Historical.

Measurement of the Intensity of Radiation.

Radio-activity of the Compounds of Uranium and Thorium.

Is Atomic Radio-activity a general Phenomenon?

Radio-active Minerals.

Polonium, Radium, Actinium.

Spectrum of Radium.

Extraction of the New Radio-active Substances.

Polonium.

Preparation of the Pure Chloride of Radium.

Determination of the Atomic Weight of Radium.

Characteristics of the Radium Salts.

Fractionation of Ordinary Barium Chloride.

Methods of Investigation of the Radiation.

Energy of Radiation.

Complex Nature of the Radiation.

Action of the Magnetic Field.

Deflected β-Rays.

Charge of the Deflected Rays.

Action of the Electric Field upon the Deflected β-Rays of Radium.

Relation of the Charge to the Mass for a Particle Negatively Charged Emitted by Radium.

Action of the Magnetic Field upon the α-Rays.

Action of the Magnetic Field on the Rays of other Radio-active Substances.

Proportion of β-Rays in the Radiation of Radium.

Penetrating Power of the Radiation of Radio-active Bodies.

Ionising Action of Radium Rays on Insulating Liquids.

Various Effects and Applications of the Ionising Action of the Rays Emitted by Radio-active Substances.

Fluorescent and Luminous Effects.

Evolution of Heat by the Salts of Radium.

Chemical Effects produced by the New Radio-active Bodies.

Physiological Effects.

Influence of Temperature upon Radiation.

Activity Induced in an Enclosed Space.

Part played by Gases in the Phenomena of Induced Radio-activity.

Dissipation in Free Air of the Induced Activity of Solid Bodies.

Dissipation of Activity in a Confined Space. Velocity of Destruction of the Emanation.

Variation of Activity of Liquids rendered Active and of Radium Solutions.

Theory of Radio-activity.

Another Form of Induced Radio-activity.

Induced Radio-activity with Slow Dissipation.

Radio-activity Induced upon Substances in Solution with Radium.

Dissemination of Radio-active Particles and Induced Radio-activity of the Laboratory.

Activity Induced Outside the Influence of Radio-active Substances.

Variations of Activity of Radio-active Bodies. Effects of Solution.

Variations of the Activity of Radium Salts on Heating.

Theory of Interpretation of the Causes of Variations of Activity of Radium Salts after Solution and after Heating.

Nature and Cause of the Phenomena of Radio-activity.

Conclusions.