sense, and sometimes in a contrary one; so that, if it be supposed, for example, that the hair is heated about the hygrometer, on one part, this air, whose dissolving faculty, with regard to the water, will be augmented, will take away from the hair a portion of the water which it had imbibed, thus tending to shorten the hair; while, on the other part, the heat, by penetrating it, will tend, though much more feebly, to lengthen it; and hence the total effect will be found to consist of two partial and contrary effects, the one hygrometric, the other pyrometric. In observations which require a certain precision, it is therefore necessary to consult the thermometer at the same time with the hygrometer; and on this account, the inventor has constructed, from observation, a table of correction, which will put it in the power of philosophers always to ascertain the degree of humidity of the air, from the effect produced by the heat.

De Luc, who devoted his attention to the same object, has followed a different method. This philosopher employed for the construction of his hygrometers a very thin slip of whale-bone, which performs the same office as the hair in the hygrometer of Saussure. He kept this whale-bone bent by means of a spring, the action of which he preferred to that of a weight: he deter mined the degree of extreme humidity, by immersing the slip of whalebone entirely under water; and to fix the opposite limit, which is that of extreme dryness, he made use of calcined lime, which he enclosed with the hygrometer under a glass bell. The choice of lime is founded on this, that the calcination having produced a higher degree of dryness, if it be afterwards left to cool, so far that it may be placed without inconvenience under the glass bell destined for the experiment, it will be still found, as to sense, in the same state of dryness, since it is very slow in acquiring humidity; and thus all its absorbent faculty will be employed to dry up, by little and little, the air contained under the receiver, and to make the hygrometer itself pass to a state which approaches the nearest possible to extreme dryness.

Another hygrometer was suggested by the following circumstance: While M. Lowitz was at Dmitriewsk, in Astracan, he found, on the banks of the Wolga, a thin bluish kind of slate, which attracted moisture remarkably soon, but again suffered it as soon to escape. A plate of this slate weighed, when brought to a red heat, 175 grains, and, when saturated with water, 217: it had therefore imbibed, between complete dryness and the point of complete moisture, 72 grains of water. Lowitz suspended a round thin plate of this slate at the end of a very delicate balance, fastened within a wooden frame, and suspended at the other arm a chain of silver wire, the end of which was made fast to a sliding nut

that moved up and down in a small groove on the edge of one side of the frame. He determined, by trial, the position of the nut when the balance was in equilibrio, and when it had ten degrees of over-weight, and divided the space between these two points into ten equal parts, adding such a number more of these parts as might be necessary. When the stone was suspended from the one arm of the balance, and at the other a weight equal to 175 grains, or the weight of the stone when perfectly dry, the nut in the groove showed the excess of weight in grains when it and the chain were so adjusted that the balance stood in equilibrio. A particu lar apparatus, on the same principles as a vernier, applied to the nut, showed the excess of weight to ten parts of a grain. Lowitz remarked that this hygrometer in continued wet weather gave a moisture of more than 55 grains, and in a continued heat of 113 degrees of Fahrenheit only 1 degree of moisture.

The hygrometer thus invented by Lowitz was, however, attended with this fault, that it never threw off the moisture in the same degree as the atmosphere became drier. It was also sometimes very deceitful, and announced moisture when it ought to have indicated that dryness had again begun to take place in the atmosphere. To avoid these inconveniences, M. Hochheimer proposes the following method.

2.

1. Take a square har of steel, about two lines in thickness, and from ten to twelve inches in length, and form it into a kind of balance, one arm of which ends in a screw. On this screw let there be screwed a leaden bullet of a proper weight, instead of the common weights that are suspended. Take a glass plate about ten inches long, and seven inches in breadth, destroy its polish on both sides, free it from all moist ure by rubbing it over with warm ashes, suspend it at the other end of the balance, and bring the balance into equilibrium by screwing up or down the leaden bullet. 3. Mark now the place to which the leaden bullet is brought by the screw, as accurately as possible, for the point of the greatest dryness. 4. Then take away the glass plate from the balance, dip it completely in water, give it a shake, that the drops may run off from it, and wipe them carefully from the edge. 5. Apply the glass plate thus moistened again to the balance, and bring the latter into equilibrium by screwing the leaden bullet. Mark then the place at which the bullet stands as the highest degree of moisture. 6. This apparatus is to be sus pended in a small box of well-dried wood, sufficiently large to suffer the glass-plate to move up and down. An opening must be made in the lid, exactly of such a size as to allow the tongue of the balance to move freely. Parallel to the tongue apply a gra duated circle, divided into a number of degrees at pleasure, from the highest point

of dryness to the highest degree of moisture. The box must be pierced with small boles on all the four sides, to give a free passage to the air; and to prevent moisture from penetrating into the wood by rain, when it may be requisite to expose it at a window, it must either be lackered or paint ed. To save it at all times from rain, it may be covered, however, with a sort of roof fitted to it in the most convenient manner. But all these external appendages may be improved or altered as may be found

necessary.

In Mr. Kater's Hygrometer, the hygroscopic substance is the beard of the grass known in the Canarese language, by the name of Oobeena Hooloo, being the Andropogon contortum of Linnæus. It is found throughout the Mysoor country in the month of January; which is the proper time to gather it, that it may be dried for use. The frame of the instrument is rectangular, and is constituted of small square bars of brass or silver; perpendicularly to this frame and at one end of it a square plate is soldered, having a projecting edge to secure from injury the index that is to turn upon it: on the face of the plate a circle is engraved, whose circumference is divided into one hundred equal parts. The index, which is made of fine wire, and balanced as nicely as possible, is attached to one extremity of an axis of silver wire, which has liberty not only to turn, but to slide freely in the direction of its length through double conical holes in two of the cross bars of the frame. This axis is extended to about half the length of the frame; and has a screw of fourteen or fifteen threads upon it, formed by twist ing tightly round it a smaller silver wire from left to right: the index is fixed at right angles to the commencement of this screw; and a loop and drop made of fine gold wire is so formed that, when suspended from the axis, it may slide along the screw with perfect freedom, and by the number of threads its runs over, indicate the number of complete revolutions of the index. The end of the axis farthest from the index is conical (enlarging outwards), and has a notch in it to receive one end of the beard of the Oobeena Hooloo, which may be confined there by the pressure of a sliding ring. The other end of the beard is fastened by means of a similar slit and ring at the further extremity of the frame; this part of the apparatus being susceptible of adjustment by a screw.

By this contrivance the gradual expansion or contraction of the hygrometric substance will communicate a rotatory motion to the index, in such manner that while the graduated circle shows the divisions under a hundred, the loop and drop will indicate with equal precision the number of com plete revolutions of hundreds on the scale. Thus, at the same time that the grass is superior to any other substance hitherto discovered for hygrometric purposes, the in

strument makes eleven or twelve revolutions ; whereas Saussure's makes little more than one revolution.

Mr. Kater recommends that all observations made with this hygrometer be reduced to what they would have been had the scale consisted of one thousand parts, or ten revolutions of the index: a circumstance which cannot always be insured by the construction of the instrument, and the determination of the extremes of dryness and moisture, The whole apparatus may be made and fixed in a portable case of three inches long. It is almost unnecessary to remark, that Mr. Kater's apparatus, which is remarkably simple, will serve full as well for many other hygrometric substances, as for the Ŏobeena Hooloo.

HYGROSCOPE. See HYGROMETER.

HYLA, in ancient geography, a river of Mysia Minor, in which Hylas, the famous boy of Hercules, was drowned.

HYLÆUS. In zoology, a tribe of the genus Apis, in the entomologic system of Fabricius. See APIS.

HYLEG, in astrology, the significator. HYLOZOISTS, formed of in matter, and

life, the name of a sect of atheists among the ancient Greek philosophers, who held matter to be animated; maintaining that matter had some natural perception, without animal sensation, or reflection in itself considered; but that this imperfect life occasioned that organization whence sensation and reflection afterwards arose. Of these, some held only one life, which they called a plastic nature, presiding regu larly and invariably over the whole corporeal universe, which they represented as a kind of large plant or vegetable: these were called the cosmoplastic and stoical atheists, because the stoics held such a nature, though many of them supposed it to be the instrument of the Deity. Others thought that every particle of matter was endued with life, and made the mundane system to depend upon a certain mixture of chance and plastic or orderly nature united together.

HY'MEN (Hymen, enis, m. vμny, from Hymen, the god of marriage, because this membrane is supposed to be entire before marriage or copulation). The hymen is a thin membrane of a semilunar or circular form, placed at the entrance of the vagina, which it partly closes. It has a very diffe rent appearance in different women, but it is generally, though not always, found in virgins, and is very properly esteemed the test of virginity, being commonly ruptured in the first act of coition; and the remnants of the hymen are called the carunculæ myrtiformes. The hymen is also peculiar to the human species.

There are two circumstances relating to the hymen which require medical assistance. It is sometimes of such a strong ligamentous texture that it cannot be ruptured, and prevents the connexion between the sexes. It is also sometimes im

perforate, wholly closing the entrance into the vagina, and preventing any discharge from the uterus; but both these cases are extremely rare. If the hymen be of an unnaturally firm texture, but perforate, though perhaps with a very small opening, the inconveniences thence arising will not be discovered before the time of marriage, when they may be removed by a crucial incision made through it, taking care not to injure the adjoining parts.

But the imperforation of the hymen will produce its inconveniences when the person begins to menstruate. For the menstruous

man

:

blood, being secreted from the uterus at each period, and not evacuated, the patient suffers much pain from the distention of the parts, many strange symptoms and appearances are occasioned, and suspicions injurious to her reputation are often entertained. In a case of this kind, for which Dr. Denwas consulted, the young woman, who was twenty-two years of age, having many uterine complaints, with the abdomen enlarged, was suspected to be pregnant, though she persevered in asserting the contrary, and had never menstruated. When she was prevailed upon to submit to an examination, the circumscribed tumour of the uterus was found to reach as high as the navel, and the external parts were stretched by a round soft substance at the entrance of the vagina, in such a manner as to resemble that appearance which they have when the head of a child is passing through them but there was no entrance into the vagina. On the following morning an incision was carefully made through the hymen, which had a fleshy appearance, and was thickened in proportion to its distention. Not less than four pounds of blood, of the colour and consistence of tar, were discharged; and the tumefaction of the abdomen was immediately removed. Several stellated incisions were afterwards made through the divided edges, which is a very necessary part of the opera tion; and care was taken to prevent a union of the hymen till the next period of menstruation, after which she suffered no inconvenience. The blood discharged was not putrid or coagulated, and seemed to have undergone no other change, after its secretion, but what was occasioned by the absorption of its more fluid parts. Some caution is required when the hymen is closed in those who are of advanced age, unless the membrane be distended by the confined menses; as the above writer once saw an instance of inflammation of the peritoneum being immediately produced after the operation, of which the patient died, as in the true puerperal fever, and no other reason could be assigned for the disease.

re

The carunculæ myrtiformes, by their clongation and enlargement, sometimes become very painful and troublesome.

HYMEN EUS and HYMEN, the god of marriage among the Greeks, was son of Bac

chus and Venus, or, of Apollo and one of the muses. The people of Athens instituted festivals in his honour, and solemnly invoked him at their nuptials, as the Latins had their Thalassius. Hymen was generally represented. as crowned with flowers, holding a burning torch in one hand, and in the other a vest of a purple colour. It was supposed that he always attended at nuptials; for, if not, matrimonial connexions were fatal, and ended in the most dreadful calamities, and hence people ran about, and called aloud, Hymen!. Hymen! &c.

HYMENÆ. Locust-tree. In botany, a genus of the class decandria, order monogynia. Calyx five parted; petals five, nearly equal; style twisted upwards; legume filled with farinaceous pulp. Three species, two natives of South America, one of Mada. gascar. Of these, H. Carbaril, an American tree, sixty feet high, and three in diameter, is the most worthy of notice. The leaflets are coriaceous, leaves stiff and smooth, standing in pairs, with peduncled flowers in panicles. The larger roots secrete a yellowish red, transparent gum, which is the gum anime of the shops, and affords an excellent varnish when dissolved in rectified spirits. See ANIME GUM.

HYMENE/AL. Į s. (úμivaios.) A marriage HYMENEAN. song (Pope).

HYMENE AL. a. Pertaining to marriage HYMENEAN. S (Pope). HYMENOPAPPUS. In botany, a genus of the class syngenesia, order polygamia æqualis. Receptacle naked; seeds crowned with many chaffy leaves: calyx many-leaved, spreading. One species-a native of Carolina, with terminal corymb, and highly odorous flowers.

HYMENOPHYLLUM. In botany, a genus of the class cryptogamia, order filices. Fructification in marginal, somewhat exerted crowded dots, seated on a small column, within the two-valved, flattish, straight involucre which opens outwardly. Twenty species, of which one only is indigenous to our own country, and from its having been found wild first of all at Tunbridge, specifically named H. tunbridgense.

HYMENOPTERA. In zoology, the fifth order in the class insecta, according to the Linnéan arrangement. See ZOOLOGY. It is thus ordinally arranged: wings four, membranaceous: females mostly armed with a sting.

HYMETTUS, in ancient geography, a mountain of Attica, near Athens: famous for its marble quarries, and for its excellent honey.

HYMN, a song, or ode, in honour of God; or a poem proper to be sung, composed in honour of some deity. See ODE, and SONG. The word is Greek, buvos, hymn; formed of the verb w, celebro, 1 celebrate. Isidore, on this word, remarks, that hymn is properly a song of joy, full of the praises of God, by which, according to him, it is dis

tinguished from threna, which is a mourning song, full of lamentation.

The hymns or odes of the ancients generally consisted of three stanzas or couplets; the first called strophe, the second antistrophe, and the last epode

St. Hilary, bishop of Poictiers, is said to have been the first that composed hymns to be sung in churches: he was followed by St. Ambrose. Most of those in the Roman Breviary were composed by Prudentius. They have been translated into French verse by Messrs. Du Port Royal. The Te Deum is also commonly called a hymn, though it be not in verse; so also is the Gloria in excelsis.

In the Greek Liturgy there are four kinds of hymns; but then the word is not taken in the sense of a praise offered in verse, but simply of laud or praise. The angelic hymn, or Gloria in excelsis, makes the first kind; the trisagion the second, the cherubic hymn the third, and the hymn of victory and triumph, called is, the last.

To HYMN. v. a. (uéw). To praise in song; to worship with hymns (Milton).

To HYMN. v. n. To sing songs of adoration (Milton).

HY'MNIĆ. a. (uvos). Relating to hymns. HYO. In anatomy, names compounded of this word belong to muscles which originate from, or are inserted into, or connected with, the os hyoides; as hyo-glossus, hyo-pharyngeus, genio-hyo-glossus, &c.

HYOBANCHE. In botany, a genus of the class didynamia, order angiospermia. Caly seven-leaved; corol ringent, without any lower lip; capsule two-celled, many seeded. One species. A scarlet parasytic plant of the Cape, with ovate oblong branches.

HYO-GLOSSUS. Cerato-glossus of Douglas. Basio-cerato-chondro-glossus of Albinus. A muscle situated at the side, between the os hyoides and the tongue. It arises from the basis, but chiefly from the corner of the os hyoides, running laterally and forwards to the tongue, which it pulls inwards and down

wards.

HYOIDES os, (Hyoides, boudes, from the Greek letter and s, likeness.) This bone, which is situated between the root of the tongue and the larynx, derives its name from its supposed resemblance to the Greek letter v, and is by some writers described along with the parts contained in the mouth. Ruysch has seen the ligaments of the bone so completely ossified, that the os hyoides was joined to the temporal bones by anchylosis. In describing this bone, it may be distinguished into its body, horns, and appendices. The body is the middle and broadest part of the bone, so placed that it may be easily felt with the finger in the fore part of the throat. Its fore part, which is placed towards the tongue, is irregularly convex, and its inner surface, which is turned towards the larynx, is unequally concave. The cornua, or horns, which are flat, and a little bent, are considerably longer than the body of the bone, and may VOL. VI.

be said to form the sides of the v. These horns are thickest near the body of the bone. At the extremity of each is observed a round tubercle, from which a ligament passes to the thyroid cartilage. The appendices, or lesser horns, cornua minora, as they are called by some writers, are two small processes, which in their size and shape are somewhat like a grain of wheat. They rise up from the articulations of the cornua with the body of the bone, and are sometimes connected with the styloid process on each side by means of a ligament. It is not unusual to find small portions of bone on these ligaments; and Ruysch, as we have already observed, has seen them completely ossified. In the fœtus, almost the whole of the bone is in a cartilaginous state, excepting a small point of bone in the middle of its body, and in each of its horns. The appendices do not begin to appear till after birth, and usually remain cartilaginous many years. The os hyoides serves to support the tongue, and affords attachment to a variety of muscles, some of which perform the motions of the tongue, while others act on the larynx and fauces.

HYOPHARYNGEUS, (50¢×pyyaios, from tons, the hyoid bone, and pay, the pharynx.) A muscle so called from its origin in the os hyoides, and its insertion in the pharynx.

HYOSCIAMUS, (Hyosciamus, i. m. boσxuaμs, from is, a swine, and xvxμos, a bean, so named because hogs eat it as a medicine, or it may be because the plant is hairy and bristly like a swine.) Faba suilla, Henbane. Hog's bean.

In botany, a genus of the class pentandria, order monogynia. Corol funnel-form, obtuse, irregular; stamens inclined; capsule covered with a lid, two-celled. Eight species chiefly natives of the Levant and Palestine. One common to our own country. H. niger, found in water, with sinuate leaves clasping the stems, and sessile flowers. The smell of this indigenous plant is strong and peculiar the leaves, when bruised, emit somewhat of the odour of tobacco: to the taste they are mild and mucilaginous. It is a powerful narcotic poison, and many instances of its deleterious effects are recorded by different authors. Nevertheless, the extract of the seeds, under proper management, may be safely employed; and it has this advantage over narcotics in general, that it never renders the bowels costive, but, on the contrary, gently opens them.

HY'OSERIS. In botany, a genus of the class syngenesia, order polygamia æqualis. Receptacle naked; calyx invested with scales; down double; the outer capillary, inner of chaffy awns. Eight species; five stemless; three caulescent; all natives of the south of Europe, or Barbary, but one, H. prenanthoides, which is an American plant.

HYOTHYROIDÆ, compounded of hyoides and thyroides, in anatomy, a pair of N

muscles of the larynx; which, arising from the anterior part of the os hyoides, are inserted into the cartilago thyroides. They serve as antagonists to the sterno-thyroides, and lift up the thyroid cartilage.

To HYP. v. a. (barbarously contracted from hypochondriac.) To make melancholy; to dispirit (Spectator).

HYPÁLLAGE, among grammarians, a species of hyperbaton, consisting in a mutual permutation of one case for another. Thus Virgil says, dare classibus austros, for dare classes austris; and again, necdum illis labra admovi, for necdum illa labris admovi.

HYPANTE, or HYPERPANTE, a name given by the Greeks to the feast of the presentation of Jesus in the temple. This word, which signifies lowly or humble meeting, was given to this feast from the meeting of old Simeon and Anna the prophetess in the temple when Jesus was brought thither.

HYPATE, in the ancient music, an appellation given to the lowest chord or sound of a tetrachord. The word is Greek, izan, which some Latin interpreters translate by suprema; as they translate, by ultima or ima. Dr. Wallis says, that the first contrivers of these names took, contrary to our custom, the grave for the highest place, and the acute for the lowest of their schemes.

The ancients also used Hypate-hypaton, for the lowest chord of the lowest tetrachord; and Hypate-meson for the first or lowest note of the mean tetrachord.

HYPŒTHROS, in ancient architecture, a kind of temple open at the top, and thereby exposed to the air.

HYPA'TIA, an illustrious female, was the daughter of Theon, an eminent philosopher and mathematician, at Alexandria, whom she succeeded in the government of that famous school. She had a number of disciples, among whom was the celebrated bishop Synesius. She explained to her hearers (says Socrates, an ecclesiastical historian of the 5th century, born at Constantinople) the several sciences that go under the general name of philosophy; for which reason there was a confluence to her, from all parts, of those who made philosophy their delight and study. Never was woman more caressed by the public, and yet never had woman a more unspotted character. She was held as an oracle for her wisdom, for which she was consulted by the magistrates in all important cases; a circumstance which often drew her among the greatest concourse of men, with out the least censure of her manners. In short, when Nicephorus intended to pass the highest compliment on the princess Eudocia, he thought he could not do it better than by calling her another Hypatia.

While Hypatia thus reigned the brightest ornament of Alexandria, Orestes was go. vernor of that place for the emperor Theodosius, and Cyril was bishop or patriarch. Orestes, having had a liberal education, ould not but admire Hypatia; and as a wise

governor often consulted her. This, together with an aversion which Cyril had against Orestes, proved fatal to the lady. About 500 monks assembling, attacked the governor one day, and would have killed him, had he not been rescued by the townsmen; and the respect which Orestes had for Hypatia causing her to be traduced among the Christian multitude, they dragged her from her chair, tore her in pieces, and burnt her limbs. This happened about the year 415.

HYPATOIDES, the general name given by the Greeks to their deep, or bass sounds, to distinguish them from the mesoides, or middle sounds, and the netoids, or high sounds.

HYPE/COUM. Wild cummin. In botany, a genus of the class tetrandria, order digy. nia. Calyx two-leaved; petals four; the two outer broader; fruit a cilique. Four species, natives of the south of Europe: low herbaceous plants with yellow flowers: the juice of the plant employed by some medical practitioners as a narcotic.

HYPELATE. In botany, a genus of the class polygamia, order monoecia. Calyx five-leaved; corol five-petalled; filaments eight; stigma deflected, three-sided ; drupe one-seeded. One species; a Jamaica shrub, with erect, leafy branches.

HYPER, a Greek preposition of compo sition, denoting excess; its literal significa tion being above or beyond.

In music, we often meet with words beginning with Hyper, as Hyperoolian, above the Eolian; Hyperdorian, above the Dorian; Hyperloleon, super-excellent; Hyperionian, above the Ionian; Hyperphrygian, above the Phrygian, &c.

HYPERANTHERA. In botany, a genus of the class decandria, order monogynia. Calyx five-parted; petals five, unequal, inserted into the calyx; legume three-valved, swelling into protuberances; seeds winged. Four species, natives of India or South America.

HYPERBATON, or HYPERBASIS, in grammar and rhetoric, is a transposition, or a figurative construction, inverting the natural and proper order of the terms of a discourse.

The word is ύπερβατον, οι υπερβασις, derived of man, transgredior, I go beyond; formed of p, ultra, beyond, and Saw, eo, I go.

The hyperbaton, Longinus observes, is no other than a transposal of sentiments, or words, out of the natural order and method of discourse, and always implies great violence, or strength of passion, which naturally hurries a man out of himself, and distracts him variously. Thucydides is very liberal in hyperbatons.

HYPERBOLA, one of the conic sections, being that which is made by a plane which cuts the opposite side of the cone produced above the vertex, or, by a plane which makes a greater angle with the base than