CONTENTS. 



PART L 



CHAPTER I. 



SCIENCES AUXILIARY TO GEOLOGY. 



Definition. — Physical Properties : Extension, Gravity, Impene- 

 trability, Divisibility, Porosity, Indestructibility, Inertia 



Page 9 



CHAPTER II. 



CHEMICAL CONSTITUTION OF THE EARTH'S SURFACE. 



Definition. — Four Elements according to the Ancients.—Chief 

 Chemical Elements which enter into the Earth's Crust : Ox- 

 ygen, Hydrogen, Nitrogen, Carbon, Sulphur, Chlorine, Fluo- 

 rine, Phosphorus. — Metallic Bases of the Alkalies and Earths : 

 Silica, Alumina, Potassium, Sodium, Magnesium, Calcium. — 

 Imponderable Agents : Heat, Light, Electricity, Galvanism. — 

 Thermometer. — Affinity. — Cohesion. — Illustrations. — Com- 

 pound Elective Affinity. — Cases 18 



CHAPTER III. 



MINERALOGICAL CONSTITUTION OF THE EARTH*S SURFACE. 



Simple Minerals : Quartz, Feldspar, Mica, Talc, Chlorite, Horn- 

 blende, Serpentine, Limestone, Slate and Clay, and Augite. 

 — Minerals found in Veins or Beds : Iron, Lead, Gold, Silver, 

 Tin, Copper, Zinc, Mercury, Manganese, Titanium, Bismuth, 

 Antimony, Cobalt 33 



CHAPTER lY. 



PHYSICAL GEOGRAPHY OF THE EARTH. 



Shape of the Earth. — Mean Density.— Ocean. — Mean Depth*. — 

 Saline Contents.— Mediterranean. — Temperature of Earth. — 

 Reason for Supposing it has undergone d Change. — Central 

 Heat.-*Facts to support such a Theory.— -Infiuence of Climato 

 A 



