The best known and most important order of insectivorous plants—Droseraceae—includes six genera: Byblis, Roridula, Drosera, Drosophyllum, Aldrovanda and Dionaea, of which the last three are monotypic, i.e. include only one species. The Sarraceniaceae contain the genera Sarracenia, Darlingtonia, Heliamphora, while the true pitcher plants or Nepenthaceae consist of the single large genus Nepenthes. These three orders are closely allied and form the series Sarraceniales of the free-petalled section (Choripetalae) of Dicotyledons. The curious pitcher-plant, Cephalotus follicularis, comprises a separate natural order Cephalotaceae, closely allied to the Saxifragaceae. Finally the genera Pinguicula, Utricularia, Genlisea and Polypompholix belong to the gamopetalous order Lentibulariaceae.
While the large genus Drosera has an all but world-wide distribution, its congeners are restricted to well-defined and usually comparatively small areas. Thus Drosophyllum occurs only in Portugal and Morocco, Byblis in tropical Australia, and, although Aldrovanda is found in Queensland, in Bengal and in Europe, a wide distribution explained by its aquatic habit, Dionaea is restricted to a few localities in North and South Carolina. Cephalotus occurs only near Albany in Western Australia, Heliamphora on the Roraima Mountains in Venezuela, Darlingtonia on the Sierra Nevada of California, and these three genera too are as yet monotypic; of Sarracenia, however, there are seven known species scattered over the eastern states of North America. The forty species of Nepenthes are mostly natives of the hotter parts of the Indian Archipelago, but a few range into Ceylon, Bengal, Cochin China, and some even occur in tropical Australia on the one hand, and in the Seychelles and Madagascar on the other. Pinguicula is abundant in the north temperate zone, and ranges down the Andes as far as Patagonia; the 250 species of Utricularia are mostly aquatic, and some are found in all save polar regions; their unimportant congeners, Genlisea and Polypompholix, occur in tropical America and south-western Australia respectively. It is remarkable that all the insectivorous plants agree in inhabiting damp heaths, bogs, marshes and similar situations where water is abundant, but where they are not brought into contact with the plenteous supply of inorganic nitrogenous food as are the roots of terrestrial plants.
INSEIN, a town of British India, in the Hanthawaddy district of Burma, 10 m. N.W. of Rangoon; pop. (1901) 5350. It is an important railway centre, containing the principal workshops of the Burma railway company, also a government engineering school, a reformatory school and the largest gaol in the province.
INSOMNIA, or deprivation of sleep (Lat. somnus), a common and troublesome feature of most illnesses, both acute and chronic. It may be due to pain, fever or cerebral excitement, as in delirium tremens, or to organic changes in the brain. The treatment, when failure to sleep occurs in connexion with a definite illness, is part of the treatment of that illness. But there is a form of sleeplessness not occurring during illness to which the term “insomnia” is commonly and conveniently applied. It must not be confounded with occasional wakefulness caused by some minor discomfort, such as indigestion, nor with the “bad nights” of the valetudinarian. Real insomnia consists in the prolonged inability to obtain sleep sufficient in quantity and quality for the maintenance of health. It is a condition of modern urban life, and may be regarded as a malady in itself. It is a potent factor in causing those nervous breakdowns ascribed to “overwork.” It may occur as a sequel to some exhausting illness, notably influenza, which affects the nervous system long after convalescence. But it very often occurs without any such cause. Professional and business men are the most frequent sufferers. Insomnia is comparatively rare among the poor, who do little or no brain work. It may be brought on by some exceptional strain, by long-continued worry, or by sheer overwork. The broad pathology is simple enough. It has been demonstrated by exact observations that in sleep the blood leaves the brain automatically. The function is rhythmical, like all the vital functions, and the mechanism by which it is carried out is no doubt the vaso-motor system, which controls the contraction and dilation of the blood-vessels. In sleep the vessels in the brain automatically contract, but when the brain is working actively a plentiful supply of blood is required, and the vessels are dilated. If the activity is carried to great excess the vessels become engorged, the mechanism does not act and sleep is banished. In insomnia this condition has become fixed.
When a breakdown has happened or is pending the only treatment is complete rest, combined, if possible, with change of air and scene; but if the mischief has gone far it will take very long to repair, and may never be repaired at all. In no matter of health is the importance of “taking it early” more pronounced. Delay is the worst economy. A few days’ holiday at the commencement of trouble may save months or years of enforced idleness. Sea-air sometimes acts like a charm. But if it is impossible to give up work and leave worry behind, even for a short time, sleep should be carefully wooed by every possible means. In the first place, plenty of time should be devoted to it, and no chance should be missed. That is to say, the night should not be curtailed at either end, and if sleepiness approaches in the daytime, as it often does, it should be encouraged. It is better to lie still at night and try to sleep than to give way to restlessness, and a few minutes snatched in the daytime, when somnolence offers the opportunity, has a restorative effect out of all proportion to the time occupied. Then all accidental causes of disturbance should be avoided. Lights and sounds should be excluded, comfort studied and digestion attended to. Fresh air is a great help. As much time should be spent out of doors as possible, and exercise, even to the point of fatigue, may be found helpful. But this requires watching: in some cases bodily exhaustion aggravates the malady. A little food (e.g. a glass of hot milk) immediately before going to bed is useful in inducing sleep, and persons who are apt to wake in the night and lie awake for hours may obtain relief by the same means. Hypnotic drugs, which have greatly multiplied of late years, should only be taken under medical advice. The real end to aim at is the restoration of the natural function, and the substitution of artificial sleep, which differs in character and effect; tends rather to prevent than to promote that end. It is often possible to induce sleep by rhythmic breathing.
INSPIRATION (Lat. inspirare, breathe upon or into), strictly the act of drawing physical breath into the lungs as opposed to “expiration.” Metaphorically the term is used generally of analogous mental phenomena; thus we speak of a sudden spontaneous idea as an “inspiration.” The term is specially used in theology for the condition of being directly under divine influence, as the equivalent of the Greek θεοπνευστία (the adjective θεόπνευστος is used of the Holy Scriptures in 2 Timothy iii. 16). Similar in meaning is ἐνθουσιασμός, enthusiasm (from ἐνθουσιάζω from ἔνθεος). Possession by the divine spirit (πνεῦμα) was regarded as necessarily accompanied by intense stimulation of the emotions. The possibility of a human being becoming the habitation and organ of a divinity is generally assumed in the lower religions. In the popular religion of China some of the priests, the Wu, claim to be able to take up into their body a god or a spirit, and thereby to give oracles. In wild frenzy they rush about half naked with hair hanging loose, wounding themselves with swords, knives, daggers, and uttering all kinds of sounds, which are then interpreted by people who claim to be able to understand such divine speech. The Maoris at the initiation of the young men into the tribal mysteries sing a song, called “breath,” to the mystic wind by which they believe their god makes his presence known. An Australian woman claimed to have heard the descent of the god as a rushing wind. In some savage tribes blood is drunk to induce the frenzy of inspiration; music and dancing are widely employed for the same purpose. Dionysus, the god of wine in Greece, was also the god of inspiration; and in their orgies the worshippers believed themselves to enter into real union with the deity. In Delphi the Pythia, the priestess who delivered the oracles, was intoxicated by the vapour which rose from a well, through a small hole in the ground. As the oracles were often enigmatic, they were interpreted by a prophet. In Rome the inspiration of Numa was derived from the nymph Egeria; and great value was attached to the books of the Cumaean Sibyl. In Arabia the kahin (priest) was recognized as the channel of divine communication. Inspiration may mean only possession by the deity, or it may mean further that the person so possessed becomes the channel through which the deity reveals his word and will. (See J. A. Macculloch’s Comparative Theology, chap. xv., 1902).
Prophecy in the Old Testament in its beginnings is similar to the phenomenon in other religions. Saul and his servant came to Samuel, the man of God, the seer, with a gift in their hands to inquire their way (1 Sam. ix. 8). The companies of prophets who went about the country in Samuel’s time were enthusiasts for Yahweh and for Israel. When Saul found himself among them he was possessed by the same spirit (1 Sam. x. 10, 11.). The prophesying in which he took part probably included violent movements of the body, inarticulate cries, a state of ecstasy or even frenzy. The phrase “holy spirit” in Acts, as applied to the Apostolic Church, probably indicates a similar state of religious exaltation; it was accompanied by speaking with tongues, inarticulate utterances, which needed interpretation (1 Corinthians xiv. 27). In every religious revival, when the emotions are deeply stirred, similar phenomena are met with. Such a movement was Montanism in the 3rd century. At the Reformation, while Luther was at the Wartburg, fanaticism broke out, and spread from Wittenberg; prophets went about declaring the revelations which they had received. The Evangelical Revival in the 18th century also had its abnormal religious features. The Revival in Scotland in 1860 was marked by one curious feature—the Gospel dance—when in their excitement men and women got up and spun round and round till they were exhausted. Spontaneous praise and prayer marked the revival in Wales in 1905-1906.