Class B.
FLAX.
FIG. 6.
Microscopic features.—Fibres transparent, regular, with tapered ends, side walls thick, consequently central canal small, smooth externally, sometimes slightly striated. Filaments easily split up into fibres.
Sections.—Polygonal, regular, angles more or less acute, lumen represented by point; slight indications of concentric arrangement of fibre substance.
Micro-chemical reaction.—Blue with iodine solution.
General chemical characteristic.—Pecto-cellulose.
Composition of raw fibre.—This varies with the different species, and is doubtless also influenced by variations in the {49} processes of retting. The following are the analyses of two samples of Belgian flax (heckled):—
| Müller. | ||
|---|---|---|
| Cellulose | 81·99 | 70·55 |
| Fat and wax | 2·37 | 2·34 |
| Aqueous extract | 3·62 | 5·94 |
| Pectous substances | 2·72 | 9·29 |
| Water | 8·60 | 10·56 |
| Ash | ·70 | 1·32 |
The chemistry of the flax fibre has been investigated by Kolb.
Forms in which employed.—Scutching refuse, spinning waste, threads, rags, new and old.
HEMP.
FIG. 7.
Microscopic features.—Compact bundles. Fibres show striæ and fissures, and often fibrillæ, detached or adherent. The central canal almost obliterated, ends of fibres large and flattened. The bundles show fine transverse markings. {50}
Section.—Well marked concentric zones of fibre substance, irregular in outline.
Micro-chemical reaction.—Blue and yellow reaction with iodine solution, the joint result showing green colouration.
General chemical characteristic.—Pecto-cellulose.
| Müller. | |
|---|---|
| Cellulose | 77·13 |
| Fat and wax | ·55 |
| Aqueous extract | 3·45 |
| Pectous substances | 9·25 |
| Water | 8·80 |
| Ash | 0·82 |
Forms in which employed.—Scutching refuse, spinning waste, threads, cuttings and rope ends.
SUNDA or SUNN HEMP.
Microscopic features.—Generally similar to those of hemp.
Micro-chemical reactions.—With iodine various, from blue to yellow. With aniline sulphate, slight yellow.
General chemical characteristics.—Pecto-cellulose (with some ligno-cellulose).
The following are the results of analysis of the raw fibre (H. Müller):—
| Cellulose | 80·01 |
|---|---|
| Fat and wax | ·55 |
| Aqueous extract | 2·82 |
| Pectous substances | 6·41 |
| Water | 9·60 |
| Ash | 0·61 |
This fibre, exported from India and the Sunda Islands, has found employment in Spain and Portugal, but up to the present has not been adopted to any extent in other parts of Europe.
CHINA GRASS, RHEA, RAMIE.
FIG. 8.
Microscopic characteristics.—Irregular in form and length; often conspicuous in respect of latter (see Table, p. [39]); fibre sometimes cylindrical, either smooth or striated, sometimes flattened; central canal well developed, often containing granules; extremities of fibres rounded, spatulated or lance-shaped. Sections marked by numerous concentric layers, often showing radiating striæ.
Micro-chemical reaction.—Blue to violet, with iodine solution.
General chemical characteristics.—Pecto-cellulose.
Composition of raw fibre (H. Müller):—
| Cellulose | 75·83 | 62·50 |
|---|---|---|
| Fat and wax | ·20 | 0·56 |
| Aqueous extract | 6·29 | 9·76 |
| Pectous substances | 6·07 | 12·00 |
| Water | 8·74 | 9·55 |
| Ash | 2·87 | 5·63 |
Forms in which employed.—Up to the present the price has been prohibitive. Has been the subject of successful {52} experiments; imparts great tensile strength to paper. The portions available will be as in flax.
COMMON NETTLE.
The fibres of this plant were, in the olden times, separated in the same way as flax, and worked up into cloth. At present it has no practical interest to the paper-maker, but deserves attention at the hand of the student, as the most easily accessible for the purpose of study. It is, moreover, possible that, under cultivation, it may yet become a source of raw material for paper-making.
JUTE.
FIG. 9.
Microscopic features.—Compact bundles; fibres smooth.
Micro-chemical reactions.—Yellow brown, with iodine; yellow, with aniline sulphate; bright yellow, with chlorine water; changed to carmine by treatment with sodium sulphite solution. {53}
General chemical characteristic.—Ligno-cellulose. The chemistry of jute as the type of ligno-cellulose has been treated on p. [17].
Composition of raw fibre (Müller):—
| 1st Quality. | Cuttings or Butts. (Root ends). | |
|---|---|---|
| Cellulose | 63·76 | 60·89 |
| Fat and wax | 0·38 | ·44 |
| Aqueous extract | 1·00 | 3·89 |
| Non-cellulose, or lignin | 24·32 | 20·98 |
| Water | 9·86 | 12·40 |
| Ash | ·68 | 1·40 |
Forms in which employed.—Threads, butts, bagging.
BAST TISSUES.
The fibres give a yellow colouration with aniline sulphate, but they contain only a small proportion of lignose. The following are the results of analyses of this bast:—
| Cellulose | 49·35 | 58·82[*] |
|---|---|---|
| Fat and wax | 0·94 | 0·41 |
| Aqueous extract | 13·57 | 7·08 |
| Pectous substances | 19·05 | 15·19 |
| Water | 10·90 | 13·18 |
| Ash | 6·19 | 4·72 |
[*] Made up of 13·75 cellulose from medullary tissue, 45·07 cellulose of fibres.