A GEOLOGICAL HISTORY. 37 



sand, with some large boulders the size of a paving 

 stone, (the largest, being 3 or 4 feet thick) then a 

 soft brown coloured sand, with little grit and con- 

 siderable mica, from two inches to sometimes a foot 

 in thickness ; then a clear sharp -grained coarse 

 sand, with very little mica, five or six feet thick ; next 

 a gravel of small pebbles, two or three inches thick ; 

 then a sand, similar to the one above, but not so 

 clean and sharp ; giving the bank a striped ribbon- 

 like appearance, of gray, brown and ochre yellow : 

 these different layers appear to have been deposited 

 under different circumstances, or from a different 

 influence, or at different times. There are some of 

 these hills, which have twenty varieties of deposit, 

 each deposit having its peculiar colour, its coarse- 

 ness or fineness, its material ; and then again, some 



compound, (if we except its earthy,) is in time dissipated, the ashes of 

 which, in the form of earth is left, and is washed down by rains, to the 

 low grounds, and there forms beds, if the locality on which the plant 

 grows is Silicious, this Alluvial clay is Silicious, if Calcareous, the clay 

 will be Calcareous, or if Aluminous, it will partake of the Aluminous 

 quality, and so on ; when these vegetable products fall in swamps, or 

 other wet places^ and are not shifted by mechanical or altered by chemical 

 changes, they retain their skeleton forms, and have been called Infusoria 

 by some, and have excited much wonder, as they are thought to be of ani- 

 malcular origin; it is not to be supposed, that all these minute skeleton 

 forms are of vegetable origin, some may be of animal, but when we take 

 into consideration, the vast quantity of vegetable matter, that the earth pro- 

 duces, and the comparitively, small quantity of animalcular, there is 

 some reason to doubt, that all the beds of clayey earth, which form the 

 bottom of ponds, &c, are of animal origin. 



