ECONOMIC GEOLOGY. 95 



useful cement, but others are little more than a highly calcareous sand- 

 stone, and it would require some discrimination to distinguish the better 

 kind by the eye alone. The limestone from the coal-seams is easily 

 burnt on account of the carbonaceous matter it contains, and the re- 

 sulting lime is white and slakes rapidly. But the supply of either 

 kind is very trifling. Enough could, perhaps, be collected to supply a 

 limited local demand, but anything beyond this cannot be hoped for. 



( 363 ) 



