Experimental and Applied 289 



purpose we need consider but the one in which caustic soda 

 is used. With this reagent, in the form of a 1-2 p.ct. 

 solution of NaOH, cotton goods are effectively cleared of their 

 non-cellulose impurities in a single treatment. The conditions 

 of the process are : (i) a saturation of the goods with the 

 alkaline lye, usually effected by passing the goods in continuous 

 length through the hot liquor, removing the excess by squeezing, 

 and piling up in the 'kier,' or boiling-vessel; (2) the boiling 

 process, in which the goods are subjected to the further action 

 of the alkaline lye at temperatures of 105-115, and under 

 corresponding steam pressures. The liquor is kept in circula- 

 tion through the goods, and the ' boiling ' is continued from 

 six to ten hours. 



After this treatment the goods are washed free from the 

 alkaline lye and the dark coloured soluble products of the 

 action, and are then of a greyish-brown colour. The residual 

 impurities are then removed in the bleaching process proper, 

 which consists in exposing the goods to the action of bleaching 

 powder solution. The goods are then washed and * soured,' 

 to remove basic residues. This round of operations is some- 

 times repeated, though with weaker solutions, in the case of 

 heavy goods, or of goods made of the more refractory 

 Egyptian cottons, which contain a red brown colouring matter. 

 The process, however, need not be followed into its technical 

 details. It is one of great simplicity, and aptly illustrates the 

 resistance of the normal cellulose to alkaline hydrolysis and 

 oxidation under somewhat severe conditions. The fibre itself 

 loses from 7-10 p.ct. in weight under the treatment. The 

 products removed in solution have been investigated by 

 Dr. E. Schunck, who resolved the dissolved products into 

 (a) Cotton wax, a neutral wax, melting at 80-86, having the 

 composition C 80-3, H 14*4 ; (b) Fat acid, which appeared to 

 be a mixture of palmitic and stearic acids. The analytical 



u 



