109. The perispirit, as we have seen, is the foundation of all spirit-
manifestations, to which the knowledge of this integral part of a spirit's personality
gives us the key; a key which, let us never forget, has been furnished by the spirits
themselves, for it is by them that the existence, nature, and functions of the perispirit
have been made known to us. This knowledge enables us to understand the action of
spirits on matter, the movement of inert bodies, the mode of production of aural, visual,
and tangible phenomena; it will also be found equally available for the explanation of
the other phenomena which we shall have to examine, before we proceed to the study
of spirit-communications properly so called, and which we shall comprehend all the
more easily with the aid of the preliminary knowledge we shall thus have acquired of
the general principles on which they rest.
