as a Branch of Natural History^ ^c. 251. 



Family 2. — Fusible vitreous metal-like Hematites. 



Capable of being immediately fused and reduced with the blowpipe. So- 

 luble in acids. Scratching only calcareous spar. 

 G«».— Red copper-ore, or ruby copper. 



Appendix to the Order Hematites. 

 Polymignit (Berzelius). 



Order II.— SULFURIDEOUS or BLENDE. (Mohs.) 



Chem, Nat. — Metallic sulphurets, formerly supposed, for the most part, to 

 contain metallic oxides, but now looked upon as entirely free from oxy- 

 gen. 

 With the blowpipe in the open tube emitting the smell of sulphurous acid, 

 and changing the Brazil wood paper introduced into the tube white. Scratch- 

 ing at most the sulphate of barytes, or only talc or gypsum. Capable of be- 

 ing acted upon by acids. 



Gen. — Red silver ; cinnabar ; zinc-blende ; red orpiment ; yellow orpiment. 

 Appendix. — Red antimony ; manganese blende. 



CLASS IIL^INFLAMMABLE CRYSTALS. 



Chem. Nat. — Inflammable, not metallic elementary bodies. 



Lithoid appearance, with a strong lustre ; still retaining something slightly 

 metallic. Burning at a greater or lesser degree of heat. Capable of acquir- 

 ing electricity by friction, or idio-electric. 



Order I.— SULPHUR. 



Burning at the flame of a candle, with a blue flame, with a smell of sul- 

 phurous acid. Very soft. Scratched by calcareous spar. Dust-yellow ; co- 

 lour bright yellow. Acquiring negative electricity. 



Gen. — Sulphur (with seleniferous sulphur of Vulcano). 



Order II.— DIAMOND. (Carbon). 



Requiring for combustion a very high degree of heat ; at the 14th degree 

 of Wedgewood's pyrometer dissipates in carbonic acid gas. The hardest of 

 minerals, scratching all the others. Dust white ; colour various, but general- 

 ly light. Acquiring positive electricity. 



G^.— Diamond. 



CLASS lY.^LITHOPffANOUS CRYSTALS. 



Chem. Nat, — Metals or metalloids, combined with some substance which 

 supports combustion, as oxygen, fluorine or chlorine. 



jMore or less transparent or translucid, at least on the edges, or in very thin 

 plates * No metallic lustre. Capable of acquiring electricity by friction, or 

 idio-electric. The greatest part acquire the positive electricity. 



• Even in the most opake-looking, the dust is white or light coloured, shewing that translu- 

 ddity is their natural state. 



