detail.

We request your honorable body to note that this Report is preliminary
and that we do not consider our investigations in this department as
finally closed, but hold ourselves ready to continue them whenever
favorable circumstances arise.

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