8 BULLETIN 366, U. S. DEPARTMENT OF AGRICULTURE. 
which these samples were taken being previously referred to as lot 
No. 1. In a like manner 2 and 2a represent the lj-inch fumigated 
and nonfumigated cotton previously referred to as lot No. 2. Sam- 
ples 8 to 15, inclusive, were selected from Peruvian cotton received 
from a manufacturing company. The cotton in samples 1, 2, 8, 9, 
12, and 13 was fumigated with hydrocyanic- acid gas. 
BLEACHING OF RAW COTTON. 
Samples of Nos. 2 and 2a were bleached by treating as follows: 
Method a. Not scoured. Bleached with a solution obtained by the 
electrolysis of salt containing 0.5 gram of chlorine per liter. In 
future this solution will be designated as " electrolytic chlorine." 
Method 1). Scoured in a solution containing 1 gram of soda ash 
in each 10 cc. then bleached as in a. 
Method c. Treated with 2 per cent acetic acid and bleached as in a. 
Finally all the samples were blued with. 0.001 per cent of blue- 
violet acid dye. 
Methods a, h, and c are the usual processes for obtaining white 
cotton for spinning except that the usual quantity of bleaching agent 
used was reduced in these tests in order to magnify any variation in 
the results obtained. No differences in the results of any of the 
methods on the two samples were apparent, which indicates fumi- 
gating the cotton with hydrocyanic-acid gas had no appreciable effect 
upon the bleaching qualities of the cotton used in any of the tests. 
To test the effect of fumigation on the various bleaching agents 
commonly used the following tests were carried out on samples No. 2, 
2a, and 8 to 15, inclusive : 
Method d. The cotton was boiled two hours in a 10 per cent solu- 
tion of soda ash. and bleached cold in " electrolytic chlorine " contain- 
ing 2 grams of chlorine per liter. 
Method e. The cotton was treated as in d except that chloride of 
lime solution containing 8 grams of chlorine per liter was used as the 
bleaching agent. 
Method /. The cotton was treated as in d except that an alkaline 
solution of sodium peroxide equivalent to 15 grams of chlorine per 
liter was used. After bleaching all of the samples were blued as in 
methods &, h, and c. 
The concentrations of bleaching agent are similar to those used 
in practice to obtain equal bleaching value. Close examinations were 
made of the samples by constructing a sample sheet with the differ- 
ent samples placed thereon for comparison. This comparison gave 
no indication that fumigation of cotton alters the bleaching value. 
All of these tests were carried out on all of the samples of cotton. 
To confirm these results, five 1-pound samples of Nos. 2 and 2a 
were treated by method cZ, the following details being observed in 
connection with the bleaching : After scouring, the cotton was rinsed 
