IRON CROWN IROQUOIS. 



151 



together for some time out of contact with the air. 

 It is generally obtained, however, for the purposes 

 of the arts, not perfectly free from the peroxide, 

 by the following processes : Native iron pyrites is 

 exposed to air and moisture, when the sulphur and iron 

 both absorb oxygen, and form the salt ; or metallic 

 iron is added to sulphuric acid, when diluted, when 

 the union takes place at once. Both methods are 

 practised : the latter is more economical in point of 

 time, and affords a purer salt, but the former is the 

 one most generally adopted. The production of cop- 

 peras from pyrites is conducted in the following man- 

 ner : The ore is broken down into pieces of a few 

 inches in diameter, and thrown into large beds, or 

 heaps, of several feet in thickness, disposed on an 

 inclined soil. Water is now let on to the heaps, in 

 moderate quantities, or they are left to derive mois- 

 ture from rain. The vitriolization immediately com- 

 mences, and is often attended with a considerable 

 degree of heat. Sometimes the whole mass kindles, 

 which is a disadvantage, as it burns off the sulphur in 

 sulphurous acid vapour, instead of converting it gra- 

 dually into sulphuric acid to form the sulphate desired. 

 The process goes on well when the pyrites is seen 

 cracking open and becoming covered with a whitish 

 efflorescence. This efflorescence is continually dis- 

 solving, from time to time, by the effect of the rains, 

 and the solution trickles down through the heaps, 

 and flows off by gutters to a common reservoir, which 

 is a leaden vessel, generally about seven feet deep, 

 twelve to fourteen long, and six or seven wide, where 

 it is evaporated for several days. As an excess of 

 sulphuric acid often exists in the liquor, a quantity of 

 iron plates or turnings is frequently added for its sa- 

 turation. From this reservoir, it is run into a crys- 

 tallizing vat, and' there remains for several weeks, 

 at the end of which time the mother liquor is pumped 

 back into the boiler, and the crystals, after draining, 

 are removed from the frames of wood-work on which 

 they have formed, and packed in hogsheads for sale. 

 Instead of going directly from the boiler to the crys- 

 tallizing pools, the liquor is sometimes allowed to 

 stand twenty-four hours, in a vessel intermediate be- 

 tween these, for the deposition of a sediment of ochre 

 which it contains. Copperas forms beautiful green 

 crystals, whose forms and other natural historical 

 characters, as well as composition, have been given 

 under the Iron Ores in the commencement of this 

 article. It is used in dyeing and making ink, in the 

 formation of 'Prussian blue, &c. The persulphate of 

 iron is formed by the simple exposure of copperas to 

 the air, especially if in the state of solution, or by 

 boiling the green sulphate with nitric acid. Its colour 

 is yellowish red ; uncrystallizable ; taste sharp and 

 styptic. The tartrate and pertartrate of iron may 

 also be formed ; and, by digesting cream of tartar 

 with water on iron filings, a triple salt is obtained, 

 formerly called tartarized tincture of Mars. 



Iron is one of the most valuable articles of the 

 materia medico,. The protoxide acts as a genial 

 stimulant and tonic in all cases of chronic debility 

 not connected with organic congestion or inflamma- 

 tion. It is peculiarly efficacious in chlorosis. The 

 peroxide and its combinations are almost uniformly 

 irritating, causing heart-burn, febrile heat, and quick- 

 ness of pulse. Many chalybeate waters contain an 

 exceedingly minute quantity of protocarbonate of 

 iron, and yet exercise an astonishingly recruiting 

 power over the exhausted frame. Their qualities may 

 be imitated by dissolving three grains of sulphate of 

 iron, and sixty-one of bicarbonate of potash, in a 

 quart of cold water, with agitation, in a close vessel. 



IRON CROWN. A golden crown, set with pre- 

 cious stones, preserved at Monza, in Milan, with 

 which anciently the kings of Italy, and afterwards 



the Roman emperors, were crowned, when they as- 

 sumed the character of kings of Lombardy, has re- 

 ceived the above name, from an iron circle, forged 

 from a nail of the cross of Christ, and introduced into 

 the interior of it. Napoleon, after his coronation 

 (1805), established the order of the iron crown. 

 When the emperor of Austria (1815) took possession 

 of the estates in Italy, which fell to him under the 

 name of the Lombardo- Venetian kingdom, he admit- 

 ted the order of the iron crown among the orders of 

 the house of Austria. 



IRON MASK. See Mask. 



IRON-WOOD. This name is given to the ostrya 

 Firginica of America a small tree, having the foli- 

 age of a birch, and the fruit somewhat resembling 

 that of the hop. It is found scattered over the whole 

 of the United States, even as far westward as the 

 base of the Rocky mountains, and is remarkable for 

 the hardness and heaviness of the wood, which, how- 

 ever, has not hitherto been applied to any very impor- 

 tant uses, partly on account of its small size. The 

 trunk usually does not exceed six inches in diameter; 

 but the excellent qualities of the wood may, at some 

 future day, be better appreciated. The term hop- 

 hornbeam, derived from the form of the fruit, is fre- 

 quently applied to the species of ostrya. 



IRONY ; a term invented by the refined Athe- 

 nians (n^aniec, dissimulation). By irony, we un- 

 derstand, in common life, that more refined species 

 of ridicule, which, under the mask of honest sim- 

 plicity, or of ignorance, exposes the faults and errors 

 of assuming folly, by seeming to adopt or defend. It 

 neither presupposes a bad heart nor a malicious pur- 

 pose, and is consistent with so much kindness and 

 true urbanity, that even the object of ridicule may 

 be forced to join in the laugh, or be disposed to 

 profit by the lesson. One mode of irony is, when a 

 person pretends to hold the false opinion or maxim as 

 true, while, by stronger and stronger illustration, he 

 so contrasts it with the true, that it must inevitably 

 appear absurd. Another mode is, when he assumes 

 the mask of innocent naivete, and excites ridicule by 

 the unreservedness of his professions. But humour, 

 concealed under seriousness of appearance, is the 

 foundation of both. (For the Socratic irony, see 

 Socrates). There is a certain sort of malicious irony 

 (persiflage), the object of which is merely to ridicule, 

 without the desire of correction. 



IROQUOIS; the name given by the French to the 

 confederacy of North American Indians, called, by 

 the English, the Five, and, afterwards, the Six Na- 

 tions. The Mohawks, Oneidas, Onondagas, Cayu- 

 gas, Senecas, and Tuscaroras were the members of 

 this confederacy. They formerly resided on the 

 Mohawk river and the lakes which still bear their 

 names, and extended their conquests to the Missis- 

 sippi, and beyond the St Lawrence. Their valour 

 and successes have procured them the name of the 

 Romans of America. Their territory abounded with 

 lakes well stored with fish ; their forests were filled 

 with game, and they had the advantage of a fertile 

 soil. The sachems owed their authority to public 

 opinion : the general affairs of the confederacy were 

 managed by a great council, composed of the chiefs, 

 which assembled annually at Onondaga. They 

 exterminated the Eries, drove out the Hurons and 

 Ottawas, subdued the Illinois, Miamies, Algonquins, 

 Lenni Lennapes, Shawanese, and the terror of their 

 anns extended over a great part of Canada, and the 

 northern and north-eastern parts of the United States. 

 In the long wars between the British and French, 

 which continued with some interruptions, for nearly 

 a century, until 1763, they were generally in the 

 British interest ; and, in the revolutionary war, 

 they were also mostly in favour of the British. 



