144 Hugh Taylor, Esq., on the Chemical ConslitiiHon 



No. 4. Bituminous Shale. — Sp. gr. 1'860 ; rests on coarse coal ; 

 two to three mches in thickness ; black, hard, and brittle, of a slaty 

 structure ; contains impressions of the Flora of the period. 



100011 



No. 5. Blue Shale (Slate-clay.) — Sp. gr. 2*536 ; in thickness 

 about three feet ; of a bluish-grey colour ; is of a much more earthy 

 appearance than last, on which it rests, is softer and not so slaty, 

 and is studded with nodules of ironstone. Is nearly related to the 

 fire-clay, both in composition and physical properties. 



Composition. 



100-000 



No. 6. Micaceous Sandstone.— Sp. gr. 2-598, over last, varying 

 from six inches to six feet in thickness; of a fine white colour, 

 close-grained, and with small plates of mica, very conspicuously 

 seen . 



