Note to the American Edition, v

Preface, vii

Chapter

I.—What is Energy? 1

II.—Mechanical Energy and its Change into Heat, . . 23

III.—The Forces and Energies of Nature: the Law of Conservation, 48

IV.—Transmutations of Energy, 87

V.—Historical Sketch: the Dissipation of Energy, . .131

VI.—The Position of Life, 154

Appendix

I.—Correlation of Vital with Chemical and Physical Forces. By Joseph Le Conte, Professor of Geology and Natural History in the University of California, .... 171

II.—Correlation of Nervous and Mental Forces. By Alexander Bain, Professor of Logic and Mental Philosophy in the University of Aberdeen, 205