B.C. 29, and spent twenty-two years at Rome in studying the Latin language and literature. His rhetorical and critical treatises-such as his Ars Rhetorica and his criticisms on the Greek orators-are of great value. His chief work is his Archæologia, or Roman history, in twenty books, of which only the first nine have reached us complete. This work contained the history of Rome from the earliest times to the year B. C. 264, and discussed fully all that relates to the Roman constitution, religion, history, and antiquities.

Dionysius Thrax, or the Thracian, was a celebrated Greek grammarian, who taught at Rome about B. C. 8o. He is remembered for the merit of his grammatical works, and for his explanations and criticism of Homer. His grammatical treatise was used in schools for many centuries.

Dionysius, surnamed Periege'tes, from his being the author of a periegēsis (Gr. 'geographical description of the earth') in Greek hexameters, was a native of Africa, and lived probably in the latter part of the 3d or beginning of the 4th c. His work, which is still extant, is written tersely, and was translated into Latin by Rufus Festus Avienus, and also by the grammarian Priscian. There still exist a commentary upon it by Eustathius, and a Greek paraphrase and Scholia. The editio princeps appeared at Ferrara in 1512, with a Latin translation. It was also printed at Venice by A. Manutius in 1513, but the best edition is that of G. Bernhardy (Leips. 1828).

Diony'sos. See BACCHUS.

Diophan'tine Analysis, a branch of algebra which treats of the solution of undeterminate questions, such as: To find three commensurable numbers whose squares are in arithmetical progression. The name is derived from Diophantus (q. v.), who solved a great many questions of this kind.

Diophan'tus, a Greek algebraist, who flourished at Alexandria probably about the 4th or 5th c. of the Christian era. Montucla, after Abulpharagius, places him at 365 A.D.; but the date is of little consequence except with reference to the question whether he obtained his algebra from the Hindus, or is to be regarded as the sole inventor of his methods. From an epitaph in Greek verse, discovered by Bachet, we gather that he married when thirty-three years old, that his son, born five years after the marriage, died at the age of forty-two, four years before himself, and that D. therefore lived eighty-four years. The information is given in the form of an algebraic problem. Of the thirteen books of his Arithmetica, only six are extant. There is also one other book, De Multangulis Numeris. The first printed edition was in Latin, by Xylander (Basel, 1575); Bachet de Meziriac published the original Greek, with Latin version and valuable notes (Paris, 1621); but the best is by Fermat (Toulouse, 1670). Miss Abigail Baruch Lousada left a complete English translation, which has unfortunately never been published.

Diop'sis, or Stalk-Eyed Fly, a genus of Diptera (q. v.) or Flies, belonging to the family Muscide, and distinguished by the elongation of the sides of the head to form stalks for the eyes. Diopsis thoracicus is a familar species of this group, the representatives of which mostly occur in warm climates.

Diop'trics. See OPTICS.

Diora'ma. See PANORAMA.

Dioscorea'ceæ, the Yam order, a natural order of Monocotyledonous plants, belonging to Lindley's sub-class Dictyogena, chiefly tropical plants. Tamus communis, the Black Bryony (q. v.), is the only British representative. There are about 160 species and seven genera. Tamus, Testudinaria, and Dioscorea are examples. The Yams (q. v.) are among the most important plants of the order. The Elephant's Food (q. v.) is another.

Dioscorides, the author of thirty-nine epigrams in the Greek Anthology, is thought to have lived in Egypt in the time of Ptolemy Euergetes. His epigrams, chiefly on the ancient poets, were included in Meleager's Garland.

Dioscorides, the name of several physicians and medical writers of antiquity.—1. D. Pedacius or Pedanius of Anazarba, in Cilicia, flourished in the 1st or 2d c. He wrote a treatise on Materia Medica, a work of immense research, and for many ages a standard authority, also a treatise on Poisons and another on Venomous Animals. Some minor works have been ascribed to him, but on insufficient grounds. His De

Materia Medica has been translated into Italian, French, German, and Spanish, and an Arabian version of it in MS. is to be found in several European libraries. The first Greek edition was published by Aldus Manutius (fol. Ven. 1499). The best edition is still that of Saracenus (Frankf. 1598); the most recent that of Sprengel (Leips. 1829-30).-2. D. Phacas, so called from the moles or freckles on his face, lived in the 2d or Ist c. B.C. His medical works, of which several are mentioned by ancient writers, have perished.-3. A grammarian and probably a physican at Rome in the time of Hadrian, who devoted his attention to medical literature, and edited an edition of the works of Hippocrates.

Dip and Strike are terms used in geology. The 'dip' is the downward inclination of beds with reference to the horizontal plane, and requires for its determination two numbers-viz., the inclination of the beds to the horizontal, and the point of the compass towards which they slope. The 'strike is the line drawn at right angles to the dip, corresponding to the outcrop when the surface is level,

Diphthe'ria (from Gr. diphthera, any leathery material), the name given to a contagious and epidemic disease of great severity, affecting chiefly the throat and neighbouring parts. It is essentially a blood disease, characterised by the formation of a false membrane on the back part of the mouth and throat. D. generally commences with headache, sickness, often diarrhoea and chilliness, and is soon followed by great prostration and the formation of dirty whitish patches on the back of the mouth, at first small, but soon coalescing so as to form a membrane whose appearance has been compared to that of 'damp, dirty, washed leather.' When this membrane begins to peel off there is a most offensive odour in the breath, and frequently the patient is unable to swallow. D. is a very fatal disease, and generally in a short time. The treatment consists in supporting the patient's strength, giving iron tonics internally, and applying Condy's fluid, or other disinfectant to the throat. Recovery is often followed by paralysis of some of the muscles. The patient should be kept warm in bed, and the air in the room should be hot and moist.

Diphthong (Gr. di, 'twice,' and phthongos, 'a sound') is the blending of two vowel sounds into one syllable, e.g., ou in house,' ai in 'aisle,' and oi in 'oil.' The distinction sometimes made between a D. to the eye and a D. to the ear is incorrect. There can be no D. which is not a D. to the ear.

Diph'yes, a beautiful genus of oceanic Hydrozoa (q. v.), or of a delicate thread-like canosarc or connecting medium, bearing Zoophytes, belonging to the order Calycophorida, and consisting pound organism is composed. At its proximal end the coenosarc the various polypites, or individual animals of which this comexpands to form two mitre-shaped Nectocalyces, or swimmingbells,' by means of which the organism is supported in the water. Each of the polypites is protected by a glassy 'bract,' or hydrophyllium. D. appendiculata is a familiar species of this genus of Calycophoride, and occurs in the Mediterranean and warm seas.

Diplacan'thus, a genus of extinct Ganoid fishes, of which D. gracilis is a familiar example. This genus belongs to the family Acanthodida, the members of which possessed small scales, and a spine implanted in the flesh in front of each fin. No operculum was developed. D. had two dorsal fins, and is confined solely to Devonian rocks. The tail was heterocercal.

Dip'loe, the cellular bony structure between the two plates or tables forming the flat bones of the skull. These cells are filled with a reddish pulpy substance, similar, when examined microscopically, to the marrow of bones.

Diplogloss'us, a genus of Lacertilia, or Lizards, found in Cuba. The colour of the best-known species (D. sagræ) is grey with bronze tints, whilst a black streak marks each side. D. is an active little creature, and inhabits dry localities.

The

Diplograp'sus, a genus of Graptolites (q. v.), an extinct group of Hydrozoa (q. v.) or Zoophytes. This genus, of which D. pristis is a familiar species, ranges in Britain and N. America from the Upper Cambrian strata to the upper strata of the Lower Silurian rocks; but in Bohemia, D. occurs in Upper Silurian rocks also.

Diplo'ma (Gr. diploō, 'I double or fold') is the writing given by universities and other learned bodies in proof of the person

which physicians can compel drunkards to be sent to these. Such a law is much required for the good of society.

The

Dip'tera (Gr. 'two-winged '), an order of Insects represented by the familiar Flies (q. v.) and other two-winged forms. D. are included in the Holometabolic group of the insect class, or in that section the members of which undergo a complete Metamorphosis (q. v.), and show the three characteristic stages of an active caterpillar or larva, a quiescent pupa or chrysalis, and a perfect winged and sexual imago. The front pair of wings are alone represented in these insects, the place of the absent hinder wings being supplied by a pair of filamentous organs, termed halteres or poisers, presumed to be serviceable to the insects in balancing them in their flight. The prothorax, or first segment of the chest, is always small, and, along with the other two thoracic segments, is generally fused into a single mass. The head is large, and the eyes are prominent. The mouth is for the most part of suctorial kind (see INSECTS), and the stomach is frequently of compound nature. The legs are usually long, and end in soft spongy bodies, by means of which these insects are enabled to obtain a firm foothold on smooth and perpendicular surfaces. In addition to the compound eyes borne by the head, several ocelli or simple eyes may also exist; and the antennæ or feelers are situated on the part of the head between the eyes. The wings may be wanting altogether in some D., and the skin of the larva for the most part forms a pupa case for the chrysalis. In some flies (such as in Pupipara), the young larvæ reside within the body of the mother, and there become pupæ; and in Cecidomyia or the Hessian-fly, each larva produces within itself another larva, which latter feeds on the primitive larva and becomes the future fly. See also articles relating to the various kinds of flies, such as CRANE-FLY, HESSIAN-FLY, &c.

Diptera'ceæ, or Dipterocarpa'ces, the Sumatra Camphor order, a natural order of Dicotyledonous trees with resinous juice, natives of the forests of tropical India, with the exception of the genus Lophira, which is found in tropical Africa, though by some this genus is made the type of a separate order (Lophiracea). There are about fifty species and seven genera in the order, all of which owe their peculiarities to the presence of the resinous juice. Wood-oil or Gurgun balsam is yielded by the trunks of D. lævis or turbinatus of the W. Indies. The oil is used in India for painting, and is employed for much the same purposes as Copaiva (q. v.). Dryobalanops aromatica yields Sumatra camphor (see CAMPHOR). Hopea odorata of Burmah yields a styptic resin. Shorea (Vateria) robusta is the Sal (q. v.) of India, and yields Dhoona pitch. Vateria indica yields the oleo-resin known as white Dammar or piny rosin, used in India for making candles and as a varnish. Piny tallow or vegetable butter of Canara a concrete oil-is obtained from the fruit of this plant, and has lately been imported into this country as a local application in rheumatism, &c. (Bentley). See ANIME, COPAL, DAMMAR, and VARNISH-TREE.

Dip'terus, a genus of extinct Ganoid (q. v.) fishes, confined exclusively in their distribution to the Devonian and Old Red Sandstone rocks. Two dorsal fins existed, and the body was covered with smooth overlapping scales. The head had a kind of helmet-covering, and the teeth were conical in form.

Dip'teryx, a genus of Leguminous plants. The seeds of D. odorata of Guiana, owing to the presence of Coumarine (q. v.), are very pleasantly scented, and under the name of Tonquin, Tonga, or Itonka beans, are used for perfuming snuff, &c. The Eboe nuts of the Mosquito Coast (D. Ebõensis) are also fragrant, and yield a fatty oil much used for anointing the hair of the natives. The timber is heavy and yellow coloured.

and metal were sometimes used, and these were often richly carved or chased.

Dip'us. See JERBOA.

Di'rect and Ret'rograde, two astronomical terms, applied to the motion of a planet, according as it appears to move in the zodiac from W. to E. or from E. to W. When it is moving neither way it is said to be stationary.

Direc'tion-Co'sines are the cosines of the angles which a given line makes with three rectangular axes given in position. Take any point (x, y, z) upon the line through the origin, whose D.-C. are l, m, n; then if r be the distance of this point from the origin, we have at once x lr, y = mr, z = nr. Squaring and adding, we obtain (12 + m2 + n2) r2 = x2 + y2 + 2a r2, or 12 + m2 + n2 = 1. Again, if there be another line, whose D.-C. are l', m', n', the angle which it makes with the first is that angle whose cosine ÏÏ' + mm' + nn'. These two fundamental formulæ are of great and growing importance in physical investigations.

Direc'tor. In commercial concerns it is usual to have a body of men-commonly about ten or twelve-whose business is to meet at short fixed intervals to consult together about the affairs of the concern, and to advise and assist the manager. The members of this body are called the Ordinary Directors. There is commonly another body called the Extraordinary Directors. These have no business functions, and are chosen as a rule from their social position being supposed to add to the reputation of the joint-stock undertaking. Ordinary Directors being paid officers, it may be held that they are bound to make themselves thoroughly conversant with the affairs of the undertaking; on the other hand, the remuneration is commonly insufficient to make it reasonable to suppose that they can afford time for this, when the concern is extensive and complicated. On the whole, the view of the commercial community seems to be that a D. is entitled to rely on the statements of the manager, unless these be such as ought to excite the suspicion of a man of ordinary business intelligence. But where this is the case, he is not enHe is bound to have the matter of sustitled to shut his eyes. picion probed to the root, and, if necessary, to consult the shareholders. Clearly the position must, in certain circumstances, be one of great danger and difficulty. As if disposing of all objection to the plenary responsibility of a D., the general truth is sometimes stated, that there can be no excuse for the neglect of a voluntarily accepted trust. But the question is as to the exact A D. is not a manager. His function is to advise, not in ordinary circumstances to investigate. Law Regarding Directors.-The following are the leading provisions of the Joint-Stock Companies' Act affecting directors: That a director shall vacate his office by the acceptance of any other office of profit in the company, by being concerned in any contract with it, or by bankruptcy; that at the first ordinary meeting after incorporation all the directors shall retire from office, and that at the first ordinary meeting in each subsequent year one-third, or the number nearest one-third, shall retire; those retiring who have been longest in office. They are reeligible. Directors may delegate their powers to committees. Minutes of business transacted at directors' meetings are to be carefully made, and signed by the chairman. Dividends are only to be paid from profit, and if a dividend is declared when the company is known by the directors to be insolvent, or when payment of the dividend will make it insolvent, they shall be jointly and severally (see JOINT AND SEVERAL) liable for the debts then existing of the company, or which shall be contracted while they remain, respectively, in office.

nature of the trust.

By 24 and 25 Vict. c. 96, directors, members, or officers of any body corporate or public company fraudulently appropriating property, or keeping fraudulent accounts, or wilfully destroying or vitiating books, or other writings, or publishing any false statement with intent to deceive, are guilty of a misdemeanour, punishable with penal servitude or imprisonment, according to degree of guilt. See JOINT-STOCK COMPANIES.

Council (viz., the Ancients and the Five Hundred) distinguish this Constitution of year 3 from the Girondist Constitution of 1791, the Democratic monarchy of 1792, and the Jacobin Constitution of 1793. The 'decrees of the two-thirds, by which the Old Convention insisted on modifying the proposal of the eleven Girondist commissioners, led to the Day of the Sections' (4th October 1795), in which Bonaparte destroyed the National Guards in the Rue St Honoré. Barras and Carnot (who replaced Sieyès) were the most prominent Directors, all of whom were elected by the two Councils. The D. soon became unpopular in spite of Bonaparte's brilliant campaigns. They crushed the Baboeuf Conspiracy (1797), and Pichegru and the Royalist party on the 18th Fructidor; but their policy of bascule, or seesaw between the Moderates and the Manéze Club in home affairs, their cruel Law of Hostages, and their misunderstandings with Bonaparte, who was the idol of the army, paved the way for the negotiations of Sieyes which resulted in the Revolution of 18th Brumaire and the Consulate.

Directory for Public Worship of God, one of the works of the Westminster Assembly, drawn up in 1644. George Gillespie, the Scottish commissioner, had a chief hand in framing it. The order of worship prescribed begins with an invocation; a chapter from each Testament is read; and the Lord's Prayer and other set forms are used. Baptism, marriage, and rebuke are to be public; and burial, without ceremony. The General Assembly of the Church of Scotland adopted the D., February 3, and the Scottish Parliament ratified it, February 6, 1645. The D., however, was not recognised at the Revolution Settlement, nor at the Union. The book was the expression of a fond illusion that uniformity of worship could be established, so as to secure the happy unity of the kirks of the three kingdoms. See A Directory for the Public Worship of God (Edinb. 1645); Principal Lee's Hist. of Church of Scotland (Edinb. 1860); Dr R. Lee's Reform of the Church of Scotland (Edinb. 1864); and Minutes of Westminster Assembly (Edinb. 1874).

Direc'trix, in geometry, is a straight or curved line on which depends the description of a curve or surface. A point, whose distances from a given point and straight line bear a constant ratio to each other, describes one of the Conic Sections (q. v.). This straight line is the D. of the curve in question. If a surface be generated by the motion of a line which always rests on other fixed lines, these latter are sometimes called directrices, but more frequently directors; the moving line is called a generator.

Dirk, a Scottish dagger or poniard formerly carried by Highland chieftains; also the name for the short sword worn as a side-arm by midshipmen in the British royal navy.

Dirk Hartog Island is one of several islands forming a breakwater for the extensive inlet of Shark Bay, on the W. coast of Australia. D. H. I. is high, and about 40 miles long by 10 broad. It lies in S. lat. 25° 28′-26° 6′, and E. long. 113°.

Dir'schau (Pol. Szczevo), a town of W. Prussia, on the Vistula, and on the Eastern Railway, 21 miles S.S. E. of Danzig, It has iron and machine works, large mills, a cattle-market, and an active timber trade. The Vistula is here crossed by an immense iron bridge, 2844 feet long and 37 feet high, erected 1850-60. Pop. (1872) 7758.

Dirt-Beds, a name given by geologists to certain deposits embraced by the Portland or Upper Oolite rocks, and more especially in connection with the Purbeck beds of these formations. The name 'D.-B.' is applied to these formations by quarrymen, and denotes old soils in which vegetable matter is thickly interspersed. These beds are in all likelihood old land surfaces formed between strata of marine origin by the intermittent elevation of the latter. Fossil cycads (Mantellia) form their chief vegetable remains.

Disability, in English law, is legal incapacity. It may be absolute, as by Outlawry (q. v.); or it may be partial, as from minority (see AGE) or Coverture (q. v.). See also CAPACITY, LEGAL.

Disban'ding, in military language, is the breaking up of a battalion or regiment. It generally occurs when peace is proclaimed after war, the officers being placed on half-pay, and the men discharged. But it was also resorted to in India to punish the mutiny of the native troops-the first instance being the D.

of the 19th regiment of native infantry at Barrackpore on the Ist of March 1857.

in England belongs to the Benchers (q. v.) of the four Inns of Disbar' is to degrade a barrister-at-law. The power to D. the courts of law. The last exercise of the power was in 1874. Court. No barrister who has been disbarred can plead before

Disc, or Disk, a somewhat vague term in systematic botany, generally applied to any organ intervening between the stamens and the ovary,' and may be in the form of a ring or scales. Frequently it consists of metamorphosed stamens forming an inner whorl. Sometimes it is glandular and secretes a honeylike fluid : in this case the older botanists called it the nectary. Disc and Discob'olus. See QUOITS.

Discharge'. A verbal obligation may be dissolved by a verbal D., but a written obligation requires a written D.; the rule of law being that the same solemnities required to constitute an obligation are required to extinguish it.

Discharging, in the navy, is relieving the ship of the commission under which it is placed in active service, the officers on full pay and the crew on the wages list. The fact that officers and crew can only serve on board ship puts them on a different footing from the officers and men in a regiment. Soldiers are on permanent pay during peace and war, sailors only while the ship is in commission. Ď. leaves the men off the wages list, and the officers mostly on half pay.

Dis'cina, a typical genus of Brachiopodous ollusca, represented by living forms, and also by fossil species, which begin in the Silurian period. The family Discinide is recognised by the shells being attached to fixed objects by a fleshy stalk or peduncle, which passes through the ventral valve. The characteristic arms of the Brachiopoda (q. v.) are fleshy in Discinidæ, and the valves or halves of the shell are not articulated by any distinct hinge. The shell in D. is circular, its upper valve being limpet-shaped, the lower valve being flat or convex. D. circe, and D. pelopea are well-known fossil species from Silurian rocks.

Dis'cipline, The First Book of, or Policie, an important landmark in the reformation of the Scottish Church. After the overthrow of Popery and the adoption of the ancient Confession in 1560, a commission, dated April 29 of that year, was given to John Knox and five others to draw up a B. of D. According to this B. of D., the minister was to be admitted with consent of the people and the approval of the ministers; ordination by imposition of hands was disapproved of; readers were to be provided for destitute places; the country was to be divided into ten districts, with superintendents for planting churches, appointing ministers, and visiting vacant places; elders and deacons were to be elected annually; every church was to have a schoolmaster; and the ancient patrimony of the Church was to be devoted to the threefold support of the ministry, education, and the poor. This book was dated May 20, 1560; and on January 27, 1560-61, it was subscribed in secret council by twenty-six noblemen and gentlemen, but it was never ratified by Parliament. It failed to become law because those who held the patrimony of the Church did not regard Knox's 'devout imagination' with favour. See The First and Second Booke of D. (Edinb. 1621); M'Crie's Life of Knox (Edinb. 1812); Knox's Hist. Ref. (Laing's ed., Edinb. 1848); and Cunningham's Church Hist. Scotland (Edinb. 1859).—The Second B. of D. was the result of an effort to make the Church of Scotland more strictly Presbyterian. The great reformer, Andrew Melville, and some others, were appointed, April 24, 1576, by the General Assembly, a committee to perfect the regulations of the Church. As the fruit of their labours they presented the Second B. of D., which was sanctioned by the General Assembly, April 24, 1578. This book set up a more elaborate form of Presbyterianism, and made a more complete distinction between civil and ecclesiastical jurisdiction.

Patron

age was abolished, also the titles of abbots, and the superiority of bishops; ministers were to be elected by judgment of eldership and consent of the people; ordination was to be by laying on of hands; and the various Church courts were appointed. The Second B. of D. was registered among the Acts of the Church by the Assembly, April 1581; but it never was ratified by Parliament, and never became a binding law of the Church.

See M'Crie's Life of Melville (Edinb. 1824), and Bryce's Ten Years of the Church of Scotland (Edinb. 1850).

Disclaim'er, in English law, is a plea of denial or of renun

ciation.

Disclama'tion, in Scotch law, signifies the disavowal by a vassal of some one who is, or claims to be, his Superior (q. v.). The penalty of D. on frivolous grounds is forfeiture of the Fee (q. v.). But any reasonable excuse will exempt the vassal from the penalty.

Discob'oli, a term formerly applied by Cuvier to certain genera of fishes, exemplified by the Lump-Suckers (q. v.), &c., with sucking-discs formed by the united ventral fins on the lower surface of their bodies. The term is not now used, lump-suckers being included in the Gobiida or Gobies (q. v.).

Discoph'ora (Gr. 'disc-bearers'), a name given in modern zoology to a subclass of Hydrozoa (q. v.), represented by the true Medusida (q. v.), or sea-blubbers and jelly-fishes. These organisms may be defined as possessing a free, oceanic body (hydrosoma), consisting of a single nectocalyx, or swimming-bell, from the roof of which a single zoöid or polypite hangs. A system of canals runs through the swimming-bell. Many forms at one time regarded as Medusa are now known to be merely the freeswimming reproductive bodies of zoophytes.

Dis'cord, in music, an interval producing Dissonance (q. v.). Strictly speaking, an interval is said to be dissonant if the notes of which it consists have any musical relation to each other, and discordant if they have none.

Dis'count is the deduction made from a debt paid before it is due. To discount a Bill of Exchange (q. v.), or a draft, means to exchange it under deduction of a percentage on account of its not having reached maturity. When this is done, it is the custom of money-dealers to subtract the interest accruing during the time between the date of their purchase and the date at which the bill or draft falls due. This causes the real charge to be greater than the nominal one, the interest being received by the lender before it is due. Thus, if you discount a bill of £100 due three months hence at 5 per cent., you will receive 100 less of £5—that is, £98, 15s.; but if you then lend your £98, 15s. for three months at 5 per cent., it is plain that the interest accruing during the period cannot be so much as the interest on £100 which has been deducted. In a true calculation of D., therefore, the question to be answered is-What sum will, at the given rate of interest, at the end of the given period, amount to the value of the deferred payment? The rule for ascertaining this is-Find the amount of £1 in the given time, and by that divide the given sum, and the quotient is the answer. Thus, What is the value of £100 to be received three months hence, interest at 5 per cent. The interest of £1 for a year will be Is., and for three months 3d., L00125. The amount of £1 therefore for the period is 10125; and the value of £100 1.0125 £98.765 £98 15 3

three months hence is = 100

The interest on which for three months at 5 per cent. is

I 4 81

Discretion. According to English law, if an agent or trustee is instructed to act according to his D., he must act according to law and reason. The law of Scotland recognises the same rule.

Dis'cus proligerus, a small heap of granular cells found within a graafian vesicle, and on which the ovum rests. See GRAAFIAN VESICLE and OVUM.

Discus'sion is a technical term of Scotch law, signifying a demand for payment against a principal debtor or against heirs. Formerly cautioners (see CAUTION), unless bound jointly and severally (see Joint and SeveraL) with the principal debtor, could insist on the creditor enforcing his demand against the principal debtor in the first place, or to discuss him, as it was called. By the Mercantile Law Amendment Act, cautioners can now only have this right by stipulation.

Discussion of Heirs.-All heirs who have incurred a representation of their ancestors are liable for his debts; but they may insist on being sued in a certain order. Where a special heir is burdened with a debt, the creditor must discuss that heir before he can insist against the heir-at-law. But where the debtor does not charge any special heir with payment of a general obligation, the D. must be in legal order. See REPRESENTATION, PASSIVE TITLE.

Disdi'aclasts, minute doubly-refracting molecules, which, according to Brücke, form part of the ultimate structure of muscle. See MUSCLE.

Disease' (lit. the opposite of ease), a medical term for that condition of the system in which there is a deviation from health. D. may or may not be accompanied with pain, but there is always a departure from the normal standard of health. D. may be local or general, structural or functional, curable or incurable, the latter always ending in death. The classification of D. is called Nosology (q. v.), and the changes in structure caused by it form the subject of Pathology (q. v.).

To find the amount of a given sum improved at compound interest at any rate, and for any number of years, the rule isMultiply the amount of £1 for a year so often into itself as there are years proposed, and the last product multiplied by the principal gives the answer. Thus-What will £10 amount to in three years at 5 per cent. compound interest-1°05 × 1'05 × 1'05 1*157625 × 10£11.57625 = £11, 11s. 5d.

By D. is also understood the depreciation of any share or stock below the original value. Thus, when a bank share on which £100 has been paid will only bring £90 in the market, it is said to be at a D. of 10 per cent. The converse position is called being at a premium.

The rate of D for bills of exchange in the United Kingdom, in ordinary times, ranges from 3 to 5 per cent. on bills of three or four months' currency. When it goes above 5 per cent. the fact indicates commercial disturbance. In recent times the rate has In recent times the rate has more than once risen as high as 10 per cent. The provincial banks, in their D. rates, follow the lead of the Bank of England. See INTEREST.

Dishonour, a term of mercantile law, denoting the refusal of the drawee in a bill of exchange or cheque to accept or pay it. If a bill be presented and acceptance refused, or a qualified acceptance only offered, prompt notice must be given to all the parties to whom the holder intends to apply for payment. In case of a foreign bill, notice should be sent by first post or earliest opportunity. post or earliest opportunity. Generally, in both foreign and inÏand bills, notice is given next day to the immediate endorser, who is allowed a day to give notice to those who are liable to him. Delay in giving notice frees the drawer and endorsers from liability. No particular form of notice is required, but it is well to send a copy of the bill. A person having taken a cheque in payment of a debt cannot sue for the debt until the cheque has been dishonoured; but a creditor is not bound to accept a cheque (case of Hough v. May, N. & M. 535). If the holder of a cheque accept payment in bank-notes, and the bank fail, the holder has no recourse against the drawer of the cheque. See BILL OF EXCHANGE, CHEQUE,