104 PREPARATION OF FLAX 



from the woody core, it is time to withdraw the stems 

 from the pools. After their removal from the pool, 

 the bundles of straw are stood on end to dry and are 

 then stacked for a few weeks. In some' places, the 

 bundles are drained and then " grassed/' i.e. spread 

 evenly over a grassy meadow to dry. 



The water used for retting should be as soft as 

 possible, and should not contain much iron or other 

 substances likely to discolour the fibre. 



In some parts of Russia, a combination of dew- 

 retting and pool-retting is practised, the straw being 

 first immersed for some time in shallow pools, and 

 afterwards spread out on the grass and exposed to the 

 action of the dew. 



The process of retting in running water is carried 

 out in the Courtrai district of Belgium, and yields 

 flax of the finest commercial grades. The bundles 

 of flax straw are packed root-end downwards in 

 wooden crates, which are about 12 feet square and 

 have a solid floor but open sides. A strip of jute 

 sacking is bound round the sides, and the crate is 

 placed in the river Lys, and loaded with stones until 

 the water just covers it. From four to fifteen days 

 are required for the necessary amount of fermentation 

 to take place, the actual time depending on the tem- 

 perature, the condition of the straw and other factors. 

 When the retting is completed, the crates are with- 

 drawn from the stream, and the bundles of straw 

 are removed and dried in the air. In some cases the 

 straw is again packed in the crates and immersed for 

 a second time. 



Many attempts have been made to improve the 

 retting process by carrying it out in tanks or vats 

 containing warm water. The first invention of this 

 kind was made in 1846 by R. B. Schenk, who designed 

 large wooden vats in which the flax straw was 

 packed with the root-ends downwards. Water was 

 introduced into the vats and maintained at a tempera- 

 ture of 75-95 F. Fermentation rapidly ensues under 

 these conditions, and the entire process only occupies 

 about fifty or sixty hours. An improvement was 

 suggested by Pownall, which consists in passing the 



