NOTE BY THE AUTHOR. In the present Manual of GEOLOGY it has been the aim of the author rather to indicate the methods of geological inquiry and reasoning, than to present the learner with a tedious summary of results. Attention has therefore been directed chiefly to the physical branches of the science--Palæontology and Historical Geology, which are very large subjects of themselves, having been only lightly touched upon. The student who has attained to a fair knowledge of the scope and bearing of Physical Geology, should have little difficulty in subsequently tackling those manuals in which the results obtained by geological investigation are specially treated of. CONTENTS. PAGE INTRODUCTORY 7 CLASSIFICATION OF ROCKS 8 MINERALOGY 12 ROCK-FORMING MINERALS 14 PETROLOGY-- MECHANICALLY FORMED ROCKS 17 CHEMICALLY FORMED ROCKS 19 ORGANICALLY DERIVED ROCKS 20 METAMORPHIC ROCKS 21 IGNEOUS ROCKS 23 STRUCTURE AND ARRANGEMENT OF ROCK-MASSES-- Stratification, &c.; Mud-cracks and Rain-prints; Succession of Strata; Extent of Beds; Sequence of Beds--Joints; Cleavage; Foliation; Concretions; Inclination of Strata; Contemporaneous Erosion; Unconformability; Overlap; Faults; Mode of Occurrence of Metamorphic and Igneous Rocks; Mineral Veins 26-46 DYNAMICAL GEOLOGY-- THE ATMOSPHERE AS A GEOLOGICAL AGENT OF CHANGE 46 WATER AS A GEOLOGICAL AGENT OF CHANGE 48 GEOLOGICAL ACTION OF PLANTS AND ANIMALS 60 SUBTERRANEAN FORCES 64 METAMORPHISM 72 PHYSIOGRAPHY 74 PALÆONTOLOGY 77 HISTORICAL GEOLOGY 84 QUESTIONS 89 [Illustration: GEOLOGY] INTRODUCTORY.