Experimental and Applied 277 



but the balance of conditions to be observed is necessarily 

 one of very fine adjustment. Any artificial treatment hitherto 

 attempted resembles the natural in being a process of hydro- 

 lysis ; the reagents to be used have been of the alkaline group, 

 and employed at relatively high temperature conditions 

 which make it extremely difficult to limit and regulate their 

 action. 



The authors have made investigations of the ' retting ' 

 action of dilute solutions of sodium carbonate, silicate, and 

 sulphite comparatively with the soda soaps, and with the 

 natural process. Of these several reagents the action of the 

 soda soaps alone resembles that of the natural process, the 

 * straw ' thus treated behaving in the scutching process very 

 similarly to the ordinarily retted product. But the scutched 

 fibre is of inferior spinning quality owing to the partial removal 

 of the pectic and oily constituents. 



Treatments of spinning fibres, after removal from the plant, 

 are sometimes resorted to in order to improve the working 

 qualities of the fibre in the mechanical processes of refining 

 and drawing preparatory to the actual spinning process. The 

 great desiderata in a yarn are uniformity and strength, and 

 yarns are valuable in proportion to fineness. The spinning 

 unit in all the vegetable fibres, with the exception of cotton 

 (and perhaps rhea), is a complex or bundle of the ultimate 

 fibres. In the processes of hackling and drawing, it is sought 

 to reduce or divide the bundles to the maximum of fineness. 

 In flax the subdivision of the bundles is carried very far and 

 without auxiliary treatment. In jute, on the other hand, the 

 bundles are much more firmly compacted ; and, as a lignocellu- 

 lose, it possesses none of the ' gummy ' properties of the pecto- 

 celluloses, and is also relatively deficient in oily constituents. 

 This fibre is subjected therefore to a preliminary treatment with 

 oily aqueous mixtures of varying composition, the incorpora- 



