SILK. 
ing crop of barley, are apt to be laid by the wind, 
or to fall down under the weight of the ear. 
The straw is too feeble in all these cases, and it 
has been said that the use of silicates would 
abate the evil. Lampadius found the growth of 
wheat and rye to be greatly promoted by the 
use of a soluble silicate of potash, but the alkali 
might be the cause of the effect observed, and 
no other experiments of an accurate kind have 
yet been made. It is still an open question, 
then, whether or not we have it in our power, at 
‘our pleasure, to strengthen the straw of our corn 
plants—whether it would be useful to apply the 
soluble silicates to all soils—whether there are 
any to which they may be applied with advan- 
tage and profit as an ordinary manure.” 
SILICATES. See St1urca. 
SILK. According to the ancients, silk was 
first brought from Serica or Serinda (China), 
whence the silk-worm was introduced into other 
countries, but not until the reign of Justinian, 
when two Persian monks succeeded in secretly 
conveying a number of the eggs to Constantino- 
ple in a hollow cane (552). From these eggs 
Kurope and America have been supplied with 
their race of worms. The time of the origin of 
the silk manufacture is uncertain, but the Chi- 
nese ascribe the invention to the empress Si-ling- 
shi, wife of Hoang-ti, about 2,700 years before 
the Christian era. However this may be, the 
raw material had been exported from China long 
before the insect which produced it, and had 
given employment to extensive manufactories in 
Persia, Tyre, &c. The invention of the cele- 
brated Coan stuff is attributed by the Greeks to 
Pamphila, who is said to have taught her coun- 
trywomen of Cos to unweave the heavy silks of 
the Hast, and recompose the material into a 
transparent gauze, thus gaining in measure what 
was lost in substance. Even manufactured silk 
was little known in Europe before the reign of 
Augustus; and it is mentioned as a wanton ex- 
travagance of the prodigal Heliogabalus that he 
had a garment made wholly of silk. For six 
hundred years the culture of the silk-worm in 
Kurope was confined to the Greek empire; but 
in the twelfth century, Roger, king of Sicily, in- 
troduced it into that island, whence it gradually 
spread to Italy, Spain, France, and other Euro- 
pean countries. 
After the worm has enveloped itself in the 
coccoon, seven or eight days are permitted to 
elapse before the balls are gathered ; the next 
process is to destroy the life of the chry- 
salides, which is done either by exposure to 
the sun or by the heat of an oven or of steam. 
The coccoons are next separated from the floss, 
or loose, downy substance, which envelopes the 
| compact balls, and are then ready to be reeled. 
For this purpose, they are thrown into a boiler 
_ of hot water, for the purpose of dissolving the 
gum, and, being gently pressed with a brush, to 
which the threads adhere, the reeler is thus ena- 
| } 
a 
221 
bled to disengage them. The ends of four or 
more of the threads thus cleared are passed 
through holes in an iron bar, after which two 
of these compound threads are twisted together, 
and made fast to the reel. The length of reeled 
silk obtained from a single coccoon varies from 
300 to 600 yards; and it has been estimated 
that twelve pounds of coccoons, the produce of 
the labours of 2,800 worms, who have consumed 
152 pounds of mulberry leaves, give one pound 
of reeled silk, which may be converted into six- 
teen yards of gros de Naples. Those coccoons 
which have been perforated cannot be reeled, 
but must be spun, on account of the breaks in 
the thread. The produce of these balls, when 
worked, is called fleuret. The raw silk, before 
it can be used in weaving, must be twisted or 
thrown, and may be converted into singles, tram, 
or organzine. The first is produced merely by 
twisting the raw silk, to give more firmness to 
its texture. Tram is formed by twisting to- 
gether, but not very closely, two or more threads 
of raw silk, and usually constitutes the weft or 
shoot of manufactured goods. Organzine is 
principally used in the warp, and is formed by 
twisting first each individual thread, and then 
two or more of the threads thus twisted, with 
the throwing mill. The silk, when thrown, is 
called hard silk, and must be boiled in order to 
discharge the gum, which otherwise renders it 
harsh to the touch, and unfit to receive the dye. 
After boiling about four hours in soaped water, 
it is washed in clear water to discharge the soap, 
and is seen to have acquired that glossiness and 
softness of texture which forms its principal. 
characteristic. The yarn is now ready for weay- — 
ing. 
Velvet (Italian, velluto, shaggy) is one of the 
richest of silken fabrics, and has been made in 
Kurope for several centuries. In addition to 
the warp and shoot, of which the substance of 
plain goods is formed, it has a soft shag or pile, 
produced by the insertion of short pieces of silk 
under-thread doubled under the shoot, and which 
stand upright on its upper surface, so crowded 
together as entirely to conceal the interlacings 
of the warp and shoot. It is this pile which 
gives it its characteristic appearance, and soft- 
ness to the touch. The beauty of velvet results, 
in a great degree, from the uniform evenness of 
its pile ; and this depends on the perfect equality 
of the threads of which it is composed. The pile 
is inserted during the operation of weaving the 
warp and shoot. Gauze is a very light, transpa-. 
rent fabric of silk, said to have derived its name 
from having been originally brought from Gaza, 
a city of Palestine. Besides brocade and damask 
there are numerous descriptions of silk goods, 
popularly known by distinctive names, though 
varying only in the thickness of the fabric or the 
quality of the material, and not at all differing 
in the arrangements of its interlacings. Thus 
the plainest mode of silk weaving takes the 
