GEOLOGY. 117 



bottoms of Lake Erie and Ontario are principally 

 lime-stone, which is in a state of augmentation. 

 In the county of Onondaga, at a place called the 

 Little Lakesj I observed the great elaboratory of 

 nature at work in the formation of calcareous 

 rocks, and as T humbly conceive, by a double 

 process. First, by depositions from its waters in 

 which lime was diOused — and second, by the 

 ! operation of springs rising from the bottom of the 

 lakes, and extruding calcareous matter from the 

 bowels ol the earth. Whether I am correct as to 

 this complex power, I cannot say— but as to the 

 fact of the creation of tufa, it must be obvious to 

 the most inexperienced eye. In order to gain all 

 the light I could on this interesting subject, I 

 took a short journey to the village of Marcellus, 

 in the connty of Onondaga. The production of 

 lime stones of large size at nine mile creek, near 

 this place, is a ver}^ extraordinary thing. On the 

 banks of the creek, there is a petrified or fossil 

 tree, over wiiich there is a large limestome, and 

 which stone must have been formed after the petri- 

 faction of the tree, and the wliole process is appa- 

 rent to the observer. After the first deposition, 

 and a consequent induration, the stone is covered 

 by a lichen which retains a subsequent deposition, 

 and which hardens and enlarges as before. The 

 hardness of the lime stone Increases with its depifi 



