this diversity, I might, perhaps, be inclined to look to the view now given of the real nature of vibration, and its progressive effects on the auditory part of our nervous system, as furnishing some slight ground, not, indeed, for any theory, which is far too presumptuous a word, but for the preference of one mere possibility, to other mere possibilities, which is all that can be hoped in any conjecture, on so very dim and impalpable a subject. We have seen that the series of pulses of the vibrating air,-if vibration, or a series of pulses be necessary to sound,-must produce a series of changes in the sensorial organ, which produce no corresponding affection of the mind, till, at last, a state of the organ is produced, which is attended with sensation. This, and this only, can be meant, when we speak of vibration as the antecedent of sound,-a series of organic changes, and, after this series, an affection of the mind. In such circumstances, it is certainly more probable, that the organ thus affected with a series of progressive changes, does not pass instantly from the greatest change to the state in which it was originally, before the first pulse, but that it retains this state, for a time, however short, or, at least, passes through some series of states, in its gradual return, so that, if a new vibration be excited by the pulse of any sounding body, before the organ of hearing have returned to its original state, the effect may be supposed to be different from that which it would have been, if the same vibration had been primarily communicated to the organ, in its state of rest, or in that state, which, from our want of a better word, may be termed its state of rest. The phenomena most analogous to these vibratory affections of the ear, as depending on successive impulses, are unquestionably the phenomena of titillation, or rather, to express what is so familiar and simple, by a more homely and appropriate word, the phenomena of tickling. In this, the great circumstance distinguishing musical feeling, is to be found, that the feeling arises not from the separate impressions, but from their successions or coexistence. When the palm of the hand is gently tickled, as the finger passes rapidly and repeatedly over the palm, the parts first affected are again affected with various degrees of pressure, as the ear, in melody, is successively affected by repeated varieties of vibration; and various parts of the organ of touch exist, at the same moment, in various states, forming one joint result of sensation, as, in harmony, various vibrations of the organ of hearing coexist, and blend together in one mingled delight. To produce tickling, a certain rapidity of succession is necessary; for, if the parts first affected, have returned to their original state, before other parts begin to be affected, or themselves to be affected again, the slow motion, it is evident, may be continued, for any length of time, without any effect, different from that of simple pressure. The quicker, then, the return of the parts may be to their original state, the less will be the titillation; and it is, very probably, a difference in this quickness of return, which constitutes the difference of ticklishness, so remarkable in different individuals, who feel, equally, the light pressure of each separate touch. That there is a difference of ticklishness, in different persons, you all know; some being easily excited even to convulsive laughter, by slight motions, that scarcely produce any effect in others, beyond that of the simple primary sensation of touch. A person who is ticklish, and a person who is not ticklish, agree in receiving this first tactual sensation; but they differ afterwards, in this respect, that when the same VOL. I. 27 slight impulse is rapidly repeated, on the same surface, it produces a livelier effect than before, in the one, but not in the other. The organ of the one who is not ticklish, is in the same state, or nearly in the same state, when it receives the second, third, and fourth impression, as when it received the first, and no peculiar excitement, therefore, is produced. The organ of the other, more susceptible, or more tenacious of the affection produced, has not returned to its original state, when the rapid impression is repeated, and is, therefore, at every new impression, affected in a very different man ner. Proceeding on the analogy of these phenomena,-of mere tickling, with which I may suppose you to be all acquainted,—an analogy which, striking as it is in many circumstances, I readily own, does not justify more than conjecture in the case to which I would apply it, I conceive it to be, at least, not absolutely impossible, since a diversity of some kind there must be, that in those who receive no pleasure from music, as in those who are not ticklish, there is a rapid return of the nervous organ, after each separate affection, to its original state; that each separate touch or pressure in the one case, and each separate tone in the other case, produces its particular effect, that effect which it would have produced in all, if unaccompanied by any other tone in music, or slight pressure in tickling, but that a succession of these produces no effect different from that which each would have produced singly. A certain interval is necessary for distinct hearing in every case; and, before this interval has passed, the auditory nerves, in this case, may be imagined to be again quiescent, or nearly quiescent. I need not add, that in an inquiry of this sort, all which is necessary, is to account for the mere original defect of pleasure; since, if the relations of notes, as reciprocally high or low, never gave any delight, the ear, having no object of interest in these successions, would soon habitually neglect them, and at length cease altogether to distinguish them, attending only to the verbal meaning of sounds, and not to their tone; in the same manner, as we pay little attention to another relative difference of voices as more or less loud, unless when the difference is very considerable, and not in those common differences of intensity which distinguish every voice in conversation from every other voice, or as, after living long in a province, the dialect of which is distinguished by any accentual peculiarities, we at last become unconscious of these, and hear the words, as it were, stripped of their peculiarity of tone. In what is termed the cultivation of a musical ear, however, we have not an analogy merely, but a direct proof of this influence of habit. That the ear may be improved by cultivation, or, in other words, by nice attention to the differences of musical sound, every one knows; and if this attention can enable us, even in mature life, to distinguish sounds as different in themselves, which, but for the habitual attention, we should have regarded as the same, it may well be supposed, that continued inattention, from earliest infancy, may render us insensible of musical relations still more obvious and precise, than those which we have thus only learned to distinguish; or, which is the same thing, that continued attention from infancy to slight musical differences of sound,-an attention which may be regarded as the natural effect of pleasure received,-may render us capable of distinguishing tones as very dissimilar, the differences of which, however obvious at present, we should scarcely, but for such original attentive discrimination, have been able to detect. What, in comparison, the refined musical ear of a performer, almost every hour, and every moment, of whose life has been spent amid sounds, "Untwisting all the chains, that tie is to a common musical ear, that common musical ear may be to those in whom this discriminating skill seems to be wholly or nearly defective. The refined musician,-who, but for the long practice of his art, would have shared that incapacity which now excites his wonder,-is astonished, that persons of common ear do not distinguish the nice differences which appear to him almost as remarkable as those differences which they are capable of perceiving; and the person of common musical ear only does the same thing, when he is astonished that the less refined differences, remarked by himself, are not obviously distinguishable by all mankind, or, at least, by all who have no deafness to incapacitate them from hearing the separate sounds. The discrimination in both has depended on previous attention, which has necessarily been greater in one case than in the other; and what attention can we suppose to have been originally given, if, from the cause which I have ventured to state as a possible one in persons without musical ear, no pleasure had originally been felt by them in any sequence of notes as successive, and the whole value of sound been to them the meaning of which it was symbolically representative, which, accordingly, they have learned to discriminate in every case, as accurately as others. I might follow out this speculation at much greater length; but I have already dwelt too long on what is at best a conjecture, and what, perhaps, even as a mere conjecture, is founded only on a slight analogy. After the examination of the phenomena of Smell, Taste, and Hearing, which are peculiarly simple, I proceed to the consideration of Senses, which afford phenomena that are more complicated, or, at least, which seem more complicated, as considered in the mature state of the mind; when the sensations that arise from one set of organs, by frequent coexistence with sensations that arise from affections of other sets of organs, are, as it were, blended with them in one compound perception, and so permanently modified for ever after, that it is difficult in all cases, and in many cases perhaps impossible, to form any accurate notion of the sensations as they existed in their original elementary state. Since, of the two senses of Sight and Touch, that of Sight, as far, at least, as we are able by intellectual analysis at present to discover its original sensations, is more simple, and more analogous to the senses before considered, I should be inclined, on these accounts, to proceed to the consideration of it, previously to any inquiry into the sense of Touch. But this order, though unquestionably the more regular, if we had to consider only the original sensations of each organ, would be attended with great inconvenience in considering their subsequent modified sensations; since those of Vision depend, in a very great degree, on the prior affections of Touch, with the nature of which, therefore, it is necessary for you to be acquainted in the first place. I am aware, indeed, that, in considering even Touch, I may sometimes find it necessary to refer, for illustration, to the phenomena of * Milton's L'Allegro, 143–145. Vision, though these have not been considered by us, and must, therefore, for the time, be taken upon trust. But when phenomena are at all complicated, such occasional anticipations are absolutely unavoidable, Sensation, indeed, says Aristotle, is a straight line, while intellect is a circle,—Aïconcis reapun, vous xúxλos, or, to use the paraphrastic translation of Cudworth, in his treatise on Immutable Morality, "Sense is of that which is without. Sense wholly gazes and gads abroad; and, therefore, doth not know and comprehend its object, because it is different from it. Sense is a line, the mind is a circle. Sense is like a line, which is the flux of a point running out from itself; but intellect like a circle, that keeps within itself."* That sense is not a circle is, indeed, true, since it terminates in a point; but far from being a straight line, it is one of the most perplexing of curves, and is crossed and cut by so many other curves,—into many of which it flows, and unites with them completely,-that when we arrive at the extremity of the line, it is almost impossible for us to determine with accuracy what curve it is, which, in the strange confusion of our diagram, we have been attempting to trace from its initial point. I proceed, then, to the consideration of the phenomena of the sense of TOUCH. Ir priority of sensation alone were to be regarded, the sense of touch might deserve to be considered in the first place; as it must have been exercised long before birth, and is probably the very feeling with which sentient life commences. The act of birth, in relation to the mind of the little stranger, who is thus painfully ushered into the wide scene of the world, is a series of feelings, of this class; and the first feeling which awaits him, on his entrance, in the change of temperature to which he is exposed,-is still to be referred to the same organ. It is at this most important moment of existence, when one dark and solitary life of months, of which no vestige is afterwards to remain in the memory, is finished, and a new life of many years, a life of sunshine and society,—is just beginning, that, in the figurative language of the author, whom I am about to quote to you, Pain, the companion of human life, receives him on the first step of his journey, and embraces him in his iron arms. "Primas tactus agit partes, primusque minute Non idem huic modus est qui fratribus; amplius ille Circumfusus adhuc; tactus tamen aura lacessit Idque magis, simul ac solitum blandumque calorem Frigore mutavit cœli, quod verberat acri Impete inassuetos artus; tum sævior adstat, Humanæque comes vitæ Dolor excipit; ille Cunctantem frustra et tremulo multa ore querentem It is at this moment, so painful to himself, that he is affording to another bosom, perhaps the purest delight of which our nature is capable, and has already kindled, in a heart, of the existence of which he is as ignorant as of the love which he excites in it, that warmth of affection which is never, but in the grave, to be cold to him, and to which, in the many miseries that may await him,-in sorrow, in sickness, in poverty, and perhaps too in the penitence of guilt itself,-when there is no other eye to whose kindness he can venture to look, he is still to turn with the confidence that he has yet, even on earth, one friend, who will not abandon him,—and who will still think of that innocent being, whose eye, before it was conscious of light, seemed to look to her for the love and protection which were ready to receive him. LECTURE XXII. ON THE FEELINGS USUALLY ASCRIBED TO THE SENSE OF TOUCH,AND ANALYSIS OF THESE FEELINGS. - IN my last Lecture, gentlemen, I finished the remarks which I had to offer, on our sense of hearing; and in the conclusion of it, had begun the consideration of a very important order of our feelings, those which belong to the sense of touch. Of these, I may mention, in the first place, the sensations of heat and cold,—sensations that arise from affections of our nerves of touch, or at least from affections of nerves, which, as equally diffused and intermingled with them, it is impossible to distinguish from those which constitute our organ of touch, the same wide surface rendering us sensible, as it were, at every point, of warmth as of pressure. I have already remarked to you, how little analogy there is of our sensations of warmth, to the other sensations commonly ascribed to this organ; and the great difference of the feelings has led some physiologists to believe, that the organs of sensations so different, must themselves be different. But even though the sensations were as dissimilar as is supposed, there is no reason a priori to believe, and to experience, it is evident, that, in this case, we cannot appeal, so as to derive from it any ground for believing, that sensations, which are very different, must arise from affections of different organs. As far, indeed, as we can safely appeal to experience, in this very case, there are sensations which we never hesitate in referring to our tactual nerves, as different from the more common sensations ascribed to touch, as the sensation of warmth itself. I allude to the pain of puncture or laceration of the skin. Indeed, if the brain be ultimately the great organ of all our sensations, it is evident that we must refer to affections of one sensorial organ, not the various feelings of touch only, but, with them, the still greater variety of feelings, that constitute our sensations of smell, taste, sound, and colour. But are we indeed sure, that there truly is that great dissimilarity supposed, or may not our belief of it arise from our reference to touch of sensations that truly do not belong to it? Such, at least, is the opinion, to which, I think, a nicer analysis will lead us. The primary original feelings, |