OF the parts of the body there may be many divisions: the most approved is that of Laurentius, out of Hippocrates: which is, into parts contained, or containing. Contained, are either humours or spirits.
Humours.] A humour is a liquid or fluent part of the body, comprehended in it, for the preservation of it; and is either innate or born with us, or adventitious and acquisite. The radical or innate, is daily supplied by nourishment, which some call cambium, and make those secondary humours of ros and gluten to maintain it: or acquisite, to maintain these four first primary humours, coming and proceeding from the first concoction in the liver, by which means chylus is excluded. Some divide them into profitable and excrementitious. But Crato out of Hippocrates will have all four to be juice, and not excrement; without which no living creature can be sustained: which four, though they be comprehended in the mass of blood, yet they have their several affections, by which they are distinguished from one another, and from those adventitious, peccant, or diseased humours, as Melancthon calls them.
Blood.] Blood is a hot, sweet, temperate, red humour, prepared in the meseraic veins, and made of the most temperate parts of the chylus in the liver, whose office is to nourish the whole body, to give it strength and colour, being dispersed by the veins through every part of it. And from it spirits are first begotten in the heart, which afterwards by the arteries are communicated to the other parts.
Pituita, or phlegm, is a cold and moist humour, begotten of the colder part of the chylus (or white juice coming out of the meat digested in the stomach), in the liver; his office is to nourish and moisten the members of the body, which as the tongue are moved, that they be not over dry.
Choler is hot and dry, bitter, begotten of the hotter parts of the chylus, and gathered to the gall: it helps the natural heat and senses, and serves to the expelling of excrements.
Melancholy.] Melancholy, cold and dry, thick, black, and sour, begotten of the more feculent part of nourishment, and purged from the Spleen, is a bridle to the other two hot humours, blood and choler, preserving them in the blood, and nourishing the bones. These four humours have some analogy with the four elements, and to the four ages in man.
Serum, Sweat, Tears.] To these humours you may add serum, which is the matter of urine, and those excrementitious humours of the third concoction, sweat and tears.
Spirits.] Spirit is a most subtile vapour, which is expressed from the blood, and the instrument of the soul, to perform all his actions; a common tie or medium between the body and the soul, as some will have it; or as in Paracelsus, a fourth soul of itself. Melancthon holds the fountain of these spirits to be the heart, begotten there; and afterward conveyed to the brain, they take another nature to them. Of these spirits there be three kinds, according to the three principal parts, brain, heart, liver; natural, vital, animal. The natural are begotten in the liver, and thence dispersed through the veins, to perform those natural actions. The vital spirits are made in the heart of the natural, which by the arteries are transported to all the other parts: if the spirits cease, then life ceaseth, as in a syncope or swooning. The animal spirits formed of the vital, brought up to the brain, and diffused by the nerves, to the subordinate members, give sense and motion to them all.