Amazon.com description: Product Description: "[...]the lowest and densest sub-plane of the astral; but nevertheless its particles are constantly and rapidly changing their relative position, moving among one another as easily as those of a liquid on the physical plane might do. So that there is no permanent association between any one physical particle and that amount of astral matter which happens at any given moment to be acting as its counterpart. This is equally true with respect to the astral body of man, which for our purpose at the moment we may regard as consisting of two parts—the denser aggregation which occupies the exact position of the physical body,[...]".