our species, the scarf-skin being nearly transparent and colourless; and this has given rise to many very minute investigations, which we have no room to detail, respecting the question, whether Negroes, Americans, Hindoos, and Europeans are all of the same species. This membrane is wholly wanting in Albinos; in Europeans, Dr. Gordon and Mr. Lawrence both failed in separating it in form of a continued membrane ;* in the Negro, on the other hand, it is distinctly continuous. Dr. Gordon says, the colour of Europeans depends wholly on the red inner skin shining through the grey scarf-skin.

The True Skin.†-The innermost or true skin is greatly thicker than the other two, and all together is not much less in thickness, in man, than the skins of most other animals. On the eyelids and lips this layer is very thin, and nearly transparent; so that a bright light is easily distinguished through it, although the eyes be closely shut. A strong light, on this account, will often awaken a person from sleep, and even, if it do not, may injure the eyes.

The texture of the true skin is fibrous and close, full of minute pores, glands, vessels, and terminations of nerves. These pores are so minute, as

* Mr. PLUMBE, in his work on Diseases of the Skin, has taken it upon him to deny its existence altogether, without a shadow of proof beyond his own assertion ! ! !

+ Called, by the learned, Dermis, Cutis, and Corium.

the microscope proves, that a grain of sand would cover 25,000 of them. They are the mouths of vessels made of solid sides, which convey away the insensible perspiration, and receive what is absorbed from without.

The extremities of the nerves on the true skin are almost like the pile of silk velvet, in fineness and softness, rising out of the surface of this inner layer like close-set down. When magnified, these points appear in some parts like warts, in others like little mushrooms, and in others like the extremities of threads. Except on the lips, however, and after long maceration, it is very difficult to discover these appearances. Majendie says, the whole account of these terminations of the nerves on the skin is purely imaginary; but, if so, why is the skin the most sensible part of the body? In surgical operations, the cutting through the skin is always the most painful.

This velvet-like texture is, in some degree, observable externally on the inner surface of the fingers, particularly near their tips, being placed in spiral lines. It is here that the sense of touch is found to exist the most acutely, with the exception, perhaps, of the lips. By attention, these fleecy ends of the nerves may be seen to raise or erect themselves, as in frights and shiverings. These soft and close-set extremities of the nerves are defended, as we have already seen, by the mucous net-work and insensible scarf-skin, so that any impression

made from without is, by their means, modified and somewhat blunted.

The whole skin is capable of being stretched or contracted, in consequence of its fibrous and spongy texture. The numerous vessels which every where run through the true skin, are more abundant in some parts than others. In the cheeks, for example, they are in countless numbers, yet so very small and close set, that the surface appears of a uniform redness.

Any irritating substance applied to the skin, such as mustard, increases the size of these vessels, and deepens the redness of the skin. The passions, also, of joy and anger have a similar effect; while sorrow, fear, and disappointment, and cold, or a fit of the ague, will cause the skin to become dry, and full of little raised portions, known by the name of goose-skin. The pores of the skin seem to open at the same time; hence small pox, it is worthy of remark, typhus, and plague, are easily contracted by fear.

Moisture of the Skin.-None of the organs of sense appear to be capable of performing their functions perfectly, without the presence of moisture, as we find in tasting, smelling, hearing, and vision. Accordingly, it is remarkable, when the skin is dry and rough, that the sense of touch is very much impaired in nicety. The importance of moisture, to life and feeling, is proved by the simple experiment of putting a common garden snail in a dry

place, where it will soon become torpid and apparently lifeless. The most wonderful circumstance is, that it may be at any time restored to vigour by sprinkling it with water. Spallanzani revived some animalculæ, after they had been deprived of moisture for twenty-seven years.

The moisture which softens the skin is a soft, halffluid wash, somewhat of the nature of soap. It is prepared immediately under the true skin, in very numerous little glands or fountains, which separate it from the blood, and it oozes through minute pipes to the surface.

SKETCH OF THE FOUNTAINS OF THE SKIN, MAGNIFIED.

The glands, magnified sixty or eighty times, are seen in the first figure, arranged regularly, as is the

H

case in the hand; in the second, they are irregularly scattered, as on the back. The third figure shows the mouths of the little pipes, as they appear in the foot. There is another substance, by which the skin is anointed, rather dry, white, and of a waxy consistence in the face, but oily in the armpits. It is probably this ointment, which, in certain diseases of the stomach and bowels, becomes deteriorated, and gives the face a swarthy, greasy appearance.

Independent of glands, the fat gives out a third ointment to the skin, particularly where the skin is covered with hair. It is this which causes the peculiar unpleasant smell, which the hair is sometimes observed to emit, and which is only to be corrected by careful and repeated washing, and, if that will not do, by sweet-smelling essences.

PERSPIRATION.

With respect to the glands under the skin, we cannot assert that they are found in every part of it, as they cannot be every where discovered by dissection. But in most parts of the body, though washed ever so carefully, the linen is found to be soiled with what appears to be the excrements of the skin. Very corpulent persons will soil their linen in twenty-four hours. After drinking plentifully of red wines, this soiling is of a purple colour.

There is, in health, a constant flow of moisture