All the larger divisions here are from Yarrell's truly beautiful work on British Ichthyology; and a glance will suffice to show in what need they stand of revision. I have, however, made some approach to exactitude in nomenclature, and have not given up all attempts at correctness because perfection was at first unattainable. Indeed, the space taken up by the catalogue would have been lost, and worse than lost, if it had been a mere transcript of the commonly-received lists; for it is better to remain in ignorance than to be led into error. I have lately seen some passages of Swainson on nomenclature, which he should have been the last to have written: and, doubtless, he will be heartily ashamed of them ere long. The public has, on several memorable occasions, lately shown itself superior to the weakness of being led away by a great name from the paths of truth; indeed it is now arriving at years of discretion, and will no longer suffer itself to be drawn into the bog of error by every one who pretends to superior wisdom.

October 15, 1836.

S. D. W.

[This is certainly a most laudable attempt at a correct nomenclature of British Fishes. We, in general, approve of the names adopted; but fear that some of them will be found too uncouth by lovers of the euphonious. However, we are glad the attempt has been made, especially as such appellations as are objected to can easily be altered at any time. We wish that our Correspondent could be ashamed out of the absurd mode of spelling he has thought fit to employ; as we feel convinced that this trifling will deter many from adopting his really useful alterations.-EDS.]

ON THE EFFECTS OF CERTAIN MENTAL AND BODILY STATES UPON THE IMAGINATION.

BY LANGSTON PARKER, ESQ.

V. ON THE HALLUCINATIONS PRODUCED BY THE

IMAGINATION.

OUR present lecture relates to a mood of the Imagination distinct from the three we have noticed in the previous discourses. Hallucination is mistaken or diseased perception. It is the seeming presence of that which does not really exist to the senses of a waking man. It may extend to all the organs through which we derive ideas of the nature of things, but those of hearing and sight are most commonly affected, and of these two most frequently the latter. The Imagination derives all the materials from which it compounds its extraordinary scenes from the sense of vision. Sight is the most active, the most varied, and the most useful of all the bodily senses; most extended in its relations, and from which the mind derives by far the greater part of its ideas. It has to do merely with the surfaces of bodies, with their form, size, and colour; it is liable to misconception of these properties from many causes- -from distance, from the state of the atmosphere, and from imperfection in the structure or functions of the eye itself. From these multiplied sources are produced a variety of mistaken perceptions, termed optical illusions; and from a number of causes of a similar character the ear is misled, and conveys a mistaken and false account to the brain. If these illusions be extended to the other senses, of course they derange the operations of the mind with regard to those properties of bodies which it is exclusively the destiny of such sense to ascertain. But these are not hallucinations, properly so called; it is true they convey erroneous ideas, and therefore may, in some measure, merit the term: but it is, as far as I am acquainted with medical or philosophical language, and the application of that language, exclusively applied to those illusions where no physical agent is concerned in their production. As the senses furnish the mind exclusively with all its ideas, and as this is dependent for their truth upon the fidelity of its servants, so does the mind by a reciprocal action, and by a mysterious property inherent in itself, direct the actions of the senses, and enable them to

judge truly and correctly.* As long as the mind remains perfectly sound, and its three great powers bear a strict and healthy relation to each other, the actions of the senses will be correct, and the ideas they furnish consonant to the order and perfection of nature. But when the faculties of the mind become unduly exalted, or the reciprocity of these actions destroyed-whether, as we have before seen, from disease of body or disorder affecting the mind in the abstract—a false action will be given to one or more of the senses, and hallucination will take place. From this view it will at once be seen that hallucinations will be most common in persons whose minds are totally deranged, in those labouring under the various forms of melancholy or mania; and this is actually the case, scarcely any form of insanity being totally devoid of hallucination of one or more of the senses. Hallucination may be confined to one sense, as monomania is limited to one series of ideas; the eye may be false whilst the ear remains true, the taste may be deceptive whilst the touch accurately informs of all the properties its functions permit it to ascertain. It is commonly the case that hallucination, as affecting one or more senses, bears a correspondent relation to that state of mind which produces the affection in the first instance; thus, the maniac will be deceived by the actions of every sense, while the hallucinations of the monomaniac will be confined to one. A very remarkable instance of this is related in a recent publication, and though probably well known, it illustrates so clearly this point, and throws so much light on the theory I have just promulgated, that I do not think it necessary to resort to works less known for an example, since I know not where I could find one so suitable and so authentic. It was not originally related to illustrate a point of similar character to that to which I am about to

*Hallucinations, according to Esquirol, are images produced by memory, and associated by imagination. Foville, with more truth, considers them entirely as the product of a morbid imagination, which gives reality to the ideas existing in the mind; i. e., the mind presents its ideas to the senses in a form which calls into action the functions of that sense to which the hallucination is addressed. 'Thus, the mind calls up the idea of a form which the eye beholds, it conceives of sounds which the ear detects, yet which have no existence. A priest, a man of strong mind and good education, was subject to hallucinations of the ear; he heard voices which continually threatened him. Being reasoned with upon his affection, and the nature of depraved sensation and false perception being explained to him, he constantly replied "I ought then to doubt what you say to me and what I see; for the sounds which appear to you to have no existence, appear to me as certainly to be real as anything else which I see or hear around me."

VOL. V.-NO. XVIII.

2E

apply it. A person confined for that form of mental derangement which we considered in the last lecture as amenomania, or gay melancholy, fancied the asylum in which he was confined his own, and he contrived to account for all that seemed inconsistent with his imaginary right of property. There were many patients in it, but that was owing to the benevolence of his nature, which made him love to see the relief of distress. He went little, or rather never, abroad, but then his habits were of a domestic and rather sedentary character. He did not see much company, but he daily received visits from the first characters in the renowned medical school of the city, and he could not, therefore, be much in want of society. With so many supposed comforts around him-with so many visions of wealth and splendour-one thing alone disturbed the peace of the poor optimist, and would, indeed, have confounded most "bons vivans." "He was curious," he said, "in his table, choice in his selection of cooks, had every day three regular courses and a dessert; and yet, somehow or other, everything he ate tasted of porridge. This dilemma could be no great wonder to the friend to whom it was related, who knew that the poor lunatic ate nothing but this simple aliment at any of his meals." His eyes were made the fools of his other senses, spreading before his deluded vision a splendid banquet, whilst the taste remained true to nature, and spoiled all his ideal dainties by not taking part in the deception.

There are certain states of mind in which we are carried, in our ideas, beyond the ordinary routine of thought and the influence of customary impression. This may arise from many sources-it may be caused by certain medicinal or morbid agents, as opium, nitrous oxide, and febrile miasma. But that to which I now allude is not produced by any of these; it is a condition of mind the consequence of great excitement, when, on the eve of some great enterpriseof some literary undertaking—about the success of which we are uncertain, the senses, though wandering over the forms of outward objects, take little cognizance of their presence. The mind, at these periods, throws no part of its being into the actions of the senses; they are inert and powerless. The whole mental faculties are concentrated about the one great object of our anxiety. There are many persons in whom this state of mental concentration is habitual. When alone, from the activity and vigour of their fancies, some novel idea soon intrudes, becomes cherished and isolated.

*Letters on Demonology and Witchcraft, by Sir W. Scott.