VOLUME 1

Introduction 5 Atomic Weights 6 Electricity 11 Units of Electricity 11 Cathode Rays 13 Radioactivity 17 The Structure of the Atom 25 Atomic Numbers 30 Isotopes 35 Energy 47 The Law of Conservation of Energy 47 Chemical Energy 50 Electrons and Energy 54 The Energy of the Sun 55 The Energy of Radioactivity 57