IRON. 



137 



intermingled with carbon, so as occasionally to lose 

 its malleability, approximating it to the character of 

 steel; and that of Pennsylvania was alloyed with 

 1.56 per cent, of arsenic. A piece, weighing 7 oz. 

 from the large mass of North Carolina, was crystallized 

 in the form of the regular octahedron, the surfaces of 

 which exhibited a plaited structure: it was examined 

 for other metals without success, though its imperfect 

 malleability left no doubt of its containing a small 

 proportion of arsenic. The meteoric iron differs 

 very considerably from the terrestrial, native iron. 

 Its colour is a light steel-gray, resembling platina ; 

 it is easily cut with the knife, and it is flexible and 

 perfectly malleable when cold. Specific gravity, 

 7.768. It occurs in large masses, sometimes of 

 many tons weight, marked externally by impressions, 

 like those produced by the hands and feet upon 

 a soft, plastic mass ; also in small globular and 

 filiform masses, disseminated through meteoric stones. 

 Occasionally, it presents imperfectly-formed octa- 

 hedral crystals. A crystalline texture becomes visi- 

 ble, however, in cutting the large masses, and 

 exposing the surfaces produced to the action of nitric 

 acid, or allowing them to tarnish by heat. It 

 invariably contains from 3 to 12 per cent, of nickel, 

 and often traces of cobalt, neither of which metals 

 have ever been found alloying terrestrial native iron. 

 Meteoric iron is contained in all meteoric stones ; in 

 some, it exists in a very feeble proportion ; in others, 

 it forms one quarter of their weight ; and again in 

 others, it constitutes nearly the entire mass; while 

 the largest masses of it ever found consist of it 

 wholly, without the smallest mixture of foreign 

 matters. In the two first-mentioned conditions, it 

 has often been seen to fall from the heavens, while 

 in the solid state, it never has been observed, by 

 credible witnesses, to fall, but on one occasion, at 

 Agram in Croatia. Some of the largest masses of 

 meteoric iron known, are the following : that found 

 by Pallas, in Siberia, weighing 1680 Russian pounds ; 

 that discovered by Rubin de Celis, in the district of 

 Chaco-Gualamba, in South America, and which 

 weighs 15 tons ; and that found near Red River, in 

 Louisiana, weighing 3000 pounds, and which is now 

 deposited in the collection of the lyceum of natural 

 history in New York. Besides these, other very 

 considerable pieces have been noticed in Africa, 

 Mexico, and Bohemia. Meteoric iron has been 

 worked, as an object of curiosity, into knives, 

 swords, and other instruments. For additional 

 particulars concerning meteoric iron, and its origin, 

 see Meteoric Stones. 



2. Magnetic Iron Ore, or Oxydulated Iron, is of 

 an iron-black colour, more intense than belongs to 

 metallic iron ; its powder is of a pure black. It 

 occurs crystallized, in the form of the regular octa- 

 hedron, which is its fundamental form ; it usually, 

 however, presents itself in large lamelliform masses, 

 with distinct octahedral cleavages, in granular con- 

 cretions, or compact. It is brittle, has the hardness 

 of feldspar, and a specific gravity of j.094. It exerts 

 a decided action on the magnetic needle ; and certain 

 specimens, especially of a compact variety, attract 

 and repel, alternately, the poles of a needle, accord- 

 ing as we present the same point of a fragment of 

 the ore to one or the other of the extremities of a 

 needle. This variety, which is found in several 

 countries, is called native loadstone. Its magnetic 

 virtue strengthens by exposure to the air. The mag- 

 netic iron consists of 28.14 protoxide of iron, and 

 71.86 of peroxide of iron. It is infusible before the 

 blowpipe, but assumes a brown colour, and loses its 

 nttractory power, after having been exposed to a great 

 heat. It is soluble in nitric acid, and may be ob- 

 tained crystallized by fusing it, as often happens in 



the roasting of it, in furnaces, to effect its reduction. 

 It occurs in primitive rocks, chiefly in gneiss, mica- 

 slate, hornblende-slate, and chlorite slate, and rarely 

 in limestone, when it forms veins, beds, or even entire 

 mountains. It also composes the chief ingredient of 

 certain sands, which have been washed and deposited 

 by the same currents which separated it from its 

 original beds. The different varieties of this ore are 

 exceedingly rich in metal, often yielding eighty per 

 cent, of iron, and are every where explored, when 

 found in sufficient quantities, and connected with 

 abundance of fuel and facility of transportation. In 

 Sweden, it forms the object of numerous important 

 explorations, among which may be cited that of the 

 mountain of Taberg, near Jonkoping, in Smoland, 

 where it is so abundant as to be worked under the 

 open sky ; that of the island of Utoe, where excava- 

 tions extend to a great distance under the contiguous 

 sea ; that of Dannemora, in Upland, which is at pre- 

 sent under the control of the British ; that of Galli- 

 vara, beyond the polar circle, where the ore forms an 

 entire mountain; and, finally, those immense deposits 

 of ferruginous sand which are so extensively wrought 

 in Daleearlia, in Smoland, and in Wermeland. The 

 oxydulated iron is also explored at several places 

 in Siberia, Piedmont, and the kingdom of Naples. In 

 the United States, it exists in the greatest abundance, 

 and is wrought at numerous localities. The primitive 

 range of mountains upon the western side of lake 

 Champlain, affords numerous veins and beds of it, 

 sometimes more than twenty feet in thickness, and 

 little intermingled with foreign substances. The 

 principal works for its reduction are at Peru, and 

 near Crown Point. A valuable deposit of the com- 

 pact magnetic iron, precisely similar to that worked 

 at Dannemora in Sweden, occurs at Franconia in 

 New Hampshire, and is worked extensively at Mun- 

 roe, Hamburg, and many other places. The present 

 ore forms the best iron which is made for the manu- 

 facture of steel; and hence the employment of 

 Swedish iron by the English for this purpose. 



3. Chromated Oxide of Iron (Chromate of Iron) is 

 found crystallized in regular octahedra, and massive. 

 Lustre, imperfectly metallic ; colour, between iron- 

 black and brownish-black ; streak, brown ; opaque, 

 brittle; hardness, the same with the preceding 

 species ; specific gravity, 4.498. Vauquelin and 

 Klaproth make it consist of 



Oxide of chrome, 43.00 . . 55.50 



Protoxide of iron, 34.70 . . 33.00 



Alumina, 20.30 . . 6.00 



Silica, 2.00 . . 2.00 



Alone, before the blowpipe, it is infusible, but acts 

 upon the magnetic needle, after having been exposed 

 to the reducing flame. It is dissolved when heated 

 with borax, to which it imparts a beautiful green 

 colour. It was first found in the department Du Var, 

 in France, in the form of nodules and kidney-shaped 

 masses. It was afterwards discovered in Stiria and 

 Scotland ; at the former place, imbedded in serpen- 

 tine, at the latter, in limestone. In the United States, 

 it exists abundantly in Maryland, near Baltimore ; 

 also, in small quantities, in Connecticut, near New 

 Haven, in limestone, with serpentine. It is a highly 

 valuable mineral, when it occurs in quantity, for 

 extracting the oxide of chrome, which is employed 

 either alone or in various combinations with the oxides 

 of other metals, as cobalt, lead, mercury, &c., both 

 for painting on porcelain, and for painting in oil. 

 The quantity of chromate of lead, or chrome yellow, 

 manufactured in Baltimore annually, is estimated at 

 50,000 pounds. See Chrome. 



4. Specular Iron Ore, and Red Iron Ore. This 

 species, scarcely less interesting than the last in eco- 

 nomical importance, presents many difficulties to th 



