s are composed, like all vegetable
fibers, of cellulose, attempts have been made to prepare an artificial
silk product from waste paper--that is, by treating waste paper or
wood or cotton fibers with various chemicals in order to obtain pure
cellulose. This artificial silk is perhaps the most interesting of
artificial fibers, but its manufacture is dangerous, owing to the ease
with which it catches fire and explodes. Cellulose, chemically
treated, can be transformed into a fluid solution known as collodion.
The collodion is placed in steel cylinders and expelled by pressure
through capillary tubes. After drying, denitration, and washing, it
may be spun and dyed like natural silk. Colored threads may be
produced by the addition of certain dyes.

Artificial silk bears a deceptive resemblance to the natural article,
and has nearly the same luster. It lacks the tensile strength and
elasticity, and is of higher specific gravity than true silk.

=Tests.= A simple way of recognizing artificial silk is by testing the
threads under moisture, as follows: First, unravel a few threads of
the suspected fabric, place them in the mouth and masticate them
vigorously. Artificial silk readily softens under this operation and
breaks up into minute particles, and when pulled between the fingers
shows no thread, but merely a mass of cellulose or pulp. Natural silk,
no matter how thoroughly masticated, will retain its fibrous strength.
The artificial silk offers no resistance to the teeth, which readily
go through it; whereas natural silk resists the action of the teeth.

CHAPTER XX

SUBSTITUTES FOR COTTON

On account of the high price of cotton various experiments have been
made in an effort to replace it with fiber from wood pulp, grasses,
leaves, and other plants.

=Wood Pulp.= A Frenchman has discovered a process, _la soyeuse_, of
making spruce wood pulp into a substitute for cotton. Although it is
called a substitute, the samples show that it takes dye, bleaching,
and finishing more brilliantly than the cotton fiber. It resists
boiling in water or caustic potash solution for some minutes, and does
not burn more quickly than cotton. The fiber can be made of any
length, as is also the case with artificial silk. The strength of the
yarn apparently exceeds cotton, and the cost of manufacture is much
lower. Arrangements are being made in Europe for the extensive
production of this fiber.

=Ramie.= Ramie or China grass is a s