Page:A tour through the northern counties of England, and the borders of Scotland - Volume I.djvu/107

 quitting this place, we dropped the sandy soil which had accompanied us for several miles, and entered upon a stiff clay, the external covering to these productive mines of coals, and that peculiar nodulated iron ore, which now began to appear on all sides of us.

The locality of coal and ore in these parts is somewhat singular, since they only extend to the distance of about six miles round Dudley, and are then lost, and succeeded by sand. Indeed, the whole geology of this district is curious, and well deserves the attention of the naturalist. Fortunately for the lovers of science, its peculiarities have been ably developed by Mr. Keir, the celebrated chemist and natural philosopher; whose paper on this subject makes the most valuable feature in the History of Staffordshire. A constant resident on the spot, and an attentive observer of the phenomena it presents, his observations form a complete history of local geology, and afford an admirable model for writers on the same subject who, instead of extending their remarks so widely as they are accustomed to do, and attempting general geological histories, would do well to embrace merely the district within their own constant observation; and when facts have thus been