108 GEOLOGY OF ILLINOIS. 



The limestone over No. 6 coal may also be used for the manufacture of quick 

 lime, but at some localities it is too argillaceous, and when burned does not 

 slack readily, and might make a good hydraulic cement, to which it seems best 

 adapted. The limestone above No. 7 coal, is generally a purer carbonate of 

 lime than any other of the Coal Measure limestones in this county, and might 

 be extensively used in the vicinity of Farmington for lime burning. 



Sand and Clay for Brick. These materials are abundant on all the uplands 

 in the county. On the bluff lands, adjacent to the Illinois river, the Loess 

 affords an excellent material for this purpose, in which the ingredients are 

 often mixed in just the right proportions. The sub-soil of the prairies, and of 

 the oak ridges, furnish an abundance of brown clay, which, mingled with sand, 

 that is abundant in the beds of the streams, forms a good material for this 

 purpose. These materials are so universally distributed, that they may be 

 readily found in every neighborhood, and on almost every farm in the county. 



Soil and Agriculture, There is considerable variety in the soils of this 

 county, though there are none so poor that they will not produce good crops 

 annually of most of the cereals usually grown in this region, when judiciously 

 cultivated. The most productive soils are those covering the prairie lands, and 

 those underlaid by the Loess, in the vicinity of the river bluffs. The latter 

 were originally covered with a heavy growth of timber, consisting of sugar- 

 maple, black and white walnut, linden, elm, hackberry, wild cherry, honey- 

 locust, black and white oak, and two or three varieties of hickory. This is the 

 character of the best lands in the vicinity of Lewiston, and over a considerable 

 area along the eastern borders of the county. They produce quite as heavy 

 crops of corn, wheat, oats, barley and grass, as the best prairie soil, and are 

 much better adapted to the growth of fruit, especially grapes and apples. The 

 peach seems to grow equally well on the prairie, though it is doubtful whether 

 the trees would live as long, or produce as freely, as on the timbered lands. 

 The prairie lands are very productive, and have a deep chocolate brown or black 

 loamy soil, rich in organic matters, and when sufficiently rolling, produce 

 annually large crops of corn and grass. Wheat is a far more uncertain crop 

 on the prairie soil than on lands originally covered with timber. The poorest 

 lands in the county are the white oak ridges, that skirt the borders of the 

 small streams. These lands have a thin soil, with a stiff clay sub-soil, but will 

 produce fair crops of wheat, oats and clover, and are also equal, if not superior, 

 to the prairie lands for the growth of fruit. They require a more generous 

 treatment, and are greatly benefited by occasional fallowing, and plowing under 

 green crops. 



For the following complete list of the forest trees and shrubs indigenous to 

 this county, I am indebted to Mr. John Wolf, of Canton, whose quiet and un- 

 obtrusive labors in botany, geology, and conchology, have resulted in import- 



