From our notes taken upon the spot, we give a few items more in detail of Mr. Newton's operations, than he has done in the preceding quotations. The tract of land he speaks of is gently undulating; of a sandy loam, with a greater amount of clay in the subsoil; had been literally _worn out_ in former years by the shallow plowing, skinning system of farming, until it would produce no more, when it was abandoned and suffered to grow up again in forest timber, principally pine of the "old field" species. No land could offer less inducements to the cultivator or give smaller hope of renovation, than these old fields of Virginia. Such was the conviction of impossibility to raise a crop upon this kind of land, that Mr. Newton's first essay was looked upon by his neighbors with a conviction that the fool and his money would soon part company. One sensible old servant told us he thought his master "for sartain was done gone crazy, cause he nebber seed no nothing grow on dat land, no how could fix him." The negroes, wherever guano has been introduced, have been violently opposed to using it; not alone from its disagreeable odor and effect upon the throat and nostrils while handling it in a dry state; but because they could not be persuaded that such a small measure of stuff--200 lbs. measures about three bushels--could possibly produce any effect upon the crop. Their astonishment and consequent extravagant laudation of the effect produced, has often afforded us hours of amusement while listening to their recital of "massa's big crop," of perhaps ten bushels to the acre, which was at least double that of any one ever seen upon the same field, "fore he put dem little pinch of snuff on him." _The increase of wheat from guano_ may be safely calculated upon at five bushels for each hundred weight of guano used, one year with another, and up to what may be considered a fair judicious amount to be applied, which may be set down at an average of 200 lbs to the acre, upon all light soils, similar to those of that part of the country we are writing about. GUANO vs. MANURE--EFFECTS UPON HEAVY LAND.