A GILDED live pig is a sight rarely seen. The rarity of putting gold leaf all over a living animal of any kind comes from the fact that the animal dies so soon after the operation. It has been tried several times and always with the same result.

The idea arose from an experiment unfortunately performed upon a child on the accession of Leo X. to the papal chair. The child was gilded all over to represent the Golden Age. The people of Florence were delighted with the idea, but the death of the child took place so quickly that some thought the brief duration of the Golden Age was miraculously represented as well as its great glory.

The experiment has never been repeated upon a human subject, but men of science cautiously tried to find out the secret of the child's living but a few hours after the operation, and so gilded pigs and varnished rabbits and other small animals. From such tests of the value of an open skin to animal life they found that all things that have breath must have open skin pores in order to maintain life.

Closing the pores of the skin causes the temperature to fall directly and the heart and lungs become gorged with blood. The circulation of the blood is seriously interfered with and death follows with the usual symptoms of asphyxiation.

Strange as it seemed to those who first witnessed such experiments, the life of an animal is more directly dependent upon the action of the skin than upon that of the stomach, the liver, or even the brain. Monstrosities have been born without brains; but they have frequently lived for some time, taking their food regularly and having the appearance of as much comfort as others of their kind with brains. They died early, but their life was uniformly longer than the time which elapsed after the application of a coating which stopped the skin of other animals until death ensued.

A man will live much longer without stomach action than without the proper functions of the skin. In fact, the skin may take the place of the stomach in sustaining life for awhile, where the act of swallowing has been prevented by disease or accident. Feeding the patient through the skin has been accomplished with varying degrees of success. A bath of warm water or milk and water assuages thirst. Sailors deprived of fresh water wet their clothes with salt water, and the absorption of moisture sustains them where salt water taken into the stomach might have resulted fatally.

The health of the skin is closely connected with that of the whole system. Its appearance and condition as to moisture and dryness, as well as its temperature and color are regularly examined when the system is out of order. Since the skin is so important to the general health and its condition is placed so completely within our control, it is wise to care for it judiciously. We often find other organs of the body in an unsound condition and begin to doctor them when the whole trouble has arisen from bad treatment of the skin. The skin needs more care than the liver or the stomach, and many of the troubles laid at the door of one or both these organs may be avoided by proper care of the one organ over which we have entire control, the skin. Where the skin is prevented from doing its proper work other organs try to carry it on, and the result is that those organs which are really beyond our control, and which will work properly without any attention from us, become diseased by our bad treatment of the organ that comes first in the natural order of attention.

The skin throws off waste matter from the system. Two and one-half pounds of watery vapor is poured out daily from the average man. A clogged skin retains certain salts in the system supposed to have something to do with such diseases as rheumatism and gout if left in the blood by too little exercise of perspiration.

Besides the sweat glands there are glands which exude fatty substances upon the skin, keeping it suitably lubricated and somewhat impervious to water. In some animals this secretion is so abundant that the skin cannot become wet in swimming. Beneath the skin are frequently cushions of fat to protect the soles of the feet and the outside of the larger joints. The blubber of the whale, the thickest skinned of all animals, is of this sort, and is evidently intended to make his tremendous weight less destructive when brought in contact with other objects. The hide of the swifter ones is peculiarly fitted with large papillÆ of feeling which are supposed to warn them of the presence of rocks and other objects by the action of the water while swimming near them.

Insects, not having lungs, receive air into their bodies through holes in the skin. These are called spiracles. They are so protected by hairs within the holes that water will not enter them. This is why it is so difficult to drown an insect. But if you touch the abdomen of one of these skin-breathing creatures, for instance the yellow part of a wasp, with a drop of oil, the minute openings become almost immediately clogged and the insect falls dead as if choked completely.

The skin consists of two layers, both of which are exceedingly interesting. The outer or scarf skin is called the cuticle on the outside of the body, while wherever the skin dips into the body it is modified into what is called mucous membrane. This outer skin is not what is rubbed off the surface in a Turkish bath manipulation or what is brought off by the rubbing one gives the body with a rough towel. These rubbings bring off merely the dead outer surface of the cuticle which should be out of the way because no longer useful. In man it continually wears off, in serpents it is shed annually in one slough.

The cuticle is the portion of the covering of the body which may best be noticed when a blister has been raised in the skin. The blister is an accumulation of fluid between the cuticle and the true skin.

The cuticle, or epidermis, is modified in many other ways than the one in which it becomes mucous membrane. Where the habits of the animal make warmth desirable the epidermis dips into the skin and without any break in its connection rises in the form of wool, which covers the body of the sheep so effectually. Where the animal is designed for flight there is the same characteristic dip into the material of the body, and out of the little sac so formed rises the feather which gives the bird its beauty and powers of flight. The feather is a modification of the scarf skin.

Where protection is needed for the body beneath the surface of the water this changeable substance covers the true skin with hard scales that make the friction of the water as slight as possible, while giving a firm and light resisting surface to prevent wounds. Horns and hoofs are modifications of the scarf skin. Where claws or talons are needed in the business of fighting or tearing food in bits or digging holes in the ground or elsewhere, the scarf skin changes itself at the extremities of paws and feet and produces nails, talons, and claws, whose powers are both marvelous and varied. For the protection of most mammals the whole of the body is favored by this power of the scarf skin to produce whatever seems necessary for the comfort of the individual, and the body is indented with innumerable minute holes called hair follicles into which the scarf skin dips and rises again to the surface transformed into hairs of varying degrees of fineness and color, beautifully arranged in order, and all pointing in such directions as will add to the beauty or comfort or terrifying aspect of the animal.

Not only are our hairs numbered, but each particular hair is furnished with a little individual muscle of its own running from the base of the follicle to the inner surface of the true skin, so that when the proper occasion arises for erection of that individual hair the muscle contracts apparently of its own accord, and up stands the hair along with its fellows, ready to frighten the animal that dares to approach in hostile attitude the owner of the precious coat. Similar muscles erect the feathers of the owl, and the gorgeous tail of the peacock dazzles us in the sunlight moved in like manner, while to those more powerful dermal appendages, the claws, talons, and nails, are attached more powerful muscles still, with proper nerve connections for the most effective use of the weapons nature has formed out of the soft outer skin, which is usually so mild and yielding as to have earned the name of scarf skin.

This outer skin is formed of cells, flat on the surface, but near the true skin where they originate, rounded and in many cases even tall and apparently reaching out towards the surface. It gives the color to the person by means of pigment cells which lie in its midst.

The black man is dark because of the abundance of pigment cells in his scarf skin. The albino is light because of their absence. The colors of hair and feathers are due to these cells in their receptacles, but white and iridescent feathers are doubtless so partly because of their absence and partly because of hollow spaces which catch and reflect or refract the light.

This arrangement of cells into scarf skin has much to do with the healing of wounds. In cases of old sores that refuse to heal, or where the skin has been extensively destroyed, the doctors have found that good, healthy skin may be grafted upon the sores in such a manner as to invigorate and perfect the process of healing. Small particles of fresh skin taken from a healthy subject or from some other part of the patient's body are placed upon the sore, the portions used being about the size of a small pinhead, and new life seems transplanted in the deadened part. The skin of a black man grafted upon that of a white man shows afterwards no trace of its origin, but becomes the same shade as that which it adjoins.

Several animals change their tints to correspond with their surroundings. This subject has been exaggerated by observers of an imaginative turn of mind, but the fact remains that there is a decided change in the coloring of certain crabs and shrimps as well as in soles, chameleons, tree-frogs, and two kinds of horned toads wherever they are found against any well-defined shade or color. Some have maintained that man takes on a tint somewhat resembling the soil of the territory where he abides in an uncivilized condition, but Beddard considers Schweinfurth's statement that the Bongos have a reddish-brown skin similar to the soil of their country, and the Dinhas, their neighbors, are as black as their alluvial ground, merely as an account of what is purely accidental in the instances given.

The coloring of most fish so that they cannot readily be seen by looking down into the water because of the blackness of their backs, is highly protective. And the fact is more apparent when we note that an enemy looking at the same fish from below is hindered in discovery because the white under parts of the fish are hard to distinguish against the light of the sky above. Nearly all the protective color markings of animals are modifications of the scarf skin.

The true skin is of great interest both because it is the seat of what is called the sense of touch and because it is used so extensively in the arts in the form of leather.

Nerves of sensation expand over the whole surface of the body, and their minute branchings in the skin make contact with other substances highly discernible. But the sense of touch is peculiarly developed in few of the lower animals, and we may almost regard it as an attribute of man alone. Our ability to turn our fingers about things and move our hands over their surface gives us a power that is rare in nature. We can tell whether things are hot or cold, rough or smooth, sharp or blunt, wet or dry, and gather many other items of interest which the other senses are incapable of compassing.

A monkey can wind his tail about a nut and tell by the sense of touch whether it is worth his while to crack it. The elephant moves the tips of his trunk carefully over the surface of what he wishes to examine and gets knowledge he can depend upon. But it is the hand of man that shows the highest order of development of touch. By it blind men know their friends and read their books, bank clerks detect the qualities of the notes they handle, and a thousand deft acts in the arts are accomplished.

The true skin is covered with minute projections called papillÆ. They may be traced in the palm by the ridges of the scarf skin. They are arranged there in rows so that while the naked eye does not discern the projections individually the rows of them may be noticed on the surface of the scarf skin. Some of these papillÆ contain blood vessels and others corpuscles of touch. Some papillÆ are small and simple, others compound. In one square inch of the palm have been counted 8,100 compound and 20,000 smaller papillÆ arranged in regular rows. There seem to be different end organs for different sensations. There are different spots which may be touched with a fine pointed pencil of copper which is quite hot and no feeling will result. Perhaps the same identical spots touched by the same point, after having been immersed in ice water, will give sensations of cold. Hot spots and cold spots may be found and marked upon the skin. There are more hot spots than cold ones. Either of these when disturbed electrically will give sensations of heat or cold when neither heat nor cold is applied.

Ashe mentions an experiment which shows that the body is not equipped exactly alike on both sides, for when both hands are placed in hot water the heat seems greater to the left than to the right hand. Aristotle wrote of the peculiar feeling produced by placing the ends of the first and second fingers upon a small substance like a pea. With the fingers in their natural position you feel one small round body. Place the same fingers upon the same pea, but with one finger crossed over the other so as to touch the pea on the other side, and you distinctly feel two peas. Another of the freaks of touch may easily be tried by placing the palms together so that fingers and thumbs are against their fellows. Close the hands partly and open them again repeatedly and in a short time instead of each finger's feeling another finger there will seem to be an oiled pane of glass between the hands keeping the fingers about a quarter of an inch apart. The delusion subsides when you look at your hands.

Leather was very early known in Egypt and Greece, and the thongs of manufactured hides were used by all nations for ropes, harness, and other instruments. The renowned Gordian knot, 330 B. C., was of leather thongs. A leather cannon was made in Edinburgh at the time of the American revolution. Although it was fired three times and found to answer, and other firearms were made of this material, it never became common. Had it not been for Mother Goose the leather gun might have dropped from the memory of man.

Leather is made from the true skin and tannic acid. The processes of tanning have recently undergone such changes and improvements that it is out of the question to follow them briefly. The union of the white fibres of gelatin, gluten, and kindred substances with the tannic acid, forms insoluble compounds which have great resistance and strength. This acid is found in oak and hemlock bark, and also in that of many other trees such as willow, ash, larch, sumac, and terra japonica. Tea is one-fourth tannic acid.

Deer skin makes the finer kinds of morocco, while sheep and goat skin make the grades that are used in book-binding. Seal skin makes a superior kind of enamelled leather for boots, bags, dressing-cases, and ornamental articles. Hog skin is so full of oil that it resists the tannic acid, yet saddles are made from it, and it has other uses. The French glove makers produce a very good kid glove from rat skin which can be distinguished from the real article only with a microscope.

The tanner applies the term, skin, to the smaller product taken from calves, dogs, rats, cats, and small game, reserving the dignified name of hide for that of the full-grown ox or horse, while the skin from a two-year-old steer is called a kip.

The highest use of skins is in the form of parchment and vellum on which are printed and engrossed the most valuable documents prepared by man.