This invincible persistence of the activity of the cere bral cells reveals itself very clearly in the following circumstances. Just as the phenomena of their diurnal encroach upon those of their nocturnal activity, so,• in versely, we often see those of their nocturnal activity perpetuated while we lie awake or are dreaming, and not ceasing even at the moment of total awaking of the brain.
We all know that when we awake we may, for a while, generally in the early morning, preserve the re membrance of the dreams that have traversed our brain during the night. We have all met with a certain number of persons who arc more or less intensely pre-occupied with the dreams that have assailed them. Certain feeble characters are even more or less depressed by them, and preserve a painful impression, which they sometimes consider a true presentiment of what may happen to them.
It is, however, in certain forms of mental maladies that this power of dreams to persist during waking moments acquires the greatest degree of intensity.
Thus we see a certain number of patients, paralytics, or victims of hallucination, change the character of their delirious conceptions and take up new ideas, which are nothing but persistent dreams that have been suddenly developed in their minds at night. Thus when I find patients expressing certain • ideas and certain appre hensions in the morning, I infer that they have had terrifying impressions of a certain kind, and should expect to see this emotional condition persist in the form in which it was implanted until it became a fixed and permanent idea, a delirious conception of new formation. We must, therefore, seek the origin of the transformation of certain deliriums, and certain ideas which unexpectedly change the direction of the mental state of certain individuals, in the continuation of the period of erethism of certain groups of cerebral cells, which have come into action during the period of sleep, ..Ind continue to vibrate even during the waking con dition.