CONTENTS. 



Chapter I. — On the Different Classes of Rocks. 



Geology defined — Successive formation of the earth's crust — Classification of rocks 

 according to their origin and age — Aqueous rocks — Their stratification and im 

 bedded fossils — Volcanic rocks, with and without cones and craters — Plutonic 

 rocks, and their relation to the volcanic — Metamorphic rocks, and their probable 

 origin — The term "Primitive," why erroneously applied to the crystalline forma- 

 tions — Leading division of the work, - page 1 



Chapter II. — Aqueous Rocks — Their Comjiosition and Forms of Stratification. 



Mineral composition of strata — Arenaceous rocks — Argillaceous — Calcareous — Gyp- 

 sum — Forms of stratification — Original horizontally — Thinning out — Diagonal 

 arrangement — Ripple mark, - - - - - 10 



Chapter III. — Arrangement of Fossils in Strata — Freshicater and Marine. 



Successive deposition indicated by fossils — Limestones formed of corals and shells 

 — Proofs of gradual increase of strata derived from fossils — Serpula attached to 

 spatangus — Wood bored by teredina — Tripoli and semi-opal formed of infusoria 

 — Chalk derived principally from organic bodies — Distinction of freshwater from 

 marine formations — Genera of freshwater and land shells — Rules for recognizing 

 marine testacea — Gyrogonite and chara — Freshwater fishes — Alternation of ma- 

 rine and freshwater deposits — Lym-Fiord, - - - - 21 



Chapter FY — Consolidation of Strata and Petrifaction of Fossils. 



Chemical and mechanical deposits — Cementing together of particles — Hardening by 

 exposure to air — Concretionary nodules — Consolidating effects of pressure — Min- 

 eralization of organic remains — Impressions and casts how formed — Fossil wood 

 — Goppert's experiments — Precipitation of stony matter most rapid where putre- 

 faction is going on — Source of lime in solution — Silex derived from decomposi- 

 tion of felspar — Proofs of the lapidification of some fossils soon after burial, of 

 others when much decayed, - - - - - - 33 



Chapter V. — Elevation of Strata above the Sea — Horizontal and Inclined Stratifi- 

 cation. 



Why the position of marine strata, above the level of the sea, should be referred to 

 the rising up of the land, not to the going down of the sea — Upheaval of exten- 

 sive masses of horizontal strata — Inclined and vertical stratification — Anticlinal 

 and synclinal lines — Bent strata in east of Scotland — Theory of folding by 

 lateral movement — Creeps — Dip and strike — Structure of the Jura — Yarious 



