COMPARATIVE SPINNING TESTS. 
15 
The pinks were dyed in a bath containing 0.05 per cent of rhodu- 
line red B, 0.5 per cent of acetic acid, cooled 30 minutes, then raised 
to 140° during 30 minutes. The blues were dyed in the same manner 
as the pink, except that 0.05 per cent of methylene blue B B was 
used. 
MERCERIZING. 
Samples of each of the nine kinds of yarns (60/2) were singed and 
mercerized collectively at one of the mills of New Bedford, Mass., 
and subsequently tested for their tensile strength and degree of 
mercerization. The tensile strength and the numbers of the yarn 
of all nine samples were taken before and after mercerization. The 
results are shown in Table XV. 
Table XV. — Tensile strength before and after mercerization. 
Gray yarn. 
Mercerized yarn. 
Number of sample. 
Number 
of yarn. 
Tensile strength. 
Number 
of yarn. 
Tensile strength. 
Pounds 
per skein 
(60 
yards). 
Ounces 
per 
single 
thread. 
Pounds 
per skein 
(60 
yards). 
Ounces 
per 
single 
thread. 
1 
31.6 
31.6 
31.6 
31.6 
31.6 
31.6 
31.6 
31.6 
31.6 
48.5 
4S.0 
49.3 
49.9 
51.0 
48.9 
51.4 
51.5 
51.3 
11.6 
10.9 
11.7 
11.8 
33.6 
33.6 
33.6 
33.6 
33.6 
33.6 
33.6 
33.6 
33.6 
57.5 
59.9 
56.8 
56.9 
60.4 
57.0 
59.8 
59.4 
56.5 
16.5 
2 : 
16.7 
3 
17.2 
4 
5 
16.4 
17.9 
6 
11.5 
12.1 
12.3 
12.1 
18.4 
7 
18.3 
8 
1S.1 
9 
17.3 
31.6 
31.6 
31.6 
31.6 
50.0 
48.9 
50.0 
51.4 
11.8 
11.5 
33.6 
33.6 
33.6 
33.6 
58.2 
57.8 
58.7 
58.6 
17.4 
16.7 
18.2 
12.2 
17.9 
It will be noticed in Table XV that the mercerized samples 1-4, 
inclusive, show a lower breaking strength than samples 5-6 or 7-9. 
The yarns were tested for degree of mercerization by dyeing them 
in 1 per cent benzo purpurin 4B, 10 per cent salt, 1 per cent soluble 
oil for 30 minutes at 160°, volume of bath equal to 100 times the 
weight of goods treated. In order to determine the degree of mer- 
cerization, samples of mercerized Egyptian yarn were dyed in the 
same baths after dyeing the samples 1-9. These exhaust skeins 
furnished a means of measuring the degree of mercerization, for the 
better mercerized samples of cotton absorb more dyes tuff and con- 
sequently leave less in the dye bath. 
Table XVI represents a set of standards obtained by dyeing mer- 
cerized Egyptian yarn with the following percentages of dyes tuff 
salt and soluble oil by method given above, benzo purpurin 4B being 
used as the dyes tuff . 
