students who are trying to comprehend its physiology seem to find it
difficult to reconcile with the statements that have been made as to
the perfect inter-penetration of the physical body by astral matter,
the exact correspondence between the two vehicles, and the fact that
every physical object has necessarily its astral counterpart.

Now all these statements are true, and yet it is quite possible for
people who do not normally see astrally to misunderstand them. Every
order of physical matter has its corresponding order of astral matter
in constant association with it--not to be separated from it except by
a very considerable exertion of occult force, and even then only to
be held apart from it as long as force is being definitely exerted to
that end. But for all that the relation of the astral particles one to
another is far looser than is the case with their physical
correspondences.

In a bar of iron, for example, we have a mass of physical molecules in
the solid condition--that is to say, capable of comparatively little
change in their relative positions, though each vibrating with immense
rapidity in its own sphere. The astral counterpart of this consists of
what we often call solid astral matter--that is, matter of 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, and the cloud of rarer astral matter which surrounds
that aggregation. In both these parts, and between them both, there is
going on at every moment of time the rapid inter-circulation of the
particles which has been described, so that as one watches the
movement of the molecules in the astral body one is reminded of the
appearance of those in fiercely boiling water.

This being so, it will be readily understood that though any given
organ of the physical body must always have as its counterpart a
certain amount of astral matter, it does not retain the same particles
for more than a fe