298 iron. 



Sp. 8. Sparry Iron-Stone. Pl . XLII. tig. 2.— Spath 

 Eithenstein, Werner ; Fer oxyde carbonate, Ham/. — Its colours 

 are yellowish-white, or brown. It occurs massive, and crystalized, 

 in a great variety of forms. It is translucent or opaque, and the 

 lustre is shining or pearly. The structure is lamellar ; it yields 

 easily to the knife ; it effervesces in muriatic acid. Before the 

 blow-pipe it becomes magnetic, but does not melt. The specific 

 gravity varies from 3-6 to 3'8. A specimen, analysed by Bayen, 

 yielded, oxide of iron 66, carbonic acid 34. In Germany it is 

 smelted as an ore of iron. 



Sp. 9. Blue Iron -Ore. Pl. XLII. fig. 3.— Fer phosphate, 

 Hauy. — The colour is indigo-blue, smalt-blue or greenish-blue. 

 It occurs crystalized in small translucent prisms, with dihedral 

 summits. It also occurs massive, earthy, and opaque. The crys- 

 talized variety contains, phosphate of iron 41 '25, phosphoric acid 

 19.25, water 31*25, alum in c 5, ferruginous silex T25. 



Sp. 10. Chromate of Iron. Pl. XLII. fig. 4. — Chromein- 

 stein, Werner ; Fer chromate, Hauy. — The colour is brownish- 

 black. It occurs massive, disseminated, and in granular distinct 

 concretions ; also crystalized in oblique four-sided prisms. The 

 fracture is fine-grained, uneven. Internally, it is shining or glis- 

 tening, and the lustre imperfect metallic. It scratches glass. It 

 is infusible before the blow-pipe, but yields a bright green colour 

 with borax. In England it occurs in serpentine and talc, in the 

 Shetland islands, and is employed to obtain the chromic acid, which 

 forms a beautiful yellow pigment, with lead. 



Sp. 11. Arseniate of Iron. Pl. XLII. fig. 5. — Wurfelerz, 

 Werner; Fer arseniate, Hauy, Cube Ore, Jameson. — Its colour 

 is green. It occurs massive and crystalized, in small translucent 

 cubes. The crystals are aggregated, smooth, and splendent. In- 

 ternally, they are glistening, and the lustre is intermediate between 

 vitreous and resinous. It is rather brittle, and easily frangible. 

 Before the blow-pipe it melts, and gives out arsenical vapours. 

 Arseniate of iron contains, oxide of iron 46, arsenic acid 18, water 

 32. — Vauquelin. It is found in Cornwall. 



In Sweden and the north of Europe the supply of iron is chiefly 

 derived from the species named magnetic iron ore • but in this 



