CHAPTER VII.

HABITS OF SENSATION AND PERCEPTION.

46. General view of the law of habit and of its applications. THERE is an important law of the mental constitution known as the law of Habit, which may be described in general terms as follows: That the mental action acquires facility and strength from repetition or practice. The fact that the facility and the increase of strength, implied in HABIT, is owing to mere repetition, or what is more frequently termed practice, we learn, as we do other facts and principles in relation to the mind, from the observation of men around us, and from our own personal experience. And as it has hitherto been found impracticable to resolve it into any general fact or principle more elementary, it may justly be regarded as something ultimate and essential in our nature.

The term Habit, by the use of language, indicates the facility and strength acquired in the way which has been mentioned, including both the result and the manner of it. As the law of habit has reference to the whole mind of man, the application of the term which expresses it is, of course, very extensive. We apply it to the dexterity of workmen in the different manual arts, to the rapidity of the accountant, to the coup d'œil or eye-glance of the military engineer, to the tact and fluency of the extemporaneous speaker, and in other like instances. We apply it also in cases where the mere exercise of emotion and desire is concerned; to the avaricious man's love of wealth, the ambitious man's passion for distinction, the wakeful suspicions of the jealous, and the confirmed and substantial benevolence of the philanthropist.

47. The law of habit applicable to the mind as well as the body. It is remarkable, that the law under consideration holds good in respect to the body as well as the mind. In the mechanical arts, and in all cases where there is a corpo

real as well as mental effort, the effect of practice will be found to extend to both. Not only the acts of the mind are quickened and strengthened, but all those muscles which are at such times employed, become stronger and more obedient to the will. Indeed, the submission of the muscular effort to the volition is oftentimes rendered so prompt by habit, that we are unable distinctly to recollect any exercise of volition previous to the active or muscular exertion. It is habit which is the basis of those characteristic peculiarities that distinguish one man's handwriting from another's; it is habit which causes that peculiarity of attitude and motion so easily discoverable in most persons, termed their gait; it is habit also which has impressed on the muscles, immediately connected with the organs of speech, that fixed and precise form of action, which, in different individuals, gives rise, in part at least, to characteristics of voice. The habit, in the cases just mentioned, is both bodily and mental, and has become so strong, that it is hardly possible to counteract it for any length of time.-The great law of Habit is applicable to all the leading divisions of our mental nature, the Intellect, the Sensibilities, and the Will; and as we advance from one view of the mind to another, we shall have repeated occasion to notice its influence. In the remainder of this chapter we shall limit our remarks to Habit, considered in connexion with the Sensations and Perceptions.

§ 48. Of habit in relation to the smell.

We shall consider the application of the principle of Habit to the senses in the same order which has already been observed. In the first place, there are habits of Smell. This sense, like the others, is susceptible of cultivation. As there are some persons whose power of distinguishing the difference of two or more colours is feeble; so there are some who are doubtful and perplexed in like manner in the discrimination of odours. And as the inability may be overcome in some measure in the former case, so it may be in the latter. The fact that the powers of which the smell is capable are not more frequently brought out and quickened, is owing to the

circumstance that it is not ordinarily needed. It sometimes happens, however, that men are compelled to make an uncommon use of it, when, by a defect in the other senses, they are left without the ordinary helps to knowledge. It is then we see the effects of the law of Habit. It is stated in Mr. Stewart's account of James Mitchell, who was deaf, sightless, and speechless, and, of course, strongly induced by his unfortunate situation to make auch use of the sense we are considering, that his smell would immediately and in.variably inform him of the presence of a stranger, and direct to the place where he might be; and it is repeatedly asserted, that this sense had become in him extremely acute." It is related," says Dr. Abercrombie, "of the late Dr. Moyse, the wellknown blind philosopher, that he could distinguish a black dress on his friends by its smell."

In an interesting account of a deaf, dumb, and blind girl in the Hartford Asylum, recently published, statements are made on this subject of a similar purport."It has been observed," says the writer, "of persons who are deprived of a particular sense, that additional quickness or vigour seems to be bestowed on those which remain. Thus blind persons åre often distinguished by peculiar exquisiteness of touch; and the deaf and dumb, who gain all their knowledge through the eye, concentrate, as it were, their whole souls in that channel of observation. With her whose eye, ear, and tongue are alike dead, the capabilities both of touch and smell are exceedingly heightened. Especially the latter seems almost to have acquired the properties of a new sense, and to transcend the sagacity even of a spaniel."-Such is the influence of habit on the intimations of the sense under consideration.

§ 49. Of habit in relation to the taste.

The same law is applicable to the Taste. We see the results of the frequent exercise of this sense in the quickness which the dealer in wines discovers in distinguishing the flavour of one wine from that of another. So marked are the results in cases of this kind, that one is almost disposed to credit the story which Cervantes ce

lates of two pers ns, who were requested to pass their judgment upon a hogshead which was supposed to be very old and excellent. One of them tasted the wine,

and pronounced it to be very good, with the exception of a slight taste of leather which he perceived in it. The other, after mature reflection and examination, pronounced the same favourable verdict, with the exception of a taste of iron, which he could easily distinguish. On emptying the hogshead, there was found at the bottom an old key with a leathern thong tied to it.

Another practical view of this subject, however, presents itself here. The sensations which we experience in this and other like cases, not only acquire by repetition greater niceness and discrimination, but increased strength; (and perhaps the increased strength is in all instances the foundation of the greater power of discrimination.) On this topic we have a wide and melancholy source of illustration. The bibber of wine and the drinker of ardent spirits readily acknowledge, that the sensation was at first only moderately pleasing, and perhaps in the very slightest degree. Every time they carried the intoxicating potion to their lips, the sensation grew more pleasing, and the desire for it waxed stronger. Perhaps they were not aware that this process was going on in virtue of a great law of humanity; but they do not pretend to deny the fact. They might, indeed, have suspected at an early period that chains were gathering around them, whatever might be the cause; but what objection had they to be bound with links of flowers; delightful while they lasted, and easily broken when necessary! But here was the mistake. Link was added to link; chain was woven with chain, till he who boasted of his strength was at last made sensible of his weakness, and found himself a prisoner, a captive, a deformed, altered, and degraded slave.

There is a threefold operation. The sensation of taste acquires an enhanced degree of pleasantness; the feeling of uneasiness is increased in a corresponding measure when the sensation is not indu.ged by drinking; and the desire, which is necessarily attendant on the uneasy feeling, becomes in like manner more and more imperative. F

To alleviate the uneasy feeling and this importunate desire, the unhappy man goes again to his cups, and with a shaking hand pours down the delicious poison. What then? He has added a new link to his chain; at every repetition it grows heavier and heavier, till that, which at first he bore lightly and cheerfully, now presses him like a coat of iron, and galls like fetters of steel. There is a great and fearful law of his nature bearing him down to destruction. Every indulgence is the addition of a new weight to what was before placed upon him, thus lessening the probability of escape, and accelerating his gloomy, fearful, and interminable sinking. We do not mean to say that he is the subject of an implacable destiny, and cannot help himself. But it would seem that he can help himself only in this way; by a prompt, absolute, and entire suspension of the practice in all its forms, which has led him into this extremity. But few, however, have the resolution to do this; the multitude make a few unwilling and feeble efforts, and resign themselves to the horrors of their fate.

50. Of habit in relation to the hearing.

There is undoubtedly a natural difference in the quickness and discrimination of hearing. This sense is more acute in some than in others; but in those who possess it in much natural excellence, it is susceptible of a high degree of cultivation. Musicians are a proof of this, whose sensibility to the melody and concord of sweet sounds continually increases with the practice of their art.

The increase of sensibility in the perceptions of hearing is especially marked and evident, when uncommon causes have operated to secure such practice. And this is the state of things with the Blind. The readers of Sir Walter Scott may not have forgotten the blind fiddler, who figures so conspicuously with verse and harp in Red Gauntlet; a character sufficiently extraordinary, but by no means an improbable exaggeration. The blind necessarily rely much more than others on the sense of hearing. By constant practice they increase the accuracy and power of its perceptions. Shut out from the beauties that are seen, they please themselves with what is