CHAPTER X.

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, 173-189