1846.] Jigricvltural Geology of Onondaga County. 183 



An uncultivated soil in Manlius, upon the same rock, gave 



100.15 



Some differences may be observed in the composition of the 

 soils of the Marcellus shales and the green shales below the 

 Onondaga limestone, the most important of which is due to the 

 diminished quantity of lime and magnesia. The soil is brown, 

 and so far, the color may be considered as an advantage. It is 

 from two to five hundred feet above the plain where the green 

 shales predominate. The slopes are steeper, and there is less 

 level meadow land and more drift, for it is rather a singular fact 

 that far more drift is lodged upon the terraces above, than on the 

 plains below, and it is not at all difficult to detect the soil of the 

 green shales by its peculiar color. Some districts upon the ter- 

 races are quite stony, and among the stones some large boulders, 

 and all of primary rocks. In those districts we find the poorest 

 soils of the county; and they are sometimes hard, stiff and wet 

 The hill sides when the rock is near the surface, are usually 

 gullied, and deep ravines are not unfrequent. The facilities for 

 draining are excellent on this account, and even draining appears 

 unnecessary. The water of the shales contains less lime and less 

 matter in solution. Some wells, however, sunk in them are fer- 

 ruginous when the water is low, from the presence of pyrities in 

 the rock. 



Some of the sources for Mamire. — Onondaga county abounds, 

 as is well known, in plaster. The quantity, value and position 

 of this article we need not dwell upon. The other substances 

 which may be employed to advantage are the marls, peat and the 

 refuse of the salt works. A remarkable bed of marl is exposed 



