101 



the river has in the lapse of time varied its course, 

 most probably from some local cause. 



On the Hudson river, above the high lands I believe 

 the same may be observed. With respect to other 

 rivers, I refer to the authors \vhom I have already 

 named. 



2dly. It is a well known fact, that in digging for 

 wells and other purposes along upon the northern 

 borders of the great alluvial district, (and in some in- 

 stances, perhaps, at a greater distance from the primi- 

 tive range,) we find at the depth of forty or fifty feet, 

 the remains of a variety of vegetable substances, and 

 in some cases, in a high state of preservation. 



On Long Island, the remains of trees have been 

 found at the depth of forty-five, and fifty feet.* I am 

 likewise informed, that in New Jersey, Delaware, 

 and in the city of Philadelphia, remains of trees are 

 found at the same depth. 



The same thing occurs in different parts of Mary- 

 land. In Baltimore, at the depth of forty-five or fifty 

 feet, we find the remains of trees and their fruits, par- 

 ticularly the black walnut, (luglans Nigra) in abun- 

 dance. 



In Virginia this fact is notorious, and I believe in 

 all the states from Virginia to that of the Mississippi. 



In the western country beyond the Alleghany, re- 

 mains of trees are said to be found at a great depth 



* See Bruce's Mineralogical Journal for Mitchell's account of 

 Long Island, pages 132 & 162 -63. 



