178 BOARD OF AGRICULTURE. 



ascribes the formation of all these loose materials to the agency 

 of ice. 



But now, if that is true, there comes a work to be done which 

 will be very interesting to the agriculturist. These sheets of ice 

 have moved over rocks of different mineralogical composition. 

 When these sheets of ice moved from the north over Vermont 

 and then over our State, they passed successively over granitic, 

 over limestone, over slaty regions, and, grinding all those mate- 

 rials, made a paste which consists of a mixture of the elements 

 of granite, the elements of slate, the elements of limestone. 

 When they passed through the more Western States, they passed 

 over a more extensive limestone and clay region. The amount 

 of quartz material is less, because round to the north of the 

 State of New York there are not such extensive tracts of gran- 

 itic rock as we have to the north of us. Hence the soils of those 

 Western States contain a larger amount of limestone than ours ; 

 but they contain also silicious materials, the result of the decom- 

 position of granite, mica, slate, gneiss and like rocks, because 

 there are some such rocks to the north of those States, and 

 therefore there is a similarity in the component elements of the 

 agricultural soil of every Northern State, and the differences are 

 accounted for by the different masses of rock to the north of the 

 spot where we carry on our investigations. It would be a mat- 

 ter of great interest to survey these accumulations of loose 

 materials all over our State, with a view to ascertain the compo- 

 sition of the paste, the nature of the fragments of rock which 

 remain unbroken, which are only worn to smaller dimensions 

 and have not been ground down to powder, and which would 

 give us a general analysis of our soil, preparatory to the more 

 minute analysis of each locality. 



The later action, arising from the flow of water over these 

 surfaces after they had been uncovered — that is, after the ice 

 had melted away — is seen in the precipitation of more minute 

 materials to lower levels. All our river basins exhibit a great 

 amount of boulders and large fragments, and these large boul- 

 ders have been pointed out as evidence of the stupendous action 

 of the water. I say that they testify just the contrary— to the 

 inability or to the want of power of the currents to carry them 

 further. The water-courses have only carried the loose materials 

 of smaller dimensions and made the river bed ; the large mate- 



