Great variety of action in the muscles of the hand. motions of the upper extremity, all of which, of course, have more or less reference to the hand. Indeed the hand is the part of the upper extremity to which all its other parts are tributary, and therefore we may properly consider all these muscles as in a great measure belonging to the hand. If now you call to mind the fact, that each one of these muscles can vary the amount of its contraction in all degrees, from the most powerful action down to the slightest movement, you can readily see that fifty muscles with this power of variation can produce an almost endless number of combinations of motion. The variety would be exceedingly great, even if every muscle, whenever it acted, had always the same amount of contraction. But the power of varying the amount of contraction multiplies the variety to an inconceivable extent. 321. If you watch the movements of the hand with its fingers, as you exercise it in a great variety of motions, you can get some idea of its capabilities in this respect. If, too, you observe its movements in different individuals in all kinds of labor and handiwork, you will be still more impressed with the extreme variety of its movements. It is capable of performing the heaviest and rudest work, and at the same time the most delicate. How wide the difference between wielding the ax or the sledge-hammer, and moving the engraver's tool in some of the finest productions of his art! How firm is its grasp of the hammer, and yet how gentle is its pressure upon the graver, as it moves it in almost invisible lines! The shape of the hand, with its fingers of unequal length, and its thumb opposite to them, capable of touching the tip of each of the fingers, or all of them together, enables it to accommodate itself to a vast variety of shapes and sizes of objects; and its delicate papillæ, filled with nerves, and arranged in rows, as you can see, on the tips of the fingers under the skin, endow this wonderful instrument with a sensibility which guides its muscular movements. When, therefore, we consider the almost endless variety of its motions, the delicacy and accuracy of its sense of touch, and besides these, the force and grace with which it acts in the expression of thought and feeling, we hardly wonder that some have fixed upon the hand as man's distinguishing characteristic, and we are impressed with the thought, that it is a fitting instrument of work and expression for that mind, which is the image of God in man. 322. Having thus taken a survey of the muscular system, let us look for a moment at the whole machinery, as it works when Nice adjustment of the muscular movements. How effected. par it is engaged at the same time in some general movement, and in some special movements of some departments of it. Look, for example, at some one who is busied in conversation while he is walking, and is perhaps at the same time twirling something in different directions in his fingers. Here you have a general action of the muscles as described in § 318, and with it ticular action of two sets of muscles in two different parts of the body; and yet so well do the nerves regulate these various movements, that there is no disturbance or confusion in the complicated machinery. While the muscles of the arm and fingers are at work executing their diversified motions, the little muscles of the larynx are ever varying the notes of the voice, and the muscles of articulation are putting that voice into every variety of shape. And while these movements are going on in these particular parts of the system, the machinery as a whole is executing one of its grand general movements. And besides all this, the muscles of respiration are at work all the while, introducing air into the lungs to change the blood, and forcing it out through the trachea to make the vocal ligaments vibrate; and that compound muscle the heart is pumping at the rate of seventy times a minute sending the blood through its tubes every where; and if there be any food in the stomach, the muscular fibres of that organ are at work churning the food to make more blood. How complicated is the machinery that performs all these operations, and yet with what precision every muscle, nay, every individual fibre works in obedience to the nerves! 323. The question arises, how in all the diversified action of the muscles their nice adjustment is effected. How do the muscles know, as we may express it, just how much to do in each movement? When, for example, you reach your hand up to touch some object, how does each muscle know just what degree of contraction is necessary to make the hand go with precision to the particular point arrived at? And so when one is playing on an instrument with the fingers, as the piano, varying their pressure continually in accordance with the desired loudness of the sound, how does each muscle know just what amount of contraction is required of it in each movement? Though the senses of vision and touch afford some assistance in the guidance of muscular action in such cases, something else is manifestly necessary. Sir Charles Bell, therefore, supposes that there is what he calls a muscular sense, which acts as a guide to the muscles, in connection with the senses of sight and touch. In some cases it is the sole guide. On this subject, Sir Charles Sir Charles Bell's description of the muscular sense. says, "When a blind man, or a man with his eyes shut, stands upright, neither leaning upon or touching aught; by what means is it that he maintains the erect position? The symmetry of his body is not the cause; the statue of the finest proportion must be soldered to its pedestal, or the wind will cast it down. How is it, then, that a man sustains the perpendicular posture, or inclines in due degree towards the winds that blow upon him? It is obvious that he has a sense by which he knows the inclination of his body, and that he has a ready aptitude to adjust it, and to correct any deviation from the perpendicular. What sense then is this? for he touches nothing, and sees nothing; there is no organ of sense hitherto observed which can serve him, or in any degree aid him. Is it not that sense which is exhibited so early in the infant, in the fear of falling? Is it not the full development of that property which was early shown in the struggle of the infant while it yet lay in the nurse's arms? It can only be by the adjustment of muscles that the limbs are stiffened, the body firmly balanced, and kept erect. There is no other source of knowledge, but a sense of the degree of exertion in his muscular frame, by which a man can know the position of his body and limbs, while he has no point of vision to direct his efforts, or the contact of any external body. In truth, we stand by so fine an exercise of this power, and the muscles are, from habit, directed with so much precision, and with an effort so slight, that we do not know how we stand. But if we attempt to walk on a narrow ledge, or stand in a situation where we are in danger of falling, or rest on one foot, we become then subject to apprehension; the actions of the muscles are, as it were, magnified and demonstrative of the degree in which they are excited." The mo 324. It is obvious then that this muscular sense informs the mind of the changing postures of the body, and guides the muscles in effecting these postures. And it has a particular set of nervous fibres devoted to it, separate from those fibres which excite the muscles to action, though they are ordinarily inclosed in the same sheath. This sense, it may also be remarked, is a source of pleasure, as well as the other senses. tions of the body are attended with a sense of enjoyment, which lightens labor, and adds zest to our active sports. The enjoyment of the muscular sense we see constantly exemplified in the gambols of animals. It may be still further remarked, that this sense is capable of being educated like the other senses. of this I shall speak in another place. But All thought and feeling communicated by muscles. CHAPTER XIII. LANGUAGE OF THE MUSCLES. 325. AS THE nerves of sensation are the inlets of all knowledge to the mind, the nerves of motion are the outlets by which all knowledge is communicated. Thought and feeling are expressed only by muscular motion. It is true that there are some accompanying and subordinate modes of expression, as the flowing of tears, the action of the capillaries producing blushing, and the paleness occasioned by fear. But these could not of themselves alone communicate thought and feeling, and can do so only by being associated with other signs. They only add force to the expression already produced by muscular action. Indeed they are signs which can not be understood, unless muscular action interpret them. Thus if tears flow, we know not whether they are tears of joy or sorrow, except as the expression of the countenance informs us; and expression, as I shall show you in this chapter, is wholly the result of the action of muscles. So too, the muscles of the face tell us, whether the blush that mantles there is the blush of shame, or of modesty. And when we see paleness caused by fear, we know that this is the cause, only from the expression of the countenance and the attitude of the body, which may very properly be called the expression of the body, though it is much less marked than the expression of the countenance. 326. It is by the voice chiefly that thought and feeling are communicated. And every variation of note, or of articulation, is caused, as I shall show you in the next chapter, by the action of muscles. When the muscles of the hand communicate to others thought and feeling by writing, they merely translate the language of the muscles of the vocal organs into conventional signs. Leaving the language of these vocal muscles for another chapter, I shall in this notice the language of the other muscles of the body and especially of those of the face. 327. As we watch an animated speaker, we see that it is not the face alone, that adds force to his utterances by its corresponding expressions. Various parts of the body in a measure do the same thing. The head is nodded or shaken, the shoulder is shrugged, the foot is stamped, and above all, the hand exe Extent of range of the language of the muscles. cutes a great variety of motions, in correspondence with the thoughts and feelings which the mouth utters. Sometimes too, the whole frame is brought into action. The gestures and the attitudes, which are but gestures of the whole body, are important aids to the orator in conveying his thoughts and feelings into the minds of his auditors. 328. This language of the muscles is used to a greater extent than we are conscious of in our ordinary intercourse. We are not aware how much we communicate in this way. This language is by no means confined to those palpable acts which this subject suggests at once to the mind, the broad laugh of merriment; the sighing, and sobbing, and weeping of grief; the stamping of the foot in anger; the pointing of the finger in calling attention to any particular subject; the gesture used in beckoning one to come to you, &c. But it includes numerous little and scarcely observed motions, which in great variety add to the significance of the words which we utter. And in the case of the countenance, far more is communicated in the aggregate by the constant gentle play of the muscles, than by the broader and more palpable expressions, which are occasionally produced by their stronger action. The deaf mute can gather from the language of the muscles, as it accompanies the voice that he can not hear, much more information as to the passing conversation than one would suppose that he could. And the full capabilities of this language we can only learn, by observing to what wonderful extent the deaf and dumb can communicate with each other by the use of natural signs, without any aid from those which are artificial.* 329. While in man the muscles of the face are the chief agents of expression, in other animals the very limited expression of which they are capable, is chiefly effected by other parts of the body. For example, the dog wags his tail, the cat puts up her back, the game-cock spreads out his ruff of feathers on his head, &c. Rage is almost the only passion which can be expressed by animals in the countenance. They can snarl, but *I was much struck with an illustration of the great range of the language of natural signs, in an exhibition made many years ago by the lamented Gallaudet before the legislature of Massachusetts. Previous to exhibiting the attainments of his pupils, he requested, that if any deaf and dumb person who had not been educated in an asylum were present, his friends would bring him forward, that he might show how much could be communicated by natural signs. A man came forward, and Mr. Gallaudet learned from him by natural signs alone such facts as these,-the place of his residence, the fact that his parents were living, the number of his brothers and of his sisters, the fact that he had seen Mr. G. before in a certain place, &c. Any one, it may be remarked in this connection, who has been engaged in teaching the deaf and dumb, and who has, therefore, become skilled in the use of sign-language, can converse quite readily by signs with foreigners from any part of the won |