io6 PREPARATION OF FLAX 



the straw is treated, the flax is more even in strength 

 and colour than that produced in other ways. More- 

 over, the time is reduced to three or four days, much 

 less labour is required, and the process can be carried 

 on all the year round without cessation. During 

 recent years, a somewhat modified form of this 

 process has been employed at certain factories in 

 Belgium and Holland. 



In the retting process, whatever method is employed, 

 it is of great importance that the fermentation should be 

 stopped at the right point, since over-retting weakens 

 the fibre and increases the amount of tow, or " codilla," 

 produced on scutching, whilst under-retting causes 

 part of the gummy encrusting matter to be retained, 

 and interferes with the subsequent manufacturing 

 processes. 



Various efforts have been made to replace the 

 retting process by treating the straw with chemical 

 reagents, such as dilute caustic alkali, but such 

 methods have not yet proved successful on the large 

 scale. 



Methods have also been suggested for preparing 

 the fibre by purely mechanical means without retting, 

 but these involve the loss of much of the fibre, and 

 yield a rough, hard product, which is of much poorer 

 spinning quality than that obtained by the retting 

 process . 



Breaking. The dry, retted stalks are passed be- 

 tween pairs of grooved or fluted rollers in order to 

 break the woody core into small pieces. There are 

 usually from six to twelve pairs of such rollers, which 

 are so adjusted that each pair works more closely 

 than the preceding pair. 



Scutching. The fragments of wood resulting from 

 the " breaking " process are removed by scutching. 

 The fibre is suspended in a. machine which is pro- 

 vided with a revolving cylinder, or drum, bearing 

 tough, flexible wooden blades on its periphery. As the 

 cylinder revolves the blades strike the flax, and thus 

 expel the broken wood, which is termed the " shieve " 

 or " boon." The operation necessarily causes a 

 considerable waste of fibre, some being broken by the 



