INTRODUCTORY.
Natural Advantages of the Territory of the Roman Empire—Physical Decay of that Territory and of other parts of the Old World—Causes of the Decay—New School of Geographers—Reaction of Man upon Nature—Observation of Nature—Cosmical and Geological Influences—Geographical Influence of Man—Uncertainty of our Meteorological Knowledge—Mechanical Effects produced by Man on the surface of the Earth—Importance and Possibility of Physical Restoration—Stability of Nature—Restoration of Disturbed Harmonies—Destructiveness of Man—Physical Improvement—Human and Brute Action Compared—Forms and Formations most liable to Physical Degradation—Physical Decay of New Countries—Corrupt Influence of Private Corporations, Note, [1]
TRANSFER, MODIFICATION, AND EXTIRPATION OF VEGETABLE AND OF ANIMAL SPECIES.
Modern Geography embraces Organic Life—Transfer of Vegetable Life—Foreign Plants grown in the United States—American Plants grown in Europe—Modes of Introduction of Foreign Plants—Vegetables, how affected by transfer to Foreign Soils—Extirpation of Vegetables—Origin of Domestic Plants—Organic Life as a Geological and Geographical Agency—Origin and Transfer of Domestic Animals—Extirpation of Animals—Numbers of Birds in the United States—Birds as Sowers and Consumers of Seeds, and as Destroyers of Insects—Diminution and Extirpation of Birds—Introduction of Birds—Utility of Insects and Worms—Introduction of Insects—Destruction of Insects—Reptiles—Destruction of Fish—Introduction and Breeding of Fish—Extirpation of Aquatic Animals—Minute Organisms, [57]
THE WOODS.
The Habitable Earth originally Wooded—The Forest does not furnish Food for Man—First Removal of the Woods—Effects of Fire on Forest Soil—Effects of the Destruction of the Forest—Electrical Influence of Trees—Chemical Influence of the Forest.
Influence of the Forest, considered as Inorganic Matter, on Temperature: a, Absorbing and Emitting Surface; b, Trees as Conductors of Heat; c, Trees in Summer and in Winter; d, Dead Products of Tree; e, Trees as a Shelter to Grounds to the leeward of them; f, Trees as a Protection against Malaria—The Forest, as Inorganic Matter, tends to mitigate extremes.