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QUARTERLY JOURNAL 



New- York. I allude more particularly to the hills of Chester an- 

 Middlefieldj along which the great Western Railway passej 

 Still, I have seen good crops of rye growing there, though th 

 soil may have derived a beneficial- influence from the decompoi 

 tion of the neighboring rocks composed of hornblende and sieniU 

 Here is also a peculiar vegetation: the Ilex canadensis^ and so: 

 other herbaceous plants, are only found here, and this is the onh 

 place where any thing like a pine grove has been planted bj 

 nature. For localities where serpentine prevails, see the Repo: 

 of the Second Geological District. 



In this connection, it would be proper to state the compositio 

 of basalt and greenstone^ although in New-York they do not for; 

 very extensive beds. 



Basalt. Greenstone- 



Silica, 46.50 57.25 



Alumina, 16.75 25.50 



Lime, 9.50 2.75 



Magnesia, 2.25 



Soda, 2.60 8.10 



Iron and manganese, 20.12 3.50 



Water, 2.00 3.00 



99.72 100.10 



The composition, however, of these varieties of rock is m 

 tremely variable, but all are known to contain the alkalies 

 alkaline earths ; and it is owing to this fact that the greenstoij 

 soils are remarkably fertile, so much so that they may often" 

 employed to increase the fertility of less favored ones. 



§ 4. Character of granitic soils. 

 Returning once more to the consideration of granitic soils, 1] 

 mark, that they are too siliceous and porous when derived pui 

 from granite. Position, however, alters their character ; for whe 

 they lie upon sloping surfaces, sand predominates ; but in the vi 

 leys, the fine alumine or clay of the felspar accumulates and fori 

 an admixture of clay and sand, which is more favorable to 1 

 support of grass and grain. On reviewing the composition oft 

 minerals which enter as elements in rocks, we find that the m( 

 abundant of them contain the proper proportions for a good sc !l • 

 Silex rarely forms less than one-half- the remainder is made 



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