

 ing being continued for a confiderable time. 



In order to render the oxyd of iron more eafily foluble by 

 any acid, let the part ftained be lleeped for fome time in a 

 folution of fuipluuet of potiilTi, or, what is more eafily ob- 

 tained, fulphr.ret of lime, riniing it afterwards in clean water. 

 The oxyd v-\\\ be deprived of lome of its oxygen, and may 

 be removed by almoft any acid, when it is fo dilute, even, as 

 not io injure the ftuff, however long it may remain in it. 



It may be proper here to obferve, that the tartaric and ox- 

 alic acids remove iron-moulds equally well with the citric 

 acid. 



When the fubftance iron-moulded is printed calico, and 

 of a buff colour, or any other colour in which iron is 

 employed as a mordant ; it will be found that, in removing 

 the iron-mould, the proper colour will alfo difappear. In 

 this cale there is no cftectual remedy. 



Moll of the iron-moulds are produced in the walhing, for 

 want of fufficient c?.ution. In thofe utenfils in which metal 

 is at all neceiTary, copper or zinc (liould be employed inftead 

 of iron. With care, however, iron veffels may be fafely 

 ufed. When they are not in ufe, the furfacc of the iron 

 (hould, after being made clean and dry, be fmeared over 

 with oil or tallow, and rubbed dry at the time they are 

 ufed, 



Inoi^-moulJj, yellow lumps of earth or Hone, found in 

 chalk-pits about the Chiltern, in Oxfordfliire, and elfe- 

 where, being in reality a kind of pyrites, or indigefted 

 iron -ore. 



Ili0}ijhot, in Mineralogy, is a term applied by Mr. 

 Jamefon (Geognof. vol. iii. p. 47. 1 59.) to lucii rocks and 

 ftones as are coloured or clouded by the oxyds of iron. 

 Ferruginous is a more common name for this very common 

 appearance in the ilrata. 



iKOS^ci, a Nautical Term, fignifying the decay of the 

 iron fallenings by its corrofion with the fea water, by which 

 the continuity of the parts is gnawed away by degrees, 

 whereby the veffel is not only rendered weak, but leaky. 



ln.os-J/oiie, is that fpecies of iron ore which abounds with 

 a cnnliderable proportion of earth, fuch as lime, or alumine, 

 and is the ore moll common in this country. See luox. 



The manner of getting iron-llone is divided into three 

 departments: i. Vtyji all -work : 2.3y ifll-J>its : and 3. By 

 open-ifork. The firil of thci'e methods is employed when 

 the Hone lies at a coiiliderabledepth. After finking a (liaft 

 to the lower part of the ilratum, the ground is excavated 

 in an horizontal dire&ion, leaving at intervals certain parts 

 Handing to fupport the roof of the excavation. The fpaces 

 between tliefe pillars are caWcd JlaJls. 



The L-ll-pil is employed when the iron-Hone lies at fo.me 

 diflancc from the furfact, and where the ground is not fuffi- 

 ciently firm to admit of Hall-work. Thefe pits, when lirll 

 oj>ened, are narrow, butbeco.Tic wider below, affuming the 

 ihape of a bell. . . 



Vol. XIX. 



I R O 



The third method, or the epen'^u.-ori, is made ufe of when 

 the ftratum containing the ftone is nearly baffeting, or is very 

 near to the furface. The earth is liiH removed, laying the 

 ftratum containing the ore bare, and the ftone is got out as 

 from an open quarry. 



The argillaceous iron ores are generally called iron-floncs, 

 and abound iu many of the coal diftricls. In Mr. Farey's 

 Agricultural and Mineral Report on Derbyfliirt', vol. i. 

 p. 217, a lift of fevcnty-five places in and near that coimty 

 is given, where iron-llone has been dug, or where the rakes 

 of iron-done, as they are there called, liave been worked. 



IiiON it'W, in Bolaiiy. S«e SiDEim.wi.uN. 



Iron-wo;/", in a Ship, denotes ali the pieces of iron, of 

 whatfoever figure or fize, which are ufed in its conftrurtion ; 

 as bolts, boom-irons, which are compoled of two rings, 

 nearly refembling the figure of 8, nails, Ipikes, chains., 

 and chain plates, block-ftrops, cranks, braces, pintles, and 

 goodgings. 



IiiOK-ii'or/j, a name given to the cftablifiiments for the 

 manufadlure of pig-iron. (See BtAST-yurKt;*'? and Ikon.) 

 The moft proper fituation for iron- works is on the fide of a 

 lull, from which a perpendicular defcent could be formed 

 nearly equal to the height of the bb.il -furnace. The upper 

 ground by this means is on a levil with the mouth of the 

 furnace, where all the materials are introduced, and is there- 

 fore the fituatiofi where the ore is roafted, and the cokes 

 prepared ; the lower ground being the moll proper for the 

 rell of the works. 



Where fuch local advantages do not exift, the materials 

 are drawn up on an artificial inclined plane, by appropriate 

 machinery. 



IllON-w^r/, in Botany. See G.Vi.EOPSis and Sidekitis. 



Ikon IJland, in Geography, a fmall ifland in the Eaft In- 

 dian fea, near the coalt of Siam. N. lat. 12 ^^'. E. long* 

 98'. 



Iron Lough, a lake of Ireland, in the county of Weft, 

 meath, through which the river Inny paffes. It is about 

 five miles N.W. from Mullingar. 



Iitox Movnlains, a chain of American mountains, in Te- 

 neffee, extending fram the river Teneffee to that of French 

 Broadtown, S.W. to N.E. and conftituting the boundary 

 between Teneffee and North Carolina, and reaching from 

 near the lead mines, on t!ie Kanhaway, through the Chero- 

 kee country, to the fouth of Chota, and terminating near 

 the fource of Mobele. This chain abounds with caverns and 

 catara£ls. 



IRONDEQUET, a bay on the fouth fide of lake On- 

 tario. 



IRONSIDE, Gilbert, in Bir.graphy, an Englifli pre- 

 late, was born at Hawkftsury, in Oxfordfcire, in 1588, and 

 educated at Trinity college, Oxford. Soon after he entered 

 upon holy orders, he obtained the reftory of Wiuterbarn, 

 in Dorfetiliire. At the reftoratiou he was made bifliop of 

 Brittol. He died in 1 67 1. He was author of " QuellioiM 

 on the Sabbath," and a fermon. V.'ood. 



IRONY, derived from u^-.ny., difimiilalion, in Oratory, a 

 figure in fpccch, whereby we plainly intend fomething very 

 different from what our words exprefs ; as when wc feem to 

 praife a pcrfon at a time when we evidently rally and difcom- 

 mendhim. 



Quintilian calls this figure iHverflojuimi, tllffinmlallon, and 

 iUiifion; and obi'erves that it may be known by the manner 

 ofthe pronunciation, or from the nature of the perfon or the 

 thing. The fubjefts of irony are vices and follies of all 

 kinds : and it has thus been uied by the moft grave perfoRs 

 on proper occafious. Socrates ufed it fo much as to acquire 

 the name of *:.•/. or the droll. It was alfo iiled by the pro. 

 3M plivt 



