122 Scientific Intelligence. 



and on detached stones. It is often crystalline, either in folia, or in 

 concentric fibrous aggregations like Wavellite. It is greenish with a 

 greasy luster, and a specific gravity 2*77 after long desiccation. Hard- 

 ness, that of talc. The analyses vary much. In one, Scheerer ob- 

 tained silica 52*28, alumina 7*33, magnesia 31*24, protoxyd of iron 

 3-79, protoxyd of manganese 0*89, lime 0*28, water 404=99*85. ^ In 

 another, silica 47*35, alumina 10*27, magnesia 24*73, protoxyd of iron 

 7*92, protoxyd of manganese 2*64, water 6*28=99' 19. 



6. On Volknerite, a new mineral from the mines of Schischimsk ; by 

 M. Hermann, (Jour. f. Prakt. Ch., xl, 11; Annuaire de Ch., 1848, 

 p. 154.) — Volknerite occurs in white pearly laminse on talc schist, and 

 sometimes in hexagonal tables, with a perfect basal cleavage. Feel 

 greasy. Density 204. 



tit 



Composition Al 3H-f-6(Mg, 2H). 



7. Analysis of Pyrophyllite of Spaa; by M. Rammelsberg, (Pogg. 

 Annalen, Ixviii, 505.) — The analysis afforded: silica 66*14, alumina 

 25-87, magnesia 1*49, lime 0-39, water 5*59=99-48 — leading to the 

 formula (neglecting the lime and magnesia) 5Si0 3 2AI 2 O 3 -f-2H0. 



8. Analysis of Talc of Rhode Island and Steatite of Hungary ; by 

 M. A. Delesse, (Rev. Sci. et lndust., xxv, 107.) — The Talc of Rhode 

 Island occurs in large clear foliated masses. It has two optical axes 

 intersecting at a small angle. Density =2*5657; after calcination 



1*64. Hardness =1; after calcination =6, so that it scratches 

 glass, although with some difficulty. It exfoliates when heated. 



On analysis it afforded silica 61*75, magnesia 31-68, protoxyd of 

 iron 1*70, water 4*83=99*96 ; and Delesse thence deduces the formula 

 2(4Si0 3 +3MgO)+3(MgO,HO). 



This author also examined a steatite from Nyntsch in Hungary, and 

 obtained for its composition, silica 64'85, magnesia 2853, protoxyd 

 of iron 1*40, water 5-22=100-00, this result leading to the formula 

 5(Si03 MgO)-f 2HO. 



9. On a new Hydrosilicate of Alumina ; by MM. Damour and Sal- 

 vetat, (Ann. de Ch. et de Ph., 3e ser., xxi, 376.) — This mineral occurs 

 massive in nests in a brownish clay near Montmorillon (Vienna). It 

 has a soapy feel, and a clear rose color, and becomes plastic in water. 

 Composition, according to Damour, silica 5004, alumina 20*16, sesqui- 

 oxyd of iron 0*68, lime 1-46, potash 1*27, magnesia 023, water 26*00. 

 It is hence allied to Halloysite. 



10. Philippsite and Gismondine; by M . Marignac, (Ann. de Ch. 

 et de Phys., 3e ser., xiv, 41.) — Marignac separates these species, which 

 Kobell and Brooke had united. Under Gismondine he includes speci- 

 mens having an octahedral form, and rarely mammillated, and faces 

 not striated ; and under Philippsite, those whose crystals have a rectan- 

 gular prismatic form terminated by a 4-sided pyramid, with the faces 

 striated in two directions oblique to one another. Density of Gismon- 

 dine 2*265, of Philippsite 2*213. 



11. On the Composition of Heulandite ; by M. Damour, (Comptes 

 Rendus, xxii, 926; Annuaire dc Chim., 1847.) — Damour has detected 

 in Heulandite a portion of soda and potash which simplifies the formula. 



His analysis gives: silica 59*64, alumina 16*33, lime 7-44, soda M6> 



