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DOMAIN I. SIDEROUS. 



Grunstein 

 slate. 



STRUCTURE I. COMPACT BASALTON. 



Compact basalton, from some of the interior 

 pillars of Stonehenge. 



Basalton, or whin, from Salisbury Crags, near 

 Edinburgh. 



The same, from the Malvern hills. 



Basalton is common in the pavement of London. 



STRUCTURE II. SLATY BASALTON. 



This is the green-stone slate of the Germans, 

 being composed of siderite and compact felspar, 

 or felsite, which is sometimes more abundant than 

 the former. It is said to form mountains in 

 Sweden, and abounds near the mines of Adelfors, 

 being often metalliferous. If the felsite generally 

 exceed in quantity, it ought to be classed under 

 that rock. 



KKnkstein. The porphyry slate, or clink-stone porphyry, of 

 Werner, basalte en table of the French, seems an 

 intimate mixture of iron and felsite, and is often 

 found in basaltic countries. It has been analysed 

 by Klaproth, who found eight parts of soda in a 

 hundred. How it came to be classed among the 

 basaltic family can scarcely be imagined, except 

 from its local situation, a circumstance too pre- 

 ponderant with Werner ; it being as often found 

 in the vicinity of basaltin, as lava with a base of 



