I have heard, that the Opinions of the most Learned Men, are, That all Animal Creatures have Blood, or at least, such Juyces that are in lieu of Blood; which Blood, or Juyces, move circularly: for my part, I am too ignorant to dispute with Learned Men; but yet I am confident, a _Moth_ (which is a sort of Worm, or Fly, that eats Cloth) hath no Blood, no, nor any Juyce; for, so soon as it is touched, it dissolves straight to a dry dust, or like ashes. And there are many other Animals, or Insects, that have no appearance of Blood; therefore the life of an Animal doth not consist of Blood: And as for the Circulation of Blood, there are many Animal Creatures that have not proper Vessels, as Veins and Arteries, or any such Gutters, for their Blood, or Juyce, to circulate through. But, say the Blood of Man, or of such like Animal, doth circulate; then it is to be studied, Whether the several parts of the Blood do intermix with each other, as it flows; or, whether it flows as Water seems to do; where the following parts may be as great strangers to the Leading parts, as in a Crowd of People, where some of those behind, do not know those that are before: but, if the Blood doth not intermix as it flows, then it will be very difficult for a Chyrurgion, or Physician, to find where the ill Blood runs: besides, if the Blood be continually flowing, when a sick Man is to be let blood, before the Vein is opened, the bad Blood may be past that Part, or Vein, and so only the good Blood will be let out; and then the Man may become worse than if he had not been let blood. CHAP. V. Of the Radical Humours, or Parts. There are many Parts in a Human Body, that are as the Foundation of a House; and being the Foundation, if any of those Parts be removed or decayed, the House immediately falls to ruine. These Fundamental Parts, are those we name the _Vital Parts_; amongst which are those Parts we name the _Vital_ and _Radical Spirits_, which are the Oyl and Flame of a Human Creature, causing the Body to have that we name a _Natural Heat_, and a _Radical Moisture_. But it is to be noted, That these Parts, or Corporeal Motions, are not like gross Oyl, or Flame: for, I believe, there are more differences between those Flames, and ordinary Flames, than between the Light of the Sun, and the Flame of a Tallow Candle; and as much difference between this Oyl, and the greasie Oyl, as between the purest Essence, and Lamp-Oyl. But, these Vital Parts are as necessary to the Human Life, as the solid Vital Parts, viz. the Heart, Liver, Lungs, Brains, and the like. CHAP. VI. Of Expelling Malignant Disorders in a Human Creature.