115 



ore of this description, from its earthy appearance in most cases 

 and its total want of an external metallic aspect, had been rejected 

 as of no value, and it was only by accident that its character was 

 revealed to those who were working in the mines. 



The sulphuret or blue ore (galena,) occurs in veins of rotten or 

 chalky limestone ; the carbonate, in beds generally situated at the 

 intersection of the veins. In the extraction of the metal the fuel 

 employed is wood, and the operation is performed in a simple rever- 

 beratory furnace. 



The gypsum, as far as certainly known, occurs over a space about 

 20 miles in length, and half a mile in breadth, but probably the area 

 actually occupied by it is much more considerable. The depth to 

 which it extends in some places is enormously great. It lies in beds 

 between strata of limestone, slate, and sometimes sandstone, and 

 has to be penetrated for a great depth in boring for salt water. In 

 some cases it is said to have a thickness of nearly 300 feet, including 

 the bands of rock among which it is stratified. Its condition is cither 

 that of a fibrous crystalline mass of nearly perfect purity, or a granu- 

 lar bluish-gray and veined rock, containing a small amount of earth, 

 but still as little mingled with extraneous matter as any of the im- 

 ported plaister. This precious material, owing to the difficulty of 

 transportation, is yet unknown at any distance towards the sea- 

 board, but during favourable seasons it is conveyed in arks down 

 the Holston, to the south-western states, and in this way yields a 

 handsome profit. "With facilities of transportation, what incalculable 

 benefits might the great valley of Virginia, and much of the region 

 west, as well as east of it, derive from this invaluable deposite, and 

 what an active and productive commerce might it give rise to 

 throughout that region in which it is found. 



The salines constitute another of the treasures of this district of 

 he state. As yet but little has been done, either towards determin- 

 •ng the extent of the saliferous strata, or the chemical nature of the 

 various ingredients, besides the common salt, which the brine hoicks 

 dissolved. At the saJt-works on the Holston, the wells are usually 

 from two to three hundred feet in depth, presenting strata of lime- 

 stone near the surface, sandstone or slate alternating with beds of 

 gypsum several feet in thickness, next beneath, and finally, a stra- 

 tum of clay, within which the salt-water is procured. This clay is 

 of a reddish aspect, and a very argillaceous texture, being in all 



