CONTENTS 
Preface, 
Objects and Methods of Geology, ------ o 
Of the Earth as a Mass, - - - - - - - -13 
Primary Classification of Rocks, - - - - - - 18 
Of Mineral Beds or Strata, i<) 
Composition and Structure of the Rocks—Werner, - - 21 
Werner’s Theory, --------- 22 
Of Granite, ......... 2i 
01 Gneiss, .......... 
Of Mica Slate or Micaceous Schistus, ----- 29 
Of the Siinjtle Primitive Rocks—Serpentine, Limestone, Clay 
Slate, etc., ---. .----30 
Of the Transition Rocks, ------- 32 
Of Argillaceous Schistus or Cla_v Slate, - - - - 33 
Of the Saiulstones, --------- 3o 
Of the Secondary and Tertiary Rocks and Strata, - - - 37 
Of the Overlying and Volcanic Rocks, - - • - - 38 
Inlluence of the Rocks upon the fertility' of the Soils produced 
by them, - -- -- -- --39 
Of Metallic V'eins and Beds of Valuable Minerals, - - - 43 
Distribution of Metallic Veins and Mineral Beds, through the 
Strata, ---------- 47 
Secondary Strata of England, ------- .59 
Of Fossil Salt and Gypsum, ------- 52 
Of Mineral Coal, - - ------- ,57 
Theoretical Geology—Introduction, ----- (jo 
Hutton’s Theory', --------- 92 
Causes of Geological Changes, ------ 94 
Volcanoes, ---------- 99 
Earthquakes, ......... 
Of the Causes of the Phenomena of Volcanoes, - - . - 77 
Changes produced by Volcanoes and Earthquake®, - ' - 89 
