[Illustration: THE WALLACHIAN SHEEP.]
On the skin of most animals is placed a covering of feathers, fur, hair,
or wool. These are all essentially the same in composition, being
composed of an animal substance resembling coagulated albumen, together
with sulphur, silica, carbonate and phosphate of lime, and oxides of
iron and manganese.
Wool is not confined to the sheep. The under-hair of some goats is not
only finer than the fleece of any sheep, but it occasionally has the
crisped appearance of wool; being, in fact, wool of different qualities
in different breeds--in some, rivalling or excelling that of the sheep,
but in others very coarse. A portion of wool is also found on many other
animals; as the deer, elk, the oxen of Tartary and Hudson's Bay, the
gnu, the camel, many of the fur-clad animals, the sable, the polecat,
and several species of the dog.
Judging from the mixture of wool and hair in the coat of most animals,
and the relative situation of these materials, it is not improbable that
such was the character of the fleece of the primitive sheep. It has,
indeed, been asserted that the primitive sheep was entirely covered with
hair; but this is, doubtless, incorrect. There exists, at the present
day, varieties of the sheep occupying extensive districts, that are
clothed outwardly with hair of different degrees of fineness and
sleekness; and underneath the external coat is a softer, shorter, and
closer one, that answers to the description of fur--according to most
travellers--but which really possesses all the characteristics of wool.
It is, therefore, highly improbable that the sheep--which has now
become, by cultivation, the wool-bearing animal in a pre-eminent
degree--should, in any country, at any time, have ever been entirely
destitute of wool. Sheep of almost every variety have at times been in
the gardens of the London (Eng.) Zooelogical Society; but there has not
been one on which a portion of crisped wool, although exceedingly small,
has not been discovered beneath the hair. In all the regions over which
the patriarchs wandered, and extending northward through the greater
part of Europe and Asia, the sheep is externally covered with hair; but
underneath is a fine, short, downy wool, from which the hair is easily
separated. This is the case with the sheep at the Cape of Good Hope,
and also in South America.
The change from hair to wool, though much influenced by temperature, has
been chiefly effected by cultivation. Wherever hairy sheep are now found
the management of the animal is in a most disgraceful state; and among
the cultivated sheep the remains of this ancient hairy covering only
exists, to any great extent, among those that are comparatively
neglected or abandoned.
The filament of the wool has scarcely pushed itself through the pore of
the skin, when it has to penetrate through another and singular
substance, which, from its adhesiveness and color, is called _the yolk_.
This is found in greatest quantity about the breast and shoulders--the
very parts that produce the best, and healthiest, and most abundant
wool--and in proportion as it extends, in any considerable degree, over
other parts, the wool is then improved. It differs in quantity in
different breeds. It is very abundant on the Merinos; it is sufficiently
plentiful on most of the southern breeds, either to assist in the
production of the wool, or to defend the sheep from the inclemency of
the weather; but in the northern districts, where the cold is more
intense and the yolk of wool is deficient, a substitute for it is
sometimes sought by smearing the sheep with a mixture of tar, oil, or
butter. Where there is a deficiency of yolk, the fibre of the wool is
dry, harsh, and weak, and the whole fleece becomes thin and hairy; where
the natural quantity of it is found, the wool is soft, oily, plentiful
and strong.
This yolk is not the inspissated or thickened perspiration of the
animal; it is not composed of matter which has been accidentally picked
up, and which has lodged in the wool; but it is a peculiar secretion
from the glands of the skin, destined to be one of the agents in the
nourishment of the wool, and at the same time, by its adhesiveness, to
mat the wool together, and form a secure defence from the wet and cold.
Chemical experiments have established its composition, as follows:
first, of a soapy matter with a basis of potash, which forms the greater
part of it; second, a small quantity of carbonate of potash; third, a
perceptible quantity of acetate of potash; fourth, lime, in a peculiar
and unknown state of combination; fifth, an atom of muriate of potash;
sixth, an animal oil, to which its peculiar odor is attributable. All
these materials are believed to be essential to the yolk, and not found
in it by mere accident, since the yolk of a great number of
samples--Spanish, French, English, and American--has been subjected to
repeated analyses, with the same result.
The yolk being a true soap, soluble in water, it is not difficult to
account for the comparative ease with which sheep that have the natural
proportion of it are washed in a running stream. There is, however, a
small quantity of fatty matter in the fleece, which is not in
combination with the alkali, and which, remaining attached to the wool,
keeps it a little glutinous, notwithstanding the most careful washing.
The fibre of the wool having penetrated the skin and escaped from
the yolk, is of a circular form, generally larger toward the extremity,
and also toward the root, and in some instances very considerably
so. The filaments of white wool, when cleansed from grease, are
semi-transparent; their surface in some places is beautifully polished,
in others curiously incrusted, and they reflect the rays of light in a
very pleasing manner. When viewed by the aid of a powerful achromatic
microscope, the central part of the fibre has a singularly glittering
appearance. Minute filaments, placed very regularly, are sometimes seen
branching from the main trunk, like boughs from the principal stem. This
exterior polish varies much in different wools, and in wools from the
same breed of sheep at different times. When the animal is in good
condition, and the fleece healthy, the appearance of the fibre is really
brilliant; but when the state of the constitution is bad, the fibre has
a dull appearance, and either a wan, pale light, or sometimes scarcely
any, is reflected. As a general rule, the filament is most transparent
in the best and most useful wools, whether long or short. It increases
with the improvement of the breed, and the fineness and healthiness of
the fleece; yet it must be admitted that some wools have different
degrees of the transparency and opacity, which do not appear to affect
their value and utility. It is, however, the difference of transparency
in the same fleece, or in the same filament, that is chiefly to be
noticed as improving the value of the wool.
As to the size of the fibre, the terms "fine" and "coarse," as commonly
used, are but vague and general descriptions of wool. All fine fleeces
have some coarse wool, and all coarse fleeces some fine. The most
accurate classification is to distinguish the various qualities of wool
in the order in which they are esteemed and preferred by the
manufacturer--as the following: first, fineness with close ground, that
is, thick-matted ground; second, pureness; third, straight-haired, when
broken by drawing; fourth, elasticity, rising after compression in the
hand; fifth, staple not too long; sixth, color; seventh, what coarse
exists to be very coarse; eighth, tenacity; and ninth, not much
pitch-mark, though this is no disadvantage, except the loss of weight in
scouring. The bad or disagreeable properties are--thin, grounded, tossy,
curly-haired, and, if in a sorted state, little in it that is very fine;
a tender staple, as elasticity, many dead white hairs, very yolky. Those
who buy wool for combing and other light goods that do not need milling,
wish to find length of staple, fineness of hair, whiteness, tenacity,
pureness, elasticity, and not too many pitch-marks.
The property first attracting attention, and being of greater importance
than any other, is _the fineness_ of the pile--the quantity of fine wool
which a fleece yields, and the degree of that fineness. Of the absolute
fineness, little can be said, varying, as it does, in different parts of
the same fleece to a very considerable degree, and the diameter of the
same fibre often being exceedingly different at the extremity and the
centre. The micrometer has sometimes indicated that the diameter of the
former is five times as much as that of the latter; and, consequently,
that a given length of yield taken from the extremity would weigh
twenty-five times as much as the same length taken from the centre and
cleansed from all yolk and grease. That fibre may be considered as
coarse whose diameter is more than the five-hundredth part of an inch;
in some of the most valuable samples of Saxony wool it has not exceeded
the nine-hundredth part; yet in some animals, whose wool has not been
used for manufacturing purposes, it is less than one twelve-hundredth
part.
The extremities of the wool, and frequently those portions which are
near to the root, are larger than the intermediate parts. The extremity
of the fibre has, generally, the greatest bulk of all. It is the
product of summer, soon after shearing-time, when the secretion of the
matter of the wool is increased, and when the pores of the skin are
relaxed and open, and permit a larger fibre to protrude. The portion
near the root is the growth of spring, when the weather is getting warm;
and the intermediate part is the offspring of winter, when under the
influence of the cold the pores of the skin contract, and permit only a
finer hair to escape. If, however, the animal is well fed, the
diminution of the bulk of the fibre will not be followed by weakness or
decay, but, in proportion as the pile becomes fine, the value of the
fleece will be increased; whereas, if cold and starvation should go
hand-in-hand, the woolly fibre will not only diminish in bulk, but in
health, strength, and worth.
The variations in the diameter of the wool in different parts of the
fibre will also curiously correspond with the degree of heat at the time
the respective portions were produced. The fibre of the wool and the
record of the meteorologist will singularly agree, if the variations in
temperature are sufficiently distinct from each other for any
appreciable part of the fibre to form. It follows from this, that--the
natural tendency to produce wool of a certain fibre being the
same--sheep in a hot climate will yield a comparatively coarse wool, and
those in a cold climate will carry a finer, but at the same time a
closer and a warmer fleece. In proportion to the coarseness of a fleece
will generally be its openness, and its inability to resist either cold
or wet; while the coat of softer, smaller, more pliable wool will admit
of no interstices between its fibres, and will bid defiance to frost and
storms.
The natural instinct of the sheep would seem to teach the wool-grower
the advantage of attending to the influence of temperature upon the
animal. He is evidently impatient of heat. In the open districts, and
where no shelter is near, he climbs to the highest parts of his walk,
that, if the rays of the sun must still fall on him, he may nevertheless
be cooled by the breeze; but, if shelter is near, of whatever kind,
every shaded spot is crowded with sheep. The wool of the Merinos after
shearing-time is hard and coarse to such a degree as to render it very
difficult to suppose that the same animal could bear wool so opposite in
quality, compared with that which had been clipped from it in the course
of the same season. As the cold weather advances, the fleeces recover
their soft quality.
Pasture has a far greater influence on the fineness of the fleece. The
staple of the wool, like every other part of the sheep, must increase in
length or in bulk when the animal has a superabundance of nutriment;
and, on the other hand, the secretion which forms the wool must decrease
like every other, when sufficient nourishment is not afforded. When
little cold has been experienced in the winter, and vegetation has
scarcely been checked, the sheep yields an abundant crop of wool, but
the fleece is perceptibly coarser as well as heavier. When the frost has
been severe, and the ground long covered with snow, if the flock has
been fairly supplied with nutriment, although the fleece may have lost a
little in weight, it will have acquired a superior degree of fineness,
and a proportional increase of value. Should, however, the sheep have
been neglected and starved during this continued cold weather, the
fleece as well as the carcass is thinner, and although it may have
preserved its smallness of filament, it has lost in weight, and
strength, and usefulness.
Connected with fineness is _trueness of staple_--as equal in growth as
possible over the animals--a freedom from those shaggy portions, here
and there, which are occasionally observed on poor and neglected sheep.
These portions are always coarse and comparatively worthless, and they
indicate an irregular and unhealthy action of the secretion of wool,
which will also probably weaken or render the fibre diseased in other
parts. Included in trueness of fibre is another circumstance to which
allusion has already been made--a freedom from coarse hairs which
project above the general level of the wool in various parts, or, if
they are not externally seen, mingle with the wool and debase its
qualities.
_Soundness_ is closely associated with trueness. It means, generally
speaking, strength of the fibre, and also a freedom from those breaches
or withered portions of which something has previously been said. The
eye will readily detect the breaches; but the hair generally may not
possess a degree of strength proportioned to its bulk. This is
ascertained by drawing a few hairs out of the staple, and grasping each
of them singly by both ends, and pulling them until they break. The wool
often becomes injured by felting while it is on the sheep's back. This
is principally seen in the heavy breeds, especially those that are
neglected and half-starved, and generally begins in the winter season,
when the coat has been completely saturated with water, and it increases
until shearing-time, unless the cob separates from the wool beneath, and
drops off.
Wool is generally injured by keeping. It will probably increase a
little in weight for a few months, especially if kept in a damp place;
but after that it will somewhat rapidly become lighter, until a very
considerable loss will often be sustained. This, however, is not the
moral of the case; for, except very great care is taken, the moth will
get into the bundles and injure and destroy the staple; and that which
remains untouched by them will become considerably harsh and less
pliable. If to this the loss of the interest of money is added, it will
be seen that he seldom acts wisely who hoards his wool, when he can
obtain what approaches to a fair remunerating price for it.
_Softness_ of the wool is evidently connected with the presence and
quality of the yolk. This substance is undoubtedly designed not only to
nourish the hair, but to give it richness and pliability. The growth of
the yolk ought to be promoted, and agriculturists ought to pay more
attention to the quantity and quality of yolk possessed by the animals
selected for the purpose of breeding.
Bad management impairs the pliability of the wool, by arresting the
secretion of the yolk. The softness of the wool is also much influenced
by the chemical elements of the soil. A chalky soil notoriously
deteriorates it; minute particles of the chalk being necessarily brought
into contact with the fleece and mixing with it, have a corrosive effect
on the fibre, and harden it and render it less pliable. The particles of
chalk come in contact with the yolk--there being a chemical affinity
between the alkali and the oily matter of the yolk--immediately unite,
and a true soap is formed. The first storm washes a portion of it; and
the wool, deprived of its natural pabulum and unguent, loses some of its
vital properties--its pliability among the rest. The slight degree of
harshness which has been attributed to the English South-Down has been
explained in this way.
_The felting property_ of wool is a tendency of the fibres to entangle
themselves together, and to form a mass more or less difficult to
unravel. By moisture and pressure, the fibres of the wool may become
matted or felted together into a species of cloth. The manufacture of
felt was the first mode in which wool was applied to clothing, and felt
has long been in universal use for hats. The fulling of flannels and
broadcloths is effected by the felting principle. By the joint influence
of the moisture and the pressure, certain of the fibres are brought into
more intimate contact with each other; they adhere--not only the fibres,
but; in a manner, the threads--and the cloth is taken from the mill
shortened in all its dimensions; it has become a kind of felt, for the
threads have disappeared, and it can be cut in every direction with very
little or no unravelling; it is altogether a thicker, warmer, softer
fibre. This felting property is one of the most valuable qualities
possessed by wool, and on this property are the finer kinds of wool
especially valued by the manufacturer for the finest broadcloths. This
naturally suggests a consideration of the various forms in the structure
on which it depends.
The most evident distinction between the qualities of hair and wool is
the comparative straightness of the former, and _the crisped or
spirally-curling form_ which the latter assumes. If a little lock of
wool is held up to the light, every fibre of it is twisted into numerous
minute corkscrew-like ringlets. This is especially seen in the fleece of
the short-woolled sheeps; but, although less striking, it is obvious
even in wool of the largest staple.
The spirally-curving form of wool used, erroneously, to be considered as
the chief distinction between the covering of the goat and the sheep;
but the under-coat of some of the former is finer than that of any
sheep, and it is now acknowledged frequently to have the crisped and
curled appearance of wool. In some breeds of cattle, particularly in one
variety of the Devons, the hair assumes a curled and wavy appearance,
and a few of the minute spiral ringlets have been occasionally seen. It
is the same with many of the Highlands; but there is no determination to
take on the true crisped character, and throughout its whole extent, and
it is still nothing but hair. On some foreign breeds, however, as the
yak of Tartary, and the ox of Hudson's Bay, some fine and valuable wool
is produced.
There is an intimate connection between the fineness of the wool and the
number of the curves, at least in sheep yielding wool of nearly the same
length; so that, whether the wool of different sheep is examined, or
that from different parts of the same sheep, it is enough for the
observer to take advice of the number of curves in a given space, in
order to ascertain with sufficient accuracy the fineness of the fibre.
To this curled form of the wool not enough attention is, as a general
thing, paid by the breeder. It is, however, that on which its most
valuable uses depend. It is that which is essential to it in the
manufactory of cloths. The object of the carder is to break the wool in
pieces at the curves--the principle of the thread is the adhesion of the
particles together by their curves; and the fineness of the thread, and
consequent fineness of the cloth, will depend on the minuteness of
these curves, or the number of them found in a given length of fibre.
It will readily be seen that this curling form has much to do with the
felting property of wool; it materially contributes to that disposition
in the fibres which enables them to attach and intwine themselves
together; it multiplies the opportunities for this interlacing, and it
increases the difficulty of unravelling the felt.
The felting property of wool is the most important, as well as the
distinguishing one; but it varies essentially in different breeds, and
the usefulness and the consequent value of the fleece, for clothing
purposes, at least, depend on the degree to which it is pursued.
_The serrated_--notched, like the teeth of a saw--_edge_ of wool, which
has been discovered by means of the microscope, is also, as well as the
spiral curl, deemed an important quality in the felting property.
Repeated microscopic observations have removed all doubts as to the
general outline of the woolly fibre. It consists of a central stem or
stalk, probably hollow, or, at least, porous, possessing a
semi-transparency, not found in the fibre of hair. From this central
stalk there springs, at different distances, on different breeds of
sheep, a circlet of leaf-shaped projections.