PREFACE TO THE SIXTH EDITION. *

I. THE CONSTITUTION OF NATURE. *

II. RADIATION. *

1. Visible and Invisible Radiation. *

2. Origin and Character of Radiation. The Aether. *

3. The Atomic Theory in reference to the Aether. *

4. Absorption of Radiant Heat by Gases. *

5. Formation of Invisible Foci. *

6. Visible and Invisible Rays of the Electric Light. *

7. Combustion by Invisible Rays. *

8. Transmutation of Rays: Calorescence. *

9. Deadness of the Optic Nerve to the Calorific Rays. *

10. Persistence of Rays. *

11. Absorption of Radiant Heat by Vapours and Odours. *

12. Aqueous Vapour in relation to the Terrestrial Temperatures. *

13. Liquids and their Vapours in relation to Radiant Heat. *

14. Reciprocity of Radiation and Absorption. *

15. Influence of Vibrating Period and Molecular Form. Physical Analysis of the Human Breath. *

16. Summary and Conclusion. *

III. ON RADIANT HEAT IN RELATION TO THE COLOUR AND CHEMICAL CONSTITUTION OF BODIES. *

IV. NEW CHEMICAL REACTIONS PRODUCED BY LIGHT. *

1. DECOMPOSITION BY LIGHT. *

§ 2. ON THE BLUE COLOUR OF THE SKY, AND THE POLARISATION OF SKYLIGHT. *

§ 3. THE SKY OF THE ALPS. *

V. ON DUST AND DISEASE. *