My principal object will be to place on record a series of actual occurrences which have taken place in my own house, in the presence of trustworthy witnesses, and under as strict test conditions as I could devise. Every fact which I have observed is, moreover, corroborated by the records of independent observers at other times and places. It will be seen that the facts are of the most astounding character, and seem utterly irreconcilable with all known theories of modern science. Having satisfied myself of their _truth_, it would be moral cowardice to withhold my testimony because my previous publications were ridiculed by critics and others who knew nothing whatever of the subject, and who were too prejudiced to see and judge for themselves whether or not there was truth in the phenomena. I shall state simply what I have seen and proved by repeated experiment and test. Except where darkness has been a necessary condition, as with some of the phenomena of luminous appearances, and a few other instances, everything recorded has taken place _in the light_. In the few cases where the phenomena noted have occurred in darkness I have been very particular to mention the fact. Moreover, some special reason can be shown for the exclusion of light, or the results have been produced under such perfect test conditions that the suppression of one of the senses has not really weakened the evidence. I have said that darkness is not essential. It is, however, a well-ascertained fact that when the force is weak a bright light exerts an interfering action on some of the phenomena. The power possessed by Mr. Home is sufficiently strong to withstand this antagonistic influence; consequently, he always objects to darkness at his _seances_. Indeed, except on two occasions, when, for some particular experiments of my own, light was excluded, everything which I have witnessed with him has taken place in the light. I have had many opportunities of testing the action of light on different sources and colors,--such as sunlight, diffused daylight, moonlight, gas, lamp, and candle-light, electric light from a vacuum tube, homogeneous yellow light, etc. The interfering rays appear to be those at the extreme end of the spectrum. Professor Crookes next proceeds to classify the phenomena observed by him, going from the more simple to the more complex and giving in rapid review under each head, a sketch of some of the facts. In the abridgment of his report which follows I eliminate what has already been fully demonstrated elsewhere in this book. FIRST CLASS: _The movement of Heavy Bodies with Contact, but without Mechanical Exertion._ (This movement has been fully proved in this volume.) SECOND CLASS: _The Phenomena of Percussive and other Allied Sounds._