Produced by Jon Richfield FRAGMENTS OF SCIENCE: A Series of Detached ESSAYS, ADDRESSES, AND REVIEWS. BY JOHN TYNDALL, F.R.S. Printed By Spottiswoode AND CO. NEW-STREET SQUARE PARLIAMENT STREET SIXTH EDITION, VOL. 1. LONDON: LONGMANS, GREEN, AND CO. 1879. All rights reserved. PREFACE TO THE SIXTH EDITION. VOL. I. INORGANIC NATURE. 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. Figure 1 Spectrum of 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. Physical Considerations. Production of Sky-blue by the Decomposition of Nitrite of Amyl. 2. ON THE BLUE COLOUR OF THE SKY, & THE POLARISATION OF SKYLIGHT. 3. THE SKY OF THE ALPS. V. ON DUST AND DISEASE. Experiments on Dusty Air. The Germ Theory of Contagious Disease. Parasitic Diseases of Silkworms. Pasteur's Researches. Origin and Propagation of Contagious Matter. The Germ Theory applied to Surgery. The Luminous beam as a means of Research. The Floating Matter of the Air. Dr. Bennett's Experiments. Application of Luminous beams to Water. Chalk-water. Clark's Softening Process. Cotton-wool Respirator. Fireman's Respirator. Helmholtz on Hay Fever. VI. VOYAGE TO ALGERIA TO OBSERVE THE ECLIPSE. VII. NIAGARA. VIII THE PARALLEL ROADS OF GLEN ROY. IX. ALPINE SCULPTURE. X. RECENT EXPERIMENTS ON FOG-SIGNALS. XI. ON THE STUDY OF PHYSICS. XII. ON CRYSTALLINE AND SLATY CLEAVAGE. XIII. ON PARAMAGNETIC AND DIAMAGNETIC FORCES. XIV. PHYSICAL BASIS OF SOLAR CHEMISTRY. XV. ELEMENTARY MAGNETISM. XVI. ON FORCE. XVII. CONTRIBUTIONS TO MOLECULAR PHYSICS. XVIII. LIFE, AND LETTERS OF FARADAY. XIX. THE COPLEY MEDALIST OF 1870. XX. THE COPLEY MEDALIST OF 1871.