426 Scientific Geology. 



an internal force erupting the matter of the vein, I know not how 

 such proof could be given. But more of this in another place. I 

 thought the case too interesting not to he noticed, although out of 

 Massachusetts ; and I shall take the liberty in several other instances, 

 as I have already done in some cases, to introduce examples from 

 other parts of New England, illustrative of important geological 

 principles. In respect to the veins of the unstratified rocks, especial- 

 ly, I shall give the results of my observations for the last twelve or 

 fifteen years in various paits of New England, since the subject is 

 one of special interest.* 



* To show how the examples which I shall adduce are regarded by a distinguished 

 geologist in Europe, I take the liberty to subjoin a translation of a letter which I 

 received, two or three years ago, from Counsellor Von Leonhard, Professor 

 of Mineralogy in the university of Heidelberg, Germany, in answer to a com- 

 munication which I had previously made to him at his request, detailing several 

 of the most striking cases of veins and protruding masses, which are embodied in 

 this Report. I give the letter entire, since several of the examples given by this 

 veteran savant^ although to be met with in a few works, are yet not commonly to be 

 found. 



"Heidelberg, December 14, 1829. 



11 SIB, Your letter of the 20th October, with which you have favored me, I have 

 duly received. A thousand thanks for the trouble you have taken to enlighten me 

 with so many interesting facts concerning the granitic eruptions of your country. 

 Your observations are of the highest importance, and it is very much to be desired 

 that you should publish them forthwith.* You have requested that I should give 

 some account of the elevation of granite in this country as well as in England and 

 France. 



" One of the most interesting observations that have been made on this subject, 

 is that of Weiss, near Meissen in Saxony. Granite, or rather sienite, there ap- 

 pears superimposed upon the planerkalk which belongs to the chalk formation. 



A hundred paces from my house is a protrusion of granite. The predominant 



* In a subsequent letter I requested Prof. Leonhard to make such a use of these 

 facts as he thought proper ; and not unlikely some of the cases which I shall pro- 

 duce, have ere this been published in Germany. 



