The human hand is an organ so delicately fashioned that the biologist has, not unnaturally, turned to it in search of a typical structural significance. By reason of its mobility and its articulated structure, it is specially adapted to be an organ of touch; and the fine sense which education confers on it tends still further to widen the difference between the human hand and that of the ape. Hence Cuvier’s long-accepted determination of a separate order for man as bimanous. But this classification is no longer tenable. Man is, indeed, still admitted to form a single genus, Homo; but in the levelling process of scientific revolution he has been relegated to a place in the same order with the monkeys and, possibly, the lemurs, which in the development of the thumb are more manlike than the apes. In reality, looking simply to man as thus compared with the highest anthropoid apes, the order of Quadrumana is more open to challenge than that of the Bimana. The hind-limb of the ape approaches anatomically much more to the human foot than the hand; while the fore-limb is a true though inferior hand. The ape’s hind-limb is indeed prehensile, as is the foot of man in some degree; but alike anatomically and physiologically the fore-limb of the ape, like the hand of man, is the prehensile organ par excellence; while the primary function of the hind-limb is locomotion.
There are unquestionably traces of prehensile capacity in the human foot; and even of remarkable adaptability to certain functions of the hand. Well-known cases have occurred of persons born without hands, or early deprived of them, learning to use their feet in many delicate operations, including not only the employment of pen and pencil, but the use of scissors, with a facility which demonstrates the latent capacity for separate action of the great toe, and its thumblike apposition to the others. In 1882 I witnessed, in the Museum at Antwerp, an artist without arms skilfully use his brushes with his right foot. He employed it with great ease, arranging his materials, opening his box of colours, selecting and compressing his tubes, and “handling” his brush, seemingly with a dexterity fully equal to that of his more favoured rivals. At an earlier date, during a visit to Boston, I had an opportunity of observing a woman, under similar disadvantages, execute elaborate pieces of scissor-work, and write not only with neatness, but with great rapidity. Nevertheless the human foot, in its perfect natural development, is not a hand. The small size of the toes as compared with the fingers, and the position and movements of the great toe, alike point to diverse functions and a greatly more limited range of action. But the capacity of the system of muscles of the foot—scarcely less elaborate than that of the hand,—is obscured to us by the rigid restraints of the modern shoe. The power of voluntary action in the toes manifests itself not only in cases where early mutilation, or malformation at birth, compels the substitution of the foot for the hand; but among savages, where the unshackled foot is in constant use in climbing and feeling its way through brake and jungle, the free use of the toes, and the power of separating the great toe from the others, are retained in the same way as may be seen in the involuntary movements of a healthy child. When camping out in long vacation holidays in the Canadian wilds, repeated experience has proved to me that the substitution for a few weeks of the soft, yielding deerskin moccasin of the Indian, in place of the rigid shoe, restores even to the unpractised foot of civilised man a freedom of action in the toes, a discriminating sense of touch, and a capacity for grasping rock or tree in walking or climbing, of which he has had no previous conception. The Australian picks up his spear with the naked foot; and the moccasin of the American Indian scarcely diminishes the like capacity to take hold of stick or stone. The Hindu tailor, in like manner, sits on the ground holding the cloth tightly stretched with his toes, while both hands are engaged in the work of the needle.
Such facts justify the biologist in regarding this element of structural difference between man and the apes as inadequate for the determination of a specific zoological classification. Nevertheless man still stands apart as the tool-maker, the tool-user, the manipulator. A comparison between the fore and hind limbs of the Chimpanzee, or other ape, leaves the observer in doubt whether to name them alike as hands or feet, both being locomotive as well as prehensile organs; whereas the difference between the hand and foot of man is obvious, and points to essentially diverse functions. The short, weak thumb, the long, nearly uniform fingers, and the inferior play of the wrist in the monkey, are in no degree to be regarded as defects. They are advantageous to the tree-climber, and pertain to its hand as an organ of locomotion; whereas the absence of such qualities in the human hand secures its permanent delicacy of touch, and its general adaptation for many manipulative purposes.
The hand of man is thus eminently adapted to be the instrument for translating the conceptions of intelligent volition into concrete results. Dr. George Wilson in his fine prose poem: “The Five Gateways of Knowledge,” speaks of it as giving expression “to the genius and the wit, the courage and the affection, the will and the power of man.... The term handicraftsman or hand-worker belongs to all honest, earnest men and women, and is a title which each should covet. For the Queen’s hand there is the sceptre, and for the soldier’s hand the sword; for the carpenter’s hand the saw, and for the smith’s hand the hammer; for the farmer’s hand the plough, for the miner’s hand the spade, for the sailor’s hand the oar, for the painter’s hand the brush, for the sculptor’s hand the chisel, for the poet’s hand the pen, and for the woman’s hand the needle. If none of these, or the like, will fit us, the felon’s chain should be round our wrist, and our hand on the prisoner’s crank. But for each willing man and woman there is a tool they may learn to handle; for all there is the command: ‘Whatsoever thy hand findeth to do, do it with all thy might.’”
Other animals have their implements for constructive skill, and their weapons, offensive and defensive, as parts of their organic being; and are armed, equipped, clad, and mailed by no effort of their own. But man, inferior to all in offensive and defensive appliances, is a match for his most formidable assailants by means of appliances furnished by his dexterous hand in obedience to the promptings of intelligent volition.
The matured capacity of the hand is the necessary concomitant of man’s intellectual development; not only enabling him to fashion all needful tools, and to place at a disadvantage the fiercest of his assailants armed by nature with formidable weapons of assault; but also to respond no less effectually to every prompting of the æsthetic faculty in the most delicate artistic creations. The very arts of the ingenious nest-makers, the instinctive weavers or builders, the spider, the bee, the ant, or the beaver, place them in striking contrast to man in relation to his handiwork. He alone, in the strict sense of the term, is a manufacturer. The Quadrumana, though next to man in the approximation of their fore-limbs to hands, claim no place among the instinctive architects, weavers, or spinners. The human hand, as an instrument of constructive design or artistic skill, ranks wholly apart from all the organs employed in the production of analogous work among the lower animals. The hand of the ape accomplishes nothing akin to the masonry of the swallow, or the damming and building of the beaver. But, imperfect though it seems, it suffices for all requirements of the forest-dweller. In climbing trees, in gathering and shelling nuts or pods, opening shell-fish, tearing off the rind of fruit, or pulling up roots; in picking out thorns or burs from its own fur, or in the favourite occupation of hunting for each other’s parasites: the monkey uses the finger and thumb; and in many other operations performs with the hand what is executed by the quadruped or bird less effectually by means of the mouth or bill. At first sight we might be tempted to assume that the quadrumanous mammal had the advantage of us, as there are certainly many occasions when an extra hand could be turned to useful account. But not only do man’s two hands prove greatly more serviceable for all higher purposes of manipulation than the four hands of the ape: a further specialty distinguishing him as he rises in the scale of intellectual superiority is that he seems to widen still more the divergence from the quadrumanous anthropoid by converting one hand into the favoured organ and servant of his will, while the other is relegated to a wholly subordinate place as its mere help and supplement.
CHAPTER II
THE EDUCATED HAND
The reign of law is a phrase comprehensive enough to embrace many points of minor import; and among those assigned to its sway the prevalent habit of right-handedness has been recognised as one of too familiar experience to seem to stand in need of further explanation. It has been accepted as the normal usage and law of action common to the whole race; and so no more in need of any special reason for its existence than any other function of the hand. Nevertheless it has not wholly eluded investigation; nor is it surprising that the exceptional but strongly marked deviations from the normal law should have attracted the notice of thoughtful observers to the question of right-handedness as a curious and unsolved problem. A philosophic speculator of the seventeenth century, the famous old Norwich physician, Sir Thomas Browne, reverts characteristically to the mystic fancies of the Talmud for guidance, as he turns to the question in its simplest aspect, and quaintly ignores the existence of its foundation. With his strong bent towards Platonic mysticism, this question, like other and higher speculations with which he dallied, presented itself in relation to what may well be called “first principles,” as an undetermined problem. “Whether,” says he in his Religio Medici, “Eve was framed out of the left side of Adam, I dispute not, because I stand not yet assured which is the right side of a man, or whether there be any such distinction in nature.” That there is a right side in man is a postulate not likely to be seriously disputed; but whether there is such a distinction in nature remains still unsettled two centuries and a half after the inquiry was thus started. The same question was forced on the attention of an eminent philosophic speculator of our own day, under circumstances that involved a practical realisation of its significance. Towards the close of a long life in which Thomas Carlyle had unceasingly plied his busy pen, the dexterous right hand, that had unflaggingly toiled for upwards of threescore years in the service of his fellow-men, was suddenly paralysed. The period of life was all too late for him to turn with any hope of success to the unaccustomed and untrained left hand; and more than one entry in his journal refers to the irreparable loss. But one curious embodiment of the reflections suggested by this privation is thus recorded by him upwards of a year after experience had familiarised him with all that the loss involved: “Curious to consider the institution of the Right hand among universal mankind; probably the very oldest human institution that exists, indispensable to all human co-operation whatsoever. He that has seen three mowers, one of whom is left-handed, trying to work together, and how impossible it is, has witnessed the simplest form of an impossibility, which but for the distinction of a ‘right hand,’ would have pervaded all human things. Have often thought of all that,—never saw it so clearly as this morning while out walking, unslept and dreary enough in the windy sunshine. How old? Old! I wonder if there is any people barbarous enough not to have this distinction of hands; no human Cosmos possible to be even begun without it. Oldest Hebrews, etc., writing from right to left, are as familiar with the world-old institution as we. Why that particular hand was chosen is a question not to be settled, not worth asking except as a kind of riddle; probably arose in fighting; most important to protect your heart and its adjacencies, and to carry the shield on that hand.”
This idea of the left hand being preoccupied with the shield, and so leaving to the other the active functions of the sword and spear hand, is familiar to the classical student, and will fitly come under review at a later stage. Nor can such secondary influences be overlooked. Whatever may prove to be the primary source of right-handedness, it cannot be doubted that, when thoroughly developed and systematically recognised as determining the character of many combined operations, the tendency would inevitably be to foster the preferential use of the right hand even in indifferent actions. Two causes have thus to be recognised as operating in the development of right-handedness, and begetting certain differences in its manifestation under varying social influences. There is a progressive scale, from the imperfect to the more perfectly developed, and then to the perfectly educated hand: all steps in its adaptation to the higher purposes of the manipulator. The hand of the rude savage, of the sailor, the miner, or blacksmith, while well fitted for the work to which it is applied, is a very different instrument from that of the chaser, engraver, or cameo-cutter; of the musician, painter, or sculptor. This difference is unquestionably a result of development, whatever the other may be; for, as we have in the ascending scale the civilised and educated man, so also we have the educated hand as one of the most characteristic features of civilisation. But here attention is at once called to the distinctive preference of the right hand, whether as the natural use of this more perfect organ of manipulation, or as an acquired result of civilisation. The phenomenon to be explained is not merely why each individual uses one hand rather than another. Experience abundantly accounts for this. But if it can be shown that all nations, civilised and savage, appear to have used the same hand, it is vain to look for the origin of this as an acquired habit. Only by referring it to some anatomical cause can its general prevalence, among all races and in every age, be satisfactorily accounted for. Nevertheless this simple phenomenon, cognisant to the experience of all, and brought under constant notice in our daily intercourse with others, long baffled the physiologist in his search for a satisfactory explanation.
The sense of touch—“The Feel-Gate” of Bunyan’s famous Town of Mansoul,—is not limited, like the other senses, to one special organ, but pervades the entire body; and in its acute susceptibility to every irritant contact, communicates instantaneously with the vital cerebral centre of the whole nervous system by means of the electric chords or nerves. So effectual is this that “if one member suffer, all the members suffer with it.” Nevertheless the hand is correctly recognised as the active organ of feeling; and by the delicately sensitive and well-trained fingers impressions are promptly conveyed to the brain and to the mind, relative to the qualities of all bodies within reach of the unfailing test of touch. In hearing and seeing the dual organs are in constant co-operation, and the injury of either involves a loss of power. But though we have two hands sensitive to all external impressions, only one of them is habitually recognised as the active agent of the brain; and except in a comparatively small number of cases, this is the hand on the right side of the body. It is surprising that this phenomenon so universally recognised as what may be styled an instinctive attribute of man, should not long since have been traced to its true source. Yet, as will be seen, some among the ablest anatomists have been content to refer it to mere habit, stereotyped by long usage and the exigencies of combined action into a general practice; while others have referred it to the disposition of the viscera, and the place of the heart on the left side.