Waters of Paltzozoic Rocks. 553 



the soda or potash being chiefly derived from the 

 felspathic ingredients of the various formations, and 

 therefore the waters are soft. For this reason, at a vast 

 expense, Glasgow has been supplied with water from 

 Loch Katrine, which, lying amid the gneissic rocks, is, 

 like almost all other waters from our oldest formations, 

 soft, pure, and delightful. The same is the case with 

 the waters that run from the Silurian rocks of the 

 Lammermuir Hills ; and the only fault that can be 

 found with all of these waters, excepting by anglers in 

 times of flood, is that they are apt to be a little 

 flavoured and tinged by colouring matter derived from 

 peat. 



The water of the rivers drained from the Silurian 

 Cumberland mountains is also soft, and so little of the 

 waters of that country rises in the lower plateaux of 

 Carboniferous Limestone that it scarcely affects their 

 quality. 



The water from the Welsh mountains is also in 

 great part soft, the country being formed of Silurian 

 rocks, here and there slightly calcareous, from the 

 presence of fossils mixed with the hardened sandy or 

 slaty sediment, that forms the larger part of that 

 country. So sweet and pleasant are the waters of Bala 

 Lake, compared with the impure mixtures we some- 

 times drink in London, that it has been more than once 

 proposed to lead it all the way for the supply of water 

 for the capital; and the same proposition has been 

 made with regard to the waters of Plinlimmon 1 and 

 the adjacent mountains of Cardiganshire. But when 

 in Wales, and on its borders, we come to the Old. Red 

 Sandstone district, the marls are somewhat calcareous, 

 and interstratified with impure concretionary limestones, 

 1 Properly Plymlumon. 



