Fig. 6.*

dermis. They are of a conical figure, round or blunted at the top, and are received into corresponding pits on the under surface of the cuticle. They measure on the hand from goo too of an inch in height. In the ridges, the large papillæ are placed sometimes in single, but more commonly in double rows, with smaller ones between them,

that is, also on the ridges, for there are none in the intervening grooves. These ridges are marked at short and tolerably equal intervals with notches, or short transverse furrows, in each of which, about its middle, is the minute funnel-shaped orifice of the duct of a sweat gland. Fine blood-vessels enter the papillæ, forming either simple capillary loops in each, or dividing, according to the size of the papillæ, into two or more capillary branches, which turn round in form of loops, and return to the veins. Filaments of nerves are also to be discovered ascending into the papillæ, but their mode of termination is doubtful In other parts of the skin, endowed with less sensibility, the papillæ are smaller, shorter, fewer in number, and irregularly scattered. In parts where they are naturally small, they often become enlarged by chronic inflammation round the margin of sores and ulcers of long standing, and are then much more conspicuous.'-QUAIN.†

'Papillæ of the palm, the cuticle being detached.-Magnified 35 diameters.'-(TODD and BOWMAN.)

Inside the papillæ are either nerves or blood vessels, seldom both; and at their base, the nerves are disposed in the form of net-work. In great part of the skin, the nerves cannot be traced farther than this net-work; it is in the hands, feet, lips (red part), and tongue that they are followed into the interior of the papillæ. In these parts they end in a peculiar structure, known as the 'little bodies of touch,' discovered by Wagner and Meissner. These are little sacks, covered by a thin skin, and filled with a round little mass. The skin is pierced by one or two nerves, which often wind spirally, but end by dividing and spreading their twigs in the little sack. These bodies lie in the interior of papillæ destitute of blood vessels, in such a manner as to project far above the upper end of the papillæ, and in immediate contact with

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I have quoted the description of the papillæ at length because of their connexion with the sensibility of the skin. I shall refrain from quoting the minute account of the nails and hairs, however interesting their structure in other points of view. Respecting the glands, it is only necessary to advert to the totally different nature of the two sorts, as respects the material secreted. The sweat glands are enormously numerous, and exist in all regions of the skin; they are reckoned to vary from 400 to 2,800 in a square inch. 'The sebaceous or oil glands pour out their secretions at the roots of the hairs, for, with very few isolated exceptions, they open into the hair follicules, and are found wherever there are hairs.'

4. With respect to the functions and vital properties of the skin in general, I quote part of Dr. Sharpey's summary.

'The skin forms a general external tegument to the body, defining the surface, and coming into relation with foreign matters externally, as the mucous membrane, with which it is continuous and in many respects analogous, does internally. It is also a vast emunctory, by which a large amount of fluid is eliminated from the system, in this also resembling certain parts of the mucous membrane. Under certain conditions, moreover, it performs the office of an absorbing surface; but this function is greatly restricted by the epidermis. Throughout its whole extent the skin is endowed with tactile sensibility, but in very different degrees in different parts. On the skin of the palm and fingers, which is largely supplied with nerves and furnished with numerous prominent papillæ, the sense

the cuticle. They are most numerous on the inside of the finger tips, and decrease towards the palm; the same happens with the foot. Meissner found in a square line (r of a square inch) on the index finger, 108 on the last joint, 40 on the second, 15 on the first. In the red part of the lips, the papillæ carrying nerves are not distinguishable from those carrying blood vessels, the same papilla appearing to have both.

The little muscles discovered by Kölliker in the skin, and especially in the glands, excite peculiar movements as in shivering, the creeping sensation, &c. These are especially affected by changes of temperature, and may serve to regulate the supply of blood under such changes.

attains a high degree of acuteness; and this endowment, together with other conformable arrangements and adaptations, invests the human hand with the character of a special organ of touch. A certain, though low degree of vital contractility, seems also to belong to the skin.'-QUAIN.

Of the other parts sensible to Touch, besides the skin, namely, the tongue and mouth, the needful description has been already furnished under the sense of Taste.

The nerves of touch are the sensory or posterior roots of the spinal nerves for the limbs and trunk, and certain of the cerebral nerves (the fifth pair) for the head, face, mouth, and tongue.

5. The action in touch is known to be simple pressure. The contact of an object compresses the skin, and through it the embedded nerve filaments. That the squeezing or pinching of a nerve can produce sensibility is proved in many experiments in touch, the squeezing is of a more gentle nature, owing to the protection that the covering of skin gives to the nerves. The only point of interest connected with the mode of action is the singular fact, that very light contacts often produce a great sensibility, as the touch of a feather or of a loose hanging piece of dress, which sensibility is diminished by making the contact more intense. Great pressures yield comparatively little sensation in the skin; they are felt mainly in the muscles as a feeling of force and resistance.

This fact of the disproportion of the feeling to the pressure I can account for in no other way than by supposing, that great compression has an effect in deadening the conducting property of the nerve. We know from various observations that the compression of a nerve does tend to arrest its conductibility; the deadening of the sensibility of the hand by leaning the elbow on a table, so as to squeeze the nerve that

It is supposed that the important nerves of touch in the extremities have a different course in the brain from the nerves of the trunk. Türk has shown that in the hand and foot the same spot is supplied from different roots in the spinal cord.

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passes near the surface on the elbow joint, is a familiar instance.

6. We come now to the sensations, or feelings of touch, which are various in kind, and have many of them a considerable degree of interest, from their bearing on the higher operations of mind. In the order of enumeration, I shall commence as usual (I.) with those having reference to pleasure or pain, or that may be called predominantly emotional.

Sensations of Soft Touch.-In this class of feelings, we suppose the gentle contact of some extended surface with the skin. I keep out of view the feeling of temperature. A good example is furnished by the contact of the under clothing with the general surface of the body, which is most perfect under the bed-clothes at night. The glove not too tight on the hand is another instance. The extended hand, resting on a cushion, or other soft body, is a sufficiently good type of the situation.

The resulting sensation is of the pleasurable kind, not acute, but massive. It closely resembles agreeable warmth. It is less powerful, but probably more retainable in idea, than the muscular or the digestive sensibilities. Its relationship to the tender emotion is elsewhere discussed. (THE EMOTIONS AND THE WILL, Tender Emotion.)

The habitual inattention to the sensibility of the clothing is a striking example of the law of Relativity. The remission of the contact is felt, on the same principle, as a sensation of blankness.

In the feelings of the lachrymal, mammary, and sexual organs, the mode of action appears to be something more than simple contact; the quality of the touching substance affects the sensation. In the tranquil flow of the lachrymal fluid, under genial tender emotion, there is a certain amount of agreeable sensation in the eye; but when the eyes are flooded in profuse grief, the contact of the liquid with the eye-lids is scarcely pleasurable. There is probably, if not a chemical, at least a dialytical action on the sensitive surfaces, in those instances.

The mutual contact of living animal bodies yields a complex sensation of softness and warmth, and excites the corresponding emotions. There may be, in addition, magnetic or electric influences of a genial kind, but the reality of such currents is by no means established.

The attraction between the mother and offspring is partly grounded upon the pleasure of the soft warm contact. This keeps the new-born animal by the mother's side, before it has come under the farther gratification of being fed and nourished; and continues to co-operate with that still more powerful motive to close proximity. At a later period, the contact of the opposite sexes, stimulated, in the first instance, by the pleasure of mere touch, discloses and inspires in each the sexual urgencies, and the tentatives for gratifying them.

Many of the habitual attitudes and modes of outward expression are regulated by the pleasure of soft touch. The child puts its finger or hand to its mouth, either for the mere pleasure of the act, or as a comforting sensation in distress; and all through life the contact of the hand with the parts of the face is practised from the same motives. Many other attitudes and actions are governed by the pleasures of touch; some, as scratching the head, are apparently the search for pungency.

7. Pungent and painful Sensations of Touch.—When, instead of a diffusive soft contact, we have an intense action on limited spots, mere points, as in the stroke of a whip, a sensation of smartness is produced very different from the above. In moderate degree, this gives a pleasurable pungency, beyond which it is acutely painful. The nerves are shocked as by the prick of an instrument, and the overintensity and suddenness of the stimulus is a cause of pain. The nature of the sensation is not radically different from a cut in the skin; its peculiar smartness excites the whole system. It prompts the most decisive actions for avoiding the pain, and an intense mental aversion to all that relates to it. The intensity gives to it a hold on the memory not possessed by the luxurious feeling of diffused softness.