278 Cellulose 



tion of which greatly improves the spinning qualities. The 

 treatment and its effects are, however, rather mechanical than 

 chemical. Hemp has been chemically treated for the same 

 general purpose, by a process devised by the authors, con- 

 sisting in a digestion of the fibre with dilute solutions of basic 

 sodium sulphite at high temperatures. This enables the fibre 

 to be drawn and spun to finer numbers, and has proved 

 especially valuable in the manufacture of the finer counts of 

 shoe-threads. 



Rhea, or China grass, is a fibrous material that also requires 

 chemical treatment preparatory to spinning, but for a different 

 reason. This fibre is separated from the mature stems by 

 stripping the entire bast and cortex from the wood. The 

 ribbons thus obtained are treated by various processes for the 

 removal of what is commonly termed the 'gum.' The pectic 

 constituents of the fibre and parenchyma readily yield to the 

 action of alkaline solutions, and the disintegrated cellular 

 residues are then easily removed by mechanical operations. 



The process of purification is, in the case of this fibre, 

 carried to the full extent of isolating a pure cellulose. The 

 ultimate fibre, being of the unusual length of 40-200 mm., is a 

 spinning unit of sufficient dimensions, comparable with the flax 

 filament. Its spinning qualities are, on the other hand, inferior 

 to those of flax, and it is probable that much better results 

 would be obtained with this fibre by spinning it in a condition 

 more nearly that in which it occurs in the plant. 



Generally it may be said that the chemical treatment of 

 these fibres preparatory to the mechanical operations of the 

 spinner has been investigated on purely empirical grounds. 

 There are a number of questions of both theoretical and 

 practical import which await systematic inquiry. The purpose 

 of this superficial and general discussion of the subject is to 

 indicate some of the directions in which the theoretical con- 



