The spirit realm is the realm of the ether, the boundless range of unknown interstellar space. Blindly, gropingly, the men of science are putting out feelers--theories--pragmatical assumptions that serve them as laws. Little by little it is being recognized that the physics of the ether is the underlying superscientific structure of modern Spiritualism. Little by little their discoveries fall into harmony with our claims, and we must look upon science as the handmaiden rather than the antagonist of our truth. The theories of apparition that are held vary according to the classification of the apparition. There are numerous instances of apparitions of the living[13] and there is an infinite mass of data concerning veridical apparitions of the dead. A statistical analysis of 17,000 cases collected by the Society for Psychical Research resulted in the finding by the Committee that “Between deaths and apparitions of the dying person a connexion exists which is not due to chance alone.”[14] A clear distinction must, however, be drawn between apparitions which may appear to relatives, friends, and acquaintances, and then disappear for ever, and those definite and persistently recurring apparitions that go by the name of haunts. The terminology of matters psychic is loose and inexact, but it is well to have a clear mental distinction between the occasional “apparition” and the periodic or repeating “ghost.” For purposes of scientific investigation the casual apparition is almost valueless, but the established ghost is the nearest approximation that we can get to a serious test standard for experimental purposes. There are in England at least half a dozen ghosts whose periodical manifestations are regular enough to serve as test instances. The genuine ghost is so rare that from the point of view of psychical research it is vitally important that the haunt should not be harried by every party of sensation-avid amateurs who think they would “like to see a ghost.” The amateur exorcists, the psychically gifted ladies, and all the ragtag and bobtail of well-meaning idiots that disturb a haunt once it becomes known, can only be compared to a set of egg-stealing, bird-scaring boys who invade a woodland sanctuary and destroy the fruition of the work of a painstaking observer of nature who has been recording the life of the rare birds. In parenthesis it may be remarked that if the ghost is a full-blooded manifestation it will take more than the well-meaning effort of some anæmic amateur psychic to lay it. The very last person who should go near a violent ghost is anyone whose capacity for mediumship is in any way developed. Mediums should only be present when adequate and experienced mortal controls are there also.