This case differs from the others in the circumstance that the period of somnambulic life was more vigorous and healthy than the ordinary condition. This seems to suggest an explanation of the forgetfulness which marked the period of normal life. During that period the functions of the brain were depressed, so that its molecular movements could not reach the level of the field of consciousness occupied during the second period. Other observations, such as that of Sir Henry Holland,[89] who, while exhausted by fatigue, lost all recollection of the German language until he was restored by rest and food, indicate that such defects of memory depend upon a deficient nutrition of the brain substance--a condition which is undoubtedly associated with an enfeebled cerebral circulation. We may, therefore, suppose that in Dr. Azam’s case the paroxysms of somnambulic life were induced by periodical discharges of force within the brain, causing an improvement in the circulation of blood, and a corresponding gain in health and general vivacity. Such exaltation of the faculties would be perfectly consistent with an exercise of memory covering all the events of life. But, when, as in cases like that reported by Macnish, and by myself, somnambulic life is the result either of disease or simple somnambulic sleep, it is a condition in which, as in physiological sleep, the cerebral functions, taken as a whole, are depressed rather than exalted. The resulting train of ideas is developed upon a plane below the level of ordinary consciousness, and is, consequently, as easily forgotten as the dreams which are developed during sleep.