18. Men, being incarnate beings, have in part the attributes of the spiritual life; for they live in this life as well as in a corporeal one, always during sleep, and often in a conscious state. The spirit, incarnating itself, preserves its perispirit with the qualities which are proper to it, and which, as is known, is not circumscribed by the body, but envelops and radiates around it like a fluidic atmosphere.
By its intimate union with the body the perispirit plays a preponderating role with the organism. By its expansion it places the incarnated being more directly in contact with free spirits.
The thought of the incarnated mind acts upon the spiritual fluids as that of the discarnated spirit’s thought acts. It is transmitted from spirit to spirit in the same way, and, according as it is good or bad, it holds a vicious or healthy relation to the surrounding fluids.
Since the fluids of an ambient are modified by the projection of the spirit’s thoughts, his perispiritual body - which is a constituent part of his being, and which receives directly and in a permanent way the impressions of his thoughts - should receive even more so the impressions of his good or bad qualities. The fluids vitiated by the effluviums of the bad spirits can be purified by their removal. The perispirit however will always be that which it is, as long as the spirit does not modify itself.
The perispirit of incarnates, being of a nature identical to that of the spiritual fluids, assimilates itself with them readily, as a sponge absorbs water. These fluids have over the perispirit an action which is the more direct because of its expansion and radiation; it confounds itself with them.
These fluids acting upon the perispirit, the latter, in its turn, reacts upon the material organism with which it is in molecular contact. If the effluvia are of a good nature, the bodies receive a salutary impression; if bad, a painful one. If the bad are permanent and energetic, they can cause physical disorders; certain maladies have no other cause.
The midst where bad spirits abound are then impregnated with bad fluids, which are absorbed through all the perispiritual pores, as by the pores of the body pestilential miasmas are absorbed.