Horren; this artery cometh up from the heart, and is departed in
twain, and the one part cometh upward, and carrieth blood, that is
purified and spirit of life to the brain; that so the spirit of
feeling may be bred, nourished, kept, and saved. The other part goeth
downward, and is departed in many manner wise toward the right side
and toward the left.

Then mark well, that a vein is the bearer and carrier of blood, keeper
and warden of the life of beasts. And containeth in itself the four
bloody humours clean and pure, which are ordained for feeding of all
the parts of the body. Moreover, a vein is hollow to receive blood the
more easily, and as it needeth in kind, that one vein bring and give
blood to another vein. Also a vein is messager of health and of
sickness. For by the pulse of the arteries and disposition of the
veins, physicians deem of the feebleness and strength of the heart.
Also if a vein be corrupt, and containeth corrupt blood, it corrupteth
and infecteth all the body, as it fareth in lepers, whose blood is
most corrupt in the veins, of the which the members are fed by sucking
of blood, and seeketh thereby corruption and sickness incurable. Also
the vein of the arm is oft grieved, constrained and wranged, opened
and slit, and wounded, to relieve the sickness of all the body by
hurting of that vein.

The spittle of a man fasting hath a manner strength of privy
infection. For it grieveth and hurteth the blood of a beast, if it
come into a bleeding wound, and is medlied with the blood. And that,
peradventure, is, as saith Avicenna, by reason of rawness. For raw
humour medlied with blood that hath perfect digestion, is contrary
thereto in its quality, and disturbeth the temperance thereof, as
authors say. And therefore it is that holy men tell that the spittle