Singular Inscription. 121 



tegrate, and even decompose, rapidly. Mica slate and talcose slate are 

 similarly affected, though to a less extent, as is also argillaceous slate, 

 and some varieties of slaty gray wacke. 



Quartz rock, for the most part, is one of the most indestructible of 

 all our rocks. Those rounded and smooth bowlders of granular 

 quartz especially, that are so common in the western part of the State 

 among the diluvium, appear in general to have bid defiance to all 

 decomposing agencies in past ages, and to be destined to endure un- 

 changed for ages to come. Yet I had recently pointed out to me a 

 rather curious, and somewhat instructive example of these bowlders, 

 lying in the extensive fruit-tree nursery of Mr. Tracy, in Norwich. 

 It was several feet in diameter, and though not as smooth as some 

 bowlders of this kind, yet I should not have suspected that it had 

 suffered the least waste, were it not for an inscription that appears 

 npon it. The name of John Gilpin is marked on its upper surface, 

 in a large fair hand, a few of the letters only being indistinct. These 

 letters are not cut in the stone, nor do they consist of any foreign 

 substance, like ink, or paint, spread over it. But they are rendered 

 visible simply by the lighter color of the surface, where they were 

 originally written; and by passing the finger over them, it is obvious 

 that they project slightly. Hence I infer that these letters were orig- 

 inally written with some kind of paint, which prevented the rock 

 beneath it from decaying ; while the decomposing process went on 

 gradually on the other parts of the stone. Now as these letters 

 must have been written since the settlement of that part of the coun- 

 try, we cannot suppose that more than 150 years at the longest have 

 since elapsed : and probably the period is much less. We have here, 

 then, a sort of measure for determining the rate at which hard quartz 

 rock will decay by atmospherical agencies. 



Alluvium of Degradation. 



Three causes are constantly operating to degrade the mountains 

 and hills and to fill up the valleys ; viz. rains, frost, and gravity. That 

 they have not already reduced the earth's surface to a level, is decisive 

 proof that the globe has not existed in its present state eternally. 

 Such a result must ultimately proceed from these causes, if they con- 

 tinue long enough in operation : and that would be to reduce the 

 globe to an uninhabitable chaos : for if the present dry land were 

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