CONTENTS. 



I. THE CONSTITUTION OF NATURE, . . 1 



II. THOUGHTS ON PRAYER AND NATURAL LAW, . . 33 



III. MIRACLES AND SPECIAL PROVIDENCES, . . , .43 



^ IV. MATTER AND FORCE, . . . . . 71 



V. AN ADDRESS TO STUDENTS, . . . . .95 



VI. SCOPE AND LIMIT OF SCIENTIFIC MATERIALISM, . 107 



x VII. SCIENTIFIC USE OF THE IMAGINATION, . . .125 



VIII. ON RADIATION, ..... 1C7 



IX. ON RADIANT HEAT IN RELATION TO THE COLOR AND CHEMI- 

 CAL CONSTITUTION OF BODIES, . . .211 

 1L ON CHEMICAL RATS AND THE STRUCTURE AND LIGHT OF 



THE SKY, . . . . . .235 



XI. DUST AND DISEASE, ..... 275 



ADDITION TO "DUST AND DISEASE," . . . 323 



XII. LIFE AND LETTERS OF FARADAY, . . . 329 



XIII. AN ELEMENTARY LECTURE ON MAGNETISM, . . 353 

 XIV. SHORTER ARTICLES : 



SLATES, 377 



DEATH BY LIGHTNING, .... 397 



SCIENCE AND SPIRITS, .... 402 



VITALITY, . . . . . . 410 



ADDITIONAL REMARKS ON MIRACLES, . 418 



