CLOTHING.
=Physiological Considerations.=—The average temperature of the surface
of the body in man is 98·4 to 98·6°. The maintenance of a tolerably
uniform temperature is an essential condition of life. The factors
governing the temperature of the body are _the amount of heat produced_
and _the amount lost_. If more heat escapes, more has to be generated;
and the source of all the heat produced in the body is the food taken.
This becomes changed by the metabolic processes occurring in the body
which produce heat.
=Heat is lost=, (1) by the _skin_; (2) in _respiration_, the expired
air having been heated during its stay in the lungs; (3) with the _food
and drink_ taken, if not at the temperature of the body; (4) with the
_excreta_; and (5) by transformation of heat into _mechanical energy_.
Of the whole loss by these different channels, probably eighty to
ninety per cent. is through the skin.
=The Loss of Heat by the Skin= is in three different ways. First, by
_conduction_, when the skin comes in contact with anything cooler
than itself; secondly, by _radiation_ into space; and thirdly,
by _evaporation_ of the perspiration. The last cause produces a
considerable reduction of temperature, even when the perspiration is
not so abundant as to be visible, but is in the form of insensible
perspiration. The losses by these different sources vary in amount;
when one is increased, another is diminished, by way of compensation.
Thus, in very cold weather, the amount of radiation and conduction
of heat are increased; but evaporation greatly decreases, and the
diminished loss of heat in this respect counter-balances in some degree
the increased loss by radiation and conduction.
When the external warmth is considerable, increased evaporation occurs;
while when the weather is cold, the cutaneous arteries contract, and
less blood goes to the skin, and so the loss of heat is diminished.
In most climates, however, this action of the skin requires to be
supplemented by some kind of clothing.
=Requisites of Dress.=—1. The first and most important requirement is
that _clothing should maintain a uniform and equable temperature_ in
all parts of the body.
In hot climates clothes are required in order to protect the body
from external heat. In this country, they are required to prevent the
too rapid escape of heat from the body. For both these purposes,
dress must be of a non-conducting material, in order not to encourage
transfer of heat into or from the surrounding atmosphere.
The loss of heat by the skin may be prevented by interfering with
radiation or conduction of heat, or with evaporation from its surface.
Radiation of heat from the skin is prevented by clothing, the dress
taking the place of the skin as a radiating surface. The amount of
radiation from the dress will depend on the rapidity of conduction of
heat from the skin. The amount of conduction and of radiation of heat
will vary considerably with the _material_ and _colour_ of the dress.
As regards =conductivity=, the two extremes are represented by linen
and fur. It is found that if the conducting power for heat of linen =
100, then that of wool = 50 to 70. This partly explains why woollen
goods are so much warmer than linen. We shall find that there is
another explanation in the relative hygroscopic properties of the two
materials.
As regards =radiation= of heat, in one experiment it was found that
while a piece of linen took 10½ minutes to cool, a corresponding
piece of flannel took 11½ minutes.
Apart from the material, the =colour of dress= has some influence
in regulating the loss of heat. Dark-coloured materials absorb more
light and heat than lighter coloured materials; they may be good or
bad conductors of heat, according to the nature of the material. White
reflects the rays of light and heat; hence it is a poor absorber. In
summer it prevents the passage of heat inwards, and, in winter, may
prevent its passage from the body. It is thus well adapted for both
winter and summer clothing, and has the additional advantage of being
the cleanest colour.
Franklin placed a number of squares of different coloured cloths of the
same material on snow, and found after a time that the snow covered
by the black piece was most, and by the white piece least melted. In
another set of experiments, shirting materials dyed various colours
were taken, and it was found that if the rays of heat received by white
were represented as 100, pale straw received 102, dark yellow 140,
light green 155, Turkey red 165, dark green 168, light blue 198, black
208.
The influence of colour is antagonised to a large extent by the nature
of the material; the increased heat absorbed by a dark material may
be counterbalanced by the material being a good conductor. Also the
influence of colour is only exerted superficially; hence, although it
produces considerable effect in thin textures, as gauze, it has little
influence on thick materials.
2. _The dress should not interfere with perspiration._ In order that
it may not do this, it should be competent to absorb moisture easily,
without its surface becoming wetted. Materials like linen which lose
their porosity and rapidly become wetted by perspiration, cause rapid
loss of heat from the body, inasmuch as water is a better conductor of
heat than air. Pettenkofer found that while the maximum hygroscopic
power of wool (flannel) is 174 and the minimum 111; the maximum of
linen is 75 and the minimum 41. Hence, with a flannel vest next the
skin, the liability to chill is much less than with a linen one. There
is one slightly counterbalancing drawback; hygroscopic materials absorb
moisture from the air, as well as from the skin. A woollen coat during
a damp day, without rain, increases considerably in weight.
Waterproof clothing is injurious when worn beyond a short period, on
account of its being non-porous and consequently keeping the body
enveloped in a vapour bath composed of its own perspiration. For a
similar reason India-rubber boots are objectionable, except for short
periods; they make the feet damp, and even sodden. Sealskin jackets
are objectionable for walking, not only because of their weight, but
because they are not porous.
3. _The warmth of clothing should be uniformly distributed_ throughout
the body. This principle is very frequently departed from; and
consequently one part may be chilled while another is over-heated.
This is seen especially in female apparel. The same evil is seen in
the short sleeves, and short and low-necked dresses of young children.
“Combination” garments for women, and sleeves and leggings for young
children are happily becoming more generally adopted, and will diminish
the diseases due to exposure to cold.
4. _The clothing should not be tight_; and this for three reasons.
First, because _loose clothing is warmer_ than tight; this everyone
has experienced in the case of gloves. The retention of air in the
meshes of clothing is one of the main causes of its warmth, air being
a bad conductor of heat. The imprisonment of air in the meshes of the
material largely explains the warmth of eider-down quilts, furs, and
flannels as contrasted with linen.
Secondly, clothing should not be tight, in order _to avoid interference
with the action of the muscles_. Tight sleeves prevent the muscles of
the arms and chest from being exercised. Tightly laced corsets imprison
the trunk muscles, prevent their contractions, and so lead to muscular
weakness and occasionally spinal curvature. Tight skirts similarly
prevent free play of the lower limbs, leading to a halting gait, a
diminished amount of exercise, with all the evils following deficient
exercise. Tight clothing is not confined to one sex, and in all cases
leads to hampered movements and deficient muscularity.
Thirdly, tight clothing tends to _impede the functions of circulation,
respiration, and digestion_. The fashion which more than any other
interferes with important functions is _tight-lacing_. This produces
(1) compression and displacement of the viscera; the liver and the
stomach especially suffer. (2) Respiration and circulation are impeded,
the action of the diaphragm being impeded. (3) The muscles of the trunk
being tightly encased, are incapable of movement, and consequently
tend to waste and atrophy. The general outline of the body is altered.
Instead of the waist being elliptical, as it naturally is, it becomes
nearly circular; and instead of its circumference averaging twenty-six
to twenty-seven inches, it may be eighteen to twenty-one inches. Tight
_garters_ tend to produce varicose veins.
_Tight boots_ are injurious, as they tend to destroy the natural
elasticity of the movements, and confine them within narrow limits.
They act to some extent the part of splints. By interfering with the
circulation of blood through the feet, they cause cold feet, and not
uncommonly chilblains. _High-heeled boots_ do not allow the natural
elasticity of the foot to come into action. They distort the movements
of the body and cause corns and bunions. Similar effects are produced
by boots which are too narrow and have pointed toes, thus not allowing
free movement of the toes.
5. _The weight of the clothing should be the smallest amount consistent
with warmth, and it should be evenly distributed._ The chief weight
should not be suspended from the waist, as here the parts are not
well supported by bones. The shoulders and hips should share in the
suspension of clothing, thus diminishing the danger of compression and
displacement of internal organs. In order that garments may be as light
as possible, they should be made to fit to each limb separately, thus
diminishing the amount of material required.
6. _The materials of dress should be as far as possible
non-inflammable._ This may sometimes be disregarded, but is often
important, as in the nursery. In this respect, as in many others,
wool possesses great advantages. Woollen fabrics smoulder rather than
burst into flames, and thus the injury resulting from any accident is
limited. Cotton is more inflammable than linen, linen than silk, and
silk than wool. A closely woven cloth is less inflammable than one with
open meshes.
Dress materials, and more particularly muslin, have been rendered
non-inflammable by treating with a solution of ammonic phosphate,
or ammonic phosphate and ammonic chloride mixed. The best material,
however, is sodic tungstate, which, unlike the others, is not affected
by ironing. Sodic molybdate is used in arsenals to render the workmen’s
clothing non-inflammable. All the above plans are objectionable, as
the weight of the material is increased 18 to 29 per cent., and they
all wash out. To remedy this, a “fire-proof starch,” containing sodic
tungstate has been devised.
Perfect non-inflammability is only required in certain dangerous
occupations. The plans hitherto mentioned simply prevent the fabric
breaking out into flame. The only cloth absolutely unaffected by fire
is asbestos cloth.
7. _Elegance of dress_, although not so important as utility, is not to
be neglected, and the two are perfectly compatible. In fact, elegance
is indirectly associated with utility, for nothing which is awkward,
or leads to obstructed movements or distortions of the body, is really
elegant. A sudden constriction, as in a very tight waist, is not only
bad from a hygienic point of view, but is also ugly.
=Materials for Clothing.=—The materials used are derived partly from
the vegetable world, as hemp, flax, cotton; and partly from the animal
world, as silk, wool, hair, feathers. The most important materials are
wool, silk, cotton, and flax.
1. _Wool_ varies somewhat in character, according to the animal from
which it is derived. In all its varieties, however, it preserves the
character of a bad conducting and porous substance, the two most
important requisites in a dress material.
(1) Wool from the sheep is really a soft and elastic hair, composed of
fibres three to eight inches long, and about 1∕1000 inch thick. The
finer and shorter wools are used for fine cloth, the longer and coarser
for “poplins,” “worsted pieces,” etc. Flannel is a woollen stuff of
rather open and slight fabric. Wool is irritating to delicate skins,
and may be so much so, that it cannot be worn next the skin, whether
as flannel, worsted, or merino. In these cases, it may be worn outside
a linen or gauze vest, and so all its advantages secured. It is one of
the worst conductors of heat, and ought always to be worn in winter;
while even in summer, it ensures a greater immunity from chill after
perspiration than any other material.
(2) _Cashmere_ is made from the down found about the roots of the hair
of the Thibet goat. Imitation cashmere is made of various materials
mixed together.
[Illustration: FIG. 56.
MICROSCOPICAL APPEARANCE OF FIBRES OF A—COTTON. B—SILK. C—LINEN.
D—WOOL.]
(3) _Alpaca_ is obtained from the fleece of the llama, alpaca, and
vicuna. It is longer than the fleece of the sheep, the fibres, which
are soft and strong, averaging six inches in length. It is commonly
made up with cotton or silk.
(4) _Mohair_ is the hair of a goat inhabiting the mountains near
Angora. It is woven into an almost waterproof cloth, and used in making
plush, braid, etc.
2. _Hair_ derived from the horse or cow differs from the hair usually
called wool, in the greater solidity of its structure, which makes it
ill adapted for clothing. Its chief use is in the manufacture of felts,
of which hats are made.
3. _Leather_ is a kind of natural felt, very close and firm in its
texture. It is used in this country chiefly for boots, but in some
colder climates also for coats, etc. It is impervious to moisture, like
sealskin, and is consequently not very healthy. The same objection
applies to _chamois-leather underclothing_, which is non-porous,
and consequently keeps the skin hot and clammy; also, it cannot be
washed without becoming stiff on drying. This necessitates wearing the
material after it has become impregnated with perspiration.
4. _Silk._ The thread spun by the silk-worm is composed of filaments
1∕2000 inch wide, and is the strongest and most tenacious of textile
fabrics. Its thread is three times as strong as a thread of flax of the
same thickness, and twice as strong as a thread of hemp.
Its fibres are round like those of linen, but softer and smaller; it
gives an agreeable sensation of freshness to the skin even more than
linen. It is a worse conductor of heat than cotton or linen. Its great
disadvantage for wearing next the skin, apart from its expense, is that
it irritates delicate skins. _Satin_ is silk so prepared as to form a
smooth, polished surface.
_Velvet_ is a silk fabric of which the pile is due to the insertion of
short pieces of silk thread under the weft or cross-thread. Cheaper
kinds are made, containing a certain proportion of cotton.
_Crape_ is made of raw silk gummed and twisted to form a gauze-like
fabric. Taffety, moire, brocade, and plush are made of silk alone or
combined with cotton.
5. _Cotton_ consists of the downy hairs investing the seeds of the
gossypium plant. The threads of which it is composed are flat,
ribbon-like, and twisted, about 1∕800 to 1∕2000 inch wide. Owing to its
flat fibres with sharp edges, it is apt to irritate delicate skins;
linen is preferable for dressing wounds for a similar reason. Cotton
is warmer than linen, being a worse conductor of heat. It also absorbs
moisture better, not becoming wet so soon; but it lacks the “freshness”
which makes linen materials pleasant to wear. Calico, fustian, jean,
velveteen, and muslin are the chief cotton fabrics.
6. _Flax_ is formed from the fibres of the flax plant. Linen is made
from it. Cambric and lawn are very fine and thin linen materials. The
fibres of linen are round and pliable; thus it is smooth and soft, and
peculiarly agreeable to the skin. It is, however, a good conductor of
heat, and consequently “it feels cold” to the skin. Furthermore its
pores quickly become filled with perspiration, which escapes rapidly,
thus chilling the body.
7. _Mackintoshes_ are valuable as a temporary protection against
external wet. Worn for more than a short period, they produce great
heat and a sense of closeness, owing to retention of the perspiration.
The best form of mackintosh is one having a cape, with a space for
evaporation between it and the rest of the garment.
=The Amount of Clothing required= varies with circumstances. 1.
_Health_; those of robust constitution require less than the feeble.
The more active are digestion and assimilation, the less is the amount
of clothing required. If heat is preserved by clothing, less food is
required. Thus a distinct saving of food is effected by warm clothes.
Warm clothes are the equivalent of so much food that would have been
required to keep up the temperature of the body, if the clothes had not
been worn. Thinly clad persons under conditions of starvation die more
quickly than those who are better protected.
2. Clothing requires to be adapted to _climate and season_. In winter
and in cold climates the amount of clothing must be increased, and
warmer materials chosen. In the changeable climate of Great Britain, it
is difficult to adapt the character of one’s dress to the requirements
of the weather. _Clothing ought, however, not to be changed according
to the calendar_, but according to the weather. The tendency is to
assume summer clothing too early in the spring, and to continue it too
far into the autumn. According to Boërhave, winter clothing should be
put off on Midsummer day, and resumed the day after. This, although
rather exaggerated, may serve to impress the caution required. The same
authority says that only fools and beggars suffer from cold, the latter
not being able to procure sufficient clothes, the former not having the
sense to wear them.
3. _Age._ Those at the two extremes of life are specially susceptible
to cold. The mortality of infants during the first three months of
life is nearly doubled in winter. Bronchitis and pneumonia prove fatal
chiefly at the two extremes of age.
The younger a child the larger is its surface as compared with its
bulk, inasmuch as the area of a body varies as the square of its
dimensions, while its mass varies as their cube. Thus a cube 1 inch
each side has 6 square inches of surface to 1 cubic inch of bulk, while
a cube 10 inches each side has 600 square inches of surface to 1000
cubic inches in bulk. Similarly a child 1∕10 the size of its mother,
besides its feebler powers of producing heat, has ten times as much
surface in proportion to its size by which heat is lost.
After the age of thirty-five, it is better to exceed than to be
deficient in clothing. A degree of cold that would act as a useful
tonic to the robust and middle-aged, produces serious and even fatal
depression of the vital powers in children or aged people. For the same
reason it is advisable to discontinue cold baths as age advances.
A very pernicious delusion is prevalent, that children ought to be
“hardened” to the influences of cold, and that too much clothing “makes
them tender.” Excessive clothing may possibly increase the tendency
to “catch cold,” owing to its exciting perspiration, or owing to the
fact that the extra clothing is commonly thrown off at irregular
intervals—witness the effects of wearing a scarf round the neck
occasionally. But to suppose that children can be hardened by exposure
of arms and legs, and other parts of their bodies, is irrational.
A large amount of heat is lost from these bare surfaces, and apart
altogether from the danger of chill, more food must be taken to
compensate for this loss of heat, and keep up an equable temperature.
Also if the food taken is expended in preserving the warmth of the
unprotected body, less material is left for the purpose of growth. From
these causes it frequently happens that children remain stunted in
growth, even if latent disease is not actually developed by the extra
strain on their resources.
The children of the very poor are often pointed to as demonstrating the
power of hardening. It is forgotten how many of these poor children
have perished under the hardening system, and that the good health of
those remaining is in spite of the hardening.
=Poisonous Dyes in Clothing.=—These, like poisonous wall-papers, were
formerly much more common than at present, and, as in wall-papers, the
poisonous agent has most frequently been arsenic, large quantities
of which were formerly used in the preparation of certain dyes.
Occasionally such poisonous pigments are still employed.
The means of detecting arsenic in any fabric or wall-paper are given on
page 216.