MANUFACTURING TESTS OF COTTON. 9 
30 minutes in cold water, squeezed, and treated 2.5 hours cold with 
" electrolytic chlorine," 1.46 grams of chlorine per liter ; was rinsed 
well, treated 30 minutes in a 5 per cent solution bisulphite of soda, 
cold; was rinsed well, and blued with a solution containing three- 
fourths of a gram vat blue in 10 liters of water. 
Samples 10, 11, 14, and 15 were combined into one lot, samples 
8 and 9 into a second lot, and samples 12 and 13 into a third lot, and 
each lot was bleached by the method outlined in the previous para- 
graph for samples Nos. 2 and 2a. 
By comparison of these samples it was evident that there was as 
much difference in bleaching quality between the two bales of non- 
fumigated cotton as there was between the bales of fumigated and 
ronfumigated cotton of the same quality. 
DESCRIPTION OF FURTHER TEST. 
Samples of fumigated and nonfumigated Chinese cotton which 
had been both bleached and blued. by a representative cotton mill 
were submitted for examination. As a result of the bluing process, 
the sample of fumigated cotton was a more intense blue than the sam- 
ple of nonfumigated cotton. On receipt, tests were made on these 
samples for iron to ascertain if there had been a formation of Prus- 
sian blue, due' to the presence of hydrocyanic acid in the fumigated 
cotton, which would cause the intensifying of the color of the cotton. 
Negative results were obtained. The bluing matter was extracted 
with water until the samples were practically the same color. These 
water extracts were of different depths of blue. The deepest extract 
was then diluted until both were of the same shade of blue. The 
extracted cotton samples were treated again in their respective solu- 
tions. The resultant samples were of the same color. 
From the above results the conclusion was reached that the in- 
creased depth of blue on the fumigated sample was because it had 
been treated with a greater quantity of bluing and not because of the 
presence of hydrocyanic acid or because of any chemical change in 
the fiber such as the formation of hydrocellulose. 
TEST FOR THE PRESENCE OF HYDROCYANIC ACID. 
Small specimens from each of the following samples, 2, 2a, and 
8 to 15 inclusive, were tested for the presence of hydrocyanic acid as 
follows : 
The sample was covered with a solution of 10 c. c. of distilled 
water, 5 drops concentrated sulphuric acid, 5 c. c. 2/normal ferrous 
sulphate and 6 c. c. normal sodium hydroxide heated nearly to a boil, 
then 5 c. c. 6/normal hydrochloric acid were added. 
These tests gave no blue coloration which indicated the absence 
of hydrocyanic acid in all of the samples at the time of treatment. 
