1. Volition is suspended in sleep. 2. Sensation continues.  Dreams prevent delirium and inflammation. 3. Nightmare. 4. Ceaseless flow of ideas in dreams. 5. We seem to receive them by the senses.  Optic nerve perfectly sensible in sleep.  Eyes less dazzled after dreaming of visible objects. 6. Reverie, belief. 7. How we distinguish ideas from perceptions. 8. Variety of scenery in dreams, excellence of the sense of vision. 9. Novelty of combination in dreams. 10. Distinctness of imagery in dreams. 11. Rapidity of transaction in dreams. 12. Of measuring time.  Of dramatic time and place.  Why a dull play induces sleep, and an interesting one reverie. 13. Consciousness of our existence and identity in dreams. 14. How we awake sometimes suddenly, sometimes frequently. 15. Irritative motions continue in sleep, internal irritations are succeeded by sensation.  Sensibility increases during sleep, and irritability.  Morning dreams.  Why epilepsies occur in sleep.  Ecstacy of children.  Case of convulsions in sleep.  Cramp, why painful.  Asthma.  Morning sweats.  Increase of heat.  Increase of urine in sleep.  Why more liable to take cold in sleep.  Catarrh from thin night-caps.  Why we feel chilly at the approach of sleep, and at waking in the open air. 16. Why the gout commences in sleep.  Secretions are more copious in sleep, young animals and plants grow more in sleep. 17. Inconsistency of dreams.  Absence of surprise in dreams. 18. Why we forget some dreams and not others. 19. Sleep-talkers awake with surprise. 20. Remote causes of sleep.  Atmosphere with less oxygene.  Compression of the brain in spina bifida.  By whirling on an horizontal wheel.  By cold. 21. Definition of sleep.

1.  There are four situations of our system, which in their moderate degrees are not usually termed diseases, and yet abound with many very curious and instructive phenomena; these are sleep, reverie, vertigo, drunkenness.  These we shall previously consider, before we step forwards to develop the causes and cures of diseases with the modes of the operation of medicines.

As all those trains and tribes of animal motion, which are subjected to volition, were the last that were caused, their connection is weaker than that of the other classes; and there is a peculiar circumstance attending this causation, which is, that it is entirely suspended during sleep; whilst the other classes of motion, which are more immediately necessary to life, as those caused by internal stimuli, for instance the pulsations of the heart and arteries, or those catenated with pleasurable sensation, as the powers of digestion, continue to strengthen their habits without interruption.  Thus though man in his sleeping state is a much less perfect animal, than in his waking hours; and though he consumes more than one third of his life in this his irrational situation; yet is the wisdom of the Author of nature manifest even in this seeming imperfection of his work!