COMPARATIVE SPHsTlSriNG TESTS. 11 



Referring again to page 6, it may be seen that the comparisons 

 between the three grades of Arizona-Egyptian and Sakellaridis 

 Egyptian show that the average differences in waste cotton were 6.80 

 per cent, 6.38 per cent, and 7.07 per cent, respectively, in favor of 

 the Arizona-Egyptian. In the comparisons of the two grades of Sea 

 Island cotton with Arizona-Egyptian there were differences of 4.49 

 per cent and 5.73 per cent, respectively, in favor of the Arizona- 

 Egyptian. 



The tensile strength of the yarns made from the different cottons is 

 affected by the percentage of waste discarded. Therefore, where the 

 differences in waste are so evident, in order to make a more com- 

 prehensive determuiation as to the comparative tensile strength, it 

 would seem advisable to remove the same amount of waste from 

 each kind of cotton. 



BLEACHING, DYEING, AND MERCERIZING. 



Investigations were made to ascertain the relative values of 

 Arizona-Egyptian, Sea Island, and SakeUaridis cottons as to their 

 bleaching, dyeing, and mercerizing qualities. These tests ^ were 

 made upon both loose cotton and yarns. The following numerical 

 designations arbitrarily represent the different grades and kinds of 

 cotton. For example, 1 to 4 represents Arizona-Egyptian, 5 to 6, 

 Sea Island, and 7 to 9, SakeUaridis. 



Number. Grade. Kind. 



1 Extra Arizona-Egyptian. 



2 Choice Do. 



3 .Standard Do. 



4 ..Medium Do. 



5 Fancy Sea Island. 



6 Extra choice Do. 



7 Good Sakellaridis Egyptian. 



8 Fully good fair ....... Do. 



9 Fair Do. 



ELEACHING LOOSE COTTON. 



The different methods used in bleaching will be referred to as 

 methods (a), (b), (c), (d), (e), (f), (A), and (B). 



Method (a). — The cotton was bleached by treating it, without 

 scouring, with a solution, obtained by the electrolysis of salt, con- 

 tainmg 0.5 grams of chlorine per liter. In the future this solution 

 will be designated as ' ' electrohtic chlorine." 



Method (h). — The cotton was scoured m a solution containing 1 

 gram of soda ash in each 10 cubic centimeters; then bleached as in (a). 



Method (c) . — The cotton was treated with 2 per cent acetic acid 

 and bleached as in (a) . 



1 These tests were made at the New Bedford Textile School in the laboratory of the department of 

 chemistry, by Everett H. Hincljley, professor in charge of this department. 



