d to the temperature of the body, 98.6 deg. F. The
fabric should be dipped a number of times, and then dried, without
rinsing, between parchment paper.

_Questions_

1. What is the effect of the acid solution upon the fabrics?

2. Would they necessarily withstand the effect of perspiration, even
if they did withstand the acetic acid solution? Why?

=Experiment 51--Test for Determining Dressing=

Apparatus: Magnifying glass, porcelain dish.
Materials: Various fabrics.
Reference: _Textiles_, page 242.

_Directions_

1. A great many cotton fabrics such as muslin often contain
considerable sizing or dressing. In order to examine a fabric and
determine whether too much dressing has been used, take a small sample
of the fabric and crush it in the hand and rub it together, so that
the dressing is removed and the quantity employed may be determined.
If much dressing has been used, dust will be produced in rubbing.
Prick the surface with your finger nail. Notice whether the starch
comes off. Then wet your finger and rub it on the cloth and allow it
to dry. Does the gloss disappear?

2. Another method is to hold the sample before the light and notice
whether you can recognize the dressing. Examine the sample with a
magnifying glass (or pick glass) and notice whether the dressing is
superficial or penetrates the substance of the fabric.

3. Would you buy low priced cotton goods with a thick gloss and pasty
look?

4. Notice the effect (lusterless) of fabrics containing much dressing
after washing.

5. A very simple way for telling the amount of loading or weighting in
a cotton fabric is to weigh a given sample, then "boil the fabric out
in hot water,"--boiling for several hours and then drying it. The
difference in weight after drying and before boiling gives the weight
of sizing material per sample piece.

6. If mineral loading has been used to a great extent, a large residue
is left after burning.

=Experiment 52--Testing the Strength of Cloth=

Apparatus: Dynamometer.
Materials: Various fabrics.
Reference: _Textiles_, page 237.

_Directions_

1. An excellent way to test the strength of a fabric is to place the
two thumbs together and press them down on the sample, holding it
tight underneath. Then try to break the threads, first in one
direction and then in the other. Do they break easily? Notice whether
one set is very much stronger than the other.

2. Manufacturers us