1 83 5] GEOLOGY. 26l 



temporaneous with the plains of Patagonia (or about with 

 the upper strata of the Isle of Wight). If this result shall be 

 considered as proved,* it is a very important fact in the theory 

 of the formation of the world ; because, if such wonderful 

 changes have taken place so recently in the crust of the globe, 

 there can be no reason for supposing former epochs of 

 excessive violence. These modern strata are very remark- 

 able by being threaded with metallic veins of silver, gold, 

 copper, &c. ; hitherto these have been considered as apper- 

 taining to older formations. In these same beds, and close 

 to a gold-mine, I found a clump of petrified trees, standing 

 upright, with layers of fine sandstone deposited round them, 

 bearing the impression of their bark. These trees are 

 covered by other sandstones and streams of lava to the 

 thickness of several thousand feet. These rocks have been 

 deposited beneath water ; yet it is clear the spot where the 

 trees grew must once have been above the level of the sea, 

 so that it is certain the land must have been depressed 

 by at least as many thousand feet as the superincumbent 

 subaqueous deposits are thick. But I am afraid you will 

 tell me I am prosy with my geological descriptions and 

 theories. . . . 



Your account of Erasmus' visit to Cambridge has made me 

 long to be back there. I cannot fancy anything more de- 

 lightful than his Sunday round of King's, Trinity, and those 

 talking giants, Whewell and Sedgwick ; I hope your musical 

 tastes continue in due force. I shall be ravenous for the 

 pianoforte. . . . 



I have not quite determined whether I will sleep at the 

 * Lion ' the first night when I arrive per ' Wonder,' or disturb 

 you all in the dead of the night ; everything short of that is 

 absolutely planned. Everything about Shrewsbury is growing 

 in my mind bigger and more beautiful ; I am certain the 



* The importance of these results has been fully recognized by 

 geologists. 



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