PREPARATION OF FLAX 103 



The fermentation is due to the agency of bacterial 

 organisms, which convert the pectose into soluble 

 products but do not attack the cellulose or true fibre 

 substance. This change is said to be brought about 

 by the activity of a special enzyme, pectosinase, 

 which converts pectose successively into pectin and 

 sugar, the bacteria afterwards fermenting the sugar 

 with the production of hydrogen, carbon dioxide, and 

 a little butyric acid. There are several different 

 methods employed for carrying out the retting process. 



In many parts of Russia, especially the Archangel 

 district, " dew-retting " is practised. The freshly- 

 pulled straw is spread out in rows on the grass in a 

 moist meadow, about a ton to the acre, and is left 

 exposed for two or three weeks or more to the action 

 of the air, light, dew and rain. From time to time 

 the straw is turned over with a fork or a pole in order 

 to ensure that it may all become equally retted. 

 Dew-retting is the least satisfactory method, as the 

 product is liable to be uneven. 



The method of retting most commonly adopted is 

 that of " water-retting " or " steeping.'' This pro- 

 cess may be carried out either in pools or in running 

 water. In the former case, the bundles of flax straw 

 are placed side by side in a pool or dam with the 

 root-ends downwards ; when one layer is finished a 

 second layer is placed on top of it in the same way, 

 and so on until the dam is full. The whole is then 

 covered with stones or with boards on which grass 

 sods, stones or clods of earth are piled in order to keep 

 the flax submerged. As fermentation proceeds, the 

 gases which are evolved tend to raise the flax above 

 the surface of the water, and at this point therefore 

 it must be more heavily weighted. On the other 

 hand, as the fermentation subsides the flax begins to 

 sink, and some of the load must be removed. The 

 straw must be examined from time to time in order 

 to ascertain whether the retting has proceeded far 

 enough. The determination of the exact point at 

 which to stop the process requires considerable experi- 

 ence and judgment. In general, it may be said that 

 when the fibre can be readily and completely separated 



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