by E. Comelmst 217 



found by digging away the earth on the side of the road, and 

 appears to have been the trunk of a considerable tree. It is 

 firmly fixed in the ground, and penetrates it obliquely ; how 

 far has not yet been ascertained. At the time I saw it about 

 two feet had been exposed. The diameter is about eight 

 inches. Its colour is white, sometimes resembling that of wood. 

 The fibres are well preserved, and so is the general structure. 

 It is much to be desired, that some one would clear it from its 

 bed, and give it entire to one of our mineralogical cabinets. 



Geological Features. 



Next to the alluvial and secondary formations, as you pass 

 to the west and northwest, are to be found ranges of granite 

 and shistose, and other primitive rocks ; interspersed with 

 these may be seen sandstone, clay, slate, quartz, and limestone. 

 Granite ranges were particularly seen in the neighbourhood 

 of Fredericksburgh, crossing the Rappahannock; and in 

 Orange and Albemarle counties, extending nearly to the Blue 

 Ridge. Great quantities of quartz and quartz rock, sometimes 

 covering with their fragments the sides of hills, are frequent. 

 Another, and more interesting rock in the same connexion, is 

 found in Albemarle county. For some time I doubted to what 

 class to refer it. But from its resemblance to the rocks of the 

 east and west mountains near New-Haven, I ventured to call 

 it trap or whinstone. It becomes more abundant as you ap- 

 proach the Blue Ridge, and the granite disappears. On the 

 sides and summit of the mountain, its appearance is more de- 

 cidedly that of greenstone. In crossing the southwest moun- 

 tain, the range to which Monticello belongs, and distant from 

 the Blue Ridge about 25 miles, I observed the same rock. 

 Whether this opinion is just, you will be able to decide from 

 the specimens which have been forwarded. 



Bine Ridge. 



I have repeatedly named the Blue Ridge. It is the first of 

 those long and parallel ranges of mountains, called the AUe- 



