Medium, primarily a person through whom, as an intermediate, communication is deemed to be carried on between living men and spirits of the departed, according to the spiritistic hypothesis; such a person is better termed sensitive or automatist. The phenomena of mediumship fall into two classes, (I) "physical phenomena" (q.v.) and (2) trance and automatic phenomena (utterances, script, &c.); both these may be manifested by the same person, as in the case of D. D. Home and Stainton Moses, but are often independent.
I. No sufficient mass of observations is to hand to enable us to distinguish between the results of trickery or hallucination on the one hand, and genuine supernormal phenomena on the other; but the evidence for raps and lights is good; competent observers have witnessed supposed materializations and there is respectable evidence for movements of objects.
Mediumship in the modern sense of the term may be said to have originated with the Rochester rappings of 1848 (see Spiritualism); but similar phenomena had been reported by such authors as Apollonius of Tyana; they figure frequently in the lives of the saints; and the magician in the lower stages of culture is in many respects a counterpart of the white medium. Among physical mediums who have attained celebrity may be mentioned D. D. Home (q.v.), Stainton Moses and Eusapia Palladino; the last has admittedly been fraudulent at times, but no deceit was ever proved of Home; Stainton Moses sat in a private circle and no suspicion of his good faith was ever aroused.
W. Stainton Moses (1839-1892) was a man of university education, a clergyman and a schoolmaster. In 1872 he became interested in spiritualism and soon began to manifest mediumistic phenomena,which continued for some ten years. These included, besides trance communications, raps, telekinesis, levitation, production of lights, perfumes and musical sounds, apports and materialized hands. But the conditions under which the experiments were tried were not sufficiently rigid to exclude the possibility of normal causes being at work; for no amount of evidence that the normal life is marked by no lapse from rectitude affords a presumption that uprightness will characterize states of secondary personality.
Eusapia Palladino has been observed by Sir O. Lodge, Professor Richet, F. W. H. Myers, and other eminent investigators; the first named reported that none of the phenomena in his presence went beyond what could be accomplished in a normal manner by a free and uncontrolled person; but he was convinced that movements were produced without apparent contact. Among other phenomena asserted to characterize the mediumship of Eusapia are the production of temporary prolongations from the medium's body; these have been seen in a good light by competent witnesses. It was shown in some sittings held at Cambridge in 1895 that Eusapia produced phenomena by fraudulent means: but though the evidence of this is conclusive it has not been shown that her mediumship is entirely fraudulent. Automatic records of seances can alone solve the problems raised by physical mediumship. It has been shown in the DaveyHodgson experiments that continuous observation, even for a short period, is impossible, and that in the process of recording the observations many omissions and errors are inevitable. Even were it otherwise, no care could provide against the possibility of hallucination.
II. The genuineness of trance mediumship can no longer be called in question. The problem for solution is the source of the information. The best observed case is that of Mrs Piper of Boston; at the outset of her career, in 1884, she did not differ from the ordinary American trance medium. In 1885 the attention of Professor William James of Harvard was attracted to her; and for twenty years she remained under the supervision of the Society for Psychical Research. During that period three phases may be distinguished: (I) 1884-1891, trance utterances of a "control" calling himself Dr Phinuit, a French physician, of whose existence in the body no trace can be found; (2) 1892-1896, automatic writing by a "control" known as "George Pelham," the pseudonym of a young American author; (3) 1896 onwards, supervision by "controls" purporting to be identical with those associated with Stainton Moses. There is no evidence for regarding Mrs Piper as anything but absolutely honest. Much of the Piper material remains unpublished, partly on account of its intimate character. Many of those to whom the communications were made have been convinced that the "controls" are none other than discarnate spirits. Probably no absolute proof of identity can be given, though the reading of sealed letters would come near it; these have been left by more than one prominent psychical researcher, but so far the "controls" who claim to be the writers of them have failed to give their contents, even approximately.
Professor Flournoy has investigated a medium of very different type, known as Helene Smith; against her good faith nothing can be urged, but her phenomena - trance utterance and glossolalia - have undoubtedly been produced by her own mind. These represent her to be the reincarnation of a Hindu princess, and of Marie Antoinette among others, but no evidence of identity has been produced. The most striking phenomenon of her trance was the so-called Martian language, eventually shown by analysis to be a derivative of French, comparable to the languages invented by children in the nursery, but more elaborate.
Authorities.-F. W. H. Myers, Human Personality; F. Podmore, Modern Spiritualism; the Proceedings and Journal of the Society for Psychical Research, passim; for a convenient survey of the Piper case, see F. Sage, Madame Piper; J. Maxwell, Les Phenomenes psychiques (1903; Eng. trans. 1905); Th. Flournoy, Des Indes a la planete Mars. For fraudulent methods, see Confessions of a Medium (London, 1882); Truesdell, Bottom Facts of Spiritualism, and works cited by Myers, II., 502-503. (N. W. T.)