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CHAPTER XXV.

DR. MACNISH, ON THE PHILOSOPHY OF SLEEP.-ARGUMENTATIVE

DREAMS.

CONSCIENCE.-SOMNAMBULISM.-ABSENCE OF MIND.-MORAL APOPLEXY.— RESTORATION OF THE

SPEECH GIVEN BY

FACULTIES.

TERROR.COMA.-SUDDEN

DR. MACNISH, in his "Philosophy of Sleep," gives the following account of some delusions to which he was subject during an attack of fever; the only thing at all remarkable is that he was perfectly conscious of the fallacy of his impressions during the whole period of their existence--otherwise, they do not differ from the common form of delirium in idiopathic fever. Indeed, similar delusions sometimes accompanied by consciousness are not very rare at the commencement of irruptive diseases, especially in children. Mr. George Combe cites the case, as if it were very extraordinary. Dr. Macnish says "the allusions did not appear except when the eyes were shut, or the room perfectly dark, so that I was obliged to keep my eyes open or admit more light than they could well bear. I had the consciousness of shining and hideous faces grinning at me in the midst of profound darkness, from which they glared forth in horrid and diabolical relief; they were never stationary, but kept moving in the gloomy background; sometimes they approached within an inch or two of my face, at others receded to a distance. They would break into fragments, which after floating about would

unite, portions of one face coalescing with those of another, and thus forming still more uncouth and abominable images. The only way I could get rid of these phantoms was by admitting more light into my chamber, and opening my eyes, when they instantly vanished, but reappeared when the room was again darkened or the eyes closed. One night, when the fever was at its height, I had a splendid vision of a theatre, in the arena of which Ducrow, the celebrated equestrian, was performing. On this occasion, I had no consciousness of a dark background like to that on which the monstrous images floated; but every thing was gay, bright, and beautiful-I was wide awakemy eyes were closed, yet I saw with perfect distinctness the whole scene going on in the theatre: Ducrow performing the wonders of his horsemanship, and the assembled multitude, among whom I recognised several intimate friends, in short, the whole process of the entertainment, as clearly as if I were present at it. When I opened my eyes, the whole scene vanished like the enchanted palace of the necromancers; when I closed them, it as instantly returned. But though I could thus get rid of the spectacle, I found it impossible to get rid of the accompanying music. This was the grand march in the opera of Aladdin, and was performed by the orchestra with more superb and imposing effect, and with greater loudness, than I ever heard it before-it was executed, indeed, with tremendous energy," etc. He goes on to say that the theatrical scene lasted five hours, and the whole delusion two days; and he then proceeds to account for it by asserting that the state of the reflecting organs was unchanged, but that certain other portions of the brain, which he

calls idealty, form, wonder, colour, and size, were all in intensely active operation.

Now let us see if this assumption will bear examination, and whether we cannot give an explanation of the facts without the unqualified assent he requires.

It is agreed that the external object only gives sensation, and that perception is a subsequent act of the intellectual faculties. Whatever be the movement, undulation, vibration, concussion, circulation, or other act, which an organ of special sense takes on when the objects to which it is adapted are presented to it (odours to the nose, sounds to the ears, etc.), we know by multiplied experience it may take on spontaneously from disorder, and thus lead to perception as completely as the object itself. With only one brain, such false information given by a special sense must be credited, unless, by a long process of ratiocination, we at last prefer the testimony of friends to the evidence of our own senses. Without such testimony, and without the opposing evidence of other senses, the perception must be believed; but, if only one brain be the subject of disease, a very different process takes place in the mind; the recognition of the phenomenon as a delusion seems, indeed, positive proof that the other brain does not believe it. When the eyes were open, and real impressions made both on the sound organ and on the disordered organ, both together were sufficient to dissipate the erroneous impressions, and prevent sensation and perception from creating belief; but if the eyes were closed, the false impressions being no longer counterbalanced by the true, the delusion continued, and it was only the comparison formed by the state with the eyes shut and the state with the eyes open which could raise a

doubt. Had both brains been the subject of the disorder, it would have been the common form of delirium -there would have been entire belief in the reality of the scene represented by the disordered organs, which would have lasted till the disturbance of the organs had subsided into the natural state again.

There are few individuals accustomed to dream, who have not sometimes, when in that state, held a controversy apparently with another person. Like Dr. Johnson, they may have been overpowered by the greater prowess of their imaginary antagonist, and felt mortification at the superior wit of their collocutor. Dr. Johnson, in relating a dream of this kind, remarks, "Had I been awake I should have known that I furnished the wit on both sides."

I consider this process to be the action of two brains separately carrying on their respective trains of thought, and to be a state precisely similar to that of the madman talking to himself, or rather arguing with himself --one of the most common phenomena of insanity. The only difference I can perceive is, that, in the case of the madman, one at least of the trains of thought is diseased, while in the dream each may be rational.

Perhaps there is a still greater analogy between the kind of dream I have described and the state of pervigilium which sometimes precedes madness. In all these cases the two cerebra are carrying on separate and distinct (even when not conflicting) trains of thought; it is a mere accident whether they shall take the form of an argument or not.

This form of dreaming is often an object of curiosity, and a source of much metaphysical mysticism. No

one, that I am aware of, has ever attempted a physical explanation, yet, now it is suggested, I do not think that any one will hesitate to give a full assent to my theory of its origin. It is not long ago that I was myself annoyed with a dream of this kind. My conscious self, in possession of one of my brains, strenuously but vainly endeavoured to convince the other that certain acts I had committed many years ago were justifiable; the arguments by which they were condemned were so plausible that I awoke in very great anxiety at not being able to recollect the reasons for the condemned measures, but with a conviction that there were good and valid motives for them which had passed away from my memory. When thoroughly awake, and able to exercise that most incomprehensible of all the mental faculties-recollection, I could have justified my conduct before any tribunal. There remained on my mind throughout the day a feeling like that which would possess a man who recalled, after an unsuccessful defence of a client in a court of justice, an overpowering argument which he had intended to use, but which had passed away from his mind at the proper time.

Memory may exist in each brain; but recollection is a conjoint act of the two, and cannot, I believe, take place in a dream. "I do not say that this explanation is probable; I do not say it is possible; yet I fully believe it." Let the reader consider the matter a while, and he will be of my opinion. It will appear to him fanciful and absurd perhaps, if I express my belief that the process here described, as taking place during sleep, is only a modification of that which in our waking state we term conscience. Persons