sibility.

Community of sensation is as common a phenomenon as community of
thought between a hypnotizer and his subject, and what are called
sympathetic pains are included in common experience. Sensitive persons
will simulate all the symptoms of a virulent disease, _e.g._ mock
measles. The phenomena of psychometry reveal the fact of bodies being
able to retain records and of the human possibility of reviving these
records as sensations and thought images, although there is no direct
community of sensation between an inanimate object and the
nervous organism of a sensitive. It need not, therefore, be a
matter of surprise that the crystal can exert a very definite and
sensible effect upon the nervous organism of a certain order of
subjects. It does not affect all alike nor act in a uniform
and constant manner on those whom it does so affect. The
modifications of sensibility taking place in the subject or
sensitive render the action of the agent a variable quantity.
Where its action is more or less rapid and remarkable, however,
the quartz or beryl crystal may be regarded as the most effective
agent for producing clairvoyance.

In other cases the concave mirror, either of polished copper or
black japan, will be found serviceable. In certain cases where
the faculty is already developed but lying in latency, any
shining surface will suffice to bring it into activity. Ecstatic
vision was first induced in Jacob Boehme by the sun's rays
falling upon a bowl of water which caught and dazzled his eyes
while he was engaged in the humble task of cobbling a pair of
shoes. In consequence of this exaltation of the visual sense we
have those remarkable works, _The Aurora, The Four Complexions,
Signatura Rerum_, and many others, with letters and commentaries which,
in addition to being of a spiritual nature, are also to be regarded
as scholarly when referred to their source. In Boehme's case, as in
that of Swedenborg, whose faculty did not appear until he was
fifty-four years of age, it would appear that the faculty was
constitutional and already developed, waiting only the conditions
which should bring it into active operation.

The agent most suitable for developing clairvoyance cannot
therefore be definitely prescribed. It must remain a matter of
experiment with the subject himself. That there are some
persons in whom the psychic faculties are more prone to
activity than in others is certain, and it would appear also that
these