It has already been mentioned, that the predominant soil to the eastward of the Blue Ridge is a red earth, and that it is always a matter of some difficulty to lay down a piece of land in grass, on account of the rains, which are apt to wash away the seeds, together with the mould on the surface. In Bottetourt County, on the contrary, the soil consists chiefly of a rich brown mould, and throws up white clover spontaneously. To have a rich meadow, it is only necessary to leave a piece of ground to the hand of nature for one year. Again, on the eastern side of the Blue Mountains, scarcely any limestone is to be met with; on the opposite one, a bed of it runs entirely through the country, so that by some it is emphatically called the limestone county. In sinking wells, they have always to dig fifteen or twenty feet through a solid rock to get at the water. [Sidenote: INSECTS.] Another circumstance may also be mentioned, as making a material difference between the country on one side of the Blue Ridge and that on the other, namely, that behind the mountains the weevil is unknown. The weevil is a small insect of the moth kind, which deposits its eggs in the cavity of the grain, and particularly in that of wheat; and if the crops are stacked or laid up in the barn in sheaves, these eggs are there hatched, and the grain is in consequence totally destroyed. To guard against this in the lower parts of Virginia, and the other states where the weevil is common, they always thresh out the grain as soon as the crops are brought in, and leave it in the chaff, which creates a degree of heat sufficient to destroy the insect, at the same time that it does not injure the wheat. This insect has been known in America but a very few years; according to the general opinion, it originated on the eastern shore of Maryland, where a person, in expectation of a great rise in the price of wheat, kept over all his crops for the space of six years, when they were found full of these insects; from thence they have spread gradually over different parts of the country. For a considerable time the Patowmac River formed a barrier to their progress, and while the crops were entirely destroyed in Maryland, they remained secure in Virginia; but these insects at last found their way across the river. The Blue Mountains at present serve as a barrier, and secure the country to the westward from their depredations[24]. Footnote 24: