306 SILICATES. Analyses of acrnite a by Strom, b by Berzelius, c by Lebunt, d by Bammelsberg:— a b c d 64'2 7 66-25 62-02 64-13 34'44 3126 (II 0-69) 34-44 1-08 3-49 Ti 3'10 — — 28-08 — 9'74 10-40 1333 not det. — 0-72 0-88 — 1-88 iig 0-60 — Silica .... Bed oxide of iron Protox. mang. . Protoxide of iron Soda .... Lime .... Loss by ignition . The titanic acid is supposed to be derived from a mechanical mixture of ilmenite. Is found in the south of Norway in long crystals imbedded in quartz and felspar in granite at Bundemyr in the parish of Eger, and in syenite at Kless near Porsgrund. The angles between the faces a, b, m, s are very nearly the same as in augite, with which it has been supposed isomorphous. Its constituents, however, are not isomorphous with those of augite. 171. ZOISITE.—Zoisit; Werner. Oblique. no, k 210. sb 68° 8' kb 72 44 ss 116 10 kk' 145 48 wk 56 30 fig. 321. Cleavage, b, very perfect. Lustre vitre ous. Greyish-white, yellowish-grey... brown, green. In the matrass yields moisture, which reddens litmus paper, and the assay grows darker. Before the blowpipe, in forceps, intumesces and fuses, without difficulty, into a slightly translu cent, greenish-white, irregular mass. With a certain propor tion of soda on platinum wire, in the outer flame, fuses into a transparent slightly greenish glass ; with any other proportion of soda the globule is opaque. With borax, in the outer flame, fuses slowly into a perfectly transparent glass of a very light yellow colour whilst hot; perfectly colourless when cold. W itli salt of phosphorus fuses readily into a transparent glass, which