Page:Encyclopædia Britannica, Ninth Edition, v. 11.djvu/681

Rh many-rayed umbels of small white flowers, the general in volucres consisting of several, the partial ones of about three short lanceolate bracts, the latter being usually turned towards the outside of the umbel. The flowers are succeeded by broadly ovate fruits, the mericarps (half-fruits) having five ribs which, when mature, are waved or cre- nated; there are no vittce or oil-cysts; and when cut across the albumen is seen to be deeply furrowed on the inner face, so as to exhibit in section a reniform outline. The fruits when triturated with a solution of caustic potash evolve a most unpleasant odour. Hemlock is a virulent poison, but it varies much in potency according to the conditions under which it has grown, and the season or stage of growth at which it is gathere 1. In the first year the leaves have little power, nor in the second are their properties developed until the flowering period, at which time, or later on when the fruits are fully grown, the plant should be gathered. The wild plant growing in exposed situations is to be preferred to garden-grown samples, and is more potent in dry warm summers than in those which are dull and moist. The poisonous property of hemlock resides chiefly in th alkaloid conine or conia which is found in both the fruits an I the leaves, though in exceedingly small proportions in the latter. Conine ressmbles nicotine in its deleterious action, but is much less powerful. No chemical antidote for it is known. The plant also yields a second less poisonous crystallizable base called conhydrine, which may bs converted into conine by the abstraction of the elements of water When collected for medicinal purposes, for which both leaves and fruits are used, the former should be gathered at the tirm the plant is in full blossom, while the latter are said to possess the greatest degree of energy just before they ripan. The fruits are the chief source whence conine is pre pared. The principal forms in which hemlock is employed are the extract and juice of hemlock, hemlock poultice, anl the tincture of hemlock fruits. Large doses produce vertigo, nausea, and paralysis ; but in smaller quantities, administered by skilful hands, it has a sedative action on the nerves. It has also some reputation as an alterative and resolvent, and as an anodyne. The acri.1 narcotic properties of the plant render it of soni3 importanco that one should be able to identify it, the more so as some of the compound-leaved umbellifers, which have a general similarity of appearance to it, form wholesome food for man and animals. Not only is this knowledge desirable to prevent the poisonous plant being detriment illy used in place of the wholesome one; it is equally important in the opposite case, namely, to prevent the inert being substituted for the remedial agent. The plant with which hemlock is most likely to be confounded is the Anthriscus sylvestris, or cow-parsley, the leaves of which are freely eaten by cattle and rabbits ; this plant, like the hemlock, has spotted stems but they are hairy, not hair less ; it has much-divided leaves of the same general form, but they are downy and aromatic, not smooth and nauseous when bruised; the fruit of the Anthriscus, besides, is linear- oblong and not ovate.  HEMP, Cannabis sativa, an annual herb, having angular rough stems and alternate lobed leaves. The bast fibres of Cannabis are the hemp of commerce, but under the name of hsmp fibrous products from many different plants are often included. Sunn hemp is the bast fibre of a papilio naceous plant, Crotolaria juncea, of India and the Sunda Islands ; Hibiscus cannabinus, an Indian malvaceous plant, yields brown or Bombay hemp ; Jute or Paut hemp is pro duced by Corchorus capsularis and C. olitorius, and to some extent by G. fusciis, C. jascicularis, and C. decem- anyidatus. Manila hemp or feather fibre is derived from the fibro-vascular bundles of certain monocotyledons, namely, several species of Musa, chiefly from M. textilis, but to some extent from M. sapientum, M, ensete, M, minda- nensis, and M. Cavendishii, 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, Cannabinacece, is dioecious, 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, sativa, var. gi&amp;lt;jantea)las 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 sativa, the C. indica, Lam., and G. chinensis, Delile, owing their differences to climate, and losing many of their peculiarities when cultivated in temperate regions. Rumphius (in the ) 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 south ward 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 vigor ously as far up as 6000 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. Herodotus (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 ) records the use of hempen ropes for rigging the ship &quot;Syracusia&quot; 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. 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, 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 