To the subject of 'Spirit-rappings' we have devoted some time and attention, but our investigations have not been sufficiently extensive to warrant us at present in offering any positive conclusions. The difficulty attending the investigation of this mode of Spiritualistic manifestation is increased by the fact, familiar to physiologists, that sounds of varying intensity may be produced in almost any portion of the human body by voluntary muscular action. To determine the exact location of this muscular activity is at times a matter of delicacy. What we can say, thus far, with assurance is that, in the cases which have come under our observation, the theory of the purely physiological origin of the sounds has been sustained by the fact that the Mediums were invariably, and confessedly, cognizant of the rappings whenever they occurred, and could at once detect any spurious rappings, however exact and indistinguishable to all other ears might be the imitation. For the details of the investigation which guided us to this conclusion we refer to the Appendix. There are among Mediums certain Specialists, whose alleged Spiritual manifestations we have endeavoured to investigate, not always successfully, as, for instance, in the case of Mr. W.M. Keeler, through whose Mediumship 'Spiritual Photographs' are produced. The 'conditions' which this Medium demanded would have made any attempt at investigation a mere waste of time, and his terms of remuneration were, in addition, as we have before mentioned, prohibitory and suggestive of unwillingness to come before the Commission. In these days of 'Composite Photography' it is worse than childish to claim a Spiritual source for results which can be obtained at any time by any tyro in the art. Mr. Keeler's letter will be found in the Appendix.