66 tl^r* Kain on the Geology and 



probably die there ; that the aborigines have made them a place 

 of burial ; and that the streams of water which flow through 

 them in wet weather, carry with them not only great quantities 

 of leaves but many other vegetable productions. 



The natural bridge is celebrated as one of the greatest curi- 

 osities of the world. Viewed by a geologist, it would proba- 

 bly be considered as a cave (so to speak) unroofed in all but 

 one place. It seems improbable that if the ravine had been 

 made by a convulsion, which had split and separated the rocfc 

 to the distance of fifty or sixty feet, any part of it, and particu- 

 larly so large a mass as that which forms the bridge, should 

 have been left, without exhibiting any marks of violence. The 

 rock is limestone. It is known that this rock wears away 

 rapidly under the attrition of water ; and the supposition does 

 not appear improbable, that, in the lapse of ages, so large a 

 creek as that which flows below the bridge, may have worn as 

 deep a ravine as that which now strikes us with so much sur- 

 prise. In short, may not a cave have been originally formed 

 where the ravine is now, and the pending portion of it have 

 fallen in at evei-y place except that which now forms this cele- 

 brated natural curiosity ? 



Mineral Springs. — The mineral springs of this region are 

 numerous and diversified. Chalybeate springs are promiscu- 

 ously scattered over the whole of it ; and springs impregnated 

 with sulphuretted hydrogen are quite common. Salt springs 

 and licks are found more in the western than the eastern range 

 of mountains. That which was first wrought by WiUiam King, 

 is well known. The salt here is associated with gypsum. In 

 the same range of mountains, farther to the southwest, there 

 are now several other salt-works, and also one to the west, on 

 Goose Creek, in Kentucky, which has been very productive. 



The Warm Springs. — These springs are situated in a country 

 which presents many attractions to the travelling geologist ; 

 and much light, it is hoped, will yet be thrown on the geology 

 of our country, by a more minute and accurate examination of 

 it than has yet been made. 



The warm springs ooze through the sand on the south bank 

 of the French. Broad river, in the mountains which divide th« 



