CONTENTS. 
Preface, 3 
Objects and Methods of Geology, 9 
Of the Earth as a Mass, 13 
Primary Classification of Rocks, 18 
Of Mineral Beds or Strata, 19 
Composition and Structure of the Rocks — Werner, - - 21 
Werner's Theory, --------- 22 
Of Granite, 24 
Of Gneiss, 27 
Of Mica Slate or Micaceous Schistus, ----- 29 
Of the Simple Primitive Rocks — Serpentine, Limestone, Clay 
Slate, etc., ---..----30 
Of the Transition Rocks, 32 
Of Argillaceous Schistus or Clay Slate, 33 
Of the Sandstones, ---------35 
Of the Secondary and Tertiary Rocks and Strata, 37 
Of the Overlying and Volcanic Rocks, - - ■ - - 38 
Influence of the Rocks upon the fertility of the Soils produced 
by them, 39 
Of Metallic Veins and Beds of Valuable Minerals, - - - 43 
Distribution of Metallic Veins and Mineral Beds, through the 
Strata, ---------- 47 
Secondary Strata of England, ------- 50 
Of Fossil Salt and Gypsum, -------52 
Of Mineral Coal, - - 55 
Theoretical Geology — Introduction, ----- 60 
Hutton's Theory, - 62 
Causes of Geological Changes, -----, 64 
Volcanoes, .--......- 69 
Earthquakes, - ---75 
Of the Causes of the Phenomena of Volcanoes, - - . - 77 
Changes produced by Volcanoes and Earthquakes, - - - 80 
