Hemp , the common name of the plant cannabis sativa, of the order cannabineoe, which is by some botanists included in the nettle family (urticaceoe) as a suborder. The same name is applied to the fibre of the inner bark, which is largely used in the manufacture of cordage. It is also used for the fibres of plants of widely different genera; for the most important of these, see Manila, Jute, and Ramie. The true hemp is an annual plant, probably a native of India, which has been in cultivation from very early times; it grows from 4 to 12 ft. high, with a branching, angular, rough stem; the lower leaves are opposite, the upper alternate, and all digitately divided, with five or more coarsely toothed leaflets; the flowers are dioecious, and without petals; the staminate flowers in drooping panicles, each with five sepals and stamens, the pistillate clustered in erect spikes, each consisting of an ovary with two styles embraced by a calyx of one sepal. Hemp is a plant influenced in a remarkable degree by climate, soil, and other conditions; in India it produces a resinous exudation of a marked character (to be presently mentioned), which is entirely wanting in the plant grown in northern climates, and there is a great difference in the hemp produced upon the plains and the mountainous regions in the same latitude; when the plant is so grown that seeds may be developed, the fibre is nearly worthless.

In many countries hemp is an important agricultural product. The principal hemp-producing countries are Russia, Italy, Holland, Turkey, Great Britain, the East Indies, and the United States. St. Petersburg exports this product largely, receiving it from various parts of Russia. Special attention is given to its storage and shipment, and great care is taken to prevent the bundles from becoming damp, in which condition the hemp would be liable to ferment as in the rotting process. The best Russian hemp is said to be that of Riga, which is brought down the Duna. That known as " Italian garden hemp," the fibre of which is obtained from plants raised by spade culture, is of unusual fineness and length, and superior to all other kinds. English hemp is chiefly woven into coarse sheeting and shirting for laboring men, and into the cloth called huckaback, of which coarse towels and table cloths are made. The material improves in whiteness as it is worn, and the finer varieties of it much resemble Irish linens. - Attempts were made at a very early period to cultivate both flax and hemp in the Plymouth colony, the seeds being ordered there in 1G29. In Virginia hemp was raised and spun by Capt. Matthews previous to 1648. In 1651 its culture was encouraged by bounties offered by the government, as was that of flax in 1G57. But the greater profit derived from tobacco has always operated against the culture of hemp.

In Pennsylvania also the bounties offered by the government of the colony in 1730 failed to render this an important crop. Its culture has proved most successful in Ohio, Kentucky, and Indiana, and more recently in Missouri. It has also prospered to considerable extent in the other northern, and in the northeastern states. In the northern part of New York the crop is valued chiefly for the seed, of which from 20 to more than 40 bushels are obtained to the acre. But little American hemp has ever been exported. The product to the acre is from 700 to 1,000 lbs. According to the census of 1870, the total production of the United States was 12,-746 tons, of which Kentucky produced 7,777, Missouri 2,816, and Tennessee 1,033 tons. - The soil best suited to hemp is a rich alluvial loam, but it will thrive in a moderately tenacious one if it is well pulverized. It is usually sown broadcast as early as possible without the risk of exposing the young plants to late frosts; four to six pecks are sown to the acre, but if sown in drills less is required. As the plants soon completely shade the ground, no after cultivation is required. It is customary to sow at intervals, that the harvesting may not all come at once.

The crop is ready to harvest when the blossoms turn yellow and the leaves begin to drop; formerly the plants were pulled, but now they are cut by means of a heavy cradle, or where they are tall and heavy by means of a sickle or hook something like a brush scythe. The stalks are made to fall evenly, and at the end of three days they are bound into sheaves and put up in stacks or large ricks, so capped as to prevent rain from penetrating. To separate the fibre, the hemp is dew-rotted or water-rotted. In the former process the hemp is spread upon the ground in October or a month or two later, according to the climate; when the lint readily separates upon breaking a stalk, the process, which requires about two months, is completed; if hemp were exposed in this manner in warmer weather, there would be danger of injuring the fibre. In water-rotting the hemp is immersed in water for ten days or more, according to the season; this is done in streams, in artificial pools made near the margin of a river, or in large wooden vats under cover; the last mentioned method gives the brightest and best fibre; when rotted in vats, the hemp is subjected to a partial breaking which lessens its bulk.

After the hemp is rotted and dried it is taken to the break, which is either a rude affair worked by hand like a flax break, or an improved machine operated by steam or other power; 100 lbs. is an ordinary day's work with the hand break. After breaking, the hemp is twisted into bundles and baled for market. - When hemp is raised for the seed, the cultivation is quite different from that when raised for the fibre. A richer soil is selected, and prepared as for a crop of corn; hills are marked off about 3 1/2 ft. apart each way, and a dozen or more seeds put in each and lightly covered; the ground is from the beginning kept clear of weeds by use of the cultivator and hoes; when well up the plants are thinned to seven or eight in each hill, and when a foot or more high they are again thinned to leave but four to a hill; subsequently the plants in the hill are reduced to three. As soon as the plants have sufficiently developed to allow the male or staminate ones to be distinguished, these are so far removed as to leave but one to every four hills, and after these have shed their pollen they are cut away.

When ripe the seeds are threshed out, and if intended for sowing are kept spread in a thin layer until cold weather to prevent them from heating, which on account of their oily nature they are apt to do. The Russians and Poles roast the seeds and eat them upon bread as a condiment; they are used as food for cage birds, and are said to greatly improve the brilliancy of their plumage, and in the case of the bullfinch and some others to cause it to turn black. Hemp seeds upon expression furnish about 25 per cent. of hempseed oil, the commercial supply of which comes principally from Russia; it is a drying oil, greenish yellow at first, turning yellow, with an acrid odor but a mild taste; it is very soluble in boiling alcohol, but requires 30 parts of cold alcohol for its solution; it solidifies at 17° F. It is used in preparing soap, in mixing paint, for making varnish, and for burning, but on account of its drying tendency it is apt to form a viscid varnish upon the wick. - Indian Hemp. The hemp produced in India and other eastern countries is covered with an adhesive resinous exudation, which under favorable circumstances is so abundant.as to come off and adhere to the hands if the plant be handled.

For a long time it was supposed that this was a different species from the common hemp, and the name cannabis Indica was given to it; but Royle and other eastern botanists were unable to find any difference between it and the European plant; and from this and the fact that hemp grown in some portions of India is almost without this resin, botanists now regard the Indian hemp as only a form of the common, though as a matter of convenience the term C. Indica is retained in the pharmacopoeias. The stimulant and narcotic properties of Indian hemp have been known from early times; it is known in India by various names expressive of these qualities, such as "causer of the reeling gait," "laughter mover," etc.; and Royle ("Materia Medica") suggests that it is as likely as any other plant to have been the nepenthe, the "assuager of grief," of the ancients. The plant and its preparations are found in the eastern bazaars in several forms, some of which are imported. Gunjah is the dried plant, collected after flowering, and consists of the stems, leaves, and petioles pressed together; it is also called guazah. Bang, also subjee or sidhee, consists of the larger leaves and seed vessels without the stalks.

Hashish is the tops and the tender parts of the plant gathered after flowering; this name is also applied to some preparations of the plant. Churrus is the resinous exudation collected by men clad in leather, who go through the fields and beat the hemp violently; the resinous matter adheres to the leather, and is afterward scraped off. A finer kind, collected by pressing the plant in the hands and removing the adhering resin, is known as the Momeca or waxen churrus; this is the most highly prized and costly variety. Extract of hemp is prepared by boiling the adhesive tops in alcohol, which is afterward distilled off, leaving a resinous extract which has a somewhat fragrant odor, and a warm, bitterish, acrid taste; this extract is imported, as also is gunjah. An electuary, made of the resin with musk, essence of roses, and other aromatics, and an oleaginous extract made with butter or oil, are among the forms in which different eastern nations prepare the hemp for intoxicating purposes. The effect of Indian hemp upon different persons is as various as that of alcohol; with some it simply produces stupor, while others experience a mental ecstasy and see the most pleasurable visions. The habitual use of the drug is accompanied by both physical and mental imbecility.

The effects of hashish have been frequently described by those who have experienced them. (See Assassins.) Indian hemp has long been used medicinally; a Chinese surgeon is said to have employed it as an anaesthetic as long ago as A. D. 220, and to have operated upon patients while they were under its influence. It is employed as an anodyne and narcotic, and to affect the mental functions; it is considered safer than opium, belladonna, and similar remedies, and it does not check the secretions or impair the digestion; its action seems to be exerted chiefly upon the cerebrum, producing but little effect upon the functions even of the other portions of the nervous system. It is given in the form of the extract, in doses of a quarter of a grain to several grains, or in tincture from 10 to 15 drops. - This name is also applied to an American fibrous and medicinal plant, apocynum cannabinum. (See Indian Hemp.) - Sisal Hemp is the fibre of the leaves of agave Sisalana, a large species of Yucatan, closely related to the American aloe or century plant. (See Agave.) Under the name of Sisal hemp or jenequen are included the fibres of probably several species of agave and one or more of Fourcroya, the name referring to the product rather than the plants which yield it.

An attempt to give the native names of several of the fibre-producing plants of Yucatan may be found in the report of the United States department of agriculture for 1869, but it gives little botanical light upon the subject. Fibres of different agaves and related plants were in use by the Indians long before the Spaniards planted colonies on this continent, and the Spanish Americans have since been content with the rude methods by which the aborigines extracted the fibre, which was simply to lay the large fleshy leaves upon a flat stone and beat them with a billet of wood or rude mallet, and afterward to scrape away the pulp and bruised thick epidermis with a blunt knife. After numerous failures, Americans have contrived machines to separate the fibre successfully and rapidly. A. Sisalana, which is propagated readily from suckers, has been introduced into Florida, and become naturalized in the southern portion of the state. Sisal hemp is used for coarse bagging and for cordage. - Pita is another name applied indefinitely to fibres; in Mexico it is the fibre of agave Americana, while in Central America it is that of some Bromelia. Istle or ixtle is another term for the bromelia fibre. - Sunn Hemp, also called Bengal and Bombay hemp, is the fibre of crotalaria juncea, an annual leguminous plant, 8 to 12 ft. high, with silvery-hairy leaves and bright yellow flowers.

The i fibre is extracted by beating and washing the stems after they have been steeped in water for a few days. It is employed for all the purposes of ordinary hemp, to which it is considered equal if not superior.

Staminate and Pistillate Flowers of Hemp.

Staminate and Pistillate Flowers of Hemp.

Sunn Hemp (Crotalaria juncea).

Sunn Hemp (Crotalaria juncea).