e add a third
skin, which is termed mediastinus, which divides the chest into two parts,
right and left; of this region the principal part is the heart, which is
the seat and fountain of life, of heat, of spirits, of pulse and
respiration--the sun of our body, the king and sole commander of it--the
seat and organ of all passions and affections. _Primum vivens, ultimum
moriens_, it lives first, dies last in all creatures. Of a pyramidical
form, and not much unlike to a pineapple; a part worthy of [964]
admiration, that can yield such variety of affections, by whose motion it
is dilated or contracted, to stir and command the humours in the body. As
in sorrow, melancholy; in anger, choler; in joy, to send the blood
outwardly; in sorrow, to call it in; moving the humours, as horses do a
chariot. This heart, though it be one sole member, yet it may be divided
into two creeks right and left. The right is like the moon increasing,
bigger than the other part, and receives blood from _vena cava_,
distributing some of it to the lungs to nourish them; the rest to the left
side, to engender spirits. The left creek hath the form of a cone, and is
the seat of life, which, as a torch doth oil, draws blood unto it,
begetting of it spirits and fire; and as fire in a torch, so are spirits in
the blood; and by that great artery called aorta, it sends vital spirits
over the body, and takes air from the lungs by that artery which is called
_venosa_; so that both creeks have their vessels, the right two veins, the
left two arteries, besides those two common anfractuous ears, which serve
them both; the one to hold blood, the other air, for several uses. The
lungs is a thin spongy part, like an ox hoof, (saith [965]Fernelius) the
town-clerk or crier, ([966]one terms it) the instrument of voice, as an
orator to a king; annexed to the heart, to express their thoughts by voice.
That it is the instrument of voice, is manifest, in that no creature can
speak, or utter any voice, which wanteth these lights. It is, besides, the
instrument of respiration, or breathing; and its office is to cool the
heart, by sending air unto it, by the venosal artery, which vein comes to
the lungs by that _aspera arteria_ which consists of many gristles,
membranes, nerves, taking in air at the nose and mouth, and by it likewise
exhales the fumes of the heart.

In the upper region serving the animal faculties, the chief organ is the
brain, which is a soft, marrowish, and