10. The following is the definition or character of complete reverie. 1. The irritative motions occasioned by internal stimuli continue, those from the stimuli of external objects are either not produced at all, or are never succeeded by sensation or attention, unless they are at the same time excited by volition. 2. The sensitive motions continue, and are kept consistent by the power of volition. 3. The voluntary motions continue undisturbed. 4. The associate motions continue undisturbed.
Two other cases of reverie are related in Section XXXIV. 3. which further evince, that reverie is an effort of the mind to relieve some painful sensation, and is hence allied to convulsion, and to insanity. Another case is related in Class III. 1. 2. 2.
1. _We determine our perpendicularity by the apparent motions of objects. A person hood-winked cannot walk in a straight line. Dizziness in looking from a tower, in a room stained with uniform lozenges, on riding over snow._ 2. _Dizziness from moving objects. A whirling-wheel. Fluctuations of a river. Experiment with a child._ 3. _Dizziness from our own motions and those of other objects._ 4. _Riding over a broad stream. Sea-sickness._ 5. _Of turning round on one foot. Dervises in Turkey. Attention of the mind prevents slight sea-sickness. After a voyage ideas of vibratory motions are still perceived on shore._ 6. _Ideas continue some time after they are excited. Circumstances of turning on one foot, standing on a tower, and walking in the dark, explained._ 7. _Irritative ideas of apparent motions. Irritative ideas of sounds. Battèment of the sound of bells and organ-pipes. Vertiginous noise in the head. Irritative motions of the stomach, intestines, and glands._ 8. _Symptoms that accompany vertigo. Why vomiting comes on in strokes of the palsy. By the motion of a ship. By injuries on the head. Why motion makes sick people vomit._ 9. _Why drunken people are vertiginous. Why a stone in the ureter, or bile-duct, produces vomiting._ 10. _Why after a voyage ideas of vibratory motions are perceived on shore._ 11. _Kinds of vertigo and their cure._ 12. _Definition of vertigo._
1. In learning to walk we judge of the distances of the objects, which we approach, by the eye; and by observing their perpendicularity determine our own. This circumstance not having been attended to by the writers on vision, the disease called vertigo or dizziness has been little understood.