Mineralogy and Geology. 271 
i x1 Na cl ¢ £  dadFe 
46028 23°972 21483 7431 0857 trace =99°771 
Oxygen ratio in the silica, alumina and soda is 6:3: 1, whence the 
formula is Na Si-+ Al Si+-ClNa. 
Nepheline, variety Sommite or Dav ne.—A. Scaccui gives the fol- 
lowing as the observed inclination of the basal plane on planes of 
the series of hexagonal pyramids, 4, 4, 4, 4, 1, 2, 8,—on 4 158° 52", 
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on 3 99° 45’. Cleavage lateral, distinct. The crystal occurred in a 
geode in limestone on Mt. Somma with crystals of sodalite. (Pogg. 
Ann. 1852, Ergiinz. iii, Stuck 3, 478.) . 
On Scapolite; by R. Hermann, (J. f. pr. Chem. liv, 410).—The 
following new analyses are given in this paper. 
fo ae... #e e Mn Ga Na K CG 
1, Strogan’wite 40°58 28°57 089 — trace 20°20 3:50 —— 640=-10014 
Ox. 21:08 19°34 0°26 — — 5714 089 — 4+ 
2.Seapolite, 45:99 28:80 —— 225 0°25 1883 211 0-70 406 H0-30=98:29 
Ox. 23°37 1345  — 050 005 396 053 O11 293 
8. Ekebergite, 49:49 26-06 265 Mg.0°36 0:25 1289 4°50 0°80 3-00 Li tr.=100 00 
Ox. 2569 1214 O78 014 005 369 115 014 216 
4. Scapolite, 52-94 9764. —— Fe0:30 0:25 910 689 0°54 1:50H066=99'72 
Ox. 2750 1293 ——- 0:06 0°05 260 176 0°08 108 
5. Red Scap. 50:16 28-44Mg076 0°12 0-14 13:12 142 0°91 2:94 110°8, Litr’ce 
‘ 26:00 1328 030 0:02 0:03 867 0°36 015 212. [=988 
6. White Scap. 54°64 23:32 “ 020 100 014 905 844 124 2°50, Litr=100°53 
No. 2, from Diana, N. Y.; No. 3, from Hesselkulla, massive, oil 
but upon the hypothetical ‘* heteromerous molecules” assumed as ex- 
isting in the mineral. The groups are— % 
(1.) Gehlenite group.—Gehlenite =R* Si+ Al Si. 
(2.) Humboldtilite group.—The “ heteromerous molecules” are, a, 
having the oxygen ratio 1: 4 : 133 and 4, with the ratio 1:2: 3. Hum- 
boldtilite ==(a) ; Sarcolite =(a+d) 5 Atheriastite =(a+b)+8H. 
(3.) Dipyre group.—The ‘ heteromerous molecules” are, a, having 
the oxygen ratio 1:2 4, b, with the ratio 1 :2:6. Stroganowite = 
(a); Di — b: an i f dipy (6a+-b); athird (8a+). 
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