CONTENTS. 



I. — The Constitution of Nature, ... .7 



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, . 10*7 



VII. — Scientific Use of toe Imagination, . . .125 



VIII.— On Radiation, . . . . .167 



IX. — On Radiant Heat in Relation to the Color and Chemi- 

 cal Constitution of Bodies, . . .211 

 X. — On Chemical Rays and the Structure and Light of 



the Sky, ...... 235 



XI. — Dust and Disease, ..... 2*75 



Addition to " Dust and Disease," . . . 323 



XII. — Life and Letters of Faraday, . . . 329 



XIII. — An Elementary Lecture on Magnetism, . . 353 



XIV. — Snop.TER Articles : 



Slates, ...... 37*7 



Death by Lightning, .... 397 



Science and Spirits, .... 402 



Vitality, ...... 410 



Additional Remarks on Miracles, . . 418 



