thought which the speaker enunciates is lodged in the mind of the hearer, animated by the precise feeling of him who utters it. He who is thus endowed can hardly fail of becoming an orator. Hence, if we would improve in eloquence, we must studiously cultivate the natural tones. of emotion, in the first place by feeling truly ourselves, and, in the second, by learning to express our emotions in this language which all men understand.

REFERENCE.

Reid's Inquiry, chap. 4, sections 1, 2.

SECTION VII.- THE SENSE OF TOUCH.

THE nerves of feeling are situated under the skin, and are plentifully distributed over the whole external surface. So completely does the network which they form cover the whole body, that the point of the finest needle cannot puncture us in any part without wounding a nerve, and giving us acute pain. It is in this manner that we are guarded from injury. Were any portion of our body insensible, we might there suffer the most appalling laceration without being aware of our danger.

The chief seat of the nerves of touch is, however, in the palm of the hand, and in the ends of the fingers. The other parts of the body render us sensible of injury from external sources, but they are incapable of furnishing us with any definite perceptions. The hand, on the contrary, conveys to us very exact knowledge of the tactual qualities of bodies. For this purpose it is admirably adapted. The separation of the fingers from each other, their complicated flexions, the extreme delicacy of their muscular power, all

combine to render this organ susceptible of an infinite variety of definite impressions.

Though the fingers are separated, yet in using them together, when a single object is presented, but one perception is conveyed to the mind. It would seem, however, that, in order to produce this result, corresponding points of the fingers must be applied to the object. If we change them from their normal position, by crossing the second over the fore-finger, two perceptions will be produced, and a small object, as a pea, will seem to us double.

The sensation of touch is of two kinds, as it is caused, first, by temperature, and secondly by contact.

The sensation produced by temperature is that of cold or heat. It is awakened by any body whose temperature differs from that of our external surface. When we place our hands in water only blood warm, we are not conscious of this sensation. If we place one hand in hot, and the other in cold water, for a few minutes, and then remove them both to tepid water, we experience the sensation of heat in the one and of cold in the other.

The effect produced upon us by temperature is a simple knowledge, a pure sensation. It gives us no knowledge of anything external. During the first chill of a fever we are unable to determine whether the weather is cold, or our system diseased; that is, whether the sensation proceeds from without or from within. And when the sensation pro ceeds from without, it gives no information respecting its cause, or the manner in which it affects us.

Heat and cold are merely affections of a sensitive organism. That which causes them is called by chemists caloric. This quality in bodies has opened a wide field for philosophical investigation, which, by developing the laws of steam, has modified the aspects of modern civilization.

Secondly, the sense of touch is excited by contact. I use the term contact here in its common, and not in its strict meaning. The nerves are always covered with the skin, and when by accident the skin is abraded, we feel pain, but we are conscious of no perception. Nor, in fact, is the skin itself ever in absolute contact with the external object. A layer of air always interposes between them.

When the hand is thus brought into proximity to an external body, we are immediately made conscious of its existence. In this act there may, I think, be discovered both a sensation and a perception. I have referred to this fact in a previous section. Nothing further will here be necessary than to appeal to the experience of every individual. Let any one place his hand lightly upon a piece of marble, or any external object, fixing his attention. as much as possible upon his sensation, and he will, I think, find himself conscious of a feeling into which the idea of externality does not enter, and which gives him no knowledge of the qualities of body. Let him now take up the marble, and attempt to cognize its several qualities, and I think he will be conscious of a very different knowledge, involving the notions of externality, hardness, smoothness, form, and, it may be, some others. In this case he pays no attention to his sensations. It does not occur to him that they exist. All he is conscious of is the various qualities of the external object, and of these he obtains a very distinct cognition. It may require a small effort at first to distinguish these two forms of knowledge from each other, but I am persuaded that any one may do it who will be at the pains for a few times to make the experiment.

The perceptions given us by this sense are exceedingly definite and perfect. By it we not only know that a quality exists, but also what it is. We have the knowledge, and we know what it is that produces it. In this manner the

perceptions by touch lie at the foundation of all our knowl

edge of an external world. We rely upon them with more certainty than any other. Many of the qualities revealed to us by touch are also revealed to us by sight. If, however, in any case, we have reason to doubt the evidence of sight, we instinctively apply to the sense of touch in order to verify our visual judgment.

The principal qualities cognized by touch, besides externality, are extension, hardness, softness, form, size, motion, situation, and roughness or smoothness. Besides these, however, there are various sensations of pain and pleasure given by this sense, the specific effect of particular agents, as of electricity and galvanism, the sensation of tickling, and many others of the same kind. To this sense has also been ascribed the sensation of hunger and thirst, and the various affections belonging to our sensitive organism.

Confining ourselves, however, to the perceptions of touch, we find that they are almost exclusively given us by the hand. In this manner we obtain a distinct knowledge of extension, of size, of hardness, softness and form. When the body is small, or the discrimination delicate, we rely almost wholly on the perceptive power of the fingers. In this manner we obtain, experimentally, nearly all our knowledge of the primary qualities of body.

We may here remark the difference between the knowledge obtained by this sense, and that obtained by the senses previously considered. The others give us each a particular class of sensations, and only one kind of knowledge. By touch we are conscious of heat and cold, together with a great variety of other sensations, and also of the various perceptions of primary qualities mentioned above. The others give us no direct knowledge of an external world. This gives us that knowledge directly and immediately. The others, when the existence of an external world is sug

gested, give us no knowledge of its qualities. This gives us a positive knowledge of several of the most essential of them. We know, for instance, that form is precisely what it appears to be, and that our knowledge of it exactly conforms to the reality. We know that it must, under all circumstances, be exactly what we perceive it to be. We thus derive from it a distinct conception; we can make it an object of thought, and can form concerning it the most complicated processes of reasoning. When we see a blind person read with his fingers, we must be convinced that he has as definite a conception of the forms of letters as we ourselves have by sight. We thus learn that not only does this sense enable us to make large additions to our knowledge, but that it is really the original source of a great part of our knowledge of the world around us. Of its intrinsic importance we may form an opinion from the fact that there is no case on record in which a human being has been born without it. By it alone, as in the case of Laura Bridgman, we may learn our relations to the world around us; may be taught the use of language, and may even acquire the power of writing it with considerable accuracy. This sense is lost only in paralysis, and in those cases in which the individual, drawing near to dissolution, has no farther need any of the organs of sense.

of

REFERENCE.

Reid's Inquiry, chap. 5, sections 1, 2.

SECTION VIII. THE SENSE OF SIGHT.

THE organ of vision is the eye. It is an optical instrument, of exquisite construction, adapted in the most perfect