PART I.

SECTION 1.-ILLUSIONS.

By an Illusion, I need scarcely say that I mean an involuntary sensation without corresponding external object. By this definition I exclude those voluntary creations of memory or fancy, not rare, I believe, in childhood, which, though full of interest as illustrations of sensations generated from within, have no direct bearing on my subject. Let me say, too, that as I have no use for the word Hallucination, and some objections to it, which I need not particularise, I shall not employ it. I shall use the one term Illusion, adding to it-that I may not be misunderstood-the three words "of the senses"-Illusions of the senses; and where others employ the word "hallucination," I shall use what I deem a better term, “illusive transformation," on which, I think, I shall have something interesting and important to say. Need I add that I have no intention of misapplying the word Illusion to any object really seen, though at the time misunderstood, such as the "Giant of the Brocken," or any other kind or form of mirage? and that I shall not stop to take note of such trivial impressions on

the organs of sense as double, quadruple, inverted, or interrupted vision, sparks and flashes of light, halos of colour; musical notes; sour and bitter savours; and slight and transient disorders of the sense of touchtrivial sensations in harmony with the special functions of the organs in which they occur; but, again, not having any direct bearing on my subject. The illusions of which I am to treat are life-like moving figures, spoken words and speeches, odours, savours, and tactile sensations of a well-defined order. I shall add to the interest of this part of my subject if I premise that Esquirol estimates, as subject to illusions, four in five of the whole body of the insane.

From what I have said you will infer that I use the words "Unsound Mind" in a somewhat restricted sense, excluding those Idiots and Imbeciles in whom the mind is too undeveloped, or too inactive, to become subject to illusions of the senses, or analogous affections of the organ of thought; and who have too little force of character to perpetrate acts which raise the question of culpability in our courts of law. The Illusions to which I shall first ask your attention are such as occur in persons of perfectly sound intellect sensations originating in the brain within, not coming from the world without-sensations which the will has no power to produce, or to prevent.

As an excellent illustration of this class of cases I take the account given by Sir David Brewster, in his Natural Magic, of a lady whom he designates as Mrs. Sir David was personally acquainted with

A

CASE OF MRS. A

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the lady, and had the facts of her case from her husband, a gentleman of learning and science. He describes her as a person of high character and intelligence, with a wonderful verbal memory, and so sensitive that a description of pain in another person would conjure up a like pain, in the same part, in herself. Her waking imagination was "morbidly sensitive," and she would talk in her sleep with great fluency. Her first illusions occurred when she was weakened by a troublesome cough; the remainder were attributed to a "disordered state of the digestive organs." Sir David describes no less than twelve illusions occurring in the interval between December 26, 1830, and December 3, 1831. The first, fifth, and sixth, were illusions of the hearing, the remainder of the sight. She heard the voice of her absent husband, and held conversations with him; and she saw him once. Once she saw a spectral cat, once the duplicate of the dog she held in her lap. Once she saw a shrouded figure reflected in the glass, once a deceased friend appeared to her; twice the brothers, once the sister, and once the mother of her husband. One brother, seen in a shroud, was at the time alive and well; the other relatives were dead. The lady had always the most perfect consciousness that the sounds and sights which haunted her were mere illusions. She noticed that her spectres moved about without the sounds which should have attended their movements; and that the voice and conversation of her husband were not accompanied by his visible

presence. I have omitted to mention the strange and fantastic carriage-full of skeletons that drove up to her door, and I ought perhaps to have noted the prevailing sombre character of her visions.

I have selected this from the large number of similar cases which comprises that of Nicolai, the Berlin bookseller, Mr. Abernethy's woman in red, and Sir Walter Scott's Green figurantés, who first drove an unfortunate gentleman from his home, and then banished him from his country, partly because the case is not only well authenticated and well described, but because it gives me an opportunity of thus early correcting an error into which Sir David Brewster, following Dr. Hibbert, fell, when he penned the short formula-"the mind's eye' is actually 'the body's eye,' and the retina the common tablet on which both classes of impressions are painted." This error, condemned by cases reported by Esquirol, Abercrombie, and others, and distinctly recognised as such by the late Sir Benjamin Brodie, I can illustrate by a case that came under my own observation.

It was one of progressive locomotor ataxy of many years' standing, first attacking the spinal cord, then the base of the brain: first impairing, then destroying, the sense of sight; then, with stealthy step, travelling forward towards the anterior lobes, marking its course. by illusions of the sense of smell, failure of memory, and impairment of a naturally fine intellect. The illusions of the sense of smell, it may be observed, were preceded by the first of many epileptic fits. Now this gentleman, after he had quite lost his sense of sight,