196 



Flax, its Treatment, 



first, a destructive fermentation is carried on at the expense of 

 the extractive matter of the plant, and offensive and noxious 

 gases are generated ; in the second this matter is removed bj the 

 aid of chemical ingredients, which are costly, and render it of 

 little value ; while by the third the whole of the substance 

 abstracted is preserved in a state immediately available, and 

 valuable as a feeding substance. The process of steeping is 

 carried on differently in different districts ; the oldest is probably 

 that called " dew-retting," in which the straw is spread out on 

 the grass and carefully watered, so as to supply sufficient mois- 

 ture to support the action of fermentation in the tissues of the 

 plant. This is a very tedious process, rarely to be met with now 

 in this country, requiring several weeks for completion, and in 

 dry seasons not practicable at all. The usual method is to im- 

 merse the straw, either in tanks or pits constructed for the pur- 

 pose, or in slowly-running streams. Suitable arrangements are 

 made for effecting this : — In Belgium, where it forms a distinct 

 branch of the trade, wooden crates are made, which are lillecl 

 with the flax, and then carried into the stream and weighted 

 down ; in Ireland, and other places where pits or tanks are used, 

 the flax is placed in loose bundles, and kept down by means of 

 planks, or other convenient materials. In a few days a scum 

 appears on the surface of the water, and is succeeded by the 

 evolution of gases in the shape of bubbles, arising from the de- 

 composition now actively at work beneath. Great and constant 

 care is now required that this proceeds not too far, and thus 

 injures the quality of the fibrous portion ; it needs constant 

 watching, and removal so soon as the desired effect has been 

 obtained. This is readily seen by the experienced eye, by the 

 manner in which the fibre separates from the shove on breaking 

 a portion of the straw. This process, though less tedious than 

 the dew-retting, still requires a considerable time for its opera- 

 tion — in pools or tanks from 10 to 14 days are required ; in 

 streams, where the temperature is lower, from 14 to 21 days are 

 consumed. In both cases much depends upon the quality of 

 the water, and upon the general temperature ; any impurities, 

 especially salts of lime and of iron, are very injurious ; they 

 retard the fermentation and affect the fibre. These irregularities, 

 both as regards time and effect, produced by the cold steeping, 

 led to the consideration of another method, by which a regulated 

 temperature could be obtained, and the time and risk of the old 

 process avoided. The merit of practically employing heated 

 water for this purpose is due to Schenck, who took out a patent 

 for it in 1846, though the principle was not at all new, and had, 

 indeed, been partially applied for many centuries past. 



The first rettery on this principle was established in Mayo, 



