RETTING 105 



case of cellulose fermentation most of the cellulose was des- 

 troyed, but not all, owing to the products having an injurious 

 action on the fermentation process. 



94. Retting Practices. Most of the retting methods in use 

 at the present time are as follows 



1. Retting in ponds of stagnant water. 



2. In ponds of water which are slowly changed during the 

 process of retting. 



3. In sluggish streams or rivers of which the river Lys is 

 proverbially typical. 



4. In tanks filled with warm water, the temperature of which 

 is retained at a uniform degree, (a) with a constant inlet and 

 exit flow, under control ; (6) with no replacement of water 

 after the retting starts. 



5. Dew retting. 



6. Rossi process. 



7. Numerous chemical methods have been attempted to 

 rapidly perform the operation of decomposition, but com- 

 paratively little progress has been made since the days of 

 Pliny, when the flax was steeped in ponds of water exactly as 

 it is done to-day. The possible and inherent difficulty of 

 quick chemical retting lies in the fact that the chemical com- 

 pound which binds the flax fibres to the stem of the plants 

 is of the same composition as that which retains, in overlapping 

 longitudinal order, the bundles of ultimate flax fibres from 

 which the characteristically artificial length of the commercial 

 and scutched form of flax is derived. Any process which 

 separates the flax fibres into their ultimate lengths prior to 

 the final operation of wet spinning is fatal to itself. 



95. Pond Retting. The first consideration in pond retting 

 is the supply of suitable water ; the second, the position of 

 the pond ; and the third, its dimensions. 



If only hard water is available, i.e., water containing lime 

 or mineral salts in solution, or water rising directly from a 

 spring, then such waters are not suitable. Spring water may, 

 however, be improved for the purpose by filling the retting 



