Mr. Davey's performances, _as described_ by many of his sitters, like the descriptions of the performances of many a medium, are marvelous enough to demand the hypothesis of occult agency: "Writing between a conjurer's own slates in a way quite inexplicable to the conjurer; writing upon slates locked and carefully guarded by witnesses; writing upon slates held by the witnesses firmly against the under-surface of the table; writing upon slates held by the witnesses above the table; answers to questions written secretly in locked slates; correct quotations appearing on guarded slates from books chosen by the witnesses at random, and sometimes mentally, the books not touched by the 'medium'; writing in different colors mentally chosen by the witnesses, covering the whole side of one of their own slates; messages in languages unknown to the medium, including a message in German, for which only a mental request had been made, and a letter in Japanese in a double slate locked and sealed by the witness; the date of a coin placed by the witness in a sealed envelope correctly written in a locked slate upon the table, the envelope remaining intact; a word written between slates screwed together and also corded and sealed together, the word being chosen by the witness after the slates were fastened by himself, etc., etc. And yet, though 'autographic' fragments of pencil were 'heard' weaving mysterious messages between and under and over slates, and fragments of chalk were seen moving about under a tumbler placed above the table in full view, none of the sitters witnessed that best phenomenon, _Mr. Davey writing_." It must not be supposed that the errors of mal-description and lapse of memory thus committed are at all serious in themselves; on the contrary, they are mostly such as would be entirely pardonable in ordinary matters. Mr. Hodgson places them in four classes. In the first, the observer _interpolates_ a fact which really did not happen, but which he was led to believe had occurred; he records that he examined the slate, when he really did not. Secondly, for similar causes, he _substitutes_ one statement for another closely like it; he says he examined the slate minutely, when he really only did so hastily. Thirdly, he _transposes_ the order in which the events happened, making the examination of the slate occur at a later period than when it really took place. Lastly, he _omits_ certain details which he was carefully led to consider trivial, but which really were most important. Such slight lapses as these are sufficient to make a marvel of a clever piece of conjuring; add to this the increased temptations for mal-observation afforded by the dim light and mysterious surroundings of the medium, as well as by the sympathetic attitude of the sitters, and the wide divergence between the miraculous narratives of spiritualists and the homely deceptions which they are intended to describe, is no longer a mystery.