Seed.—That from Holland is most esteemed ; it ripens soon, and yields abundant and fine crops. Well-grown English seed is, perhaps, equal to it. Seed from the plains of India, though of good outward appearance, yields poor fibre for the first crop or two ; but Himalayan seed is inferior to none. Constant changes of seed are always beneficial. The seeds should be plump, and of bright-grey colour ; they must not have been heated in any way, and should therefore have a sweet flavour. Tho quantity required may be 2-2i or even 3 bush. an acre ; the thicker the growth on suitable land, the finer the resulting fibre. Sowing takes place in May-June; frosts injure tho young plant, but late sowing conduces to thinness and weakness. Sowing in drills produces coarse, strong fibre, fit for cordage ; broadcast sowing is preferred when the fibre is to bo used for textile purposes.
Culture.—As soon as the young plants appear, the ground is thoroughly weeded, and the plants are thinned out, according to the class of fibre required, and the capability of the ground. A second weeding is sometimes needed, but generally the plants grow so rapidly as to keep down weeds. Abundant moisture is requisite during growth, hence irrigation is practised in some localities.
harvesting.—As the fibre afforded by the male plants is tougher and better than that yielded by the females, it is usual to divide the harvest. The males are gathered as soon as they have shed their pollen, about 13 weeks after the sowing ; they are then recognized by their leaves being yellow, stems whitish, and flowers faded. Each is uprooted singly, care being taken not to injuro the stem. The ripening of the females, which occurs about a month later, is indicated by similar signs, as well as by the grey tint of the seeds, and the opening of the capsules. If the plants are left for the seed to ripen thoroughly, the fibre becomes coarse and woody, and difficult of extraction ; hence the full maturity of the seed should not be awaited. Plants which are to give sowing seed must have room to spread, and be left to ripen their seed. When it is not intended to preserve the seed (for the sake of its oil), and when the fibre alone is utilized, the plants may be pulled while in flower, and without any regard to sex. Under these circumstances, mowing would be a much more rapid method of harvesting the crop ; yet a prize for a hemp-mowing machine, offered some years since by the Hungarian Government, did not attract a single competitor. As soon as the plants are pulled, they are held by the root, and carefully shorn of leaves and flowers, which help to manure the land.
Stooking.—When the stems are stripped, they are bound in small bundles, and the now dry soil adhering to the roots is knocked off. The stalks forming each bundle should be as nearly as possible of equal length, and the roots should be placed even. The bundles are then set on end in
stooks like corn. If the crop is to be kept long, the bundles are made of larger size, and are stacked and thatched.
The female plants, after gathering, are allowed to stand in the air for 8-10 days, to allow the seed to dry and ripen ; the heads are then cut off, and the seed is threshed out. Bundles of seeded stems are best conveyed by a rope fastened round under the heads, and suspended over the shoulder. The seed remaining after threshing is combed out; but it is inferior, and unfit for sowing. The female plants are generally stacked during the winter, and not ratted till the spring. The length of time for which the pulled plants should remain in stook to dry before retting is a much debated point. Some authorities declare that 1-2 days' sun-drying is essential ; while others state that it is unnecessary, and that ripe plants should he retted the moment they are pulled, the retting being then reduced from 8 days to 4.
Extraction and Preparation of the Fibre.—The extraction and preparation of the fibres of the plant may be divided into the following heads:— Retting.—The term "retting" is applied to a modified process of fermentation, or rotting, to which the stalks are subjected, with the object of loosening the fibres, and facilitating their abstraction from the bark. The process is adopted with several other exogenous fibres, notably flax (Linum usitatissimum), and will be minutely described under that head (see p. 967). Meantime, it may be said that there are three ways of retting hemp, (1) " water-retting " or "watering," (2) "dew-retting," and (3) "snow-retting." (1) Watering or steeping is often conducted in mere ditches, 3-4 ft. deep, and of varying length and breadth, dug on the margins of rivers. The bundles of hemp are laid at the bottom, covered with straw or sods, and weighed down by logs and stones. Putrid standing water makes softer 'fibres than running water ; but the former engenders a disagreeable colour, which, however, is destroyed by bleaching. In some districts, retting is carried on in basins at different altitudes, a small stream constantly trickling from one to another. This seems to be the most satisfactory plan. The degree of retting greatly influences the strength and suppleness of the fibre ; hence that intended for making fine textiles should be ratted more than that for coarser goods, while fibre for cordage purposes should be retted least of all. The progress of the operation is readily ascertained, by taking out a stem by the root end, and drawing the thumb-nail along it to the top ; when the fibre slips up the stem, the process has been carried sufficiently far.