HEMP, Cannabis saliva, an annual herb, having angular rough stems and alternate lobed leaves. The bast fibres of Cannabis arc the hemp of commerce, but under the name of hemp fibrous products from many different plants are often included. Sunn hemp is the bast fibre of a papilionaceoas plant, Crotolaria juncea, of India and the Sunda Islands ; Hibiscus cannabinus, an Indian malvaceous plant, yields brown or Bombay hemp ; Jute or Pant hemp is produced by Core/earns capsularis and C. aitorius, and to some extent by C. .fasces, C. faseicularis, and C. decentangulatus. Manila hemp or feather fibre is derived from the fibre-vascular bundles of certain monocotyledons, namely, several species of Musa, chiefly from dL textilis, but to some extent from 111 sapientunt, L ensete, M. mindanensis, and M. Cayendiskii, in India, New Guinea, the Philippines, &:c. Pita hemp is produced from certain species of Agave; the Aloe sisalina of Central America yields grass-hemp ; and Murva or bowstring-hemp is obtained from an aloe-like plant, Sanseviera zeylanica, in Bengal, Ceylon, Java, and southern China.

The hemp plant, like the hop, which is the other member of the same natural order, Cali,mbinacece, is dicecious, that is, the male and female flowers are borne on separate plants. The male plant is smaller than the female, and ripens and dies earlier in the summer. The foliage of the female plant is darker and more luxuriant than that of the male. The leaves of hemp are constituted of 5 to 7 leaflets, the form of which is lanceolate-acuminate, and sharply serrate. The loose panicles of male flowers and the short spikes of female flowers arise -from the axils of the upper leaves. The height of the plant varies greatly with season, soil, and manuring ; a variety (C. saliva, var. gigantea) has produced specimens over 17 feet in height, but the average height of the common sort is about 8 to 10 feet. There is but one species of hemp known, Cannabis saliva, the C. ind ica, Lam., and C. chiatectsis, Delile, owing their differences to climate, and losing many of their peculiarities when cultivated in temperate regions. Rumphius (in the 17th century) had noticed these differences between Indian and European hemp.

The original country of the hemp-plant was doubtless in some part of temperate Asia, probably near the Caspian Sea. It spread westward throughout Europe, and southward through the Indian peninsula.' Wild hemp still grows on the banks of the Lower Ural and the Volga, near the Caspian Sea. It extends to Persia, the Altai range, and northern and western China. It is found in Kashmir, and on the Himalaya, growing vigorously as far up as 0000 or even 10,000 feet.

Hemp is grown for three products-(1) the fibre of its stem ; (2) the resinous secretion which is developed in hot countries upon its leaves and flowering heads ; (3) its oily seeds.

Hemp has been employed for its fibre from ancient times. Ilerodotus (iv. 74) mentions the wild and cultivated hemp of Scythia, and describes the hempen garments made by the Thracians as equal to linen in fineness. Hesychius says the Thracian women made sheets of hemp. Moschion (about 20013.c.) records the use of hempen ropes for rigging the ship " Syracusia " built for Hiero II. The hemp plant has been cultivated in northern India from a considerable antiquity, not only as a drug but for its fibre. The Anglo-Saxons were well acquainted with the mode of preparing hemp. Hempen cloth became common in central and southern Europe in the 13th century.

The medicinal and intoxicating properties of hemp have probably been known in Oriental countries from a very early period. An ancient Chinese herbal, part of which was written about the 5th century B.C., while the remainder is of still earlier date, notices the seed and flower-bearing kinds of hemp. Other early writers refer to hemp as a remedy. The medicinal and dietetic use of hemp spread through India, Persia, and Arabia in the early Middle Ages. The use of hemp (bhang) in India was noticed by Garcia d'Orta in 1563. Berlu in his Treasury of Drugs (1690) describes it as of " an infatuating quality and pernicious use." Attention was recalled to this drug, in consequence of Napoleon's Egyptian expedition, by De Sacy (1S09) and Rouger (1810). Its modern medicinal use is chiefly due to trials by Dr O'Shaughnessy in Calcutta (1838-1842). The plant is grown partly and often mainly for the sake of its resin in Persia, northern India, and Arabia, in many parts of Africa, and in Brazil.

The hemp plant grown in some parts of the United States yields the active resin so freely that less than 1 grain of the extract is a full dose. But it is as a fibre-producer that the hemp is now being more extensively cultivated in the United States. Hemp seeds were ordered for Plymouth colony as early as 1629, but the greater profit derivable from tobacco has always opposed the development of hemp-growing. The plant is chiefly grown in the States of Kentucky, Missouri, Tennessee, Ohio, Indiana, and New York. The produce of Kentucky in 1877 was 6140 tons. According to the census of 1870 the total production of the United States was 12,746 tons. In the northern part of the State of New York the crop is valued chiefly for the seeds, which may be from 20 to 40 bushels or more per acre. The produce per acre in the United States is front 700 to 1000 lb of fibre, 4 to 6 pecks of seed being usually sown.

Although the hemp-plant is grown in India chiefly for the production of its narcotic or intoxicating resin, yet a good deal of true hemp fibre is produced there. It is imported into England, however, chiefly from Russia, the United States, Italy, Holland, Germany, Hungary, and Turkey. It is grown in Ireland, and in some parts (Suffolk and Lincolnshire) of England. It thrives well in Algeria. It requires a rich deep soil and heavy manuring, and is an exhausting crop. In Great Britain about 6 pecks of seed per acre are drilled, 18 inches apart, itt the middle of April. The male plants are pulled from the end of July to the end of August, the female or seed-bearing plants being gathered in September, The British imports of hemp cannot be ascertained with accuracy, as the official returns include under that name the fibres of many hemp-substitutes. The following statement of hemp imported into the United Kingdom must therefore be taken with all necessary reserve :-