^ E. Gornelius, 219 



Blue Ridge ; and even that mountain is on those maps, in some 

 parts of it, covered with the granitic tinge. This may be true. 

 I can answer for only two points of it, and for that part of the 

 country beyond, lying near the main road to Tennessee. In 

 this route I descended almost the whole length of the great 

 valley included between the Blue Ridge on the east, and the 

 north mountain on the west. But in no instance did I meet 

 with specimens of granite ; nor west of the Blue Ridge with 

 any prevailing rock but limestone. I know of no reason why 

 the Blue Ridge should not be regarded as the first great di- 

 viding line between the granite and limestone countries. Th« 

 change in the geological formation is so sudden and striking, 

 that it would be difficult for the most careless traveller wit\> 

 his eyes open, not to observe it. The face of nature, he can- 

 not but perceive, wears a different aspect ; the air is more 

 cool and lively ; even the water which he drinks possesses 

 new properties perceptible to his taste. The inhabitants no 

 longer speak of their " sandstone water ;" but every where 

 he hears of " limestone water." Indeed for 800 miles in the 

 direction which I travelled, he tastes no other water. Every 

 spring and every rivulet, is strongly impregnated with carbo- 

 nate of lime. The vessels in which it is prepared for culinary 

 use, soon become lined with a white calcareous crust. Nor is 

 its taste the only inconvenience experienced by the traveller 

 unaccustomed to it. It often injures the health of a stranger, 

 and covers the surface of the body with cutaneous eruptions. 



Lime$tone country in inclined Strata. 



The geological observer has now entered upon a very in 

 teresting field. Its great extent, and its wonderful uniformity, 

 give new facilities to investigation. Two divisions of it seem 

 to have been made in nature. 



The Jirtt is that which includes the limestone lying in incli- 

 ned STRATA. This division extends from the Blue Ridge, to 

 the Cumberland mountain in East Tennessee, a distance in the 

 direction of my route of 500 miles. Of course it includes all 

 the ranges, five in number, of the Alleghany mountains. The 



