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admit: 1. That if a line moving on a curve be said to have a direction at all at any point, the direction must be that of a tangent at that point; 2. That it is highly convenient to say that a point moving in a curve is moving in a continually varying direction. Here, as in other cases [VELocity, CURVATURE, &c.], we obtain exactness by making definitions drawn from the inexactness of our senses apply, not to the notions which first gave them, but to the final limit towards which we see that we should approach if our senses were made more and more exact; but which, at the same time, we see that we should never reach as long as any inexactness whatsoever remained. DIRECTOIRE EXECUTIF was the name given to the executive power of the French republic by the constitution of the year 3 (1795), which constitution was framed by the moderate party in the National Convention, or Supreme Legislature of France, after the overthrow of Robespierre and his associates. [CoMMITTEE of PUBLIC §. By this constitution the legislative power was entrusted to two councils, one of five hundred members, and the other called “des anciens,’ consisting of 250 members. The election was graduated: every primary or , communal assembly chose an elector, and the electors thus chosen assembled in their respective departments to choose the members for the legislature. Certain property qualifications were requisite for an elector. One-third of the councils was to be renewed every two years. The Council of Elders, so called because the members were required to be at least forty years of age, had the power . refusing its assent to any bill that was sent to it by the other council. The executive power was entrusted to five directors chosen by the Council of Elders out of a list of candidates presented by the Council of Five Hundred. One of the five directors was to be changed every year. The directors had the management of the military force, of the finances, and of the home and foreign departments; and they appointed their ministers of state and other public functionaries. They had large salaries, and a national palace, the Luxembourg, for their residence, and a guard. The project of this constitution having been laid before the primary assemblies of the people was approved by them. But by a subsequent law the Convention decreed that twothirds of the new councils should be chosen out of its own members. This gave rise to much opposition, especially at Paris, where the sections, or district municipalities, rose against the Convention, but were put down by force by Barras and Bonaparte on the 13th Vendemiaire (4th of October, 1795). After this the new councils were formed, two-thirds being taken out of the members of the Convention, and one-third by new elections from the departments. The councils then chose the five directors, who were Barras, La Réveillère-Lépaux, Rewbell, Letourneur, and Carnot; all of whom, having voted for the death of the king, were considered as bound to the republican cause. On the 25th of October the Convention, after proclaiming the beginning of the government of the laws, and the oblivion of the past, and changing the name of the Place de la Révolution into that of Place de la Concorde, closed its sittings, and the new government was installed. Its policy was at first moderate and conciliatory, but it stood exposed to the attacks of two parties, the royalists, including those who were attached to the constitutional monarchy of 1791, and the revolutionists, or jacobins, too. by the mob. In September, 1796, a conspiracy of the latter, headed by Babeuf, who proclaimed “the reign of general happiness and of absolute democracy,” proposing to make a new and equal distribution of property, made an attack on the Direc: tory, which was repulsed by the guard, and Babeuf and other leaders were tried, condemned, and executed. By the elections of May, 1797, for a new third of the members of the councils, the royalists of various shades obtained many seats in the legislature. The policy of the Directory, both domestic and foreign, was now strongly censured in the councils, who asked for peace and economy, and for a repeal of the laws against th. emigrants and the priests. The conduct of Bonaparte towards Venice was animadverted upon. Camille Jordan, a deputy from Lyon, made a speech in favour of the re-establishment of public worship. The club of Clichi was the place of meeting of the partisans of the opposition. Barthelemy, who had been meantime appointed director, inclined to the same side, as well as General Pichégru, Barbé Marbois, and others. Carnot, another director, endeavoured to mediate between the two
parties, but to no effect. The Directory being alarmed, called troops to the neighbourhood of Paris, which was an unconstitutional measure. At length Augereau came with a violent message from Bonaparte and the victorious army of Italy, offering to march in support of the Directory, and threatening the disguised royalists in the councils, meaning the opposition. This was the first direct interference of the armies in the internal affairs of France. The majority o the Directory, consisting of Barras, Rewbell, and La Ré. veillère-Lépaux, appointed Augereau military commander of Paris, who surrounded the hall of the councils, arrested Pichégru, Willot, Ramel, and prevented by force the other opposition members from taking their seats. The remainder of the members being either favourable to the Directory, or intimidated, appointed a commission which made a report of some conspiracy, and a law of public safety was quickly passed, by which two directors, Barthelemy and Carnot, and fifty-three members of the councils, were exiled to French Guiana. Carnot escaped to Germany, but Barthelemy was transported. The Directory added to the list the editors of thirty-five journals, besides other persons. Two new directors, François de Neufchâteau and Merlin de Douai, were chosen in the room of the two proscribed. This was the coup d'état of Fructidor (September), 1797. There was now a partial return to a system of terror, with this difference, that imprisonment, transportation, and confiscation of property, were substituted for the guillotine. The laws against the priests and emigrants were enforced more strictly than ever. By a law of the 30th of September, 1797, the public debt was reduced to one-third, which was called consolidated, and was acknowledged by the state, the creditors receiving in lieu of the other two-thirds bons, or bills which could only be em.
loyed in the purchase of national property, and which fell immediately to between 70 or 80 per cent. Forced loans, confiscations, and the plunder of Italy, were the chief finan. cial resources of the government. The paper money had lost all value. [Assig Nats.] Government lotteries, which had been abolished by the Convention, were re-established by the Directory. A ministry of police was created, which interfered with the locomotion of individuals, by requiring passports and cartes de sureté, and made arrests and domi. ciliary visits under pretence of suspicion. The periodical press was arbitrarily interfered with. In the midst of all this the Directory was mainly supported by the influence of Bonaparte's Italian victories, followed by the peace of Cainpoformio with Austria. But an act which threw the greatest obloquy upon the Directory was its unprovoked invasion of Switzerland in 1798. Carnot, from his exile in Germany, was loud in his denunciations of this political crime, which he said “verified the fable of the wolf and the lamb.” The republicans in the interior were also greatly dissatisfied with the directorial dictatorship, and as by the new elections of 1799 they mustered strong in the councils, they openly assailed the government, which was no longer supported by the presence of Bonaparte, then in Egypt. At the same time a new coalition was formed against France, consisting of Austria, Russia, England, and Turkey, and the French armies met with great reverses both in Italy and on the Rhine. In one short campaign they lost all Italy except Genoa. All this added to the unpopularity of the Directory, which that year consisted of Barras and La Réveillère-Lépaux, both of the first nomination, and Treilhard, Merlin de Douai, and Sieyes. The councils demanded the dismissal of Treilhard on the score of informality in his nomination, and of La Réveillère and Merlin de Douai on account of several charges which were preferred against them. All the three gave in their resignation, and were replaced by Gohier, Roger Ducos, and Moulins, three obscure men. This change took place in June, 1799. At the same time the councils circumscribed the authority of the Directory, re-established the supremacy of the legislature, and removed the restrictions on the press. But soon after, July 1799, they passed a measure worthy of the worst times of the revolution. This was the ‘law of hostages,” by which the relatives of the emigrants, the ex-nobles, priests, &c., were made answerable for any revolts or other offence against the republic, and liable to imprisonment at the discretion of the local authorities, sequestration of their property, and even transloitation. The authority of the Executive Directory had now become very weak and the councils then selves on to be divo!'" between the violent republicans or jacobins, who were to
measures of terror, and the moderate republicans who wished to act legally according to the constitution of the year III. The policy of the government was consequently vacillating. Talleyrand, the minister for foreign affairs, gave in his resignation. All parties had exhausted themselves by i. struggles, while the mass of the people stood passive, being weary of agitation; this general prostration prepared the way for Bonaparte's ascendency in the following Brumaire, when the constitution of the year 3 and the Directory were overthrown, after four years' existence. The principal charges against the Directory are stated under the head BARRAs. See also Histoire du Directoire Erécutis, 2 vols. 8vo., Paris, 1802. The law of the conscription was passed under the administration of the Directory. DIRECTRIX. (Linea directria, a directing line.) This term is applied to any line (straight or curved) which is made a necessary part of the description of any curve, so that the position of the former must be given before that of the latter is known. Thus in the question, “required the curve described by a point in a straight line the two ends of which must be on two fixed straight lines,’ the two fixed lines are directrices. Custom has sanctioned the special application of this term to lines connected with a few curves, and particularly with the ellipse, hyperbola, and conchoid of Nicomedes. But in reality, with the exception of the circle, there can be no curve which is without one or more lines to which the name of directrix might be given. DIRGE, in music, a hymn for the dead, a funereal song. This word is a contraction of Dirige, the first word of the antiphona, ‘Dirige, Domine Deus,' chanted in the funeral service of the Catholic church. The abbreviation seems to have crept into use about the middle of the sixteenth cen
tury. Sisability (Law), an incapacity in a person to inherit lands or enjoy the possession of them, or to take that benefit which otherwise he might have done, or to confer or grant an estate or benefit on or to another. All persons who are disabled from taking an estate or benefit are incapable of granting or conferring one by any act of their own, but many persons who are by law incapable of disposing of property may take it either by inheritance or gift. Disability is ordinarily said to arise in four ways: By the act of the ancestor; by the act of the party himself; by the act of the law; or by the act of God. By the act of the ancestor, as where he is attainted of treason or murder, for by attainder his blood is corrupted, and his children are made incapable of inheriting. But by the stat. 3 and 4 W. IV., c. 106, § 10, this disability is now confined to the inheriting of lands of which the ancestor is possessed at the time of attainder: in all other cases a descent may be traced through him. By the act of the party himself, as where a person is himself attainted, outlawed, &c., or where, by subsequent dealings with his estate, a person has disabled himself from performing a previous engagement, as where a man covenants to grant a lease of lands to one, and, before he has done so, sells them to another. By the act of law, as when a man, by the sole act of law without any default of his own, is disabled, as an alien born, &c. By the act of God, as in cases of idiotcy, lunacy, &c., but this last is properly a disability to grant only, and not to take an estate or benefit—for an idiot or lunatic may take a benefit either by deed or will. There are also other disabilities known to our law, as infancy, and coverture; but these also are confined to the conferring of interests. Married women, acting under and in conformity to Powers, and formerly by fine, but, since the 3rd and 4th W. IV., c. 74, by deed executed under the provisions of that statute, may convey lands; and infants, lunatics, and idiots, being trustees, and not having any beneficial interest in the lands vested in them, are by various statutes enabled to dispose of them under the direction of the Court of ChancerV. Forticular disabilities also are created by some statutes; as, for instance, Roman Catholics, by the 10 Geo. IV., c. 7 (the Emancipation Act), are disabled from presenting to a benefice; and foreigners (although naturalized) cannot hold offices, or take grants of land under the crown. [DENIzEN.] (Cowel's Interp. ; Termes de la Ley.) DISBUDDING, in horticulture, consists in removing the buds of a tree before they have had time to grow into
young branches. It is a species of pruning which has for its object not only training, but also economy with regard to the resources of a tree, in order that there may be a greater supply of nourishment for the development of those buds which are allowed to remain. If the roots are capable of absorbing a given quantity of nutritive matter for the supply of all i. buds upon a stem, and if a number of those buds be removed, it must be evident that those which remain will be able to draw a greater supply of sap and grow more vigorously than they otherwise would have done. This fact has furnished the idea of disbudding. This kind of pruning has been chiefly applied to peach and nectarine trees, but the same principle will hold good with all others of a similar description, and might be praetised upon them if they would repay the labour so expended. The French gardeners about Montreuil and in the vicinity of Paris have carried this practice to a great extent, and with considerable success. Several of their methods have been described by Dr. Neill, the secretary of the Caledonian Horticultural Society, in his horticultural tour. In one of them, termed d la Sieulle, and invented by Sieulle, gardener at Vaux. Praslin, near Paris, the training is made to depend entirely upon the, exactness of disbudding. The peculiarity of Sieulle's method is as follows:–After the stock has been budded, two branches are trained at full length to a trellis or wall: late in autumn or in winter all the buds, with the exception of four on each shoot, are neatly cut out, or disbudded; these four in their turn form shoots in the succeeding summer, which are cut down to about one-third of their length in autumn, and also disbudded in the same manner as the two principal branches of the preceding year. This kind of pruning being always performed prevents a superfluous development of buds and the consequent necessity of cutting them out as branches in the following season. Du Petit Thouars, whose opinions are entitled to much respect, passes a high eulogium upon this system of Sieulle: he says, “by this method the young tree is more quickly brought to fill its place upon the espalier; it is afterwards more o kept in regular order: many poorer flower-buds are allowed to develop themselves, but the necessity of thinning the fruit is thus in a great measure superseded, and the peaches produced are larger and finer.” i)umoutier's system of disbudding is somewhat different from Sieulle's. Instead of performing this operation late in autumn, he defers it until spring, when the buds are unfolded: all those upon the young shoot of the previous year, with the exception of the lowest and the one above the highest blossom, are then carefully removed; of the two which are left, the first is termed the bourgeon de remplacement for the next year, and the latter is allowed to remain to draw up the sap for the maturing of the fruit. This method of pruning, as far as disbudding is concerned, is precisely the same as that practised by Seymour, of Carleton Hall, in England. It must not be thought however from this statement that the training of Dumoutier and Seymour is the same, or that their trees assume precisely the same appearance: for example, Dumoutier's branches proceed from two principal arms, Seymour's from one in the centre: in the system of the former, the fruit-bearing branches are on both sides of the old wood; while in that of the latter they are only allowed to grow from the upper sides. Disbudding in spring is frequently and beneficially practised by many intelligent j both in England and Scotland, upon English fan-trained peach-trees, with a view to thinning the young wood, taking care to leave enough for the production of fruit in the following year. When spurious buds can be removed from peach or nectarine trees before development, with the certainty of those succeeding which are allowed to remain, it must be of material consequence, as the latter will not only be better supported, but will also receive a greater quantity of light, so essential to mature and ripen the young wood. Unfortunately however Sieulle's plan cannot be practised with any degree of success in England: those buds which are left, and upon which so much dependence is placed, often do not grow; a vacancy is the consequence, and the tree is deformed. The climate of Montreuil is much more favourable to the growth of the peach-tree than that of Britain;
and although the winters of Paris are severe, yet the mean degree of summer heat is much greater there than in any part of England; and perhaps the peculiar nature of the soil renders peach-trees much more yielding to art there than in this country. For these reasons, however useful the plan of disbudding in autumn or winter may be in the gardens of France, it would be improper to practise it to any extent in those of England. The system has been fairly tried in the garden of the London Horticultural Society, but has long since been discontinued. It has however been proved, both there and from the long experience of men in private situations, that a judicious thinning of the buds after they have been unfolded in spring (when an experienced individual can foresee the strength of those which he is about to leave, and to which he looks for his fruit in the following year), is of great utility. DISC (discus, Štokoç), is used for the face of a circular plate, and frequently for a thin plate of any substance. Thus we speak of the sun's disc (referring to the appearance of the sun), and also of a disc of metal. DISCIPLINE, MILITARY, the series of duties which are to be performed by military men. It also signifies a conformity to the regulations by which those who serve in the army are governed in all matters relating to the praclice of their profession. DISCLAIMER (Law), a plea by a tenant in any Court of Record in which he disclaims to hold of his lord. This disclaimer of tenure is a forfeiture of the lands to the lord upon reasons most apparently feudal. And so likewise if in any Court of Record the particular tenant does any act which amounts to a virtual disclaimer, as if he claims a greater estate than was granted to him, or takes upon himself those rights which belong only to tenants of a su|. class, or if he affirms the reversion to be in a stranger, y attorning as his tenant, collusive pleading, and the like, such behaviour amounts to a forfeiture of his particular estate. The writ of right sur disclaimer was the old form in which the lord took advantage of the forfeiture; but as it was decided that the tenant might be treated as a trespasser, and that notice to quit was not necessary, the more convenient action of ejectment was generally used, and snow, since the stat. 3 & 4 W. IV., c. 27, the proceeding by writ of right sur disclaimer is abolished. Where a person by his plea denied that he was of the blood of another, he was also said to disclaim; and there is a disclaimer of goods as well as lands, as where on an arraignment of felony a man disclaims the goods, in which case, though he should be acquitted, he loses the goods. One of the pleadings in a suit in Chancery is also called a disclaimer, as where a defendant, in his answer to the complainant's bill, disclaims all interest in the matter in question. [EQUITY...] And where an estate is given either by deed or will to a person, he may by deed (which need not be enrolled, or, as it is called, made matter of record) disclaim all interest thereunder; but it seems that for this purpose a deed is necessary, and that a parol disclaimer would not be sufficient. An executor is said to disclaim when he renounces probate of the will of his testator; and this is generally effected by verbal renunciation before some judge spiritual, or by simple writing under his hand, in either case the disclaimer being recorded in the spiritual court; but where the will contains a devise of lands to the executor, the disclaimer is generally made by deed, for although a disclaimer by the before-mentioned means would, it seems, be operative, yet the deed is preferred as affording evidence, in deducing a title to the lands, of the fact of disclaimer. DISCONTINUITY (Algebra, &c.). Continuous changes are those which are so made that no two states exist without every possible intermediate state having been in existence between them. Thus the square on a line of 4 inches contains 16 square inches, while that on a line of 5 inches con. tains 25 square inches; and there is no possible area between 16 and 25 square inches which is not equal to the square described on some line between 4 and 5 inches. That is, if a straight line increase continuously, the square described on it increases continuously. The first introduction of discontinuity arises from the attempt to represent all magnitudes by numbers. Arithinetical symbols cannot represent continuous change of magnitude. If a foot be divided into 2, 3, 4, &c. equal parts, und so on ad insinitum, there exist infinite numbers of lengths which will not be represented by any whatsoever of the reP. C., No. 533,
sulting fractions of a foot. Hence the difficulties of INcontMENsu RABLE magnitudes, which arise from the failure of the attempt to represent flowing or continuous changes by the means of changes which always suppose finite intervals. as in passing from number to number. But the arithmetical difficulty, being introduced antecedently to the express consideration of discontinuity, is rarely treated as belonging to this subject. In the higher parts of mathematics the necessity for the sonsideration of discontinuous expressions began with the investigation of partial differential equations. In the introduction of the arbitrary functions which those equations require, discontinuous functions were thought to be admissible by Euler, an opinion which was controverted by D'Alembert, and supported, conclusively, it has always been thought, by Lagrange. It is our own opinion that not only the arbitrary function of a partial equation, but even the arbitrary constant of a common equation, may bo allowed to be discontinuous, unless the contrary be a condition of the problem, expressed or implied. By a discontinuous constant, we mean one which preserves one value between certain limits of the value of the variable, which then suddenly changes its value, preserving the new value till the variable attains another limit, and so on. The subject has begun to force itself on the attention of mathematicians, and several remarkable cases have been pointed out in which erroneous conclusions have been arrived at for want of considerations connected with discontinuity. There is a full account of the state of this question in Mr. Peacock’s “Report on Analysis.’ (1*). Brit. ...iss., 1834. DISCORD, in music, a sound which, when heard with another, is disagreeable to the ear, unless treated according to the rules of art. Discords ale the 2nd, sharp 4th (Tritonus), flat 5th (Semidiapente), minor or flat 7th, and major or sharp 7th. The ratios of these are 9 : 8, 45 : 32, 64 : 45, 9:.5, and 15: 8. The 9th (9 : 4) is also a discord, and though only the octave to the 2nd, is considered in harmony as a very different interval, and treased in a different manner. The 4th (4:3) is either discord or concord, according to the manner in which it is accompanied. [CoNcord.] Discords commonly, but not always, are j repared; i. e., the mote which is to become the i. is first heard as a concord: and their resolution is absolutely necessary; i. e., the discord must pass into a concord, though the resolution is occasionally retarded. Examples:–
6 § 6 DISCOUNT, a sum of money deducted from a debt it. consideration of its being paid before the usual or stipulated time. The circumstance'on which its fairness is founded is, that the creditor, by receiving his money before it.” comes due, has the interest of the money during the inter val. Consequently, he should only receive so * * * out to interest during the period in question, Will realize the amount of his deit at the time when it would have become due. For instance, 100l. is to be paid at the end of Vol. IX.--D
where p is the rate per pound (not per cent. : thus it is '04 for 4 per cent.). But recourse is usually had to the tables of present values which accompany all works on annuities or compound interest. [INTEREs.T.] The name of discount is also applied to certain trade allowances upon the nominal prices of goods. . In some branches of trade these allowances vary according to the circumstances which affect the markets, and what is called discount is in fact occasioned by fluctuations in prices which it is thought convenient to maintain nominally at unvarying rates. This system is practised in some branches of wholesale haberdashery business, and we have now before us a list of prices furnished to his customers by a manufacturer of tools at Sheffield, in which the nominal price of each article is continued the same at which it has stood for many .. while to every different species of tool there is applied a different and a fluctuating rate of discount, this fluctuation constituting in fact a difference of price between one period and another: the rates of discount in this list vary from 5 to 40 per cent. upon the nominal prices of the different articles. The term discount is also employed to signify other mercantile allowances, such for example, as the abatement of 12 per cent. made upon the balances which underwriters, or insurers of sea risks, receive at the end of the year from the brokers by whom the insurances have been effected. The word discount is further used, in contradistinction to premium, to denote the diminution in value of securities which are sold according to a fixed nominal value, or according to the price they may have originally cost. If, for example, a share in a canal company upon which 100/. has been paid is sold in the market for 98!., the value of he share is stated to be at 2 per cent. discount. DISCOVERY, in Law. [Equity.] DISCUS (Öiakoç, discos), a quoit of stone, brass, or iron, with which the Greeks and Romans diverted themselves in the public games. The word is Greek. The discus, when perforated like our modern quoit, was thrown by the help of a thong, put through the middle of it. It was at other times of a solid piece, and was then hurled directly from the hand. This last method is illustrated by the ce. lebrated statue of the Discobolus, or quoit thrower, attributed to Myro, an antient copy of which is among the marbles of the Townley Gallery. The figure is represented in action at the precise moment of delivering the discus. Ovid (Metam., li. x., v. 175) and Statius (Theb., vi., v. 646) have both described the diversion of the discus; see also Petri Fabri Agonisticon, sive de Re Athletica, Ludisque Peterum, 4to., Lugd. 1595, li. ii., c. i. The term discus was likewise applied to circular shields or bucklers, of a large size, placed in the temples, on which great actions were represented, or the names of those who had devoted themselves to the service of their country inscribed. One of the former of these is in the Townley Gallery at the British Museum, Room, iii., No. 36, containing the names of the ephebi of Athens under Alcamenes, when he held the office of cosmetes. Such too was the shield of Scipio Africanus, found in the Rhone in 1656, engraved in Spon’s ‘Miscellanea Eruditæ Antiquitatis, edit. 1685, p. 152. Anacreon has an ode on a disk of silver, representing Venus rising from the sea: Qd. 51,
Eic Atakov oxovra o Aopoćirny. See likewise Montfaucon, Supplem, de l’Ant. Expliq., liv. iii., p. 64. ISDIAPA'SON, the name given by the Greeks to a scale of two octaves. [D1APAsoN.] DISK, a term in botany signifying any ring or who l of glands, scales, or other bodies that surround the base of an ovary, intervening between it and the stamens. In its most common state it is a fleshy wax-like ring as in the orange : it frequently forms o lining to the calyx, as in the plum and cherry, and not unfrequently rises up like a cup around the ovary as in the tree paeony. The latter renders it probable that the disk is nothing but an inner whorl of rudimentary stamens. Previously to the expansion of the flower the disk contains saecula, and is dry and brittle; but after the blossom unfolds it perspires a sweet honey-like fluid, and becomes tough, absorbing oxygen and parting with carbonic acid. This phenomenon is similar to what occurs in the germination of seeds, and has led M. Dunal to the opinion that the conversion of the faecula of the disk into sugar is for the purpose of forming a store of nutritive matter for the stamens and ovary at the time of fertilization, just as the same phenomenon in the germination of seed is for the purpose of supplying food to the young embryo. DISLOCATION. Various parts of the body are liable to be displaced by the direct application of violence or by more gradual causes. But the term dislocation is commonly appropriated to displacements occurring about the joints. In this sense it is nearly synonymous with luration, but not entirely; for the latter term carries with it more of the idea of external force, and is not quite so generally applied. It is usual, for instance, to speak of the dislocation, not the luration, of the internal cartilage of the knee; and the latter term is seldom if ever used in describing the displacements of the small bones of the wrist or instep, or of single vertebrae. The injuries classed under this title may be effected by external violence, or by the undue contraction of muscles, or by both of these causes combined; and they result in some instances from disease within the joints themselves, by which their ligaments are weakened or destroyed, and their sockets rendered insecure by ulceration and other gradual changes. When, by the protrusion of the bone through the skin or otherwise, the dislocation is complicated with an external wound exposing the cavity of the joint, it is said to be compound : and, as in the parallel case of fracture, this aggravation of the injury is very serious, and the most skilful management is required to save the life or limb, where the injury happens to one of the larger joints. The particular dislocation takes its name either from the joint itself or from the furthest bone; and various terms are added to indicate the direction of the displacement, or the new situation of the head of the bone. Thus the most common form of the accident at the hip is called ‘a dislocation of the head of the femur' (thigh-bone) backwards upon the dorsum ilii ' (flat part of the haunch-bone). Any bone may be displaced in any direction, but the accident happens most frequently in those joints and directions in which the extent of motion is the greatest. Thus the most common dislocation is that of the shoulder, which is the most movable joint; and its most frequent variety is that in which the head of the humerus (or bone of the upper arm) is drawn downwards into the arilla (or arm-pit) by the sudden contraction of certain strong muscles. This happens when the arm is raised to the utmost, as in reaching to close a window; that is when it has moved through an angle of 180° degrees from its natural position. The most usual dislocation of the hip is that, already mentioned, on the dorsum ilii for the same reason. It is generally produced by sudden pressure or a blow on the knee when the thigh is bent upon the abdomen; the head of the femur is thus driven backwards from the socket, and is then drawn farther back and upwards by the powerful muscles of the buttock. The jaw is sometimes thrown out of joint by the mere act of yawning; and that accident happened to a gentleman known to the writer in opening his mouth to make the usual response at church. The word was cut short at the first syllable; for in such cases the chin suddenly drops and is thrown forward, and it is impossible by any effort to shut the mouth. This distressing but irresistibly ludicrous accident may be relieved immediately by any bystander wrapping a napkin round his thumbs and placing them firmly against the back teeth, so as to press them downwards, while with the fingers and palms the chin is steadily raised and pushed backwards. But the operator should be on the alért to withdraw his hands the moment the jaw snaps back into its place, or he may receive a very unpleasant intimation of the success of his efforts. t will be easily seen from these instances how important a part is played by the muscles in determining both the occurrence and direction of these accidents. Hence arises in part their infrequency, often wondered at, during infancy and childhood; for though the flexible joints of the young have a greater extent of motion than those of the adult, their muscular power is not only weaker as compared with the strength of their ligaments, but is much more tardily thrown into action, as may be observed in their tottering gait. The fragility of their bones is another cause of this infrequency, by rendering them more liable to be broken than displaced by external violence. The only dislocation that is at all common in children is that of the hip, which is the consequence of scrofulous ulceration of the ligaments and the socket, and of the ball-shaped head of the femur within it. The reader will be prepared by what has been said to learn that the spasmodic and violent contraction of the muscles consequent upon these displacements is the chief or only obstacle to their reduction. This object is effected by a process technically called cortension, consisting in the application of force in a proper direction, and steadily kept up till the muscles are fatigued. The head of the bone is thus drawn down a little below the level of the joint; and being lifted over the edge of the socket, slips easily into its place upon slightly relaxing the extending force. This force is often required to be very considerable, and in such cases it is customary to make use of a block of pullies, the bone which contains the socket having been first securely fixed to a staple in the wall by proper bandages. Luxation of the hip is here supposed; for the other joints are so inferior to that in strength that their displacements may generally be reduced by less imposing means. It is sometimes necessary to favour the relaxation of the muscles by emetics, warm baths, and bleeding, and it is reckoned a point of good management to call off the attention of the patient during the extension by annoying him with questions and even exciting him to anger. Almost all dislocations arising from accident may be reduced in this way, and the joint rendered nearly or quite as perfect as before: but this can only be done on condition of perfect rest during a period sufficient for the firm union of the ruptured ligaments; for if this precaution be not strictly observed, and the ligaments are suffered to be stretched by motion while the uniting substance is soft and extensible, the accident is ever afterwards liable to recur. No time should be lost in seeking assistance, for the swelling that comes on soon renders the nature of the accident obscure, and the reduction extremely difficult and painful. When a joint has been unreduced for a certain time, which varies with the particular joint, and with the bodily strength of the individual—the weaker having the advantage in this respect—it is unwise to make any attempt at reduction. The parts have now become consolidated and adapted to their new situation, and either the limb is permanently fixed or a new joint is under process of formation. In the latter case the substitute is often better than might be expected; and as this curious provision of nature cannot be improved upon by art, it is better to leave it alone. The most dangerous dislocations are those of the vertebrae or bones of the spine, because in that case all the parts of the body below the injury are paralyzed. But the vertebrae are so curiously locked together, and have singly so little motion, and are at the same time so well supported by ligaments and muscles, that they are seldom dislocated unless by a force sufficient to break as well as to displace them. Such an injury is almost always fatal, and instantly so in general when it takes place above the origin of the nerves of respiration, that is, above the fourth vertebrae of the neck. The object of the executioner in hanging a criminal is to produce this effect, but he more often fails than succeeds. It would be out of place in this work to describe the various dislocations more particularly. The reader will find some additional information on the subject under the head of Joi NTs. The best English treatise upon it is the large work of Sir Astley Cooper.
DISMAL SWAMP. [CARolina, North; Virginia.] DISPART, the difference between the semidiameter of the base ring, at the breech of a gun, and that of the ring at the swell of the muzzle. On account of the dispart, the line of aim, which is in a plane passing through the axis of the gun, always makes a small angle with the axis; so that the elevation of the latter above the horizon is greater than that of the line of aim ; an allowance for the dispart is consequently necessary in determining the commencement of the graduations on the tangent scale, by which the required elevation is given to the gun. DISPENSARY, an institution supported by voluntary contributions for the supply of the poor with medical and surgical advice, and will medicines gratuitously. Institutions of this kind are of very recent origin. They differ from hospitals in this, that the sick, when too ill to attend personally at the institution, are visited at their own homes by the medical officers of the charity. Each dispensary indeed is restricted to a certain district, beyond the limits of which the patients are not visited at their own houses. To every dispensary there are always attached one, and sometimes two physicians; one surgeon, and often a consulting surgeon, and a resident medical officer who dispenses the medicines prescribed by the physicians and surgeons. Every subscriber to the institution who pays annually a certain sum is called a governor, who is entitled to have at least one patient always on the books; a person who subscribes a larger amount in one sum is called a life-governor, who may have two or more patients on the list. The medicines, which are commonly purchased in considerable quantities at a time and at wholesale prices, are dispensed in unexpensive forms, and in this manner the extent of the relief afforded is great, while the cost is trifling. No other kind of charity affords so much real assistance at so small an expense, and perhaps fewer objections apply to this than to any other mode of giving eleemosynary aid to the poor. Its peculiar excellence is that it enables the sick poor to obtain advice on the very first day of their illness. Even the great metropolitan hospitals are often so full that urgent cases are constantly obliged to wait days and even weeks before admission can be obtained; but by means of the dispensary poor families, and even the heads of such families in regular employment, may procure medical and surgical assistance without leaving their occupation even for a day. It would be a great improvement in the principle of these institutions if some contribution towards their support on the part of the poor themselves were required to entitle them to avail themselves of the advantages which they afford. This would remove the only objection that can be urged against such establishments, and would enable the independent labourer, without asking charity, to procure the best advice for his sick family at a much cheaper rate than he can possibly do at present. ISPENSATION (Law). The only kind of dispensation now used is that by which the bishop of a diocese licenses a clergyman within his jurisdiction to hold two or more benefices according to their value, or to reside out of the bounds of his parish, or dispenses with some other particular of his strict duty. Formerly, not only in ecclesiastical jurisprudense, but also in the civil and criminal codes, the subject of dispensations occupied a large space. They formed a great source of the revenue of the court of Rome; for the pope's dis. pensations prevailed against the law of the country in many if not most instances, indeed in all of an eccle as tical nature; this abuse was however abolished by the statute 25 Henry VIII., c. 21; and the power of the ope to grant dispensations not contrary to the law of God, but only to the law of the land, was granted to the archbishop of Canterbury under certain restrictions. It is hardly necessary to state that from the spirit of the times this power is never exercised in civil cases, and but in a few ca es of purely ecclesiastical cognizance, and in those the usage has become the law rather than the exception. This right of the archbishop in some cases, as to grant special licenses of marriage, &c., has been expressly recognized by the legislature. Formerly also the crown claimed a dispensing power, by which it could exempt a person from the ordinary liabilities to the laws of the realm : the limits of this power were never exactly defined, but in consequence of the gross abuse of it during the reign of James II., it was **