affection or state of the mind which is immediately successive to an affection of some organ of sense, and which is referred by us to something external as its cause.

It will be recollected that the term SENSATION, when applied to the mind, expresses merely the state of the mind without reference to anything external, which might be the cause of it, and that it is the name of a truly simple feeling. Perception, on the contrary, is the name of a complex mental state, including not merely the internal affection of the mind, but also a reference to the exterior cause. Sensation is wholly within; but Perception carries us, as it were, out of ourselves, and makes us acquainted with the world around us. If we had but sensation alone, there would still be form, and fragrance, and colour, and harmony of sound, but it would all seem to be wholly internal. Perception, availing itself of the facts of sensation, connects with them the ideas of causality and externality, and thus reveals to us the visible and tangible realities of the outward world.

§ 38. Of the Connexion between Sensation and Perception.

The mental powers, Sensation and Perception, are considered together in the present chapter, because they are closely connected, and, in consequence of this connexion, throw light upon each other. Perception is the natural result of Sensation. It is that to which sensation tends, and without which, as its natural result, sensation would be almost of no value. Although susceptible of being

philosophically distinguished, they are yet so closely implicated with each other that they are, in a great degree, practically one.

It is particularly necessary to consider them together in the examination of the subject of Insanity. It is true that we may philosophically make a distinction in the aspects of the mental disorder which are presented in the two cases. And yet they are so closely connected, that the examination of them entirely apart from each other would lead to embarrassment. The insanity of external perception involves and substantiates that of sensation. The one does not exist without the other; and the former is the developement and indicator of the latter. These remarks are to be kept in view in connexion with the observations which are to follow.

CHAPTER II.

DISORDERED SENSATION AND PERCEPTION.

(1.) THE SENSES OF SMELL AND taste. § 39. Circumstances attending Disordered Sensa

tions.

HAVING remarked, so far as seemed to be necessary, on the general nature of Sensation and External Perception, we are now prepared to say farther, in the first place, that sensation, even when consid

éred as distinct from perception, is susceptible of a disordered or alienated action. In the verification of this statement two views are to be taken. FIRST.

It is evidently a law of our nature, that the inward sensation, whenever it exists, shall correspond to the condition of the outward or bodily organ. Consequently, a disordered or irregular movement of the organ necessarily communicates itself to the inward or mental state. Perhaps our meaning may not be exactly apprehended here. What we mean to assert is simply this, viz., that the sensation, in consequence of receiving its character from the diseased organ, is not such a sensation as would have existed in a different state of the organ. The product of the action of a sound organ, provided there is no irregular or abnormal affection of the mind itself, is a sensation of a well-defined and specific character. Such a sensation is a sound or normal one. hand, one that exists under the opposite ces, is an unsound or abnormal one. rightly understand the matter, is to be regarded as the result of the natural and permanent relation between the organ and the mental state.

On the other

circumstanThis, if we

SECOND. A view directly the opposite of this may be taken, in explanation of the same result. That is to say, if the organ of sense is sound, but the mind is in a disordered state, the sensation may be unsound or abnormal for this reason also, viz., of unsoundness of mind. The mind, being disordered in itself, is not in a situation to receive the natural or true impression, which the action of the organ would otherwise give. It may be either so depressG

ed in its power of action as not to be deeply enough affected, or it may be so highly susceptible as to receive a wrong impression in the other direction. It may be too vivid or too weak, or fail, in some other respects, in the natural and precise correspondence to the outward affection. We make these general statements here, and leave it to the reader himself to make an application of them, in connexion with the facts to be adduced hereafter.

§ 40. Disordered Perceptions consequent on Disor

dered Sensations.

Perception, as we have already had occasion to intimate, is something additional to sensation, and inclusive of it. Accordingly, the perception will be as the sensation is. If the sensation be actually disordered, it will be found to be the case that the perception will partake of the disorder, and will be unreal, visionary, and deceptive. Perception always has reference to some outward cause; we mean here outward, even in reference to the organ of sense. And when the perceptive power is not disordered, we perceive things, to the limits of that power, just as they are. But it will be recollected that sensation is an intermediate step, preparative to the result of perception. Consequently, if the sensation is disordered, the relation existing between the subsequent perception and the outward cause of perception is disturbed. And, under these circumstances, the perception cannot be expected to correspond, and will not, in fact, correspond to the reality and truth of things. It becomes, what has just been

asserted, unreal and visionary. In other words, it imposes upon our belief, by indicating, with such distinctness as to secure our assent, the existence and presence of objects which are not present, and often not real. It surrounds us with a world of mere illusions.

In accordance with these views, we find it to be the case that there are various kinds of diseased or disordered sensations and perceptions, corresponding to the particular outward organ of sense, whatever it is, which happens to be disordered. These sensations and perceptions (for they are so closely connected that it is not only difficult, but, for nearly all practical purposes, quite unnecessary to separate them) we propose now to examine. And, in doing this, we shall find it not only the most satisfactory, but the most convenient method, to pursue the inquiry in connexion with each of the organs of sense separately. Accordingly, as it is practically of but little consequence with which of the organs we begin, we shall commence our remarks with those which, from their results or some other cause, are generally considered the lowest in importance and rank, and proceed to those which, in their connexion with the operations of the mind at least, appear to be more important.

§ 41. Of Disordered Sensations and Perceptions, connected with the Organ of Smell.

In accordance with the suggestion which has just been made, we may properly begin with the Sense of Smell. The medium through which we have the