Scientific Intelligence. -437 



iticcompanying that communication. But on further examina- 

 tion it has been found to be more extensive than was sup- 

 posed. The texture of the rock is coarse. Plates of mica, 

 3 or 4 inches across, are common in it ; and one specimen of 

 a beautiful blue feldspar, the fragment only of a crystal, mea- 

 sured in one direction 8 inches. 



Two circumstances in this range give it an interest in the 

 eye of a geologist. The one is its proximity to sandstone and 

 puddingstone ; and the other, its small elevation in compari- 

 son with the surrounding rocks of later formations. In some 

 places no other rock could be found lying between the granite 

 and puddingstone ; though the soil prevented my observing 

 whether there is an actual contact. But in general there is a 

 .stratum of mica slate a few rods wide between these rocks, 

 and not unfrequently gneiss lies between the mica slate and 

 granite. 



Standing on this range in Leverett, you have ott the west, 

 at about 100 rods distant, a precipitous mountain of sandstone 

 and puddingstone, five or six hundred feet higher than the 

 granite. On the east, a mile or two distant, a mountain of 

 sienite gradually rises to a still greater height than the pud- 

 dingstone ; and on the southwest, at nearly the same distance, 

 you can see an alluvial formation. In general this granite 

 does not rise so high as the adjacent rocks, whether secondary 

 or primitive. 



VEINS OF ORE IN THIS GRAITITE. 



1 . Of Galena in Leverett. 



This ore forms a narrow vein in the southwest part of the 

 town, on land of Moses Smith, two miles from the Congre- 

 gational meeting-house. The direction of the vein is nearly 

 north and south, and where I saw it, only a foot wide. The 

 gangue is sulphate of barytes. 



2, Cy Qalena, Copper Pyrites^ and Blende, 



This v<ein is a little more than a mile north of the one 

 above described, and it may be a continuation of the same 



