A3

or

objections. A very important one is the tendency to the formation of a habit. Another is the difference in susceptibility to its action. Chloral hydrate is a powerful cardiac depressant, and in cases of heart disease or heart weakness from any cause, it should be used with great caution, if at all. A small dose has caused death, although fifty and sixty grains have been given in other cases without harm. (5) Bromides. These are not very powerful hypnotics, but are often used as adjuvants to others. Potassium bromide is the most useful, but sodium bromide, though less active, is not as depressing to the circulation. (6) Monobrated camphor. A feeble hypnotic. (7) Paraldehyde, a polymeric modification of acetic aldehyde. This is an efficient hypnotic, producing sleep, as a rule, in half an hour. regards its nervous effects, it is almost a pure hypnotic, and it causes but slight depression of the heart and respiration. It leaves no after effects except the odor of the breath, which is often very marked. It may cause nausea vomiting if the stomach is very irritable. Like all hypnotics, it sometimes fails. (8) Sulfonal. This is an efficient but slow-acting hypnotic. The dose is given one or two hours before the expected sleeping-time. (9) (10) Trional and Tetronal are similar drugs, with more rapid and powerful action. The three last named may produce poisoning if used for any length of time or in too large doses. (11) Ürethane, ethyl, CH,CO2NH2, has a bitter, disagreeable taste. This is an efficient hypnotic, leaving no disagreeable after effects. In large doses it may cause vomiting, but is otherwise a pure hypnotic. It has no depressing action on the heart or respiration. (12) Amylene hydrate. A colorless fluid with a sharp taste and smell. This is an efficient hypnotic, causing sleep in fifteen to forty-five minutes. The sleep is natural, and there are no bad after effects. It has no depressing effects on the heart or respiration. It has caused in a few cases a delirium resembling that of alcoholic intoxication, but followed by refreshing sleep. (13) Amylene chloral, or dormiol, is similar in action. Most of the drugs named are considered in special articles under their names. HYPNOTISM, or HYPNO'SIS (from Gk. νоs, hypnos, sleep). The general names for a group of abnormal phenomena, physical and psychical, which show a close outward resemblance to the phenomena of normal sleep and of sleep-walking. The symptoms of the hypnotic state differ considerably among different subjects, and the marking off of distinct stages within this state is rather a matter of theory than of actual observation. The artificial sleep is continuous and progressive, beginning with a languor and drowsiness not unlike those of a man suddenly waked from sound sleep, or arousing from a too protracted morning's nap after a disturbed night. As the state advances, the subject becomes partially anesthetic insensitive to pin-pricks, pinching of the skin, etc.; his senseorgans are closed to most of the impressions from his surroundings that would normally excite them; if awakened before the sleep has grown more profound, he remembers hazily what has occurred during hypnosis. He is extremely suggestible at the hands of those who, as he thinks, have induced the sleep, and will execute movements that the experimenter prescribes to him. The voluntary muscular system evinces a curious

rigidity and fixity; the subject will remain in any position in which he is placed. This feature has given the name of 'catalepsy' (seizure) to the stage in question. As the sleep is continued the subject becomes still more anaesthetic, until consciousness seems to lapse altogether; on waking, he has no memory whatsoever of the hypnotic period. The name of 'somnambulism' is given to a stage of profound hypnosis in which illusions are produced at the experimenter's suggestion: the subject takes ink for wine, a pillow for a baby, steps carefully over an imaginary book, etc., etc.

These phenomena of sleep or trance, mixed with much that is simply charlatanry, have been discussed and exploited from time immemorial. The medicine-men of primitive and savage tribes, the magicians of Egypt and Chaldæa, the Hindu ascetics, the monks of Mount Athos, the quack physicians of all ages, have made use of hypnotism to enhance their personal prestige, to cure the sick, or to induce states of religious ecstasy. The modern history of hypnotism begins with F. A. Mesmer (1733-1815), a German physician who practiced hypnotic therapeutics at Paris from 1778, causing so great a stir in scientific circles that his pretensions were made a matter of inquiry by a royal commission (1785). The report of the commission was unfavorable; but mesmerism' still flourished. In England valuable works were published in the early forties by J. Braid, a Manchester surgeon (c. 1795-1860); but their sanity and importance have but recently been fully recognized. Braid coined the word 'neurohypnotism,' or nerve sleep, from which comes the modern word hypnotism. During the last third of the nineteenth century the facts of hypnosis were thoroughly investigated by physiologists and psychologists. Heidenhain and Preyer in Germany, Richet, Charcot, Liébault, and Bernheim in France, Delbœuf in Belgium, confirmed and extended Braid's results. The French investigators split into two distinct 'schools': that of Charcot and his followers at the Paris Hospital of the Salpêtrière, and that of Bernheim and his followers at Nancy. The Salpêtrière school maintains that hypnotism is a pathological phenomenon, akin to hysteria, and characterized by three well-marked stages; the school of Nancy asserts that it can be set up in the normal individual, that it is a unitary and progressive state, and that the key to its understanding is given with the facts of suggestion. The latter views have found general acceptance; but the controversy undoubtedly hindered the advance of knowledge and threw discredit upon the whole subject. It need hardly be said that the doctrines known as animal magnetism, electro-biology, odism or odylism, mesmeric clairvoyance, etc., are one and all-save in so far as they cover the facts of hypnotism proper-fanciful and ungrounded hypotheses.

In considering the psychology of the hypnotic state, we have first to notice that its sole and essential condition is an exaggerated state of passive attention to some object or person. (See ATTENTION.) In popular phraseology there is a 'total surrender of the will' of the subject, either to a sense-impression or to the experimenter's personality. The condition of hypnosis thus lies and this fact is of extreme importance

in the mind of the subject himself; the experimenter or 'operator' has no power, except as

the subject gives him power. The reason that the professional hypnotist and the physician are accredited with a special ability to induce hypnosis is, first, that they 'suggest' to the inquirer -whether consciously, by strongly worded advertisement, or unconsciously, by the mere authority of position-that such ability resides in them; and, secondly, that they acquire, in the course of their experience, a tact or insight concerning the best means of bringing the inquirer into the necessary attentive state. The subject comes to them prepared for hypnotization; and they make conditions easy for its attainment. Further than this the ability of the operator does not extend. It is, indeed, entirely possible to hypnotize one's self. (See AUTOSUGGESTION.) Most of us have, at times, 'let ourselves go' mentally, until we were on the verge of what seemed to be a kind of fascination or trance, at the brink of which we aroused ourselves with a start. If now we place ourselves under circumstances favorable to sleep, cutting off, so far as may be, external impressions, and attend concentratedly to the idea of hypnosis, we presently drop into a similar state of 'fascination' which soon becomes hypnosis proper, and later passes off as ordinary sleep.

We notice, secondly, as a corollary to what has just been said, that all persons of normal constitution are hypnotizable. Hypnosis is abnormal' only in the sense in which dreaming (q.v.) is abnormal; and as we are all liable, though in varying degree, to dreams, so are all normal minds liable to hypnotization. The strong-minded person who declares that So-and-so tried to hypnotize him, but could not on account of his vigorous resistance, makes a ludicrous misstatement. It is not So-and-so who is to hypnotize him, but he himself; and incapacity for hypnosis is not the mark of a strong, but of a weak mind. Hypnosis (and this is a difference between it and dreaming) is impossible in the case of idiots and of very young children, because they are scatter-brained, unable to attend fixedly and continuously; the more 'powerful the will,' the easier must hypnosis be. We see this, indeed, in the tendency of vigorous minds to brown study,' a state nearly related to hypnosis, and characterized by the same singlehearted absorption, and the same arrest of bodily movement. Whether or not animals can be hypnotized is a disputed question. In the emotion of extreme fear (when, if ever, the animal mind must be dominated by one sole idea, and so approach to the requisite degree of passive attention), we have a muscular rigidity, known as 'cataplexy' (cf. the popular word stroke'), which outwardly resembles the stage of catalepsy Seize a frog firmly by a hind leg, and the animal will spread out, stiff and stark, mak ing no effort to escape. Pigeons, fowls, guineapigs, etc., can all be readily hypnotized' by similar means. The trend of expert opinion seems, however, to be that the resemblance to hypnosis is rather external than real.

in man.

We turn now to some special questions of hypnosis, and first (1) to that of the rapport. This is a supposed subjective link or bond whereby the experimenter, in virtue of his willpower or personal magnetism, attaches the subject to himself. Now it is true that there are cases in which a subject can be 'hypnotized' only if a certain operator or experimenter allows or

commands it. But there is nothing mysterious, still less supernormal, in the matter. The subject in some way (perhaps by self-suggestion, perhaps at the explicit suggestion of a physician) acquires the insistent belief that hypnosis is impossible for him without the presence or assent of the experimenter; and the belief, once acquired, is effective. It is thus the subject, again, whose 'will' is concerned, not the operator. The rapport is sometimes suggested by physician to patient, in order to prevent interference by outsiders with the conduct of a case; and thus serves a useful purpose. (2) It may be suggested to a somnambulistic subject that at such and-such a time after waking from the hypnotic sleep he shall perform such-and-such an action. This is termed post-hypnotic or terminal sugges tion. Its effectiveness depends upon the fact that the time idea is common both to the hypnotic and to the waking consciousnesses, and so forms a bridge between the abnormal and the normal states. "You will go into the kitchen and drink a glass of water at five o'clock." The subject is strongly impressed by the five-o'clock idea. When, therefore, five o'clock actually comes, its perception or idea is sufficient to throw him into the first stage of hypnosis; the suggestion recovers its hypnotic strength, and he goes, passively, to execute the prescribed act. (3) Although the somnambulist remembers nothing of the hypnotic state from which he is aroused, he may, if rehypnotized, recall what took place during his previous sleep. Memory is thus continued from one hypnotic consciousness to another, as it is from one waking consciousness to another; but there is no continuity of memory from sleep to waking, or vice versa. This fact has given occasion to various theories of double consciousness (q.v.) quite unnecessarily for it is adequately explained by the known laws of memory. We remember only when we have a cue to memory, when our present circumstances suggest' the past. When eating a good dinner after a long walk we recall other good dinners eaten in like circumstances; we do not recall such dinners when there is nothing to remind us of them. But the waking state, with all the sudden inrush of stimulations that it involves, is entirely different from the hypnotic state; there is nothing in the one (apart from the terminal suggestions just discussed) to remind us of the other: whereas there is everything in a present hypnotic state to revive our memories of foregone like states. Dreams, in the same way, are not seldom continued from night to night, though we forget all about them in the daytime. (4) Lastly, as regards the therapeutic value of hypnosis, we may say that as a 'suggestion,' in the waking life, may make us blush or cry, so may the indefinitely stronger suggestions of the hypnotic state bring about circulatory or secretory changes that are of benefit to the organism. But no command to get well can ever mend a broken bone, or cure a typhoid patient. Moreover, there is always the danger of setting up an hypnotic habit,' or of breaking down the subject's self-reliance; in which event the remedy is worse than the disease.

BIBLIOGRAPHY. For Charcot's standpoint, consult: Binet and Féré, Animal Magnetism (trans. New York, 1888); Janet, L'automatisme psychologique (Paris, 1889); Charcot, Œuvres complètes, vol. ix. (Paris, 1893); for the Nancy

standpoint, Moll, Hypnotism (New York, 1893); Beruheim, Suggestive Therapeutics (trans. New York, 1889); Etudes nouvelles sur l'hypnotisme (Paris, 1891); also in general, James, Principles of Psychology, vol. ii. (New York, 1890); Lehmann, Die Hypnose (Leipzig, 1890); Wundt, Hypnotismus und Suggestion (Leipzig, 1893); Dessoir, Bibliographie (Berlin, 1891); Jastrow, Fact and Fable in Psychology (Boston, 1900).

HYPOBOLE, hi-pob'ô-lē (Gk. vroßoλń, a throwing under, from nó, hypo, under + Báλλew, ballein, to throw). A figure of rhetoric, whereby each of several arguments that appear to favor the side of one's opponent is introduced only to be refuted in order. See RHETORIC, FIGURES OF.

HYPOCAUST (Lat. hypocaustum, hypocaus ton, from Gk. VπÓKаνσTOV, vaulted room with furnace below, from iró, hypo, under + KaVOTÓS, kaustos, burned, from kale, kaiein, to burn).

The name for the subterranean hot-air chamber under the calidarium in Roman bathing establishments. The hot air was generated by a circular furnace which heated the water and gave out streams of hot air into the hypocaust, which

consisted of a hollow double floor of concrete and tiles, between which were the pillar-like suspensura of tiles. The hot air was distributed throughout the building from the hypocaust by series of wall and floor flues, giving an even temperature. The system was invented shortly before Augustus, and was soon adopted not only in public baths, but in private houses. It is now coming again into use for heating the socalled Turkish baths.' It can be studied in all the details of its arrangement in the ruins of

Roman houses and baths. See BATHS.
HY'POCHLOʻRITES.

ACID.

See HYPOCHLOROUS

HYPOCHLOʻROUS ACID, HClO. An acid that may be assumed to be formed when chlorine monoxide (ClO) is dissolved in water. Chlorine monoxide, which decomposes into chlorine and oxygen with explosive violence, may be obtained by the action of dry red oxide of mercury upon chlorine. In aqueous solution, chlorine monoxide is not explosive. The salts of hypochlorous acid are termed hypochlorites, and some of them are valuable bleaching agents. Ordinary bleaching powder is supposed to contain the hypochlorite of calcium; Javelle water contains the hypochlorite of potassium; Labarraque's solution contains the hypochlorite of sodium. Bleachingpowder is made by the action of chlorine on lime; similarly, the hypochlorite of potassium may be obtained by the action of chlorine upon a cold solution of caustic potash. If solutions of hypochlorites are heated, the corresponding chlorides and chlorates are formed. See BLEACHINGPOWDER.

ear,

HYPOCHERIS, hi'po-ke'ris (Neo-Lat., from Gk. voxoipis, succory-plant). A genus of plants of the natural order Compositæ, of which one species, Hypocharis radicata, or long-rooted cat'sis extremely common in meadows and pastures in Great Britain and other parts of Europe. Its leaves, which are all radical, and spread on the ground, resemble in form those of the dandelion, but are rough; the stem is branched, the flowers somewhat similar to those of the dandelion, but smaller. Cattle eat this plant readily,

and its abundance is not deemed injurious to pasture or fodder.

POCHONDRIA (from Lat. hypochondrium, Gk. HYPOCHONDERS, hi'pô-kōn'derz, or HYtilage and above the navel, from Gk. ró, hypo, Vоxóvopov, soft part of the body below the carunder+xóvopos, chondros, cartilage). An old term for the two lateral and superior regions of the abdomen (q.v.) under the cartilages of the false ribs, and to the right and left of the epigastrium.

HYPOCHONDRIA, hí’pô-kõnʼdri-å. See HY.

POCHONDERS; HYPOCHONDRIASIS.

HYPOCHONDRI'ASIS (Neo-Lat., from Lat. hypochondrium, Gk. vπоxóvopov, hypochondriac region; so called because of the supposed connection of the disease with this part of the body). A disease characterized by extreme increase of simulate the greater part of diseases, exaggerated sensibility, palpitations, morbid feelings that uneasiness, and anxiety, chiefly in what concerns the health, etc. In extreme cases it becomes a species of insanity. The disease is very frequently associated with disorder of the digestive

functions.

When sombreness of disposition and anxiety concerning personal comfort become exaggerated, and attention is directed chiefly to the state of the health, it amounts to common hypochondriasis.

When it passes beyond the control of the will, when the whole mind is directed to the state of the system, or to particular organs, and exalts and misinterprets sensations, the condition is designated hypochondriacal insanity. The disease may be described as the engrossment of the attention by false impressions conveyed, or conceived to be conveyed, from internal organs. These sensations may, in many instances, be real, and proceed from actual alterations in the structure or functions of the parts supposed to be affected; but they may likewise consist of ordinary sensations, excited and intensified by the act of attention which makes them known to the patient. Neither the experience nor the sufferings of the victims are imaginary, however absurd their errors, and however groundless their apprehensions may be; the disease is real, and consists in the exaltation of sensibility and attention, and in the delusions which originate in that morbid state. fear of death; he is firmly convinced that he labors under cancer, consumption, disease of the heart, etc. Hypochondriasis is often a precursor of melancholia, or other kinds of alienation; but it must likewise be regarded as a distinct and independent affection, traceable, generally, to disorder of the digestive and assimilative apparatus, to sexual excess or other debilitating influences. Such patients always should be watched, for many of them commit suicide while temporarily under the influence of an hallucination or a delusion. Diversion, camp life, hunting, fishing, and other occupations should engross the patient's attention during an outdoor life, or travel should be his resource, always in the society of a lively, healthy companion. Drugs alone produce little benefit. Consult: Falret, De l'hypochondrie et du suicide (Paris, 1822); Buckmill and Tuke, Psychological Medicine (London, 1879); Mercier, Psychology, Normal and Morbid (London, 1902).

A man lives in constant

HYPOCOTYL (abbreviation of hypocotyledonous, from Gk. vñó, hypo, under + KOTUλndwv, kotyledon, cotyledon, from KоTúŋ, kotyle, socket). In seed-plants, the axis of the embryo below the cotyledons. This axis has been variously called 'radicle' and 'caulicle,' but since it has peculiar powers which do not belong to ordinary root and stem structures, it has received a distinctive name. See EMBRYO.

HYPOCRITE, THE. A play by Isaac Bickerstaffe, produced in 1768, and founded on Cibber's Non-Juror, which, in turn, was taken from the Tartufe of Molière.

HY POCY'CLOID. See CYCLOID.

HY'PODER/MIC MEDICATION (from Gk. ib, hypo, under + dépua derma, skin). Introduction of medicines beneath the skin, with a hypodermic syringe. This method is often preferable to that of giving them by the mouth. The stomach is sometimes in a condition which will not bear the presence of drugs, particularly narcotics, and these are the agents which are most frequently administered hypodermically. A small graduated glass syringe attached to a slender hollow needle, cut off obliquely so that its sharpened extremity may easily be made to pierce the skin, is used. The medicine may be thrown in just beneath the skin, or the point of the syringe is thrust into the body of a muscle. The wounding of blood-vessels or nerves should be carefully avoided, and therefore the operation should not be undertaken except by a physician or a trained nurse. Local pains may generally be more successfully treated in this manner than by the common method. In some cases an anesthetic may, however, be preferable. It is usual to make a special preparation of the drug which is to be introduced. The syringe must be completely filled when used, as the introduction of an airbubble into a vein might be attended with dan ger. All instruments and drugs used should be thoroughly sterilized. The hypodermic syringe should be used with great caution, and never by the patient.

HY PODER'MIS (Neo-Lat., from Gk. Tоdepuis, under-skin, from iró, hypo, under + dépua, derma, skin). In plants, a layer of cells beneath the epidermis. An archesporial cell is said to be hypodermal in origin when it arises immediately beneath the epidermis. Tissues bordering directly upon the epidermis are called hypodermal.

HYPOGYNY, hi-põj'í-ni (from Gk. vñó, hypo, under vrh, gyne, woman). The condition in a flower in which the sepals, petals, and stamens arise from beneath the ovary. As a consequence, the ovary is seen inside of the flower, and is often spoken of as 'superior.' The contrasting term is 'epigyny' (q.v.). Hypogynous flowers are considered to be more primitive in character than epigynous flowers. See FLOWER.

HY'PONASTY (from Gk. vb, hypo, under + ναστός, nastos, close-pressed, from ráooty, nassein, to pack closely). A term applied by De Vries to the occurrence of greater growth upon the under side of a dorsiventral organ, which produces therefore an upward curvature. This may be due to internal or external causes. It is the common condition of young leaves and flower parts when in the bud. The correlative term is epinasty. See GROWTH (in Plants).

Its

HY'PONI'TRITES. See HYPONITROUS ACID. HY'PONITROUS ACID, H2N2O2. An acid which may be obtained in dilute aqueous solution, or in the form of its salts, but which has not been isolated in a concentrated state. salts are termed hyponitrites. It may be obtained by allowing sodium amalgam to act upon barium nitrite, neutralizing the resulting solution with acetic acid, precipitating with silver nitrate, and decomposing with hydrochloric acid the silver hyponitrite thus obtained. hyponitrite, Ag2N,O,, explodes if heated to a moderately high temperature. The solution of free hyponitrous acid decomposes, on heating, into nitrous oxide (laughing gas') and water. HYPOPHOS'PHITES. See HYPOPHOSPHO

ROUS ACID.

Silver

HYPOPHOSPHOROUS ACID, H,PO2. A crystalline compound that melts at about 17.5°C. and is readily transformed into ordinary phosphoric acid. It may be obtained by boiling caustic potash with phosphorus, subsequently adding sulphuric acid, concentrating the solution by evaporation and allowing it to crystallize in the cold. The salts of hypophosphorous acid are termed hypophosphites, those of iron, calcium, sodium, and potassium being extensively used in medicine, and often forming ingredients of patent medicines which are claimed to be valuable remedies for tuberculosis. Most such preparations are worthless, being mixtures of the hypophosphites of two or more metals, the several ingredients of which may counteract one another; and some such mixtures are positively harmful. On the other hand, if prescribed separately, in moderate doses, by a competent physician, the hypophosphites often constitute valuable therapeutic agents, inasmuch as they have the effect of improving nutrition and relieving some of the symptoms of phthisis. The hypophosphite of potassium may be used as an expectorant in chronic bronchitis. The officinal syrup of hypophosphites contains several hypophosphites, a considerable amount of free hypophosphorous acid, and often some iron.

HYPOSTASIS (Neo-Lat., from Gk. bσraois, hypostasis, subsistence, from boтaros, hypostatos, substantial, from voorával, hyphistanai, to stand under, from ó, hypo, under + ioráva histanai, to stand). A term of Greek theology, variously employed before the fourth century, but at last technically used to denote personal distinctions in the Godhead. The Council of Nicæa (325) did not clearly distinguish between hypostasis and ousia (substance and essence), and a controversy followed. (See HOMOOUSION.) The same uncertainty appears in the West as late as Augustine, who confesses that he does not understand the difference between the two Greek words (De Trinitate, v. 8, 10). But gradually the two words were differentiated, and hypostasis came to be used exclusively for the personality of Father, Son, or Holy Spirit. It was thus interpreted as being equivalent to prosopon, which the Latin rendered by persona, whence our word 'person.' The fully developed trinitarian dogma asserts one essence, or substance (ousia), and three persons (hypostasis) in the Godhead. This has remained the orthodox faith of the Church. Consult: the Histories of Doctrine, by Harnack, vol. iv. (London, 1898);