nd that they are completed in all their parts on the fiftieth
day; the parts of the females are articulated in two months, but by the
defect of heat are not consummated till the fourth; but the members of
brutes are completed at various times, according to the commixture of
the elements of which they consist.

CHAPTER XXII. OF WHAT ELEMENTS EACH OF THE MEMBERS OF US MEN IS
COMPOSED.

Empedocles says, that the fleshy parts of us are constituted by the
contemperation of the four elements in us; earth and fire mixed with
a double proportion of water make nerves; but when it happens that the
nerves are refrigerated where they come in contact with the air, then
the nails are made; the bones are produced by two parts of water and
the same of air, with four parts of fire and the same of earth, mixed
together; sweat and tears flow from liquefaction of bodies.

CHAPTER XXIII. WHAT ARE THE CAUSES OF SLEEP AND DEATH?

Alcmaeon says, that sleep is caused when the blood retreats to the
concourse of the veins, but when the blood diffuses itself then we
awake and when there is a total retirement of the blood, then men die.
Empedocles, that a moderate cooling of the blood causeth sleep, but a
total remotion of heat from blood causeth death. Diogenes, that when all
the blood is so diffused as that it fills all the veins, and forces the
air contained in them to the back and to the belly that is below it, the
breast being thereby more heated, thence sleep arises, but if everything
that is airy in the breast forsakes the veins, then death succeeds.
Plato and the Stoics, that sleep ariseth from the relaxation of the
sensitive spirit, it not receiving such total relaxing as if it fell to
the earth, but so that that spirit is carried about the intestine, parts
of the eyebrows, in which the principal part has its residence; but when
there is a total relaxing of the sensitive spirit, death ensues.

CHAPTER XXIV. WHEN AND FROM WHENCE THE PERFECTION OF A MAN COMMENCES.

Heraclitus and the Stoics say, that men begin their completeness when
the second septenary of years begins, about which time the seminal serum
is emitted. Trees first begin their perfection when they give their
seeds; till then they are immature, imperfect, and unfruitful. After the
same manner a man is completed in the second septenary of years, and is
capable of learning what is good and evil, and of discipline therein.

CHAPTER XXV. WHETHER SLEEP OR DEATH AP