If much of the physical phenomena just described be well within the scope of natural possibility, it is somewhat otherwise with the class of manifestations I shall now touch upon. It is one thing to exert consciously or unconsciously, as Home, Cook, Paladino, Moses and other mediums have done, in the presence of scientifically trained witnesses, unknown and supernormal muscular power. Table rapping, levitation, "apports," may all be genuine enough and accounted for in a manner which, if not wholly satisfying, is at least not unreasonable. But when those assisting at a _séance_ actually behold with their eyes and touch with their hands, and even photograph with a camera, the materialised objects of the spirits with whom the medium is in communion, the pulse of the inquirer quickens. He is now indeed approaching the crucial problem, the crowning achievement of spiritualism. For although in a former chapter we have the testimony of people who saw "ghosts," these ghosts might, to my mind, clearly be the result of telepathy. They appear on special occasions at important and significant crises, but the claim of the spiritualistic medium is that he can casually, and on the demand of one of the circle, produce a visible, tangible figure of a deceased husband, wife, parent, or friend. This materialisation is wholly a recent species of manifestation. One of the first to testify to having seen a materialised figure at a _séance_ was the well-known S. C. Hall, who recognised during one of Home's _séances_ the figure of his deceased sister. Other mediums repeated the feat, and shadowy forms and faces began to appear and move about during their dark _séances_. It is a suspicious fact that in some cases these forms, made visible by a faintly luminous vapour, were accompanied by an odour of phosphorus. Sceptics naturally took great advantage of the alleged circumstance. Soon, however, a new medium, Florence Cook, was rumoured to have produced materialised forms in a good light which baffled all the sceptics. Miss Cook claimed to be "controlled" by a spirit known under the name of "Katie." We have this account from a writer who early attended to examine the mystery fairly: