So much the worse for them! I insist on only saying what I know; but I do say this. And if what I know is displeasing, so much the worse for the prejudices, the general ignorance, and the good breeding of these distinguished gentry, in whose eyes the maximum of happiness consists in an increase of their fortune, the pursuit of lucrative places, sensual pleasures, automobile-racing, a box at the Opera, or five-o'clock teas at a fashionable restaurant, and whose lives are frittered away along paths that never cross those of the rapt idealist, and who never know the pure satisfaction of his mind and heart, or the pleasures of thought and feeling. As for me, a humble student of the prodigious problem of the universe, I am only a seeker. What are we? We have scarcely shed a ray more of light on this point than at the time when Socrates laid down, as a principle, the maxim, _Know thyself_,--notwithstanding we have measured the distances of the stars, analyzed the sun, and weighed the worlds of space. Does it stand to reason that the knowledge of ourselves should interest us less than that of the macrocosm, the external world? It is not credible. Let us therefore study on, convinced that all sincere research will further the progress of humanity. _Juvisy Observatory, December, 1906._ CONTENTS PAGE PREFACE v INTRODUCTION xiii CHAPTER I. On Certain Unknown Natural Forces 1 II. My First Seances In The Allen Kardec Group, And With The Mediums Of That Epoch 24 III. My Experiments With Eusapia Paladino 63 IV. Other Seances With Eusapia Paladino 135 V. Frauds, Tricks, Deceptions, Impostures, Feats Of Legerdemain, Mystifications, Impediments 194 VI. The Experiments Of Count De Gasparin 229 VII. The Researches Of Professor Thury 266 VIII. The Experiments Of The Dialectical Society Of London 289 IX. The Experiments Of Sir William Crookes 306 X. Sundry Experiments And Observations 352 XI. My General Inquiry Respecting Observations Of Unexplained Phenomena 376 XII. Explanatory Hypotheses--Theories And Doctrines-- Conclusions Of The Author 406 INDEX 455 LIST OF ILLUSTRATIONS Plate I. Complete Levitation of a Table in Professor Flammarion's Salon through Mediumship of Eusapia Paladino _Facing page_ 8