BLEACHING. 



161 



are composed: thus, linen, cotton, woollens, and 

 silk, are whitened by different methods. In order 

 to understand the rationale of the bleaching pro- 

 cesses, it is necessary to be acquainted with the 

 nature of the materials. 



Flax, from which linen is formed, is a vegetable 

 consisting of several coats or layers. The external 

 coat is a very thin bark ; under this is a green juice 

 or sap; next lies a layer of fibres or filaments, 

 which constitutes the part used for making linen j 

 and, lastly, in the centre, there is a woody part. To 

 prepare flax for making cloth, the filaments or 

 fibrous part must be separated from the rest. The 

 filaments are held together by the sap, or succulent 

 part. To detach them from this, the flax is steeped 

 for several days in pools or ponds of soft stagnant 

 water; by which the putrefactive fermentation 

 takes place. But this fermentation must not be 

 suffered to proceed too far; otherwise the fibres 

 themselves would be affected by it, and their 

 texture injured. The flax must be taken out 

 while it is yet green, and while the wood breaks 

 easily between the fingers. The putrefaction of 

 the sap occasions the water in which the flax is 

 steeped to be extremely offensive ; and it is even 

 found that the fish are destroyed in any stream 

 where this process is used. 



In some places, instead of steeping the flax in 

 water, it is Dimply exposed to the dew by laying it 

 on the grass. 



The time required for this part of the process is 

 variable ; depending upon the state of ripeness of the 

 flax, the quality and temperature of the water, and 

 other circumstances. 



After steeping the flax, where the watering sys- 

 tem is practised, it is spread very thin on the grass, 



VOL. II, M 



