MANUFACTUKING TESTS OF COTTON. 



11 



DIRECT DYES. 



Method of application. — Dyed in a bath containing 0.1 per cent 

 benzo' rhoduline red B, 5 per cent of salt, 0.5 per cent soluble oil. 

 Volume of dye bath equals 25 times the weight of the goods. The 

 goods were entered into the dye bath cold and temperature raised to 

 a boil in 30 minutes, boiled 15 minutes, and allowed to cool in the 

 bath 15 minutes. To obtain the light blue the goods were dyed in 

 the same manner, except 0.1 per cent benzo fast blue BN was used 

 instead of the benzo rhoduline red B. 



BASIC DYES. 



Method of application. — Mordanted in a solution containing 0.015 

 of a gram of tannic acid in each 100 cc. The goods were entered 

 into the dye bath cold and temperature raised to 190° in 45 minutes, 

 then allowed to cool overnight, rinsed and treated cold for 15 min- 

 utes in a bath containing 0.01 of a gram of tartar emetic. 



The pinks were dyed in a bath containing 0.05 per cent of rhoduline 

 red B, 0.5 per cent of acetic acid, cold 30 minutes, then raised to 140° 

 duj-ing 30 minutes. The blues were dyed as the pinks, except that 

 0.05 per cent of methylene blue BB was used. 



No practical difference was seen between the whites obtained on 

 samples 1 and la or on 2 and 2a, respectively, where the same bleach- 

 ing agent was used. Nor could it be seen that the fumigation had 

 made the cotton either more easy to dye or more difficult to dye with 

 direct or basic dyes. 



MERCERIZING OF YARNS. 



Samples of yarn made of each of the above four cottons, namely, 

 1, la, 2, and 2a, were mercerized by commercial methods at one of 

 the mills in New Bedford, Mass., and these samples were subsequently 

 tested for their tensile strength and degree of mercerization. In 

 Table VIII the results of the average number of the yarn and tensile 

 strengths,^ ascertained before and after mercerization, are shown. 



Table VIII. — Tensile-strength tests of natural gray and mercerized yarns. 





N 



atural pray. 





Mercerized 





Sample". 



No. of 



yarn. 



Strength 



in 



poiinds 



per skein 



of 60 



yards. 



Strength 



in 



ounces 



per 



single 



thread. 



No. of 

 yarn. 



Strength 



in 



pounds 



per skein 



of 60 



yards. 



Strength 



in 



ounces 



per 



single 



thread. 



1 , 



20.84 

 20.84 

 30. 5 

 30.5 



58.6 

 59.9 

 56.0 

 56.5 



13.8 

 13.9 

 15.0 

 15.3 



22.0 

 22.0 

 30.7 

 30.7 



70.0 

 71.2 

 66.0 

 68.1 



20.2 



la 



21.0 



2 1 . . 



19.9 



2a... 



20.2 







1 Soe footnote, p. G. 



