A curious mineral is found in some of the Aldstone moor veins. It consists chiefly of indurated clay with a mixture of iron; is of a smoke-grey colour, very hard and sonorous, and is intersected by deep impressions of tabular crystals of heavy spar, which have in some unknown manner been decomposed.
I am not informed of more than six mineral springs in the district of the lead-mine measures, and of these only two have attained any degree of celebrity. These are the springs of Gilsland and Wardrew, which were analyzed in 1799 by the late Dr. Garnet. The sulphuretted water issues from a thick bed comprising 3 distinct strata of shale, which is covered by several measures of sandstone, forming together a perpendicular cliff about 90 feet in height on the north bank of the little river Irthing. Two gallons and a half of water