having separated the nutritive portion, they eject at the mouth of their burrows the remainder in little intestine-shaped heaps. The worm being unable to swallow large particles, and as it would naturally avoid lime and other noxious matters, the fine earth beneath those things would by a slow but certain process be removed and thrown to the surface. The earthworm, moreover, requires moisture, and in dry weather finds it necessary to burrow beneath the parched surface; and the depth to which these animals descend to avoid the drought of summer and the frosts of winter, is frequently very great. This agency, trifling as it might at first be thought, is not so slight, the great number of earthworms (as every one must be aware who has ever dug in a grass field) making up for the insignificant quantity of work which each performs. The rapidity with which the operation is sometimes carried on, in soils of favourable description, is astonishing; a very few years comparatively being sufficient to bury the refuse matters beneath the whole of the surface soil. In one field chalked fourteen years since, the chalk now forms a perfect layer about twelve inches beneath the surface. In another instance the chalk was buried three inches in ten years. The time required for the work varies much with the nature of the soil.
The circumstances already stated will therefore indicate that amongst the Romanized Britons, in the remote vales of Kimmeridge and Worthbarrow, an establishment was founded for the manufacture of ornaments, amulets, beads, and other articles, out of the easily worked material here provided by the hand of nature; and the great quantity of fragmental ware here found, the charcoal and coal ashes, of which great quantities have been exhumed, and other local indications, render it not unlikely that a pottery had been previously founded in this locality, to render available the convenient contiguity of the Purbeck clay and the Kimmeridge coal, and that accidental circumstances had demonstrated the facility with which the coal might be converted into articles of utility or ornament, and thus suggested the manufactory which, we have seen, was here established. JOHN SYDENHAM.
