1922] TANNER—FLAX RETTING 175 
harvest. Some claim that it must be pulled, not cut, and tied up 
carefully in bundles. This may be one reason why it has been 
difficult to utilize the flax from seed flax for spinning. It might 
be possible in the future to combine profitably the seed and fiber 
crop. This would tend to reduce the value of each crop taken by 
itself perhaps, but the value of the combined crops of seed and 
fiber might compensate for any decrease in the value of the single 
crop. 
The bast fibers, which are those used in making linen, are 
cemented to the other parts of the stalk and to each other by means 
of materials, for convenience, called pectins. Undoubtedly this term 
is used only in a general way to cover a number of compounds 
closely related chemically. The aim of the retting process is to 
remove these “binders”? without harming the cellulose fiber. The 
fermentation must be checked when these fibers have been freed 
by the hydrolysis of the pectose or salts of pectic acid. These 
binding materials which hold the stalk together are undoubtedly 
carbohydrate in nature, and thus susceptible to the action of 
microoganisms. 
Preparation of flax fiber 
The fiber is prepared from the flax straw by a special process 
which seems to have been built up after a long period of time with- 
out much assistance from the sciences. Proper harvesting is very 
important. Fiber flax should be pulled either by hand or by 
machinery and tied into bundles which are shocked for curing. 
Cutting the flax is claimed by some to leave the ends of the stalk 
exposed for undesirable decompositions. When the heads are 
shocked for curing, this cut end becomes susceptible to the attacks 
of undesirable bacteria. The fibers become badly stained also. 
This may not be entirely true, however, under actual practice. 
After curing, the stalks are retted. This is really a rotting 
process, which indicates the origin of our present term. Three 
general methods may be used to dissolve the binder which holds the 
cellulose fibers to the woody materials: dew retting, water retting, 
and chemical retting. The first two only are of bacteriological 
interest, and were studied in the present investigation. 
