Chapter IV: Front Matter (4)

PRONATION and SUPINATION take place in the following manner. Each of the two bones of the forearm extends from the elbow to the wrist (fig. 53); but one of them--the “ulna”--is chiefly connected with the elbow; and the other--the “radius”--is chiefly connected with the wrist, and, by means of the wrist, with the hand. The two bones are separate from one another, except at their ends. There they touch, and are jointed together in such a manner that the large lower end of the radius can play round, or partly round, the small, button-like, lower end of the ulna; and, in so doing, it carries the hand with it. In this movement the upper end of the radius (A, fig. 60) does not leave its place, but simply revolves, upon its own axis, on the surface of the arm-bone; and its edge turns in a notch cut for it in the upper end of the ulna (B), which remains still.

Hand supine.]

Hand prone.]

In the drawings (figs. 61 and 62) the relation of the parts in the supine and in the prone state is shown by the aid of a plumb-line falling from the part of the arm-bone upon which the upper end of the radius revolves. The line traverses the upper end of the radius, then passes along the interval between the two bones, then traverses the lower end of the ulna, and, finally, takes the course of the ring finger. And, provided the limb be held vertically, the line traverses the same parts whatever be the position of the forearm and hand. It does so in complete supination, as shown in fig. 61; it does so in complete pronation, as shown in fig. 62; and it does so in every intermediate position. We may call it, therefore, the axis upon which the radius and the hand turn in pronation and supination; and, according to this representation, the ring finger remains stationary during the movement, while the other fingers and the thumb perform their partial revolutions around it.

I have said there is no movement in the lower limb exactly like the pronation and supination of the forearm and hand. We have, it is true, a power of moving the leg upon the thigh in a somewhat similar manner; but this can only be done when the knee is bent. For instance, when sitting in a chair with the foot upon a fender, or with the toes upon the ground, we can make the foot revolve so as to turn the heel in or out. A little careful observation, however, will prove that this movement takes place, altogether, at the knee, and that _both_ bones of the leg participate equally in it, the _whole_ leg revolving with the foot. Whereas, in the case of the forearm, the movement takes place, partly, at the wrist, and, partly, at the elbow; and _one_ bone (the ulna) remains _still_ while the lower end of the other bone (the radius) revolves around it. Moreover, the pronation and supination of the hand and forearm are much more free than these movements of the foot and leg; and they take place with equal facility and freedom in any position of the limb. We can turn the palm up or down as easily when the elbow is straight as when it is bent.

The movement of which I am speaking is so important to the usefulness of the hand, that I will call your attention to three of the muscles by which it is effected.

And, let me remark, by the way, that all the movements in the solid parts of the body--probably all without exception, even the slight wrinklings of the skin that take place when it is exposed to cold--are the result of muscular action. Muscles are bundles of fibres which have usually a red colour and constitute what is commonly called the “flesh” or “lean meat” of animals. They are endued with the power of contracting or shortening themselves; and it is this property which gives rise to the various movements of animal bodies. At their ends muscles often dwindle into “tendons” or “sinews” which, though occupying much less space, and having no contractile power, are very strong, and serve to connect the muscles with the bones.

One of the three muscles just mentioned (A, fig. 61) passes from a projecting process on the inner side of the arm-bone, at its lower end, to the outer edge of the middle of the radius. Its contraction causes the radius to roll over, or in front of, the ulna. It thus pronates the hand, and is called a “_Pronator_” muscle. Another muscle (B, fig. 62) passes, from a projecting process on the outer side of the arm-bone, to the inner edge of the radius near its upper part. It runs, therefore, in an opposite direction to the former muscle and produces an opposite effect, rolling the radius and the hand back into the position of supination. Hence it is called a “_Supinator_” muscle.

The third is a very powerful muscle. It is called the “_Biceps_” muscle (fig. 63), because it has _two_ points of attachment to the shoulder-blade. It descends along the front of the arm, and, bulging there, forms a conspicuous feature, to which athletic persons are proud to point in evidence of their muscular development. Its tendon crosses over the front of the elbow, and is inserted into the hinder edge of a stout tubercle which is seen on the inner side of the radius near its upper end. The chief effect of this muscle is to bend the elbow; but it also rotates the radius so as to supinate the hand; and it gives great power to that movement. When we turn a screw, or drive a gimlet, or draw a cork, we always employ the _supinating_ movement of the hand for the purpose; and all screws, gimlets, and implements of the like kind, are made to turn in a manner suited to that movement of the right hand, because mechanicians have observed that we have more power to supinate the hand than to pronate it, though they are, probably, not aware that the preponderating influence of the _biceps_ muscle is the cause of the difference.

The movement of which I am speaking is performed to its full extent only by Man. Monkeys cannot completely supinate the hand; and in most of the lower animals the part corresponding with the hand remains nearly, or quite, fixed in a state of pronation. Even in Man, complete supination is rather a constrained and awkward position. It is not a position which is habitual or natural to us. When we see any one sitting or walking with the palms turned forward it strikes us as strange, and the idea is suggested to us that the individual must be strange too, that, possibly, his head may be a little turned as well as his hands. In a state of ease the hand is naturally more or less prone; so that when it is desired to place the forearm or hand at rest, as in case of disease or injury, the prone position is usually selected. If the forearm be broken, for instance, the surgeon sets the fracture and fixes the limb with the hand prone or semiprone. This is, also, the position of greatest strength, as well as of most ease. Hence, in striking a blow, or carrying a weight, or making any strong muscular effort, the palm is always kept more or less inturned.

_The Wrist._

This drawing (fig. 64) represents what is seen when a section has been made, from side to side, through the wrist and lower part of the forearm. It gives an idea of the mode in which the several bones of the wrist are adapted to one another and held together by ligaments. The upper three wrist-bones (C, E, D) are joined together, so as to present a convex surface, which is received into a wide cup, or socket, formed by the end of the radius (A) and a ligament passing from the radius to the ulna (B); and, in pronation and supination, the end of the radius, together with this ligament and the wrist-bones, revolves upon the end of the ulna.

All the bones here represented are so well fitted to one another, and so strongly bound together, that, as I have before said, displacement very rarely occurs among them. We sometimes _hear_ of a dislocation of the wrist, but very seldom _see_ one. The wrist is often bruised, or its ligaments strained, by falls upon the hand; or, what very often happens, especially after the middle period of life, the bones of the forearm are broken a little above the wrist.

You might think that, in such an accident, the radius only would suffer, inasmuch as it is especially connected with the wrist-bones, and so receives the force directly from the hand. But, if you observe the line of contact of the radius and ulna (running from F), you will see that it is oblique, and that its direction is such as to cause the ulna to support the radius, and to receive some of the force from it; and this disposition, which makes the ulna share the duties of the radius, makes it, also, share the dangers; hence, it is very frequently involved with the radius in fracture of the forearm.

By the joints of the wrist we are enabled to move the hand backwards and forwards, and also slightly sideways.

_The Movements of the Hand._

I come now to speak more particularly of the movements that take place in the Hand. I have already said that the mobility of the thumb is the chief characteristic of the hand as distinguished from the foot. Another important distinction between the hand and the foot is the greater length and mobility of the fingers as compared with the toes. The toes are short; and our power of moving them is, under any circumstances, slight. They constitute a small, and, comparatively, unimportant, part of the foot. The fingers, on the contrary, are long; they form a half, and, including the thumb, the more important half, of the hand. Without them the rest of the hand, indeed the rest of the limb, would be comparatively useless. Their movements are varied and free, and take place with singular facility and rapidity. We can bend them quite down upon the palm, and can extend them beyond the straight line; we can separate them from one another to a considerable extent; and we can bring them together with some force, as a waiter does when he carries a number of wine-glasses between his fingers; and persons who have lost the thumb contrive to hold a pen, a knife or fork, or other things, between the fingers.

Muscles of forearm and hand.]

Let me endeavour to give you an idea of some of the muscles which are concerned in executing these movements.

The wrist and hand are bent forwards upon the forearm by means of three muscles (A, B, C, fig. 65). These all pass downwards from the inner side of the lower end of the armbone. The outer and inner ones (A and C) are connected, by tendons, with the wrist-bones; and the tendon of the middle one (B) runs over the wrist and becomes spread out in the palm like a fan, so as to support the skin of the palm and to protect the nerves and blood-vessels, which lie beneath it, from injurious pressure, when we grasp any substance firmly in the hand. The fan-like expansion of this tendon in the palm is called the “palmar fascia.” It is very strong, and is connected, below, with the ends of the metacarpal bones, and with the sheaths of the fingers. The bundle of muscles near D forms what is called the “ball of the thumb,” and serves to move the thumb in various directions.

Muscles and tendons of hand.]

Beneath these three muscles which bend the wrist and strengthen the palm lies another set of muscles (A, B, fig. 66) which bend the thumb and fingers. They pass from the bones of the forearm, and end in long tendons or “leaders” which run over the wrist and palm and along the fingers and are firmly connected with the last phalanges of the fingers. They lie close to the bones in their whole course, and are held in their places by sinewy cross bands and sheaths which are seen, both at the wrist and in the fingers, in fig. 65.

Muscles and tendons on back of forearm and hand.]

Fig. 67 represents the muscles on the back of the forearm. The tendons pass from them, and run, some to the wrist and extend, or bend backwards, the wrist upon the forearm, some to the thumb and extend the several joints ofthe thumb; and others run to the back of the fingers. These leaders lie nearer to the skin than do those on the palmar aspect; and most of those which go to the thumb and fingers may be distinguished through the skin. The short muscles (A, A) situated upon and between the metacarpal bones pass from them to the sides of the fingers; some of these serve to spread the fingers out from one another, while others have the effect of drawing them together. There are several such small muscles on both surfaces of the hand, but I must not detain you by a description of them; and there are other little muscles passing from the flexor tendons to the phalanges, which have been called _fidicinales_, from their assisting in performing the short quick motions of the fingers, and from their being, accordingly, called into action in playing upon the violin and other musical instruments.

_Movements of the Thumb._

In its adaptation to the purposes of bearing the weight and ministering to the locomotion of the body the human foot excels that of any other animal; and, unquestionably, the human hand is not less preeminently distinguished by the nicety, the variety, and the freedom of its movements. This is shown by the manner in which it can be twisted about, by the exquisite play of the fingers; and it is shown, above all, by the mode in which the thumb can be moved to and fro, can be opposed to the other fingers, and to any part of them individually and collectively, and can be folded beneath them or clasped upon them as occasion may require.

The power which the thumb possesses, and gives to the hand, is signified by its name--“pollex,”--derived from the Latin word _pollere_, which means to have power. Some have supposed that the word “poltroon” is derived from _pollice truncato_, and signifies one so cowardly that he has submitted to have his thumb cut off in order that he may be incapacitated for fighting.

The faculty which we possess of moving the thumb in the way I have mentioned, athwart the other fingers, and of touching any part of the palmar surface of either of them depends, partly, upon its being set, not quite in the same plane with them, but, obliquely, so that when it is moved towards the palm it faces or opposes the other fingers; and, partly, upon the nature of the joint between its metacarpal bone and the bone of the wrist with which it is connected.

This joint is so constructed as to admit of three different movements. _First_, the thumb can be moved forwards or backwards, that is, towards, or, away from, the palm. _Secondly_, it can be “adducted” or “abducted,” that is, approximated to the forefinger or inclined away from it. _Thirdly_, it can be “circumducted,” that is, its extremity can be made to describe a circle, as in “twiddling the thumbs.” These several movements are effected with great power and rapidity by means of the bundle of muscles which forms the “ball of the thumb” (fig. 65. D), as well as by the long muscles and tendons which descend, from the forearm, to the thumb.

_Movements of the metacarpal bones of the Fingers upon the Wrist._

The movements of the thumb, through the medium of its metacarpal bone, upon the wrist are much more free than those of any of the other fingers. The middle finger, indeed, has its metacarpal bone set upon the wrist so fixedly as to admit of scarcely any such movement. The forefinger can be thus moved a little; the ring finger more and the little finger still more.

You may easily prove this by taking the knuckles or heads of the respective metacarpal bones of one hand between the fingers and thumb of the other hand, when you will find that you can press the knuckle of the little finger backwards and forwards in a very perceptible manner. Then try the knuckle of the ring finger; the movement is distinct, though not so free as in the case of the little finger. The knuckle of the forefinger you will find to be almost fixed; and in that of the middle finger you will be unable to perceive any movement at all.

In fact the joints of the metacarpal bones of the fingers with the wrist resemble those of the outer four toes with the tarsus; and the drawings of these joints of the foot (figs. 22 to 25) will serve sufficiently well to illustrate those of the hand.

These movements of the metacarpal, or knuckle, bones upon the wrist enable us to increase or diminish the hollow of the palm by bringing its edges more or less forward. Thus, when we make a cup of the hand we bring forward the metacarpal bones of the thumb and the little finger, wrinkling the skin of the palm; and when we spread the hand open we carry those bones backwards, rendering the skin of the palm tense.

These movements, moreover, enable us to bring the little fingers and the thumb more easily into contact.

Have you ever wondered what advantage is gained by the fingers and thumb all differing from one another in length; or don’t you take the trouble to reflect upon little matters of this sort? If you have, I would ask you now to remark that there is, in the several fingers, a relation between their shortness, their position near the edge of the hand, and the amount of mobility of their metacarpal bones upon the wrist. Thus the finger which is in the middle of the hand is the longest, and its metacarpal is the most fixed. The fore-finger is not quite so long; and its metacarpal is rather less immovable. The ring-finger comes next in shortness and in the mobility of its metacarpal. Then the little finger; and the thumb which is much shorter than any other has also its metacarpal much more moveable.

Observe, further, that, when the fingers and thumb are separated from one another, and then bent, the middle knuckle-bone remains stationary, but the others are advanced a little forwards, each to an extent proportionate to its mobility upon the wrist, and to the shortness of the finger. The fore-finger is, by this means, advanced a little, the ring and the little fingers more, and the thumb most of all. And the result is, that the tips of the fingers and the thumb come all to a level, and form, with the palm, a great hollow in which we can grasp any substance, a cricket-ball, for instance, and hold it very firmly. The length of the several fingers and the thumb is, therefore, just so regulated, in relation to their mobility upon the wrist, as to give us this power.

You may observe, also, that when the fingers and the thumb are spread out the space between the thumb and the fore-finger is considerably greater than either of the spaces between the other fingers. Then, by a slight movement, the thumb takes up a position in front of, or opposite to, the fingers; and in grasping any substance it has to antagonise the pressure exerted by all the fingers. Hence it needs to be much stronger than they are, and to be wielded by more numerous and more powerful muscles.

The MIDDLE FINGER is not only the longest and the largest finger; it is also, to a certain extent, the centre about which the others move. Thus, when the fingers are bent down into the palm, their tips all converge towards the middle finger; and when they are spread out, they all diverge from it. Its greater length and the greater prominence of its knuckle, expose this finger to injury more than any of the others; which may account for the fact that Surgeons are called upon to amputate the middle finger more frequently than either of the other fingers or the thumb.

The FORE-FINGER has the greatest range of independent movement. Hence it is used to point with, and is called the “Index” or “Indicator” finger.

_Writing._

In WRITING the pen should be held between the pulps of the fore and middle fingers and the thumb, in contact with all three, and firmly lodged between them. The down-stroke is made by bending the phalanges of the fingers and the thumb inwards and the metacarpal bone of the thumb outwards; and the up-stroke is made by straightening all the joints of the fingers and thumb. The hand rests lightly, not upon its whole edge, but, upon the hindermost and foremost parts of the edge, that is, upon the pisiform bone of the wrist and upon the little finger near the end, so that it can be moved easily along the paper, and can be inclined, or rolled, a little to either side. The obliquity of the stroke is not imposed by mere arbitrary rule, but is in accordance with the direction in which there is the freest movement of the fingers and thumb when thus holding the pen. Make the experiment for yourselves of moving the pen in different directions, and you will soon be satisfied that the writing-master has nature on his side in insisting on a particular movement as well as a particular mode of holding the pen. Some persons make the strokes vertical, or slope them the wrong way; but in either case the writing is stiff and awkward; it is not natural.

The custom of writing from left to right may also be regarded as correct or natural, inasmuch as we can move the pen more freely upwards and _out_wards than upwards and _in_wards. Hence the light _up_ or advancing stroke--that which connects a letter with the one which follows it--is most easily made _out_wards or to the right; and the letters are, consequently, made to follow one another in that direction. To understand this more clearly make a down-stroke upon paper in the usual manner; you will then find that you can make up-strokes from any part of it more easily to the right than to the left; and if you make a series of continuous up-and-down-strokes at a little distance from one another, the up-stroke is, not merely habitually, but naturally, made fine and inclined to the right, whereas the down-stroke is made heavier or thicker and is sloped to the left. Moreover, you will perceive that the hand slides along the paper more easily from left to right than from right to left.

It is worthy of remark that the writing of all that great class of languages called Indo-European, which includes Sanscrit, Greek, Latin, and many others, with our own, is from left to right; whereas nearly all the writing of another great class called the Semitic, which includes the Hebrew and Arabic, is in the opposite direction, viz. from right to left. Some nations write in perpendicular columns, the letters being placed under one another, of which the Chinese affords an example. But either of the two latter methods must be inferior to the Indo-European style in ease of execution and expedition.

_Reason for the Ring being usually placed upon the Fourth finger._

The RING-FINGER has less independent movement than either of the others. It cannot be bent or straightened much without being accompanied by one or both of those next it. This is, partly, because its extensor tendon is connected, by means of a band of fibres, with the tendon on either side of it. You may discern these connecting bands working up and down under the skin of the back of your hand when you move the fingers to and fro (they are represented in fig. 67). The ring-finger is, therefore, always, more or less, protected by the other fingers; and it owes to this circumstance a comparative immunity from injury, as well, probably, as the privilege of being especially selected to bear the ring in matrimony. The left hand is chosen for a similar reason; a ring placed upon it being less likely to be damaged than it would be upon the right hand.

Other reasons have been given for this preference. It has been attributed to a notion among the ancients that the ring-finger is connected with the heart by means of some particular nerve or vessel, which renders it a more favourable medium than the other fingers for the reception and transmission of sympathetic impressions; the left hand being selected, in preference to the right, because it lies rather nearer to the heart.

Some slight foundation for such a notion might be imagined to exist in the fact (supposing the ancients to have been acquainted with it) that the distribution of the nerves to the ring-finger is rather peculiar. The peculiarity will be readily understood by reference to the accompanying drawing (fig. 69). Two chief nerves are seen descending, in their course from the brain, along the arm and forearm, to supply sensation to the palmar surface of the hand. One (A), the larger of the two, passes in front of the middle of the wrist, and divides into branches which are distributed to the skin of the thumb, of the fore and middle fingers, and of the _out_er side of the ring-finger. The other nerve (B) lies on the _in_ner side of the forearm and wrist, and its branches go to the skin of the little finger, and of the inner side of the ring-finger. You see, therefore, that there is, in this finger, a meeting of the branches of the two nerves; the two sides of the finger being supplied by different nerves. It would be a mistake, however, to suppose that it gains any superiority in sensitiveness or sympathetic relations by this arrangement; and this distribution of the nerves certainly does not offer so probable an explanation of the selection of that finger for the honourable office of ring-bearer as the one I have suggested.

I must remark, here, that the nerve (B), in passing from the arm to the forearm, lies on the inner side of the back of the elbow, and is popularly known by the misnomer of the “funny-bone[8].” It lies, pretty much out of harm’s way, in a well-protected channel between two bones. Nevertheless, it is now and then hurt; and you know that when the “funny-bone” is struck, a peculiar pain, or tingling, is experienced along the little finger and the adjacent side of the ring-finger.

[8] It has been suggested, probably by _Punch_, that it is called the
“_funny-bone_” because it lies near the “_humerus_.”

The practice of wearing rings upon the hand is a very ancient one. In some instances they were badges of slavery. More generally they were marks of high esteem or authority; as when “Pharaoh took off his ring from his hand and put it upon Joseph’s hand,” and when “Ahasuerus took off his ring, which he had taken from Haman, and gave it to Mordecai.” The Roman knights also wore rings of gold. Sometimes rings were worn as charms against diseases; a practice which has been revived in our own day. They were placed upon any of the fingers, and upon the right hand as well as the left. Thus we read in Jeremiah, “though Coniah the son of Jehoiakim king of Judah were the signet upon my right hand.” The preference of the left hand and of the ring-finger seems to be comparatively modern, originating, probably, when the ring was made lighter and more fragile, and was, at the same time, adorned with precious stones, and when it became, therefore, desirable to place it upon the part of the hand where it is least exposed to injury.

_The Monkey’s Hand._

Most of you have spent some time in watching the inmates of that interesting part of a zoological collection, the MONKEYS’ cage, and have observed how nearly the hand of that animal resembles the human hand, in the presence of a thumb, in the variety and celerity of its movements, in the facility with which it can catch and pick up objects and hold them up to the mouth, and in some other points. A little closer observation, however, will show that there are some differences between the two. The several parts do not bear the same relation to one another in the Monkey’s hand which they do in the human hand; neither have they quite so great variety or range of movement. The hand is altogether narrower, and straighter. The thumb is shorter and less strong, scarcely reaching beyond the knuckle of the fore-finger. The fingers, on the contrary, are longer and of more uniform length; they do not admit of being separated so widely from each other in a fan-like manner; and the metacarpal bones at the edges of the hand, i. e. the metacarpal bones of the thumb and of the ring and little fingers, have not the same amount of play upon the wrist. Hence the thumb and the fingers of the Monkey cannot be opposed to one another so easily as in man; neither can they be so advanced in front of the middle finger as to form a hollow or cup, in the way I described when speaking of the hollow of the palm and the different lengths of the fingers in the Human hand. When you throw a Monkey a nut he usually picks it up and holds it between the thumb and the _side_ of the bent fore-finger, not between the tips of the thumb and fingers. The length of the fingers adapts the Monkey’s hand well for clasping firmly the branches of trees, and assisting the animal to climb about in its native forests, or to hold on to the bars of its cage; and so the part answers the requirements of the creature better than if these qualities had been sacrificed to a greater regard for variety and range of movement.

_The Hand the Organ of the Will._

The human hand is peculiarly an organ devoted to the will, being more directly and completely under its influence than is any other part of the body. The WILL, remember, is that self-directing faculty which can be said to exist, definitely and decidedly, in Man alone, which is associated in him with the responsibility attaching to the selection between good and evil, and which is given to him to fit him to be the reasonable servant of his Maker, and upon which, therefore, his dignity, and his capability for occupying a position between the low animal and the high spiritual world, so much depend. How appropriate is it, then, that the will should have a special organ assigned as its more peculiar minister. It is to the complete subjection of the hand to the will, no less than to the combination of strength with variety and delicacy in its movements, that Man is indebted for his dominion over the rest of the animal world, and for the ability to execute the wonderful works which his genius designs.

When we reflect how essential is the hand to Man’s well-being, power, and progress, and upon the infinite variety of purposes which it serves in obedience to the will, we are not surprised that the construction of the foot, indeed of every part of the frame, should have reference to the object of liberating the hand from the subordinate work of locomotion to a degree which we find in no other animal, and of leaving it free to execute its higher offices in a ready and efficient manner.

But, after all, notwithstanding the excellence of its mechanism and its intimate relation to the will, what would the hand be without the reflecting and designing MIND--the mind that can build upon the past and prepare for the future, and so carry on the ever-advancing work of human civilization and progress. Without it Man would remain stationary, like the other animals; and, as age succeeded age, the hand would only suffice to provide the necessary requirements of the body. Nay, even this is saying too much; for without the mind, without, at least, some higher instinctive or reflective faculty than the other animals possess, Man would, in reality, be inferior to them. He would be absolutely unable to maintain his existence, and would be a miserable victim to the fineness of his organisation. His hand would fail to supply him with food, or to defend him against his numerous enemies, or to provide for the protection of his delicate and sensitive frame from the inclemency of the elements.

The real excellence of the human hand--and the remark applies equally to the whole human body--consists, not in the admirable construction of its several parts, nor in their well-adjusted relation to one another, so much as in the adaptation of the whole to the mind that presides over it. This it is that renders Man the lord of the creation, that enables him to subdue all his foes, and gives him, in some measure, power over the elements, so that land and water, fire and air, are made to serve his purpose. By this harmonious co-aptation of mind and body Man is rendered cosmopolitan, being able to thrive in every clime, from the regions of continual snow to those burning equatorial plains where even reptiles perish from the heat and drought, and being able to convert the barren plain into a fertile field, and to draw water out of the stony rock.

At the late meeting of the British Association at Oxford, a gentleman related that he had a monkey which was very partial to oysters, and was very fond of playing with a hammer; but he never could be taught to use the hammer for the purpose of breaking the oyster-shells to gratify his appetite. How wide a gulf does the absence of intelligence in this simple matter indicate between ourselves and the animal that approaches nearest to us!

_The Hand an Organ of Expression._

Further, we cannot fail to recognise and admire the adaptation of the hand to the mind at all ages, and under various circumstances; in its weakness and suppleness, and in its purposeless and playful movements in infancy and childhood; in its gradually increasing strength and steadiness as the intellect ripens; in the stiffness and shakiness of declining years; in the iron grasp of the artizan; in the light delicate touch of the lady; in the twirlings, fumblings, and contortions of the idiot; in the stealthy movements of the thief; in the tremulousness of the drunkard; in the open-handedness of the liberal man; and in the close-fistedness of the niggard.

Thus the hand becomes an organ of expression and an index of character. What would the nervous young gentleman in a morning call give to be quit of these tale-telling members; or what would he do without a hat or a stick to employ and amuse them? How effective an auxiliary to the orator is the wave of the hand, or, even, the movement of a finger. Some men, indeed, seem to owe the efficiency of their declamations as much to the hand as to the tongue. I have seen a practised orator (he was a man of the most complete self-possession) quell an excited audience by one determined movement of his hand. It happened to me to hear two of the most celebrated preachers of the day within a short period. In each of them the movements of the hand were remarkable, though very different. In one, the free, impassioned, but natural, and, therefore, easy action of the hand showed a deep and genuine interest in the subject, and helped to waft the fervid sentiments straight from his own heart to the hearts of his audience. In the other, who was a no less accomplished speaker, the constrained and carefully regulated movements of the hands were evidently the result of forethought and study; they were intended to be impressive, but were too obviously done for effect; and, therefore, were far less effective as well as less pleasing.

Our great and venerable orator, as well as high authority on the art of speaking (Lord Brougham), tells us that the subject of a speech should be carefully studied, and the sequences well adjusted. He says that, in the most effective passages, even of practised speakers, the exact words are usually selected beforehand; but he is silent respecting the actions by which they should be accompanied. These, at least, should be unpremeditated; and they will best assist to convey to others the real feelings and emotions when they are the simple result of the natural working of the mind upon the body.

The kind of expression that lies in the hand, being much dependent on the effect of the muscles upon it, is very hard for the artist to catch, though very important to the excellence of the picture. Painters, usually, make the hand a subject of careful study, but rarely succeed in throwing the proper amount, either of animation or of listlessness, into it. In portraits, especially, the hands are a difficult part to treat satisfactorily; yet the artist feels that they are too important not to have a prominent place, and he, commonly, imposes upon himself the task of representing them both in full. I have seen them drawn held up in front, like the paws of a kangaroo, in an otherwise good picture. The stereotyped position in portraits is that one hand lies upon a table, though it, probably, evinces an uneasiness there, while the other rests, perhaps equally uneasily, upon the arm of a chair. Vandyck, in whose paintings the hand usually forms a prominent feature, is considered to have peculiarly excelled in imparting to it a sentimental air imbued with deep pathos.

_Shaking Hands._

How much do we learn of a man by his “SHAKE-OF-HAND.” Who would expect to get a handsome donation, or a donation at all, from one who puts out two fingers to be shaken and keeps the others bent as upon an “itching palm”? How different is the impression conveyed by the hand which is coldly held out to be shaken and slips away again as soon as decently may be, and the hand which comes boldly and warmly forward and unwillingly relinquishes its hearty grasp? Sometimes one’s hand finds itself comfortably enclosed, nursed, as it were, between both hands of a friend, an elderly friend probably; or it is shaken from side to side in a peculiar short brisk manner. In either case we are instinctively convinced that we have to do with a warm and kindly heart. In a momentary squeeze of the hand how much of the heart often oozes through the fingers; and who that ever experienced it has forgotten the feeling conveyed by the eloquent pressure of the hand of a dying friend, when the tongue has ceased to speak?

Why do we shake hands? It is a very old-fashioned way of indicating friendship. Jehu said to Jehonadab, “Is thine heart right as my heart is with thine heart? If it be, give me thine hand.” It is not merely an old-fashioned custom; it is a strictly _natural_ one, and, as usual in such cases, we may find a physiological reason, if we will only take the pains to search for it. The Animals cultivate friendship by the sense of touch, as well as by the senses of smell, hearing, and sight; and for this purpose they employ the most sensitive parts of their bodies. They rub their noses together, or they lick one another with their tongues. Now, the hand is a part of the human body in which the sense of touch is highly developed; and, after the manner of the animals, we not only like to see and hear our friend (we do not usually smell him, though Isaac, when his eyes were dim, resorted to this sense as a means of recognition), we, also, touch him, and promote the kindly feelings by the contact and reciprocal pressure of the sensitive hands.

Observe, too, how this principle is illustrated by another of our modes of greeting. When we wish to determine whether a substance be perfectly smooth and are not quite satisfied with the information conveyed by the fingers, we apply it to the LIPS and rub it gently upon them. We do so, because we know by experience that the sense of touch is more acutely developed in the lips than in the hands. Accordingly, when we wish to reciprocate the warmer feelings we are not content with the contact of the hands, and we bring the lips into the service. A SHAKE-OF-HANDS suffices for friendship, in undemonstrative England at least; but a KISS is the token of a more tender affection.

Possibly it occurs to you that the TONGUE is more sensitive than either the hands or the lips. You have observed that it will detect an inequality of surface that escapes them both, and that minute, indeed, is the flaw in a tooth which eludes its searching touch. You are right. The sense of touch is more exquisite in the tongue than in any other part of the body; and to carry out my theory, it may be suggested that the tongue should be used for the purposes of which we are speaking. It is so by some of the lower animals. But, in man, this organ has work enough to do in the cultivation and expression of friendship in its own peculiar way; and there are obvious objections to the employment of it in a more direct manner for this purpose.

_The Skin of the Hand._

By the aid of the accompanying drawings you will be able to form some idea of the structure of the SKIN of the hand.

One of them (fig. 70) represents a section of the skin, made perpendicular to the surface, as seen under the microscope. It is from the end of the thumb, and includes three of those delicate lines, or ridges that are found there.

The superficial, or uppermost strata (_a_ and _b_), are the “Cuticle” or “false skin.” The outer layer (_a_) is hard, horny, and dry. It is composed of numerous fine scales laid upon one another, like the tiles upon the roof of a house, but adhering more closely together, so as to form one continuous sheet extending all over the body. The outermost of these scales are continually being shed, peeling off as scurf, or being rubbed off; and fresh ones are supplied by the next layer (_b_), which is a softer material and lies immediately upon the surface of the “cutis” or “true skin.”

This softer layer (_b_) is often called the “_Rete Mucosum_.” It is made up of minute bags or bladders, named “cells” by anatomists, which grow and propagate upon the exterior of the true skin, being nourished by the blood in the skin. Those which lie nearest the cutis are the youngest and the softest. Gradually they are pushed outwards by their successors or offspring; and, as they approach the surface, they become flatter and drier and more adherent to one another, and are finally converted into the thin scales of the cuticle. Thus, there is no real line of division between the cuticle and the rete mucosum; but the cells of the latter are gradually transformed into the scales of the former.

The rete mucosum is thicker in the Negro than in the white man, and contributes somewhat to the softness of his skin. It contains also the colouring matter in the form of minute black particles diffused among its cells (fig. 72). These particles disappear, more or less, as the cells become changed into scales; hence the outer part of the cuticle of the Negro is not so dark as the rete mucosum, but, as it is transparent, or nearly so, it allows the dark colour of the rete to show through it.

Persons commonly speak of the cuticle as if it were the whole thickness of the skin. Thus, when a blister has drawn, they say the _skin_ is raised; whereas it is only the _cuticle_. This is forced off from the skin by the fluid effused into its softer layer--i. e. into the rete--in consequence of the irritating influence of the blister.

The cuticle has no nerves, and, therefore, no feeling. It may be cut or torn without pain. The snipping of a blister with the scissors is not felt, because the cuticle only is touched. It forms a covering to the whole surface of the body, and is invaluable as a means of preventing too great evaporation. Without it we should be dried up, almost mummified, by the end of a summer’s day. It also protects the delicate sensitive skin underneath. How sore is the knuckle when the cuticle has been rubbed off! The cuticle has, moreover, the accommodating property of becoming thickest where it is most wanted, as on the sole of the foot, and on the palms of the hands of blacksmiths, and artizans, and persons who handle the oar. And if any other part of the body be subjected to much friction, for instance, the knees of housemaids, or the shoulders of men who carry packs, the cuticle soon becomes thickened there.

Beneath the cuticle lies the “Cutis” or “True Skin” (_c_, fig. 70, and _c_ and _d_, fig. 71). It is a tough structure consisting of interlacing fibrous and fine muscular tissue, and contains the blood-vessels and nerves. The cuticle may be pared off without any bleeding; but directly the skin is wounded the blood flows. The cutis does not present an even surface next the cuticle, but shoots out into a number of little finger-like processes, called “Papillæ,” which project into the contiguous soft stratum of the cuticle, and are embedded in it. Thus the superficies of the skin is increased; and as the blood-vessels and nerves of the cutis are continued into the papillæ, they contribute very greatly to the sensitiveness of the skin. They are most numerous in parts where the sensitiveness of the skin is greatest; for instance, they are more numerous on the palmar, than on the dorsal, surface of the hand. Near the ends of the fingers and thumb they are arranged in a linear manner, forming the delicate ridges that encircle the cones of the pulps. Sections of these ridges are represented in fig. 70.

The superficial or papillary part of the cutis is of finer and more delicate structure than the deeper or fibrous layer, and is, therefore, sometimes described as a separate layer. It is so represented in the accompanying figure (71, _c_).

As we are upon the subject of the cuticle and the papillæ, I will take the opportunity to say a word respecting two diseases of these structures, in which most of you, probably, have a personal interest. I mean “Warts” and “Corns.”

A WART (fig. 74) depends chiefly on a diseased state of the papillary stratum of the skin. The papillæ become coarse and grow up beyond the level of the surrounding skin, so as to present an uneven or “warty” surface. They carry a layer of cuticle before them. This layer is usually thin, so that the wart bleeds easily when it is rubbed. Sometimes, however, it is very thick and hard like a piece of horn. We, now and then, hear of a horn growing upon some part of the body, perhaps on the forehead. Such a horn is, usually, nothing more than a conical mass of cuticle formed upon the surface of a large wart. Warts are generally caused by something irritating the skin, as dirt or soot rubbed into the cuticle. For this reason they are more frequent upon the hands than upon other parts of the body.

In a CORN (fig. 73), also, the papillæ are somewhat enlarged; and this accounts in part for the great tenderness of corns. But the primary and essential feature of a corn is a thickened state of the cuticle. This is caused by too great rapidity in its formation, and is, usually, dependent upon pressure, especially if the pressure be combined with some friction. Hence corns are most commonly found upon the foot, and upon the parts of the foot, where the skin is subject to pressure and rubbing against the shoe. The drawing shows the appearance presented by a vertical section through a corn and through a small portion of the skin on either side. The accumulated layers of cuticle are seen, and the enlarged papillæ shooting up into them. I need scarcely add that it is owing to ignorance, or something worse, when corn-cutters talk of curing the malady by taking out the _roots_; for, corns, evidently, have no roots.

One word of advice about corn-cutting. Most persons have some experience in this art, and some opportunity of practising it on themselves; and many pride themselves on their skill in it. The usual plan is to shave off layer after layer from the whole surface of the corn; and this, by lessening the projection of the corn, may give relief for a few days, though it does not always do that. Soon, however, the distress returns; and the area of the corn increases after each operation. Now, I would have you observe that it is at the _middle_ of the corn that the papillæ are most enlarged; and it is here that the formation of cuticle goes on most quickly, giving rise to the little white cone or cones often seen in a corn and sometimes wrongly called the roots. The proper mode is to confine the cutting to this part, and to remove as much of the thickened cuticle as you can from this spot, digging, as it were, a hole in the middle and leaving the circumference intact. The circumference, which is not usually tender, thus forms a wall round the excavated centre and defends it from pressure; and great relief is experienced. Further benefit will be found from covering the corn with some soft adhesive plaster; and you may sometimes, with advantage, lightly apply common caustic before putting on the plaster. If you follow these directions carefully you may be your own chiropodists, and almost defy your bootmakers.

If, in cutting a corn, you go too deeply, you will wound the tops of the papillæ and cause some bleeding; this is not however usually followed by any ill consequences.

_Nails._

Almost all vegetable as well as animal surfaces are covered with some kind of cuticle. It forms the smooth exterior of a leaf and the rind of an apple; and the soft down of a moth or a butterfly, the scales of fish, the feathers and claws of birds, the quills of the porcupine, the horns of oxen and the hoofs of the horse are examples of modifications of cuticle. NAILS and HAIR are also of this nature. They are both continuous with the cuticle, and peel off with it when it is, by any process, separated from the skin. Both are formed, like the cuticle, of compressed plates or scales matted together; and these are continually being shed or rubbed off on the one side, and supplied from the rete mucosum on the other.

The rete mucosum, it should be stated, extends over the whole surface of the body. In most situations, as already mentioned, it is the medium from which the ordinary cuticle is produced; but on the upper part of the ends of the fingers and toes it is converted into nail, and in the hair follicles, as I will presently describe, it is transformed into hair.

The drawings will help you to understand the relation of the nails to the cuticle and the cutis. In the upper of the three (fig. 75) the nail with the cuticle has been detached from the cutis, so that the continuity of the two, at either end, is shown. In the middle one (fig. 76) it is represented lying in its bed in the cutis; its thin hinder edge being received into a furrow made for it in the cutis. The layer of rete mucosum (_b_) extends behind and beneath it, between it (_d_) and the cutis (_c_), and continually adds fresh material to the nail, just as, in other parts, it adds to the substance of the cuticle. The cuticle, or white line (_a_) is continuous with the nail at the sides as well as at either end. The lower figure (77) shows the bed of the cutis in which the nail reposes, the nail as well as the adjacent cuticle and the rete having been cleared away.