98 MR. EDWARD SCHUNCK ON SOME 



is added to the cotton to render it impure. It can also be 

 treated without any trouble, and in large quantities, in the 

 ordinary vessels used by bleachers, without rendering it 

 necessary to set up special apparatus for the purpose. 



In the first experiment which I made, 450 lbs. of No. 20 

 yarn, carefully spun from East-Indian cotton, of the variety 

 called '^ Dhollerah,^^ was treated, in an ordinary bleacher's 

 kier heated by steam, with boiling water containing 13^ lbs. 

 of soda- ash, for ji hours. The resulting dark-brown liquor, 

 after the yarn had been taken out, drained, and slightly 

 washed, was removed into another vessel and mixed with 

 an excess of sulphuric acid, Avhich produced a copious, 

 light-brown, flocculent precipitate, while the liquid became 

 nearly colourless. This precipitate was allowed to settle ; 

 the liquid was poured off, and, after being washed with 

 cold water to remove the sulphate of soda and excess of 

 acid, the precipitate was put on strainers of calico and 

 allowed to drain — an operation which, in consequence of its 

 gelatinous nature, occupied some time. A thick pulp w as 

 thus obtained, which was found to weigh 60 lbs. Of this 

 3 lbs. was taken and dried completely, at first in a stove 

 and then in a water-bath, when it left 531 grs. of a brown, 

 brittle, horn-like substance, translucent at the edges. The 

 whole of the precipitate, if dried, would therefore have 

 weighed 10,620 grs., which is equal to 0*337 P^^ cent, of 

 the weight of the cotton ; that is to say, 1000 lbs. of cotton- 

 yarn would have yielded nearly 3^ lbs. of matter insoluble 

 in water, but soluble in alkali. This result is, of course, 

 only approximative. 



In a second experiment 2400 lbs. of yarn, made from 

 the same kind of cotton, but of rathat inferior quality, was 

 treated in the same way ; but the quantity of precipitate 

 obtained was not determined. 



The third experiment was made with 500 lbs. No. 20 

 yarn, spun from American cotton of the kind called in 



