Geology and Mineralogy of Salisbury. 259 
Hornblende—lamellar, slaty and fibrous surface ferru- 
ginous brown. In veins traversing quartz—also in fibrous 
groups constituting the fasciculite of Hitchcock. 
Actynolite—occurs in large gray masses composed of an 
aggregation of acicular and capillary fibres, silky lustre, 
scratches glass, melts with a little intumescence mto a gray 
enamel, associated with augite, mica-slate, and graphite. 
Talc—green and white, in quartz and ‘auigite—also i in- 
durated with curved layers. 
Chlorite—massive, connected with quartz. 
Argillaceous slate—in small fragments, not common. It 
occurs in place ten miles north, in the west part of Shef- 
field. 
Clay.—Potters’ clay is abundant in nearly every part of 
the town. It generally lies a few feet below the surface, 
and is of a grayish white color, sometimes tinged with blue. 
The iron ore hill lies in clay, which appears to have been 
produced by the decomposition of the slate which is of a 
very soft texture. 
Sulphur.—Pulverulent on mica-slate. 
Petroleuwm—on stagnant waters, giving: them an irised 
appearance.* 
Graphite—In a natural and artificial state. It is found 
in all the furnaces in irregular crystals, and scaly masses. 
It is disseminated in a mixture of calcareous lime and mica- 
slate in a compact form, soft, and of a Pa good quality— 
abundant. 
Tron. 
Sulphuret of Iron.—Common variety in cubes and amer- 
phous masses, also granular. Sulphate of iron is formed in 
many places by its decomposition. In limestone, quartz 
and mica-slate. 
Hepatic Pyrites—abundant in quartz. 
Magnetic oxtd of Tron. —Crystallized and massive. In 
cubes and octaedral crystals in mica-slate. 
Specular oxid of [ron—abounds in shining plates in 
quartz., Laminae of various thickness. 
* This appearance, in such cases, is commonly owing to Iron,—Ep. 
