h each dried and cooled skein and note the
increase in weight of each. Save sample for Experiment 23 and note the
effect of weighting on the yarn.

=Experiment 23--Dyeing Silk=

Apparatus: Porcelain dish, filter stand, etc.
Material: Piece of silk yarn.
Reference: _Textiles_, page 210.

_Directions_

1. Prepare a solution of coloring matter by dissolving a half ounce of
logwood in a quart of water. Filter the solution. Place a piece of
silk skein, from Experiment 22, in the liquid and boil ten minutes.
Then wash the dyed silk and notice whether the dyestuff washes off or
not.

2. Repeat the same experiment using the same weight of silk yarn
without weighing it. Compare the results.

=Experiment 24--Test to Distinguish Piece-Dyed from Yarn-Dyed Fabric=

Apparatus: Pen knife.
Materials: Woolen and cotton fabrics.
Reference: _Textiles_, pages 66-68.

_Directions_

Unravel threads of the suspected sample, and with a blade of pen knife
note whether the dyestuff has penetrated through the yarn as noted by
the depth of color in the interior of the yarn. In case there is the
same depth of color in the interior as on the surface, the fabric is
yarn-dyed. If on the other hand, the interior of the yarn is not so
highly colored as the exterior, it is piece-dyed.

_Questions_

1. What is meant by yarn-dyed fabric?

2. What is meant by piece-dyed fabric?

3. How may the two be distinguished?

=Experiment 25--Test to Distinguish Dyed from Printed Fabrics=

Apparatus: Knife-blade.
Materials: Cotton fabrics.
Reference: _Textiles_, page 65.

Printed fabrics may be distinguished from dyed by observing the back
side of the cloth, and noting whether or not the pattern on the face
of the cloth penetrates through to the back, or only the outline
shows. In case the figure or pattern is on both sides of the fabric,
it may be distinguished from the dyed by taking one thread of the
suspected sample, and by the means of a knife-blade attempting to
scrape off the coloring on the surface of the thread. If the dyestuff
has penetrated into the interior of the thread, it is _not_ printed.

Generally speaking, printed fabrics are known from dyed fabrics by the
fact that the former have the design printed on the face of the cloth.
This is called _direct printing_. The best dyed fabrics are obtained
by dyeing in what is called a _jig_, and the whole fabric is saturated
with color. M