A LARGE MUD-HEAP. 123 



precious stones again. Whether the latter have actually 

 been formed out of the decomposed materials of older rocks 

 or no, there is apparently no reason in the nature of things 

 why they should not have been, for in the Blue Ridge rocks 

 we seem to have almost the whole process before us. 

 There is the gneiss, the decayed felspar, greasy brick-clay, 

 kaolin, and finally the corundum, which seems to have needed 

 only slightly different treatment in the great laboratory to 

 convert it into precious stones.* 



However this may be, we have traced our sand and 

 mud far enough for the present purpose, and have seen how 

 Nature has sorted and transformed them into sandstones, 

 clays, shales, slates, &c., and how man has taken them up 

 where she left them and has used them from the earliest 

 ages to pile up those vast heaps of stone, brick, glass, tiles, 

 and slates, which we call towns and cities. 



What was the Tower of Babel but baked mud ? And 

 what is the " modern Babylon " in the main, but a vast 

 transformed mud-heap, rivalling the Longmynd in size, 

 though certainly not in beauty ? 



* The old naturalists said heat was required to ripen precious stones. 

 Certainly they are found only in the south ; though the common topaz is 

 found by the hundredweight at Falun, and crystals of common emerald, 

 several feet long, occur in the felspar quarries of Finland 



