When the Human Brain seems to turn round, the cause is, that some Vapours do move in a Circular Figure, which causes the Head to be dizzy; as when a man turns round, not only his Head will be dizzy, but all the Exterior Parts of his Body; insomuch that some, by often turning round, will fall down; but if, before they fall, they turn the contrary way, they will be free from that dizziness: The reason of which is, That, by turning the contrary way, the Body is brought to the same posture it was before; as, when a man hath travell'd some way, and returns the same way back, he returns to the place where first he began his Journey. CHAP. V. Of WEAKNESS. There are many sorts of _Weakness_; some Weakness proceeds from Age; others, through want of Food; others are occasioned by Oppression; others, by Disorders and Irregularities; and so many other sorts, that it would be too tedious to repeat them, could I know them: But, such sorts of Weakness, as Human Creatures are subject to, after some Disease or Sickness, are somewhat like Weariness after a Laborious or over-hard Action; as, when a Man hath run fast, or laboured hard, he fetches his breath short and thick; and as most of the Sensitive Actions are by degrees, so is a Returning to Health after Sickness: but, all Irregularities are Laborious. CHAP. VI. Of SWOUNDING. The cause why a Man in _Swound_, is, for a time, as if he were dead; is, an Irregularity amongst some of the Interior Corporeal Motions, which causes an Irregularity of the Exterior Corporeal Motions, and so a general Irregularity; which is the cause that a Man appears as if he were dead. But some may say, _A Man in a Swound is void of all Motion_.