acts of the memory spring from sensation-the memory, that noble and capacious faculty of the soul-the storehouse of our experiences, which guide us in our conduct, and of the materials which reflection converts into knowledge. At a very early age, even before the child begins to observe things very closely, he will unconsciously make a comparison among objects before him, and turn decidedly to the most striking. The strongest light, the sharpest sound attract his notice. This is discrimination; these are the incipient efforts of the judgment. After a time, he will measure with his hand, or his eye corrected by his hand, the sizes and distances of objects, or compare with his taste or smell this sweetness or fragrance with that. He has now in active use the faculty of judgment, and long indeed must he exercise it upon perceptions before he can apply it to abstract thoughts, or even trace or know any thing of the movements of his own mind. Somewhat later, when the young mind begins to unite the various infant experiences it has treasured up in the memory, perhaps when the child recognizes a friendly countenance, and out of his past simple pleasures schemes a new one, then he is exerting his imagination. Soon he will learn to weave assiduously a broad web of his past impressions, to pourtray to himself a picture of the future, whether with the bright lights of hope or the gloomy shades of fear, or with both in mingled relief. With how many fond but false expectations does the imagination, built upon erroneous perceptions, elate us; with how many dark but unreal forebodings depress us! Based upon accurate and full observations, it lights up the eye of the artist, the poet, and the orator, with their noblest conceptions, but otherwise cheats them with tinsel promises, and leaves them to lament the baseless fabrics of their visions. But let us reflect that the earliest, and for a long period the only exercise of this faculty, must be upon thoughts relative to objects of sense, or the immediate results of sensation alone. The mind is at first completely subject to the influence of out ward objects; and even for a considerable length of time bestows only a passive notice upon them; conscious of, in fact, having no power to attend to one thing alone, and exclude others simply because it is desirous of so doing. Whenever it does acquire this power, it must evidently exercise it upon a multitude of sensible objects, and give it a protracted training upon them, before it can gain the more subtile faculty of attending voluntarily to its ideas of reflection. We have traced the leading faculties of the mind to their original efforts. What then is the issue? That all of them, the memory, the judgment, the imagination, the attention, all spring into action by the influence of impressions upon the senses, and all are for a long period employed solely upon those impressions conveyed to the mind. The senses are the nursing mothers of the mental powers. In fact, for many years, and in most persons during all their lives, those faculties are chiefly employed upon such materials as the senses furnish to the mind. How then can the teacher be addressed too earnestly upon the importance of the senses to the mind, and upon the necessity of educating them to activity and accuracy, if indeed they can be educated, since their sluggishness and inaccuracy can give but little employment to the original intellectual faculties, and that little fitted to pervert them. When we read the hallowed pages of Milton, and feel our souls elevated within us as we walk in the paradise of his imagination; while we give ourselves up to conviction as we follow the clear course of the honest, acute and strong judgment of Locke; when we reflect upon that illustrious appeal for the union of these states, which subdued a senate and enlightened a nation; when we think that these immortal efforts of the human mind were produced by a memory, a judgment, an imagination and a power of voluntary attention, which for years were exerted upon sensible objects alone, and thus laid the foundation of power, we shall not easily admit that it is of small moment whether the senses be educated or not; whether they actively their send into the mind true and lively images, or sluggishly impart dull and inaccurate impressions. Is then that noblest of telescopes, the actual model of the best glasses, the human eye, capable of giving better perceptions to the mind by means of education? Is this, are our other senses susceptible of improvement by human effort? Or has the Deity made us responsible for the improvement of all our other talents and not of these? The contrary may be conjectured from the analogy of the other parts of the body; it may be inferred from the nature and operations of the senses, and it can be absolutely proved by experience. The hand must be educated to its exercises before it can perform them well. It must gain strength and power of application by several years' training; the difference between the right hand and left shows, though inadequately, the natural, undisciplined condition of the hand. Even when well brought up, the hand must still be educated to each separate accomplish-ment, as writing or playing upon the piano. So it is with the arm; the blacksmith's arm is muscular. So it is with the foot and lower extremities; long practice in dancing lends ease and gracefulness to the step. The nature and operations of the senses imply their susceptibility of improvement. When we wish to observe an object at some moderate distance, we receive the rays of light from that object into the pupils of both eyes. The two lines of light make a certain angle or opening at leaving the object, that angle being smaller as the distance is greater.* Having made a muscular effort, and observed the size of the angle made by the lines of light, and having measured by the sense of touch, or discovered in any other way the actual distance of the object, we come at last, after much experience, to compute that distance by the degree of exertion to which we put the muscles. To see things very near, we voluntarily adjust the eye. When we thus use a muscular effort to suit the eye to the dis * Bostock. tance, we cause a sensation by it, which is conveyed to the mind at the same time that the picture of the object is presented to it. Now by ascertaining the actual distance in repeated instances, by the touch or otherwise, and comparing it with the muscular effort, we soon learn to judge of the nearness or remoteness of objects by the muscular efforts alone. We have other means of estimating distances in the vividness of the light coming from them to the eye, and in the number of intervening objects. Seeing an object very indistinctly, or with á great number of others between it and us, other circumstances being out of the case, we conclude that the object is remote.* But it must require long and careful practice to be able to make accurate estimates in this way. Are not then the senses susceptible of improvement? If we judge of distances by the angle formed by the rays of light coming to us from the object, by the muscular effort we make to adapt our sight to various degrees of nearness, or by the distinctness with which we see it, or by the number of intervening objects, shall we not evidently improve our senses by exercise? Vision also needs education and is susceptible of improvement in observing the motion of bodies, for we estimate the actual motion by that pictured upon the retina or back part of the eye, and by the various sizes of the image. But we need practice to make us adepts in judg ing of the true from the represented change of place. So with the ear; we judge of distance by the intensity or weakness of sounds, pronouncing this body to be near, and that remote, because the sound from the first is full, from the second faint.‡ To be sure, we are not generally very accurate in our estimate of distances by the ear; but if we had our sense of hearing well trained, we should without doubt find it a better servant. To judge in what direction sound comes to us, we make both ears answer their purpose by a comparison of the intensity of the two sensations, and by thus forming a judgment of the place from which the sound proceeds. But we must make *Bostock. + Magendie. + Magendie. many and many a trial before our judgments will be accurate. Still it may, after all, be said that we get immediate information of the distances of objects from the sensation; that it is natural for us to see or hear the distance of things simultaneously with the color or sound, and without the intervention of the judgment, and without any such training of the sight and hearing, or such habituating of the mind to comparisons. But it is well known that infants cannot judge of distances, and do not see them, because they grasp at things far beyond their reach, as much as those within it, not having learned to measure distances by the eye. And any person accustomed to estimating distances, a surveyor for example, can judge of them with much more precision than another, without his experience. But the question was long ago settled by Cheselden's valuable observations on the blind youth whom he restored to sight. As the account is rarely to be met with, and is pertinent to the subject of this lecture, I will quote from it freely. This youth was born blind, or lost his sight so early that he had no remembrance of ever having seen, and was couched, when he was between thirteen and fourteen years of age, by Mr. W. Cheselden. "The young man could before distinguish a good light, black, white and scarlet, but could not distinguish the shape of any thing, and knew so little of the colors mentioned, that he did not recognize them on gaining his sight, and did not think them the same he had before known by those names.— When he first saw, he was so far from making any judgment about distances, that he thought all objects whatever "touched his eyes," as what he felt did his skin; and thought no objects so agreeable as those which were smooth and regular, though he could form no judgment of their shape, nor guess what it was in any object that was pleasing to him. He knew not the shape of any thing, nor any one thing from another. But upon being told what things were, whose form he before knew from feeling, he would carefully observe, that he might know them again. But having too many objects to learn at |