official name of the earth of which we now make tobacco-pipes. Its distinguishing characters are, that it is a dense, compact, heavy earth, of a dull white colour, and very close texture, not easily frangible between the fingers, and slightly staining the skin in handling. It adheres firmly to the tongue, melts very slowly in the mouth, and is not readily diffusible in water. It is found in many places. That of the Isle of Wight is much esteemed for its colour. It is found in great abundance near Pole in Dorsetshire, and near Wedensbury in Staffordshire.

Cimolia Nigra is of a dark lead colour, hard, dry, and heavy, of a smooth compact texture, and not viscid. It does not colour the hands, crumbles when dry, adheres to the tongue, diffuses slowly in water, and is not acted upon by acids. It burns perfectly white, and acquires a considerable hardness. The chief pits for this clay are near Northampton, where it is used in the manufacture of tobacco-pipes. It is also mixed with the critche clay of Derbyshire, in the proportion of one part to three, in the manufacture of the hard reddish-brown ware.