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 tha............