The soil. What shall be said of it? The Delta of the Nile, in its original opulence, was not more fertile. It consists of a rich, black, vegetable mould, from one to six feet in depth, resting upon a sub-soil of stiff clay. Its surface has as yet been only scratched. When this shall be expended, the wealth below can be brought to light by the sub-soil plow, an instrument as unfamiliar here as the Koo-i-noor. An intelligent farmer in La Salle County--an old resident--has been experimenting upon a piece of land of a few acres, by planting and harvesting a succession of corn crops, without fertilizers, for a series of years.--As yet he has found no diminution of yield. All the cereals, fruits and esculent roots, adapted to the climate, produce in perfection and abundance.--Winter blight and rust are incident to wheat culture every where, here as well as in other sections; but insects--the grasshopper, army worm, midge and weavel--have never yet made their appearance. The corn crop never fails. In two seasons out of the last twenty, a slight diminution of yield occurred--in one year by protracted rains preserving the esculency of the plant until the season of frost, and in another by drought.--With these exceptions, it has grown and ripened in all its perfection. Of course, crops are "short" with some people always. The Hibernian said that he believed that "if the steamboat never sailed somebody would be left;" so if the frost never comes, somebody's corn will be caught. So, too, the disposition among farmers to complain of short crops is chronic, here as elsewhere. If the statistics, gathered by means of agricultural fairs or otherwise, do not exhibit so large yields per acre, as in places where land is dearer, it must be recollected that cultivation is as yet conducted only in a very rude manner. No application to the soil of materials whereof it is deficient, for the production of certain crops, was ever dreamed of. None of the high cultivation, adopted where that practice is a necessity, is ever resorted to. No portions of the three counties named are more than ten miles distant from some rail road station, or river, or canal landing, at all of which a cash market is found for every kind of farm produce, and a supply of all kinds of "store goods" is for sale. Leading to these are roads whereon the low places have been turnpiked, and the sloughs and streams bridged, and which, if not so solid and smooth, in wet weather, as those over the flinty or gravelly soil of some portions of the eastern States, are infinitely superior to those corduroy affairs, running through the timbered regions of Ohio, Indiana and Michigan. In dry weather, no McAdam, no pavement, no Imperial causeway is so smooth, so even, so easy, so noiseless as the slightly elastic prairie road bed. Talk of two-forty on the Avenue! A natural prairie road is the paradise of Jehus.