in hot water, and converted into bichromate by the addition of a salt of potash. Its chemical formula is KO 2Cr O3. It contains in 100 parts 68.4 of chromic acid and 31.6 of potash. Bichromate of potash is used in immense quantities by the calico printers.-The variety of colors which may be obtained from the numerons combinations of chromium, and the permanent quality of many of them, give great interest to this substance; and the full benefits that may be derived from it are probably very far from being yet appreciated. Some compounds of this character have been lately discovered by Prof. A. K. Eaton, of New York, and have been successfully applied to the printing of bank notes. The colors powerfully resisted the various agents that might be employed to remove them; but the extremely sharp and hard nature of the powders, to whatever degree of fineness they were reduced, was found to have an injurious effect in rapidly wearing the costly steel plates. The new combinations were discovered in the course of experiments made for the purpose of devising a practicable method of obtaining the chromate of magnesia, a compound then already known. They consist of the sesquioxide united with different bases, and the series may be represented by the general formula, RO, Čr, O3. They are produced by the double decomposition of bichromate of potash and the sulphates of the different bases, using an equivalent of each. The decomposition is effected at a red heat in crucibles, the sulphate of potash produced in the operation being removed by washing. The chromite of iron, FO Cr2O3, thus obtained, corresponding to the native chromic iron, is usually a crystallized powder, resembling, except in color, the sesquioxide. The crystalline structure commonly characterizes the other compounds, unless they are produced at a low temperature, when they assume the amorphous condition. The color of the chromite of iron is dark purple. The chromite of manganese is a lighter shade of the same color. The chromite of copper is a rich bluish black. The chromite of zinc is a golden brown; of alumina, a green scarcely differing from the sesquioxide except by being somewhat paler. Chromic solutions act powerfully upon organic matters. Small animals, as mice, birds, &c., are so completely dissolved in them that in a few minutes no trace of their hair, skin, or bones can be discovered. The workmen employed in preparing the compounds are much affected with troublesome sores and ulcers which are very difficult to cure. Paper impregnated with the salt makes a very good tinder.

2

CHRONIC (Gr. Xpovкos, continuing a long time). A chronic disease is one which is inveterate, differing in many respects from an acute disease, which terminates speedily. The length of duration, however, is not the only distinction between chronic and acute disease. Intensity of pain and inflammation form the main features of an acute disease, while disorders of a dull, slow character and progress, without

much pain or inflammation, are mostly termed chronic. The different forms of rheumatism, for instance, are divided into 4 varieties, termed acute, subacute, chronic, and nervous. The acute form of a disease may run its course in a few days or weeks, and then terminate, either by disappearing altogether, or continuing with a notable diminution in the intensity of the symptoms, and thus subsiding, as it were, into the chronic form. After long continuance in a chronic form, the symptoms may suddenly increase in their intensity, and thus assume the acute form for a short period, which may possibly terminate in a com plete cure, or again relapse into the chronic form. Chronic disease is mostly associated with weak and nervous or strumous constitutions; but many originally strong constitutions become debilitated by long continued habits of excess either in bodily or mental labor, or in sensual indulgence; and all debilitated constitutions are subject to various forms of chronic disease of the digestive, the nervous, and the vascular systems.

CHRONICLE, a book narrating the events of universal history, or of the history of a particular people, epoch, prince, city, convent, or family, registering in the order of time, and without philosophical remark, all the details which either observation or tradition has furnished the writer. Chronicles were the earliest modern histories, the successors of the ballad in the order of the development of literature, and common throughout Europe during the middle ages. When wealth had been accumulated in the monasteries, and leisure was attained, the ballad, which had been the first solace and amusement of the popular mind, began to subside into the lower portions of society, while the better educated created for themselves the more learned and pretentious form of literature called the chronicle. Most of the mediaval chronicles were by monks, especially by the diligent Benedictines, who usually began their story with the creation of the world, or at least with Noah, and gave an abridged history of the events from the 1st chapter of Genesis to the immediate subject of their narrative. In their statement of facts they in general knew little distinction between fabulous and true history, were not inclined to question much either visions or miracles, and were accustomed to dwell as long upon a hail-storm or an eclipse of the sun, as upon a battle or change of dynasty. Chronicles are valuable for determining historical facts when, like that of Eusebius, they contain materials from older works which are now lost, or when they relate events contemporary with a writer, and of which he was a witness; and they are always valuable as illustrations of the spirit of an age and the sentiments of a people. It is through them that nearly all the history of the middle ages has been preserved. Every European people has numerous medieval chronicles, which recount with equal particularity the origin of a nation, the history of a monastery, or the advent of cold weather.-The oldest German chronicles

are written in Latin; the most famous of them are the chronicle of Regino, abbot of a monastery in the forest of Ardennes, whose work extends from the Christian era to 907, within a few years of his own death; that of Hermannus Contractus, entitled "A Chronicle of the Six Ages of the World," to the year 1054; that of Lambert von Aschaffenburg, which recounts the period from the beginning of the world to 1050 in brief, and from 1050 to 1077 in detail; that of Godfrey of Viterbo, giving a universal history to the year 1186, written partly in prose and partly in verse, and entitled "Pantheon;" and a chronicle found in the collection of Pistorius, composed by an Augustinian monk, which extends from the Christian era to 1474. These, with many other Latin chronicles, have been collected and published at Hanover in a series of volumes entitled Monumenta Germaniæ Historica. The oldest historical book in the German language is a rhyming chronicle, consisting of 83,000 verses, written by Ottokar von Horneck, in the 13th century. Of nearly the same antiquity are the chronicles of Rudolf von Ems and Jansen Enekel, both having the form of poems, and furnished with notes by their authors.-The national chronicles of Spain and Portugal enjoy a high reputation, and fill the space between the 13th and 16th centuries, between the ballads and the romances. The earliest of them, entitled "The General Chronicle of Spain," came from the royal hand of Alfonso the Wise, about the middle of the 13th century. It is divided into 4 parts; the 1st, opening with the creation of the world, hastens over every thing till it comes to Roman history, to which it allows large space, and in which Queen Dido, a universal favorite with Spanish poets, is defended against the charges of Virgil; the 2d part treats of the Gothic empire of Spain and its conquest by the Moors; the 3d comes down to the reign of Ferdinand the Great in the 11th century, and abounds in the rich old traditions of the country, relating the outbreak of Pelayo from the mountains, and the stories of Bernardo del Carpio, Fernan Gonzales, and the 7 children of Lara; the 4th part opens with the history of the Cid, the great popular hero of Spain, so variously commemorated in Spanish literature, and closes with the death of St. Ferdinand, the conqueror of Andalusia, and the father of Alfonso himself. The "General Chronicle was followed by the "Chronicle of the Cid," which has been translated by Southey, and is a most interesting picture of the stern violence and generous virtues of the period to which it relates. Subsequently a royal chronicler was appointed in each reign, and from the death of the wise Alfonso to the reign of Ferdinand and Isabella, every monarch became the hero of a chronicle. Ayala was the chronicler of the 4 wild reigns which occupied the last half of the 14th century, and is distinguished above all his contemporaries. for the majesty of his style and the nobleness of his sentiment, while his work has all the cool and business-like minuteness of its class. For 250 years the old Span

ish loyalty and religious faith found its expression in chronicles; not only royal persons and events were thus celebrated, but also every deed of daring or wonder in which the nation became interested. Thus there was the chronicle of the passage of arms at Orbigo, of the truce of Tordesillas, of the achievements of the great captain Gonzalvo, and lastly, the chronicle of Don Roderic, which marks the transition to the romances of chivalry. A collection of Spanish chronicles was published under the title of Coleccion de Cronicas, in 7 vols., Madrid, 1779-'87.-The chronicles of Italy begin with the early ages of Christianity, and reach to the 16th century. The oldest of them are in Latin, one of the most important of which is the Historia Romana of Paulus Diaconus; they have been collected by Grævius in a thesaurus of Italian antiquities and histories, and are also contained in the collection of Italian writers by Muratori.France is rich in chronicles, universal and particular, written in Latin, French, and various provincial dialects. It was the fancy of the earliest chroniclers to give to France a Trojan origin. Thus Hunibald makes the Franks descend from Francus, son of Priam; and Gregory of Tours adds the particulars that Francus arrived from the East first at Pannonia, whence he came with a colony to Gaul. Fredegaire, not content with a Trojan origin, makes King Clovis third in descent from a sea-deity. Eginhard, much superior to the writers who had preceded him, the friend of Alcuin, and the son-in-law of Charlemagne, chronicled the exploits, manners, virtues, and talents of that emperor. The chronicle of Guillaume de Puitlaurent concerning the Albigensian war, and that of Guillaume de Nangis concerning the reigns of Philip Augustus and St. Louis, abound in curious details. The first of the chroniclers who wrote in the popular language was Geoffroi de Ville-Hardouin, who lived in the 12th century, and was an actor in the events which he describes. His work was continued by Henri de Valenciennes; and the unrivalled chronicles of Froissart and Monstrelet embrace between them the whole of the 14th and the first half of the 15th century. The chronicles of St. Denis, so called from the place of their composition, recount the principal events of the history of France to the year 1355, and have often been consulted to regulate the ceremonial of worship, and to decide questions concerning privileges, and the prerogatives of princes and lords. The "Scandalous Chronicle," supposed to have been written by Jean de Troyes, narrates the events of the latter part of the 15th century, and was reputed a satire upon the times. The Alexandrine chronicle, found in the collection of the Byzantine historians, and relating the events from the beginning of the world to 1042, has been published in France by Du Cange. The best collections of French chronicles are those of Dom Bouquet and other Benedictines (20 vols., Paris, 1738-1842), and of Buchon (47 vols., Paris, 1824-29).-The chronicles of England are hardly less in number or importance

than those of the continental countries. Among the earliest of them is that by Geoffrey of Monmouth, a monk of the 12th century, tracing the history of Britain with the utmost gravity through a series of fabulous adventures and imaginary kings, beginning with Brutus, a son of the Trojan Eneas, who founded the British state many centuries before the Christian era, and ending with Cadwallader, who was said to have lived A. D. 689. It was in Latin, and furnished the materials for the rhyming chronicles of Wace in Norman French, of Layamon in Saxon, and of Robert of Gloucester in English. From it also Shakespeare derived the story of Lear, Sackville that of Ferrex and Porrex, Drayton much of the materials of his "Polyolbion," and the poems of Milton many of their allusions. There is a curious work by Andrew Wyntown, regular monk of St. Andrew, who died about 1420, entitled "The Origynall Chronykill of Scotland," a rhyming story in 8syllabled metre, containing much universal history. There is also "The Saxon Chronicle, from the incarnation of our Lord to the death of King Stephen." Robert Fabyan wrote the "Concordance of Stories," first published in 1516, giving the history of England from the time when "Brute entryd firste the ile of Albion" to 1485; and the wars between the houses of York and Lancaster are related in Hall's "Chronycle," first published in 1542. The collection of chronicles edited by Holinshed in 1577 embraces a history of England to that year, a history and description of Ireland by Stanihurst, and a history of Scotland translated from Hector Boethius. More than 50 works relating to the history of England, written between the 6th and 16th centuries, under the name of chronicles, have been reprinted. Translations of several of them, among which are those of Matthew Paris, Roger of Wendover, Roger Hoveden, Ordericus Vitalis, Henry of Huntingdon, Matthew of Westminster, and Florence of Worcester, have been recently published in Bohn's “Antiquarian Library.”

CHRONICLE, WILLIAM, an officer in the war of the American revolution, born in South Carolina in 1755, fell in the battle of King's Mountain, N. C., Oct. 7, 1780. He belonged to the contingent furnished by South Carolina to her sister state in 1779, after the defeat of the united American and French forces in the fatal attempt upon Savannah. In 1780 he became major of a regiment designed to arrest the progress of the British from the low country of South Carolina into the interior, and was killed while gallantly leading on his men in the first action which followed. A monument was erected to his memory upon the battlefield.

CHRONICLES, the name first given by Jerome to two historical books of the Old Testament. By the Alexandrine translators they were termed Paraleipomena, or things omitted, being regarded as supplementary to the previous histories. In the original Hebrew

they are entitled "Words of the Days" (Dibre Hayamim), and form, as their internal character demonstrates, but one book. The Chronicles open with genealogical registers of ancient and renowned families or races; they then narrate the history of David, harmonizing with the earlier account in the book of Samuel; then follows a history of Solomon, and of the increasing prosperity and glory of the Jews under him; after the division of the kingdom at his death, they trace the history of Judah, the more powerful branch, and continue the narrative till after the fall of Israel, and to the end of the exile in Babylon. They thus had a comparatively late origin, which is indicated also by the style and idiom, and by the Levitical coloring which overspreads much of the narrative. The Jewish and Christian traditions, from the earliest times down to the 17th century, have referred the Chronicles to the age and to the pen of Ezra. The first who assigned them to a later period was Spinoza, and his opinion that they originated in the time of the Maccabees has been accepted by many of the learned since him. The earlier Jewish records furnished the materials of the history in the Chronicles, and numerous books are mentioned as sources and authorities which have not been admitted into the canon. The design of the books seems to have been, by a review of the history of the theocracy, to prove that the Levitical worship had been maintained and favored by all pious kings, and that adherence to it or departure from it had been the condition of fortune or misfortune to the Jewish people. The discrepancies in numbers, dates, names, and facts,. between the books of Chronicles and of Kings, have long been recognized, and have occasioned an important discussion between two parties of critics as to whether the integrity of the text or the authority of the history of the Chronicles should be surrendered. Among the most successful writers in vindication of the Chronicles are Movers, Kritische Untersuchungen über die Biblische Chronik (Berlin, 1833), and Keil, Apologetischer Versuch über die Chronik (Berlin, 1833).

CHRONOLOGY (Gr. χρονολογια, χρόνος, time, and λoyos, discourse or doctrine) may be defined as the science of determining historical dates. The unlearned man, familiar only with the modern mode of recording events, and with the uniformity of reckoning among modern western nations from the Christian era, and by the Gregorian calendar, can hardly have a just conception of the difficulties which chronology presents; and if such a concep tion is attained by him, can scarcely understand the mode by which modern chronologists have in some instances triumphed over those difficulties. The dates of events in the history of the principal nations can be readily determined from written contemporaneous testimony for about 1600 years, counting back from our day. For the next 1100 years, still counting back, we have written records, but not always contemporary

with the events, and also engraved or sculptured records; these two sorts of history confirm each other, but the want of a common era makes it very difficult to fix dates during this period. From the monuments in Egypt, the bricks and cylinders of Assyria, and similar sources, rude estimates of the dates of Egyptian history may be made to about 2550 B. C., of Chaldean dates to 2234 B. C., and of Assyrian to 1273 B. C. Fortyfour centuries may be thus reduced to tolerable certainty. For times preceding this era we have no means of estimating dates except from vague traditions, or from the narrative of the Old Testament. But as the three forms of the Bible (Hebrew, Greek, and Samaritan) which have come down to us differ materially in the ages of the patriarchs at the time of their sons' birth, it is useless to attempt any exact estimate of the time of the flood, or of the creation of man. Nearly all the eastern nations have legends of times when gods ruled on the earth for many thousands of years, giving way to demigods, and these to men; but these claims are considered by chronologists to be undeserving of attention, and to have arisen simply from the difficulty of conceiving an abrupt commencement to the existing order of human events. It is, however, conceded by the students of Egyptian and Assyrian remains, that civilization and art had already attained a high degree of development in Egypt and Chaldea at the earliest historic dates, 2200 to 2550 B. C.; so that the creation of man must have been many centuries earlier. The Egyptians have left us carved inscriptions on the pyramids, on obelisks, or other stones, also writings on papyrus, and on the wrappings of their mummies. These inscriptions have been deciphered during the present century, and have afforded means of criticizing the Greek historians, Herodotus, who completed his history about 430 B. C., and his successors, for instance, Ctesias, whose authority is now nearly destroyed, and Manetho. The latter writer was an Egyptian, and we possess only fragments of his work, preserved through their quotation in Greek authors. The testimony of the monuments is counted as most important, because it is contemporaneous, and frequently engraved by royal authority. Occasional passages in the Egyptian history thus determined connect themselves with Chaldean, Assyrian, or Jewish history, and are confirmed by Assyrian remains, and by the Jewish Scriptures. But the chronology of all the period remains obscure, and difficult to establish satisfactorily from two causes, the uncertainty of the order of succession of the kings, and the difficulty of determining the length of their reigns.-What we have said of the monuments of the Egyptians may be repeated of the remains of the Assyrians. Within a few years the explorations on the sites of Nineveh, Babylon, and their neighborhood, have brought to light numerous inscriptions on brick, pottery, seals, clay cylinders, &c., some of which, like some of the Egyptian inscriptions, have been accompanied

by a translation carved in another tongue, thus giving a clue by which the cuneiform inscriptions are now deciphered. These remains enable us to criticize Herodotus and other Greek historians, and the fragments which they give us of Berosus the Babylonian. Their history also connects itself with the Jewish Scriptures, and the two confirm each other, and help us in judging of the difficult problem of dates. Attempts are also made to bring astronomy to the aid of chronology. Ancient historians, regarding eclipses as prodigies and portents, occasionally mention them as taking place in connection with events of human history, and astronomy enables us to determine when the eclipse took place. Thus, if the shadow moving backward on the dial of Ahaz was produced by an annular eclipse (none but a prophet could foretell such an eclipse in that age of the world), it might be possible by astronomy to fix the date when an eclipse was annular in Palestine. Again, it is said by Herodotns that in the last struggle between the Medes and Lydians, hostilities were brought to a sudden close by the day turning into night. If astronomy could determine with accuracy in what year about 610 B. C. a total eclipse passed over the scene of battle, this would fix the date of this battle. But it must be allowed that the calculation of a solar eclipse at such a distance of time is a somewhat uncertain operation; the minutest error in our modern tables might throw the shadow of the moon on an entirely different part of the earth from the scene of Cyaxares's fight, or from Ahaz's dial. Lunar eclipses are more readily used in fixing dates, as they do not require so much nicety of calcu lation, being visible to a whole hemisphere at once. Thus an eclipse of the moon, recorded by Thucydides as occurring in the 4th year of the 91st Olympiad, enables us to fix that year as corresponding to 413 and 412 before our era. During all the early periods of which we have been speaking, the accession of the reigning sovereign seems to be the only era from which to date; and as if this were not confusion enough, different kinds of years are used by different nations, and even by the same nation for different purposes. The Egyptians had 3 years: one of 360 days, a second of 365, and a third of 365. Each of these kinds of years was divided into 3 seasons, spring, summer, and winter, of 4 months each, each month having 30 days. In the second kind of year, 5 days were added to the end of the 12th month; and in the third these 5 supernumerary days were, every 4th year, made 6. The year of 360 days was the oldest; but the year of 365 days was known long before 1322 B. C. The square year of 365 days was reserved for particular occasions, when more accurate calculations of the return of the seasons were required. The oldest year in all countries was probably 354 days, as, in all languages, the month is named from the moon.-The ancient monuments of Greece afford us no means of verify

ing dates in their earliest history; and we have only ancient traditions preserved by later his torians on which to build our chronology of those times. Before the Trojan war these traditions were very vague; the epoch of the war is itself somewhat uncertain. But after this time the history assumes a more definite form; and from the time of the first Olympiad, 776 B. C., the dates of Grecian history are tolerably well fixed. The Olympiads were periods of 4 years, named from the games so famous in history, which were celebrated every 4th year, in the first half of the first moon after the summer solstice. Their first establishment is traditionally assigned to different dates in the 14th and 15th centuries B. C.; but the first historical account of them is of their reëstablishment by Iphitus, Cleosthenes, and Lycurgus, 844 B. C.; and it was not until the century after this that events began to be dated from, them. The games in which Corcbus was victor, 776 B. C., were taken as the starting point from which to count the Olympiads. For 87 Olympiads the Grecian year consisted of 354 days, in months of 29 and 30 days alternately; but they had a leap year, at first 4 times, afterward 3 times in 2 Olympiads, adding a month of 30 days to each leap year. Other attempts were made to conform these years to the actual course of the sun, and in the 4th year of the 86th Olympiad, the Metonic cycle of 19 years was introduced. This was used as long as the Olympic games were celebrated, and was revived by the council of Nice, for the determination of the period of Easter. The old adjustment, however, of putting 3 additional months into every 8 years, was followed in cívil matters even after the more perfect cycle of Meton was known. The early history of Rome is shrouded in an obscurity like that which hangs over that of Greece. All the Roman historians date from the foundation of the city, but there are 5 different years assigned as the date of this event from the 3d year of the 6th Olympiad to the 1st year of the 8th; that is, from 753 to 747 B. C., the earliest date being considered by modern chronologists as the most probable. The Roman year was of 2 kinds: the civil year, which began with the kalends of January, but whose length appeared to depend upon the whim of the pontiffs; and the consular year, which, before the 7th century of Rome, had no fixed beginning, and lasted until a new election, which might be earlier or later, according as political reasons determined the day for holding the comitia. The consulate is the date usually employed by Latin historians. The foundation of Rome was on April 21; hence the year of Rome did not correspond in its whole length to the civil nor to the consular year.-The Christian era, named from the birth of Christ, does not probably correspond in its epoch with that event by several years. It was, perhaps, invented in the 6th century by a Roman abbot, Dionysius the Little, although he reckoned from March 25, 9 months sooner than the common

era. This original era of Dionysius was used in parts of Italy and France down to a very late period; in Pisa till 1745. The chronicles of the middle ages sometimes use other periods from which to reckon the year of the Lord; such as March 25 after the common era, Easter day, March 1, Christmas, &c. A knowledge of these differences is indispensable in explaining the apparent contradictions in the dates of events in the middle ages. Care must be taken with regard to events subsequent to 1582 to determine whether the old or new style is used, the difference between which, in the 17th century, was 10, in the 18th 11, and in the present century 12 days. Care must also be taken to decide whether a writer calls the year immediately preceding our era 1 B. C. or 0 B. C.; mathematical writers usually adopt the latter notation.-The earliest Jewish, like the earliest Egyptian year, began in the autumn, and in civil affairs and in the regulation of jubilee years the autumnal equinox is still considered by the Jews the beginning of the year, while in other ecclesiastical affairs the year is counted from the passover, or from the vernal equinox. As the feasts of the Jews have reference to the seasons of the year, the entire year was by intercalation kept nearly of true solar length, while the months were purely lunar, beginning with the appearance of the crescent moon in the west. The intercalation was effected by throwing in a month of 30 days before Nisan whenever the 15th of Nisan (the day of the passover) would otherwise come before the vernal equinox. After the dispersion they adopted a cycle of 84 years, in which they were imitated by some Christians. But when the council of Nice adopted the Metonic cycle of 19 years for the determination of Easter, the Jews also employed it to determine the time of the passover. Until the 15th century the Jews used the era of contracts or era of kings (see Maccabees), which dates from the first conquests of Seleucus Nicator in Syria. But some writers make the year begin in the spring, others at various times in the autumn; some employ a year of 365 days, others of 3651 The era is commonly computed as 311 years 4 months before the common Christian era. Since the 15th century the Jews generally date from the creation, which they suppose to have taken place in September, 3761 B. C. The estimates of the real epoch of the creation of Adam, by students of the Old Testament, vary from 3616 to 6984 B. C. The Greek Christians who date from the creation, as was done in all Russia before Peter the Great, place it in Sept. 5509 B. C. The Abyssinians are said still to use sometimes the old Coptic or Alexandrian era, which was established by Julius Africanus as the true date of creation, 5502 B. C., but which, since the accession of Diocletian to the throne, has been taken as 5492 B. C. This latter era coincides nearly with that of the Syrian Christians or of Antioch. The era of Nabonassar is famous in history from being