SAECOLITE. 381 Melts without difficulty before the blowpipe. Gelatinizes with hydrochloric acid. 2E 3 Si a + 44-Si, where E is Ca, Mg, Na, K, and 44 is A1 and jPe. Analyses a, b of melilite, G — 2'95, from Capo di Bove, c of humboldtilite, g = 2-90, from Monte Somma, all by Damour, d of humboldtilite from Vesuvius by v. Kobell:— abed Silica 39’27 38-34 40-60 43-08 Alumina 6'42 8'61 10-88 11’20 Bod oxide of iron .... 10-17 io-02 4 43 fe 2-32 lame 32-47 32-05 31-81 31'98 Magnesia 8'44 6 71 4'54 6'10 Soda 1-95 2-12 4-43 4’28 Potash 1-46 1-61 036 0-38 Is found in attached crystals, granular masses and dissemi nated, with calcite, on Monte Somma, and in the lava of Capo di Bove near Eome. The want of cleavage in melilite renders its identity with somervillito rather doubtful. These minerals are united on the authority of MM. Damour and Descloizeaux. 218. SAECOLITE.—Sarcolite ; Phillips, Dufrenoy. Sarko- lith; Mohs, Haidinger. Pyramidal. 101,001 = 41° 3s'. a 100, c 001, e 101, m 110, h 210, r 111, t 113, ® 313, $ 311. The form v is hemihedral with parallel faces. FIG. 396. ha 26° 34' rc 51° 27' ma 45 0 me 90 0 a f a 90 0 m 26 40 mm f 90 0 ra 60 26 ec 41 35 re 33 34 ac 90 0 ve 12 28 tc 22 41 r rr 67 8 Combination, acmekrtsv'. Fracture conehoidal. Semi transparent ... translucent. Lustre vitreous. Flesh-red... white. Very brittle. 11 = 8'0. G = 2 515. Fusible before the blowpipe.