COMMON FLINTY-SLAT£: Geographic Situation. It occurs in different parts of the great tract of transi tion mountains which extends from St Abb’s Head to ^ T ew Galloway; also in the Pentland and Moorfoot Hills near Edinburgh. v It is also found in Norway, Saxony, Bohemia, Silesia, Franee, and other countries. Observations. 1. It is distinguished from Splintery'Hornstone, with ^hich it has been confounded, by its colours being in ge neral darker, its glimmering internal lustre, its slaty frac ture, its lamellar concretions, and its geognostic rela tions. Colour, lustre, translucencv, and more difficult trangibility, distinguish it from Lydian-stone. ( 2. In early writings it is named IIorn-Slate, r (Horn- s chiefer) ; under which denomination mineralogists in cluded a variety of slaty rocks, as Porphyry-slate, and Greenstone. Werner first accurately described it, and S a ve it its present name and place in the system. /Second