14 TEXTILE FIBRES. 



a large quantity of an oil having an orange green fluorescence, which is 

 a ketone of some kind, to which body the peculiar odour of raw flax is 

 probably due. Accompanying the cellulose there are about 25 per 

 cent, of pectose-like bodies, easily soluble in boiling solutions of alkali 

 of 1 to 2 per cent, concentration, to which solutions they impart a 

 yellow colour. Nitric acid converts these pectose substances into mucic 

 acid. 



The oil is of very considerable importance in the spinning of linen 

 thread, serving probably as a lubricant. Many attempts have been made 

 to supersede the retting process now in use, but some, if not all these, 

 have been failures, on account of the fact that the fibre prepared by 

 their means has not spun well. This may probably be ascribed to the 

 fact that they have used all the oil from the fibre, which becomes there 

 fore deficient in lubricating properties, and the fibres have not that freedom 

 of motion necessary to spin well ; on the other hand, to eliminate these 

 waxy and oily matters from the cloth after being woven necessitates a 

 most elaborate bleaching process. The flax fibre is classed as a pecto- 

 cellulose, that is, a fibre which is accompanied by a quantity of non- 

 cellulosic bodies of a pectic or pectose character, whose main characteristics 

 have already been pointed out. Another feature is that they give 

 gelatinous hydrates. 



It has been stated above that boiling with weak alkalies removes 

 the pectose constituent intact. It is considered by some authorities 

 that we must view the flax fibre as being a distinct compound of 

 these two constituents, hence the term * pectocellulose ' ; but this 

 view does not seem to be altogether correct. Probably the pectose 

 constituents are present as products of decomposition of the wood and 

 bark surrounding the fibre when in the plant ; or they may be even 

 decomposition products of the cellulose itself. Further investigation 

 on this point is needed. This should be partly chemical, partly 

 microscopical, and made on different stages of growth. 



When the true cellulose of the flax fibre has been isolated, it is 

 found to have properties identical with those of cotton fibre ; in fact, 

 so far no reactions of a chemical nature have been found by means 

 of which cotton and flax cellulose can be distinguished from one 

 another. Their identity is established by their resistance to hydrolysis 

 and oxidation, and by their containing no active CO or OH groups. 

 Acids, alkalies and solvents react with the two celluloses in precisely 

 the same manner. The only difference between them is a morphological 

 one the difference in the form of the two fibres. What has been said of 

 the properties of the cotton fibres applies equally well to linen fibre when 

 the impurities which it contains have been separated (Textile Mercury}. 



