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HORNBLENDE SCHIST. 



I HAVE thought it necessary, in the present 

 arrangement, to rank under this general title a 

 variety of rocks, which, however agreeing in 

 their general characters and geological relations, 

 have been distinguished by different names by 

 other geologists. 



Those names, as they are used in this coun- 

 try, are the following : hornblende rock, horn- 

 blende schist, primitive greenstone, and green- 

 stone slate ; it is unnecessary to enumerate the 

 terms sometimes employed for the same purpose 



by foreign geologists, as they only increase the 

 obscurity of the subject, and have already gene- 

 rated much confusion. The reasons why three 

 of those names are rejected, are the following. 



It will, I believe, be found, that wherever 

 hornblende rock occurs, it is only a portion of 

 those beds of which the greater parts present the 



