reto from
the long and lasting position and the facing of a suitable substance toward
the poles of the earth; by whose strength continued through many centuries
it has been fashioned; toward fixed and determined parts of which it has
remained since its origin firmly and constantly turned.

* * * * *

CHAP. III.

How Iron acquires Verticity through
a Loadstone, and how that verticity
_is lost and changed_.

Friction between an oblong piece of iron and a loadstone imparts to the
former magnetick virtues, which are not corporeal nor inherent and
persistent in any body, as we showed in the discussion on coition. It is
plain that the iron, when it has been rubbed hard with one end and applied
to the stone for a pretty long time, receives no stony nature, acquires no
weight; for if, before the iron is touched by the stone, you weigh * it in
a small and very exact goldsmith's balance, you will see after the rubbing
that it has exactly the same weight, neither diminished nor increased. But
if you wipe the iron with cloths after it has been touched, or wash it in
water, or scour it with sand or on a grindstone, still it in nowise lays
aside its acquired strength. For the force is spread through the whole body
and conceived in the inmost parts, and cannot in any way be washed or wiped
away. Let an experiment then be made in fire, that untamed tyrant of
nature. Take a piece of iron of the length of a palm and the thickness of a
goosequill pen; let this iron be passed through a suitable round cork and
placed on the surface of water, and observe the end which turns to the
north; rub this particular end with the true southern end of a loadstone;
the iron so rubbed turns toward the south. Remove the cork, and place the
end * which was excited in the fire until the iron is just red-hot; when it
is cooled, it will retain the strength of the loadstone and the verticity,
though it will not be so prompt, whether because the force of the fire had
not yet continued long enough to overcome all its {124} strength, or
because the whole iron was not heated to redness, for the virtue is
diffused through the whole. Remove the cork a second time, and putting the
whole iron in the fire, blow the fire with the bellows, so that it may be
all aglow, and let it remain a little longer time red-hot; when cooled (so,
however, that, whilst it is cooling, it does not rest in one position),
place it again on the water with