XVili CONTENTS. 
PAGE 
ily peculiarly characteristic of the System. — No intervening 
Formation between the Old Red Sandstone and the Coal Meas- 
ures. — The Holoptychius contemporary for a time with the 
Megalichthys. — The Columns of Tubal-Cain, . . 151-172 
CHAPTER. A. 
Speculations in the Old Red Sandstone, and their Character. — 
George, first Earl of Cromarty. — His Sagacity as a Naturalist 
at fault in one instance. — Sets himself to dig for Coal in the 
Lower Old Red Sandstone. — Discovers a fine Artesian Well. 
— Value of Geological Knowledge in an economic view. — 
Scarce a Secondary Formation in the Kingdom in which Coal 
has not been sought for. — Mineral Springs of the Old Red 
Sandstone. — Strathpeffer. — Its Peculiarities whence derived. 
— Chalybeate Springs of Easter Ross and the Black Isle. — 
Petrifying Springs. — Building-Stone and Lime of the Old 
Red Sandstone. -—Its various Soils, fea : P - 173-189 
CHAy +B as. 
Geological Physiognomy. — Scenery of the Primary Formations ; 
Gneiss, Mica Schist, Quartz Rock.— Of the Secondary ; the 
Chalk Formations, the Oolite, the New Red Sandstone, the 
Coal Measures. — Scenery in the Neighborhood of Edinburgh. 
— Aspect of the Trap Rocks. — The Disturbing and Denuding 
Agencies. — Distinctive Features of the Old Red Sandstone. — 
Of the Great Conglomerate. — Of the Ichthyolite Beds. — The 
