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OXIDES, EABTHS, AND ACIDS. cobalt in the outer flame becomes blue. With bisulphate of potash in a platinum capsule over a spirit lamp it melts into a mass which is perfectly soluble in water. Is not acted upon by acids. Fusible into a cleavable mass in the flame of the oxyhydrogen blowpipe. Al, aluminium 5319, oxygen 46-81. Analysis by Klaproth:— In imbedded crystals and in cleavable masses. The transparent blue and red varieties, called sapphire and ruby respectively, are principally found in gravel and river- sand at Matura and Saffragang in Ceylon, in the Capelan mountains twelve days’ journey from Syrian in Pegu, at llohen- stem on the Elbe, Iserwiese and Podsedlitz in Bohemia, Puy in France. The variety which occurs imbedded in rough’crystals and cleavable masses, opaque, and of a dull colour, called co rundum, occurs at Canton in China, Battagamnana in Ceylon, Permetty in the Carnatic, Mysore, in the Ural in the auriferous sands ot Slatoust among blocks of fine-grained felspar, and in granite near Miask, in felspar at Mozzo in Piedmont, in magnetic iron ore at Gelliware in Sweden, Lapland, at Newton in New Jersey, in Maryland and Connecticut, in the valley of Cha- mounix, in dolomite at Campo Longo, in basalt at Nieder- mendig on the Khine. The granular and massive variety, called emery, is found at Ochsenkopf near Schwarzenberg in Saxony in a bed of talc in mica slate, in rounded masses in Naxos, Italy, Spain, in great abundance on the summit of Gumuchdagh near Gumuchkeny about twelve miles to the east of Ephesus, and between Eskihissar and Melas in Asia Minor. ’ The combinations oartinp, oarnqvgs, and indistinct traces of the form i were observed in crystals in Mr. Brooke’s collection. The faces of the zone oa between n and a are striated to such an extent that it is extremely difficult to distinguish true reflexions from diffraction images, in observing with the reflec tive goniometer; consequently, the determination of the faces in this zone is liable to considerable uncertainty. Besides the forms enumerated above, Mohs gives 6 11 I (5 111,111 = 47° 23'), and Hansmann the forms 5 17 7 (5 17 7,111 = 65° 22'), 2 17 I3’ (2 17 13,111 = 81° 38'). Some of the crystals in Mr. Brooke’s collection appear to show traces of the forms 3 13 7 (3 13 7,111 = 71 44'), 2 11 7 (2 11 7,111 = 78° 15'), 1 16 13 (l 15 13,111 = Alumina 98-5 1-0 0-5 Bed oxide of iron Lime . . . .
