CONTENTS. 
PART L 
CHA.PTER I. 
SCIENCES AUXILIARY TO GEOLOGY. 
Definition.— Physical Properties : Extension, Gravity, Impen«)* 
trability, Divisibility, Porosity, Indestructibility, Inertia 
Page 9 
CHAPTER IL 
CHEMICAL CONSlTITUTION 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 HI. 
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 38 
CHAPTER IV. 
PHYSICAL GEOGRAPHY OF THE fiARTtt. 
Shape of the Earth.— Mean Density. — Ocean. — Mean Depth.— ^ 
Sahne Contents. — Mediterranean. — Temperature of Earth. — 
Reason for Supposing it has undergone a Change.— Central 
Heat. — Facts to support such a Theory. — Influence of Climate 
A 
