RAMIE, RHEA, AND CHINA GRASS 43 



it can be done by hand, without breaking or "slaving" the 

 fibre. If the fibre is broken in the process, the yield obtain- 

 able from the combing machine is much diminished. Many 

 decorticating machines have been patented, but most of them 

 have been found defective. 



When the commercial fibre arrives at the mill it still con- 

 tains from 20 to 30 per cent, of gum, which must be removed 

 before it can be spun into fine yarns. The degumming may 

 be conveniently affected by employing the process and the 

 apparatus invented by Boyle. This process consists in pass- 

 ing the material through tanks of chemical solutions. The 

 first trough contains a weak soda lye, and the second a feeble 

 solution of hydrochloric acid, which acts upon the soda re- 

 maining in the fibre and sets up fermentation. The third 

 tank is similar to the first. The fourth contains a solution of 

 permanganate of potash, and the fifth a mixed solution of 

 hyposulphite of soda and hydrochloric acid. The sixth tank 

 contains hyposulphite of soda, and the seventh a solution of 

 hydrochloric acid. On leaving the latter bath, the fibre is 

 washed in pure water, and then steeped in a weak solution of 

 soap and water in order to give it back a little of the oleaginous 

 matter extracted by the action of the soda. The material should 

 be passed through these successive baths between endless open- 

 work travelling aprons, in thin layers, in order that the fibre 

 may preserve its parallelism and not become too much matted. 

 Between each bath it passes between wringing rollers to 

 remove superfluous moisture. 



True China grass, from which much of the gum has already 

 been removed by hand scraping, does not require such severe 

 chemical treatment as that just described. It is sufficient to 

 boil it in soda lye, to steep it in chloride of lime solution and 

 then in an acid bath, repeating the two latter processes, with 

 a washing in pure water between each, until the gum has com- 

 pletely disappeared and a pure white filasse is produced. The 

 fibre should be placed in the boiling kiln between trays of wire 



