In most of the lower animals, however, the sense of feeling, though present, serving for protection and giving notice of injury, is not very acute. It is not much employed by them for the purpose of obtaining information respecting external objects; and they can scarcely be said to enjoy that modification of it which we call the sense of touch in any high degree. Indeed, the skins of animals have, commonly, such a covering of thick, horny cuticle, scales, feathers, or hair, as is incompatible with a fine discriminating sense of touch.
In many of them, however, some other sense is highly developed. The Vulture is guided by the smell of carrion for miles and miles; and the dog will, by the same sense, track game where man cannot detect the trace of an odour. Some birds can distinguish objects which are quite out of the range of our sight. The Eagle, for instance, soars aloft, till it dwindles to a mere speck or is lost to our view, and, then, from that great height, will pounce, with unerring certainty, on an unhappy grouse upon the ground. The sense of hearing is a great means of protection to animals, and necessitates extreme stillness and caution on the part of their pursuers. The Deer, when feeding, directs his eyes upon the ground, and depends for safety, chiefly, upon his hearing, which is so acute that the huntsman is obliged to approach with all possible wariness.
In each of these instances, it may be observed, the acuteness of the particular sense is manifested chiefly in the power it gives to the animal of distinguishing objects at a distance. Whereas, in the ability to use the several senses for the nice discernment of the qualities of substances and to derive enjoyment from them, man stands quite unrivalled. He alone appreciates the perfume of a bouquet, or takes cognisance of the various shades of colour and of the notes of music; and the sense of touch, which is of especial service in aiding us to an accurate knowledge of bodies, is much more highly developed in man than in other animals.
Fine as the sense of touch usually is in the human hand, it becomes far more so when an unusual demand is made upon it in consequence of a deficiency, or absence, of other senses. The rapidity with which blind persons can read with their fingers is truly astonishing. Some are said to be able to distinguish colours by the feel. (It should rather be said that they are capable of recognising the nice differences in certain substances by which colours are caused; for one can scarcely conceive it possible to distinguish by feeling the colours in a ray of light separated by a prism.) I am acquainted with a lady who has been, not only blind, but deaf and dumb from infancy. The sense of touch is, therefore, almost her only avenue for impressions from without; and it is surprising how much information is conveyed through it, and how quickly. It enables her to hold converse with her relatives, by the language of the fingers, almost as freely and as briskly as others do with the tongue. A few touches are sufficient to transmit a series of thoughts. After one shake of the hand her friends told me that she would recognise me again; and, true enough, although several days elapsed before I again saw her, she made the sign for my name as soon as she touched my hand. At our next meeting I presented my left hand, but was, again, immediately recognised.
Persons who have had much experience in the instruction of the deaf and dumb find that the hand, by means of writing and “dactylogy”, or the language of finger-signs, is abundantly sufficient for all the intercourse to which a deaf-mute is equal; and they are, therefore, disposed to discourage the teaching of articulation. Dr Kitto, in his little book “On the Lost Senses,” which acquires so much interest from the fact of his being himself deaf and dumb in consequence of an accident, relates that, after he had, with great difficulty, reacquired considerable facility of speech, he found it stood him in little stead. So efficient a means of intercourse had the hand become that, he tells us, he had not occasion for the use of his tongue ten times in a year.
Not only may the hand thus serve, to some extent, as a substitute for some of the other senses; it is also a most important auxiliary to them. Particularly is it so to the sense of sight, by proving, or correcting, the impressions which we receive through the eye. Without its aid we should often fail to distinguish between a real object and a picture or a reflection in a mirror, and should have difficulty in judging of size, shape, distance, &c.
Relation of the Hand to the Eye and the Mouth.
You cannot have watched a game of cricket without being struck by the manner in which the hand acts in harmony with the eye. With what almost lightning-like rapidity it is in the exact place to catch the ball; and with what precision the practised cricketer can throw the ball to a great distance. In this, however, he is surpassed by the wonderful skill with which the Indian throws the lasso. Again, it is enough for the sportsman merely to get sight of the bird; he is scarcely conscious of the process by which the hand directs the gun and pulls the trigger at the exact moment. Still more remarkable is the successful aim when taken, as it occasionally is, without bringing the gun to the shoulder.
In estimating the importance of the hand, you must not forget that the mouth is quite dependent upon it for supplies. In most other animals the jaws are prolonged, forwards, from the cranium, and the head is placed in such a position that the mouth becomes an organ of prehension, and is enabled to provide for itself. But, in man, the head is carried so high above the ground, and the jaws are so shortened and compressed beneath the forehead, that the mouth is of little use in obtaining food. Its abilities and duties are restricted to receiving, masticating, and swallowing; and, if it had to rely upon its own efforts for supplies of food, it would, indeed, be in a poor case. When we look at one of the Sphinxes from Egypt, or at one of the stately Bulls from Nineveh, in which wisdom and power are represented by joining a human head to the trunk and limbs of an animal, the question suggests itself, “How is that mouth to be fed?” In the Centaur and Mermaid this difficulty is overcome by adding the hands, as well as the human head, to the trunk and locomotory organs of the horse in the one instance, and the fish in the other; so that monstrosity does not preclude the means of sustentation. Sufficient incongruities, however, still remain to justify the exclamation
“Spectatum admissi risum teneatis amici?”