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columns. Remarkable examples of this kind are seen at the 

 Giant's Causeway, in Ireland, and at Fingal's Cave, in Stafla, 

 one of the Hebrides. The term is used by Pliny, and is said 

 to come from basal, an ^Ethiopian word signifying iron. The 

 rock often contains much iron. 



" Basin" of Paris, " Basin" of London. Deposites lying in a hollow 

 or trough, formed of older rocks, sometimes used in geology 

 almost synonymously with " formations" to express the depo- 

 sites lying in a certain cavity or depression in older rocks. 



Belemnitc. An extinct genus of the order of molluscuous animals 

 called Cephalopoda, having a long, straight, and chambered 

 conical shell. Etym., /SsASfxvov belemnon, a dart. 



Bitumen. Mineral pitch, of which the tar-like substance which is 

 often seen to ooze out of the Newcastle coal when on the fire, 

 and which makes it cake, is a good example. Etym., bitumen, 

 pitch. 



Bituminous Shale. An argillaceous shale, much impregnated with 

 bitumen, which is very common in the coal measures. 



Blende. A metallic ore, a compound of the metallic zinc with 

 sulphur. It is often found in brown shining crystals, hence 

 its name among the German miners, from the word blenden, to 

 dazzle. 



Botryoidal. Resembling a bunch of grapes. Etym., jSorpug, botrys, 

 a bunch of grapes, and skSos eidos, form. 



Bowlders. A provincial term for large rounded blocks of stone 

 lying on the surface of the ground, or sometimes imbedded 

 in loose soil, different in composition from the rocks in their 

 vicinity, and which have been therefore transported from a 

 distance. 



Breccia. A rock composed of angular fragments connected together 

 by lime or other mineral substance. An Italian term. 



Calc Sinter. A German name for the deposites from springs hold- 

 ing carbonate of lime in solution — petrifying springs. Etym., 

 kalk, lime, sintern, to drop. 



Calcareous Rock. Limestone. Etym., calx, lime. 



Calcareous Spar. Crystallized carbonate of lime. 



Calcedony. A silicious simple mineral, uncrystallized. Agates are 

 partly composed of calcedony. 



