One and the same Cause differs in the same Effect of Sleep.
SOme and the same things, or Acts, will cause Sleep, or put by Sleep; as for the Passions, sometimes Grief, Joy, Anger, and the like, will cause Sleep, othertimes hinder it; the reason is, according as the Passions work inwards, or extend outwards: for when the Passions settle or move most inwards, they draw all the Vapours backwards; and when they flow outwards, they carry Vapours with them; and as Passions many times carry out Vapours, so Vapours many times carry out Passions, as we may observe by the Effects, as Sighing, Groaning, and Weeping, as Railing, Threatning, Cursing, Fighting, Laughing, Hooping, Hollowing, Praising, Singing, and Dancing, which are all Ex∣teriour Motions: But where they work inward, the Heart beats, or works, and the Brain thinks stronglyer than the Natural Con∣stitution requires; which Motion causeth Unnatural Heat, which drinks up the Vapours; or else the Brain, or the Heart, are so strongly bound to an Object, and holding as it were so fast thereon, as it draws all the Powers of Life to assist therein: This causeth Deep Musing, Heart-griping, fix'd Eyes, and slow Pul∣ses, which draws the Vapours so much inward, as almost extin∣guisheth the Fire of Life, and smothers the Understanding, starves the Body, and makes the Senses unusefull; and many times the Slow Motions congeal the Vapours, like Ice, making them unapt to slow. As for Exteriour Action, much Labour or Exercise causeth them to flow, or produceth Sleep to those that have Gross Bodies, and too Thick Vapours (for the Vapours may be too Thick as well as too Thin) for the use of Rest in these Bodies and Constitutions, much exerciseth and rarifieth the Va∣pours to such a Degree, as makes a General Aptness to flow to the Extreme Parts, wherewith the Senses are stopp'd, as being full, which otherwise would not be so apt to slow; but to Lean Bodies, and Dry Constitutions, much Labour and Exercise ei∣ther contracts the Vapour into so Gross a Body, as it cannot slow; or rarifies that little Vapour they have, so thin, as it eva∣porates out by Insensible Inspirations, or the Unnatural Drought and Heat drinks it up, so as there is no Vapour to fill the Senses to a Repose.