COMPAEATIVE 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 nme samples were taken before and after mercerization. The 

 results are sho%\Ti in Table XV. 



Table XV. — Tensile strength before and after mercerization. 





Gray yam. 



Mercerized yam. 



Number of sample. 



Number 

 of yam. 



Tensile strength. 



Number 

 of yam. 



Tensile strength. 





Pounds 

 per skeia 



(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 



16.4 



5, 



17.9 



6 



11.5 

 12.1 

 12.3 

 12.1 



18.4 



7 



18.3 



8 



18.1 



9 



17.3 









31.6 

 31.6 

 31.6 

 31.6 



50.0 

 48.9 

 60.0 

 51.4 



11.8 

 11.5 



.33.6 

 33.6 

 33.6 

 33.6 



58.2 

 67.8 

 58.7 

 58.6 



17.4 





16.7 





18.2 





12.2 



17.9 







It wiU 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°, volum^e 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 dyestuff 

 salt and soluble od by method given above, benzo purpurin 4B being 

 used as the dyestuff. 



