metalliferous minerals. 233 dition of tincture of galls. Before the blowpipe on charcoal it be comes magnetic, and colours glass of borax green. Exposed to the air, it soon appears covered with a yellow powder, which is the persulphate of iron. This species in its native>tate is rare; in most cases it is pro duced by the decomposition of other minerals, particularly iron pyrites. It is also found dissolved in the waters of several mines. It occurs in the Ilammelsberg mine near Goslar in the Hartz, at Schwartzenberg in Saxony, and at Schemnitz in Hungary ; also in aluminous shale, at Ilurlet near Paisley; and in New England, where it forms crusts upon the surfaces of such mica-slate rocks as happen to abound in iron pyrites. It is used in dyeing, in making ink, Prussian blue, and sulphuric acid. BOTIIYOGENE. Native Red Iron Vitriol of Fahlun, HaWngcr. Rother Eisen-Vitriol, Leonhard. Neoplase, Jicndant. ’ Bisulphate of the peroxide of iron, combined with bisulphate ot the protoxide of iron, and water. • Su fc ic acid 8 ~ 35 > peroxide of iron 23-86, protoxide of iron 10-71, water 32-85. T) . „ S i’- Gr - 2 ' 039 - H. = 2-25—2-5. 1 rimary form an oblique rhombic prism of 119° 66' and 60° -V. /on/. 81° 44 J 011 q 141 0 g on g 119 50 t\,P CCUr i S i* n smad crystals which are usually aggregated in ren line'surfire°- try0ldal - mass ? s > consisting ot ' globules with a crysta from' Rnro ’ s .° metlm ? s like a bunch of grapes, hence its nam less nerffmi i 0t / a,ul 'J stria ted parallel to the axis, an to n n i y °, riue , . dle inclined planes ; cleavage parall 1 * our dee P hyacinth-red, passing, when massive, int ire-yellow, the colour ot its streak; translucent; lustre vi reous ; taste slightly astringent. When exposed to a moist a mosphere it becomes covered with a dirty yellow powder, but ri