Illustration: SILK (‡ WORMS).
Silk is by far the strongest of the textile fabrics, being nearly
three times as strong as flax; it consists of the filaments spun by
the silk-worm, _Phalœna Bombyx Anori_. These filaments are always
double, proceeding from two holes in the head of the worm, and are
united by a sort of varnish which is moist and clammy when the
threads proceed from the insect, and causes them to adhere together.
The silk-worm in spinning, moves the head backwards and forwards,
attaching the threads on alternate sides and all around till it is
completely covered in with a ball of silk; in this state it is called
a “coccoon.” The silk-worm, like others of its class, undergoes four
changes or metamorphoses--the Egg, the Grub or Worm, the Chrysalis,
and the Imago or perfect insect, which, in this case, is a moth. The
worm spins the coccoon to defend itself from injury and cold, but
man, taking advantage of the useful qualities possessed by these fine
filaments, spins them into his most gorgeous apparel. The coccoons
are unwound by placing them in a basin of warm water, which dissolves
the varnish, and they are then slowly wound off; formerly this was
done by hand, but now machinery is chiefly employed which winds off
the silk from a bowl full of coccoons at the same time. The silk
is coiled into hanks or skeins, and in this form is imported into
this country; from these hanks it is wound off on to large six-sided
wheels called “swifts,” and from these on to bobbins or reels; it is
then wound off from two or three of these bobbins on to one other
bobbin, the threads of silk being laid side by side, and in this
process a twist is given to it in one direction and two of these
wound on to another receiving a twist in an opposite direction, this
forms a fine cord called “organzine,” which is used by the silk
weaver in the same way that yarn is by the cotton weaver. The short
and broken pieces are carded and spun like cotton, and is called
floss silk. The raw silk is of a bright buff or golden yellow color,
but there are some kinds which are white.