Hair facts you should know

About the hair

• How hair grows.
• Causes of difference between men's and women's hair.
• Curly hair and straight.
• The cause of curly hair and kinkiness.
• Blondes, brunettes and red-haired beauties.
• Pigmentation.
• Racial differences in hair.

The hair grows pretty generally over all the surface of the body—except the eyes, lips, genitals, the nipples of the breast in women, the palms of the hands, and the soles of the feet. It is most plentiful, in ordinary individuals, on that portion of the skin known as the scalp. This covers the top, sides and back of the head —above and behind the ears, to the extent of about one hundred and twenty square inches.

The boundaries of hair growth are tolerably well defined, where the more or less profuse growth shades off into a surface relatively free from hair, or made so by the gentle ministrations of the barber or the hairdresser.

The scalp is made up of the cutis, or true skin; the sweat glands; the hair follicles—in which are the hair shafts; the sebaceous glands; and the little erector muscles, that pull the hair up on end, when the sympathetic nerves respond to the sudden impact of fright.

Structure of the hair

The skin of the scalp does not differ from that of other parts of the body, except for the presence of the hair follicles, and their minute appendages.

According to Loewenhock and Eichhorn, two older very eminent authorities, there are about thirty-eight sweat glands to the square inch on the average head. It is the interference with the normal functioning of these glands that is chiefly responsible for most diseases of the scalp.

The hair follicles of the scalp are set in at an angle to the skin, except in the case of the eyelashes, where they enter straight. The follicles are located in the upper part of the skin in the case of the so-called "lanugo hairs"—the soft, downy hair; somewhat deeper with the stronger hair; and deeply imbedded in the skin tissue with long, soft hairs. The length of the follicle varies from one-twelfth to one-fourth of an inch. The follicles are permanent structures, and cannot be pulled out—any more than can any other hole be pulled out.

The bottle-shaped depression, which constitutes the follicle, is slightly expanded at its lower extremity, and closed in. It is surrounded by two layers of connective tissue, the inner layer of which sends up a small conical projection which develops into the papilla. The papilla forms the base of the hair bulb.

The nerve supply to the hair follicles is a matter of importance. For any loss of nervous energy affects the nutrition of the hair root, and also the supply of pigment, or colouring matter of the hair. We shall treat of this subject more adequately in the page dealing with grey hair and its various causes.

The papilla is the organ that produces the hair. It is from the papilla, and the capillary blood vessels it contains, that the hair derives its nourishment.

If the top of the papilla is pointed, the structure may be considered to be healthy, and still capable of producing hair. If it is rounded and shrunken, the source of nutriment for the hair may usually be said to be cut off and the hair ceases to grow.

Any disorder of the papilla, or any interference with the blood supply of the little organ results in deformities of the hair shaft that grows from it, and may even cause the death of the hair, and its consequent loss.

The little blood vessels of the papillae spring from the fatty layer under the skin —perhaps the most important of all the structures connected with the hair. For if the fatty layer is absorbed, or lost from disease, lack of care, or lack of proper exercise, it is obvious that the blood supply of the hair must be lost, and the hair will cease to be nourished. We shall discuss this important subject at length in the page dealing with baldness.

How the hair grows

The growing hair pushes up through the follicle and emerges from it at the surface of the skin. That portion of the hair between the bulb and the skin is known as the root. After the hair emerges through the skin it is called the shaft. The shaft ends in a point.

The hair grows upward because the little horny cells keep growing and pushing it upward. These cells are arranged in three different layers—the outside, middle and inside layers, which vary in shape in a rather intricate way.

They are of different sizes and shapes. The manner in which they are built together—whether the cells are straight and uniform, or diversified and spiral—is what causes some hair—such as is possessed, for instance, by the Indian, or the Chinaman—to assume a straight form. While a more pronounced spiral arrangement of the cells will produce wavy, or curly, or even kinky hair.

It will be seen from this description that there is an anatomical—or rather a mechanical reason why it will never be possible completely to remove the kinkiness of a negro's hair and keep it removed, despite the firm faith of many negro gentlemen and ladies in their bottle of Anti-Kinkine or old Make-It- Straight.

For, just as when a curled-up A shaving shrinks back and resumes its original curl when dry, so will a kinky negro lock curl up, shrink back, and resumes its kinkiness when the oil or other substance used to reduce temporarily its "curl" dries up. These arrangements of the cells of the hair are primarily racial. In most individuals in whom there is no racial dilution, or admixture of other blood, the racial hair characteristics are decidedly marked.

There is also a great variation in texture or in thickness, just as there is in the finger nails—which are made up of cells similar in their nature to hair cells—due to the arrangement of the individual cells comprising the hair shaft. This is characteristically racial.

These differences in the structure of the hair are quite as well marked, to the eyes of an ethnologist—or student of racial differences—as are the differences in colour, or the shape of the nose and ears, or other featural differences.

The length of the hair

Hair usually measures from a fraction of an inch to a yard or more in length.

Dr. C. Henri Leonard, in his book on hair, states that:

"The longest hair that I have seen in the female is that belonging to Mrs. Dr. Prittie, of Detroit. She is now 28 years of age, and her hair measures some fifty-eight inches in length. It is very dark coloured. I have measured the diameter of the shaft, and find it to be 1/300 of an inch. Luxuriant hair growths have been characteristic of her father's family, especially among the male members.

"Dr. Wilson says that a lady writes to him that she is five feet five inches in height, and that when standing, many of her hairs trail three or four inches upon the floor. She is 28 years of age, hair wavy (hence from the ovoid shaft), and it gives positive pain to have one pulled from the follicle.

"A lady in Massachusetts is reported to have refused $1,000 for her head of hair, which is quite thick and heavy, and measures five feet and eleven inches in length.

"White speaks of an Italian lady whose hair trailed on the floor when she walked. In Greece it is occasionally seen of that length.
"In 1814, in Fleet Street, London, a girl was exhibited having a head of flaxen hair five feet and nine inches in length."

But all such cases are exceptional—and it is questionable that such excessive growths of hair are either comfortable or desirable. What one should seek to attain or maintain for the hair is a healthy and vigorous state—not abnormal length.

The average normal hair is, when cut through, and examined under the microscope, found to be nearly round, or else slightly oval. It sometimes is almost flat, however, although really flat surfaced hair is only rarely met. If the microscope is focussed upon the surface, the edges of the outside cells will appear as dark lines, like the edges of the slate in a slate roof. If it is focussed on the edge of the hair shaft, it will look like the edge of a fine saw blade, as the edges of the outside cells overlap one another.

The cortical substance of the hair is marked by short stripes of a darker colour, which makes the hair appear to be composed of fibres. These fibres are really long, spindle-formed cells.

In this substance fine black granules are scattered about or gathered in heaps. These are the pigment granules—that give the hair its characteristic colour.

This colour may be pure white, grey, flaxen colour or golden blond, red, reddish brown, light or dark brown, or black.

How the hair gets its colour

The colour of the hair is dependent upon four factors:

1. The amount of pigment diffused throughout the hair cells.
2. The granular pigment grouped into little clusters.
3. The amount of air in the cells, and the distribution of this air throughout the structure of the cortical cells—the inside cells—of the hair.
4. The superficial character of the hair.

It is the cortex, and the grouping or diffusion of the pigment cells in it that is the chief factor in determining the colour of the hair.

The diffused pigment or primary colour of the hair gives to the hair a light brown to a dark red colour, according to its intensity. The combination of the diffused with the clustered, or granular pigment, makes the various shades of colour met with. The darker the hair, the more granular pigment will be found in it—the lighter, the less—although even blond hair will be found to contain some granular pigment cells.

The air globules are in the outer cells of the cortex, or fibrous portion of the hair, and help give it its characteristic colour. If there is any pigment in the hair it never appears quite white, even if air is present, but is always some shade of grey.

This would account for the colour in the hair of the albino. Being devoid of pigment, it always assumes a dead white colour —whether in the human albino, or in animals. If there are no air globules in the hair, or if the pigment is in excess, the hair will partake of the colour of the pigment.

The colour of the hair generally matches the complexion and the colour of the eyes. This is one reason why dyed hair rarely deceives an experienced eye—or even a casual eye. For the dyed hair contrasts too markedly with the colour of the skin. For this reason dyed hair is most generally disfiguring.

How long does the hair stay in

The length of the hair-life varies with the sex, age, character of the hair, and individual peculiarities. The lifetime of the eyelashes has been computed to be one hundred and thirty-five days, while the length of life of an individual hair on an average head is from two to six years.

It is believed that hair grows faster in the daytime than at night-time, and faster in warm weather than in cold—probably for the same reason that any other kind of vegetable or animal life thrives best in the presence of light and by the stimulus of heat. Shaving and cutting the hair tend to make it "come out" coarser, and probably also stimulate its rate of growth.

The average length of hair among Anglo-Saxon women is from eighteen to twenty-four inches if left uncut—although, as we saw earlier, it may grow to even fifty or more inches in length.

The hair of English and American men grows to an average length of six to eight inches—although the custom, to which we all kowtow, is for men to keep the hair much shorter than these lengths.

The rate of growth of the hair is from three-eighths to about three-quarters of an inch a month. With women, after the hair reaches a length of ten to fourteen inches, its rate of growth is reduced one half, and toward the end of its life the increase in growth is hardly perceptible.

How many hairs are there to the head

The average number of hairs to the square inch is reckoned at about one thousand. The surface of the scalp, as we have seen, covers about one hundred and twenty square inches. Thus, there are about one hundred and twenty thousand hairs on the head of the average man or woman.

The diameter of the hair varies with its colour, its location on the scalp, and the age and sex of the individual.

Flaxen hair is the finest, as every observer knows; black hair the coarsest. The finest hairs are from one five-thousandth to one five-hundredth of an inch in thickness; while the coarsest are from one four-hundredth to one one-hundred and fortieth of an inch in diameter. Usually the hair of children is finer than the hair of adults.

The contour of the hair is circular, oval or flattened. Whether the hair is curly or straight depends largely upon this contour—which in turn, as we have seen, depends upon the arrangement of the various cells that go to make up the hair.

The more oval or flattened the hair, the greater will be its curl. The curliness is also influenced by atmospheric conditions. Naturally curly hair becomes even more curly when damp. Hair that has been curled over a curling iron, on the contrary, loses its attractive curl when damp, and "strings out" in a manner most discouraging to the industrious beauty.

Hair is very elastic, and is capable, if in a thoroughly healthy condition, of being stretched greatly beyond its normal length. When the strain is removed, the hair will retract to nearly its original length.

The hair possesses quite a good deal of strength, as a healthy hair is capable of holding up a weight of from two to four ounces without breaking.

"Electricity” in the hair

Healthy hair develops considerable electricity on friction, especially in cold or very dry weather. The electricity, which is negative in character, may be elicited by combing the long hair of a woman with a rubber comb, when a pronounced crackling sound will be heard.
In very susceptible people the hair will stand out straight from the head, under electrical stimulus. Certain animals, cats in particular, are so "full" of this electricity that if the fur is rapidly stroked against the grain a quite distinct electric shock may often be felt.

What is hair made of

Dry hair is composed of five-tenths to seven-tenths parts of incombustible material. It is one of the most indestructible of all our physical possessions, almost as much so as the teeth. The hair on Egyptian and Peruvian mummies is remarkably well preserved, and, under proper atmospheric conditions, will probably last a couple of thousand years longer.

Chemically, it consists of 23 per cent of alkaline sulphates, 2 to 10 per cent of oxide of iron (if it is a high per cent the hair will be quite red) and 40 per cent of silica. The analysis of the hair substance determines it to consist of 50 parts of carbon; 6.36 of hydrogen; 17.14 of nitrogen; 20.85 of oxygen, and 5 of sulphur.

The hair contains a certain proportion of oil, varying in colour with the colour of the hair. The proportions of the chemical constituents vary also with the colour of the hair.

Flaxen hair is richest in oxygen and sulphur and contains least carbon and hydrogen; brown has the most carbon and the least oxygen and sulphur; while the white hair of the aged contains a considerable quantity of phosphate of lime, or bone earth.

Has hair any purpose except as an adornment

Hair serves four great purposes:

1. It preserves the heat of the body.
2. It acts as a protective agency.
3. It is an organ of touch.
4. It promotes beauty.

Hair is a poor conductor of heat. Therefore, it protects against exposure to the rays of the sun, and it also keeps in the natural body heat, when the head is exposed to the cold.

It is interesting to note that where one is exposed even to excessive heat and excessive cold, the hair is likely to grow quite luxuriously.The hair on the head forms a cushion, which protects against blows, and thus is a splendid defence to the skull in case of blows or falls.

The eyebrows are a defence to the eyes, and turn the perspiration as well, thus preventing it from running into the eye. The eyelashes catch the flying particles of dust. Hairs in the ears and nostrils prevent insects from gaining entrance into the cavities they guard. The sense of touch in the hair connection of man is of little use. But to many of the animals it is indispensable.

The oil secretion of the hair

The natural oil of the hair comes from the sebaceous glands. The purpose of this oil, of course, is to keep the hair soft and flexible, prevent it from being broken off, and to give the hair lustre. This secretion is constant during health, and is the result of fatty degeneration in the lining cells of the sebaceous glands, which fill slowly with oily matter, then burst and discharge their contents.

These glands, emptying into the hair follicles just below the surface, are admirably located for lubricating the hair, just before it makes its appearance in the outer air. The oily secretion, by rendering the hair less absorptive of water, prevents the disintegration of its elements from exposure to moisture and air.

The secretion of the sebaceous glands also acts as a hollow cork through which the hair passes. This prevents the entrance of foreign material into the hair follicle. It will be seen from this that the hair and its attachment is a complicated little organ. It is more complex than one would think.

Therefore it is not surprising that a lack of knowledge of its function and care frequently results disastrously to the hair and most disagreeably to the owner of the hair.