COMSTOCK LODE

Comstock Lode, a ledge of silver, to which Virginia City, Nevada, largely owes its prosperity. Discovered in 1859, the lode has since yielded at times over ten million dollars annually. The shaft is 2300 feet deep, but work is now confined to the upper levels, the workmen having been driven from the depths by the heat (120 F.) and by the steam generated through the action of the air on the sulphurous rock penetrated by the different levels.

Comte, AUGUSTE, the founder of Positivism (qv), was born 19th January 1798, at Montpellier, where his father was treasurer of taxes. At the Lycee of his native place he was distinguished equally for his aptitude for mathematics and his resistance to official authority, characteristics which did not desert him on his entering the Ecole Polytechnique at Paris in his seventeenth year. Here he took the lead in a protest of the students against the manners of one of the tutors, and was expelled, after a residence of two years had obtained recognition of his abilities from the professors. A few months were spent with his parents, and then Comte returned to Paris, where for a time he made a scanty living by teaching mathematics. It would seem that, some years before, he had completely freed himself from the influence of all existing social and religious theories, and a reforming zeal was beginning to possess his mind, when in 1818 he came into contact with St Simon, by whom his inclination towards the reconstruction of thought and life was confirmed and strengthened. A definite relation was established between them, by which Comte remained for six years the disciple and collaborator of the older thinker; but there gradually became apparent a disagreement of aim and method, and the necessity felt by Comte of asserting the independence of his own conceptions led to a violent rupture. In 1825 Comte inarried, but the union proved unhappy, and after seventeen years of intermittent discord, ended in a separation. In the following year Comte began a course of lectures in exposition of his system of philosophy, which was attended by several eminent men of science, but the course was soon interrupted by an attack of insanity, which disabled the lecturer for a few months. His labours were afterwards resumed, and the six volumes of his Philosophie Positive was pubhshed at intervals between 1830 and 1842, during which period his livelihood was chiefly obtained from the offices of examiner and tutor in the École Polytechnique. After these positions were taken from him, owing to the prejudices of his colleagues, be resumed the private teaching of mathematics, beit in his later years he was supported entirely by a subsidy' from his friends and admirers. In 1845 Comte became acquainted with Clothilde de Vaux, and until her death within a year afterwards, a close intimacy was maintained between them. On Comte's side it was a passionate attachment, the parity of which was happily preserved, and its lence is clearly shown in his later works, especially in the most important of these, the Politique Positive. Comte died in his sixtieth year on 5th | September 1857. He was buried in the cemetery of Pre-la-Chaise. A full account of his system will found in the article POSITIVISM. His works are Cours de Philosophie Positive (6 vols. Paris, 1830 42; freely translated into English, and condensed by Harriet Martineau, 2 vols. 1853), Traité Elementaire de Geometrie Analytique (1843), Traité d'Astronomie Populaire (1845), Discours sur l'Ensemble du Posito Caine (1848), Système de Politique Positive (4 vols. 1851-34; Eng. trans. 1875 et seq., Longmans), and Catechisme Positiviste, ou Sommaire Erposition de la Religion Universelle (1 vol. Paris, 1852). Comte's Testment was published with a good many of his letters in 1884.

Comus, in later antiquity, a divinity of festive mirth and joy, represented as a winged youth, sometimes drunk and languid as after a debauch, or slumbering in a standing posture with legs crossed. Comus thus became the representative deity of riotous merry-making, of tipsy dance and jollity, and as such figures in Milton's noble poetic tribute to chastity, the mask of Comus; though here the poet, as elsewhere, has devised his own mythology, and made him the child of Bacchus and of Circe, much like his father, but his mother more.'

Comyn, CUMMING, or CUMYN, a family which rose to great power and eminence in England and Scotland. It took its name from the town of Comines, near Lille, on the frontier between France and Belgium. While one branch remained there, and in 1445 gave birth to the historian Philippe de Comines (q.v.), another followed the banners of William of Normandy to the conquest of England. In 1069 the Conqueror sent Robert of Comines, or Comyn, whom he created Earl of Northumberland, with 700 horse to reduce the yet unsubdued provinces of the north. He seized Durham, but had not held it for 48 hours when the people suddenly rose against him, and he perished in the flames of the bishop's palace, leaving two infant sons. The younger, William, became Chancellor of Scotland about 1133, and nine years later all but possessed himself of the see of Durham. The chancellor's grandnephew, Richard, inherited the English possessions of his family, and acquired lands in Scotland. By his marriage with Hextilda, the granddaughter of Donald Bane, king of the Scots, he had a son William, who was Great Jus ticiary of Scotland, and about 1210 became Earl of Buchan by marrying Marjory, daughter and heiress of Fergus, the last Celtic Earl of Buchan. Their son, Alexander, Earl of Buchan, married Isabella or Elizabeth, second daughter of Roger de Quenci, Earl of Winchester, and with her acquired the high office of Constable of Scotland, with great estates in Galloway, Fife, and the Lothians. By a previous marriage with a wife whose name has not been ascertained, William Comyn was father of Richard-whose son John (Red John Comyn) became Lord of Badenoch-and of Walter, who by marriage became Earl of Menteith, and was one of the guardians or regents of Scotland during the minority of Alexander III. Through other marriages the family obtained, for a time, the earldoms of Angus and Athole, so that, by the middle of the 13th century, there were in Scotland 4 earls, 1 lord, and 32 belted knights of the name of Comyn. Within seventy years afterwards this great house was so utterly overthrown that, in the words of a contemporary chronicle, there was no memorial left of it in the land, save the orisons of the monks of Deer' (founded as a Cistercian monastery by William Comyn, Earl of Buchan, in 1219). The Comyns perished in the memorable revolution which placed Bruce on the throne of Scotland. Their chief, Black John Comyn, Lord of Badenoch, great-grandson of William, Earl of Buchan, had, in 1291, been an unsuccessful competitor for the crown, as a descendant of the old Celtic dynasty through the granddaughter of King Donald Bane. His son, also called Red John Comyn, was one of the wardens of Scotland, and distinguished himself by his gallant resistance to the English. Suspected by Bruce of betraying him to Edward, Comyn fell under Bruce's dagger, before the altar of the Franciscan friars at Dumfries in 1306; and his kindred went down, one after another, in the struggle to avenge him. John Comyn, Earl of Buchan, the son of Alexander and Isabella de Quenci, was de feated by Bruce in a pitched battle, near Inverury, in 1308, when his earldom was wasted with such relentless severity, that we are told by the poet

CONCHIFERA

'Conchs from the commonness of the shells on their coasts.

Conchifera (Lat., 'shell-bearing'), a term applied by Lamarck to bivalve molluscs and the very different Brachiopoda (q.v.), but now rarely used.

Conchoid (Gr., 'shell-like,' from the shape), a plane curve invented to solve the problem of trisecting a plane angle, doubling the cube, &c. Given any straight line and a point without it, we can describe two companion curves which are dissimilar, but have the straight line as their common Asymptote (q.v.) between them. Thus both branches extend in either direction to infinity, and can never meet though continually approaching each other. The conchioid is obviously symmetrical with respect to the straight line drawn perpendicular to the given line from the given point. This curve has been utilised in architecture to give a waving outline to tapering columns. Through A the fixed

D

E

point draw any line ADE, measure DE and DE each = BC, then E and E' trace the two branches of the conchoid. When BC = BA, there is a cusp at A: when BC is greater than BA, the inferior branch has a loop as in the figure.

Conchology, that branch of natural history which deals with the shells of molluses. From the time of Aristotle the beauty and variety of these structures have made them favourite objects of study, and few zoological subjects have excited so much popular enthusiasm. The study often became unscientific, and sometimes a craze, as when extravagant sums were paid for rare forms of no particular beauty or interest. Since the shells are only external coverings, and were seldom considered in relation to their tenants, or in connection with the internal and external influences to which they owe their shapes, conchology has been somewhat barren of scientific results. It is, however, possible that with the accumulation of knowledge in regard to the constitution and conditions of molluses, the study of their shells may come to have fresh scientific interest and dignity. See BIVALVES,

MOLLUSCA, SHELLS, &c.

Concierge is the French name for a door keeper or janitor of a house, hotel, or public etice. In French towns, where a large portion of the population lives in flats, the common door by which many households have access to their several tenements is very usually under the charge of a concierge, who exercises a general supervision over all who pass his conciergerie. The ancient Paris prison, known as the Conciergerie, is still standing; though Marie Antoinette's cell, converted in 1816 into a chapel, was destroyed by the

Communists in 1871.

Conclave (Lat.), the place where the cardinals of the Roman Catholic Church assemble in private for the choice of a pope, or that assembly itself. See POPE

Concord, capital of New Hampshire, U.S., on the Merrimac River, 73 miles NNW. of Boston by

rail. It extends two miles along the river, with wide streets, and contains a fine granite statehouse and other public buildings. Its quarries of white granite are celebrated; and with abundant water-power, it has manufactures of cotton, woollen, leather, and wooden goods, machinery, carriages, organs, &c. Pop. (1870) 12,241; (1890) 17,004.

Concord, a town of Massachusetts, in the county of Middlesex, 23 miles by rail NW. of Boston. It is the seat of a large prison and reformatory. As early as 1767 the people of Concord opposed the measures of the British government, and in the revolutionary war a skir mish took place here, 19th April 1775. The place is notable as having been the home of Emerson, Hawthorne, Thoreau, and other men of letters. Pop. (1880) 3922; (1885) 3727; (1890) 4435.

Concord, in Music, is a combination of notes which satisfies the ear, without requiring any others to follow-e.g. the common chord, or com bination of a note with its perfect fifth and major or minor third. See MUSIC.

Concordance (Low Lat. concordantia), originally a system of harmonising things that differ or appear to differ. Thus there is a concordance of the Gregorian and Julian calendars, and of passages in the Bible that do not seem to agree. Subse quently it came to be used for a book arranged so as to form an alphabetical index of all passages, or at least of all the more important words in any work. For writings of universal import, from which passages are continually being adduced to prove or support principles affecting our daily life and action, such a handbook is indispensable. The necessity of a concordance for the Bible seems to have been felt at an early period. The first regular concordance of the Vulgate was made about 1244 by Hugo de Sancto Caro, with the assistance of many other Dominican monks. This work was frequently printed (e.g. Lyons, 1540, 1551), and led to Hugo's division of the Bible into chapters being universally adopted. Amended editions were prepared by Arlotto de Prato (about 1290), and (in the 14th century) by Konrad of Halberstadt. Concordances to the Vulgate were published at Basel in 1521 and 1561, by Rob. Stephanus (Paris, 1555), by Fr. Lucas (Antwerp, 1617), and by the Abbe F. P. Dutripon (Paris, 1838). A Greek concordance of the New Testament and Septuagint was prepared by Euthalios of Rhodes about the year 1300, but has been lost. Concordances of the Septuagint were compiled by Conrad Kircher (Frankfort, 2 vols. 1607), by Abraham Fromm (2 vols. Amsterdam, 1718) and by Dr Hatch (6 parts, 1889-92). Xystus Betuleius published in 1546 the first printed concordance of the Greek New Testament, which was republished and amended by Stephens (Paris, 1594; Geneva, 1600). A better concordance was compiled by Erasmus Schmidt (1638), whose work, as revised and enlarged by Bruder (1842; new ed. 1880), is now of standard value. An abridgment was issued by Schmoller (1869). The first Hebrew concordance was drawn up by Rabbi Isaac Nathan about 1438, and by Johann Buxtorf (edited by his son Johann Buxtorf, Basel, 1632). On the work of Buxtorf the later concordances of J. Fürst (1840), Bernhard Bar (1861 et seq.), and Davidson (Lond. 1876) are based. The chief concordances for Luther's Bible are those of Lankisch (1718), Büchner (1740; 17th ed. 1885), Beck (1770), Wichmann (1782), Schott (1827), Hauff (1828), Bernhard (1850). The first concordance of the New Testament in English was by Thomas Gybson (Lond. 1535), and of the whole Bible in English by John Marbek (1550). The best known of the numerous concordances for the authorised Eng lish version of the Bible was compiled by Alexander Cruden, and first published in 1737 (3d ed. with his

last corrections, 1769); Dr Robert Young's (188084) are also much used. The Englishman's Hebrew and Greek Concordances (1860) deserve mention. Crutwell's Concordance of Parallels dates from 1790. The first concordance of the Koran appeared at Calcutta in 1811. This is superseded by that of Gustav Flügel (1842). The Complete Concordance to Shakespeare, compiled by Mrs Cowden Clarke (1845; new ed. Lond. 1881), is invaluable. Concordances have also been prepared to Pope, Milton, Cowper, Tennyson, Dante, Chaucer, and Shelley. Concordat (Lat. concordatum, a thing agreed upon), though sometimes used of secular treaties, is generally employed to denote an agreement made between the pope, as the head of the Roman Catholic Church, and a secular government, on matters which concern the interests of its Roman Catholic subjects. Such concordats may take either of two forms. The pope may, after consultation with the government in question, issue a bull regulating the affairs of the Roman Catholic Church in the country, the contents of the said bull being afterwards ratified by the government and incorporated in the law of the land. Or again, a formal treaty may be drawn up and signed by plenipotentiaries on both sides. Various theories have been held on the obligation of such contracts. Secular jurists have denied that they impose any real obligation on the state, which may annul them at pleasure. Extreme Ultramontanes, on the other hand, have regarded concordats as privileges which the pope grants for the time without entering into any contract properly so called, while the more moderate of Roman canonists recognise a contract binding both sides. As a matter of fact, no modern government can engage that its stipulations with the pope will be respected by its successors in office. Thus the Austrian concordat was secured by the clerical party in 1855 and swept away by their opponents in 1870. The famous and more enduring concordat by which the church in France was re-established after the Revolution was concluded by Napoleon (as first consul) and Pius VII. in 1801.

Concordia, a town of the Argentine state of Entre Rios, on the Uruguay, 302 miles N. of Buenos Ayres by river. It has a custom-house, and a river-trade exceeded only by that of Buenos Ayres and Rosario. There is a railway to Monte Caseros (105 miles), and others to Uruguay and Corrientes are being built. Pop. 10,000.

Concordiæ Formula. See articles AUGSBURG CONFESSION and CONFESSION.

Concrete. There is but little difference between concrete and coarse mortar. The mortar used in the masonry of castles and churches erected during the middle ages is in fact a concrete with small pebbles instead of the larger ones used in modern concrete. Any mixture of lime, sand, and water, with broken stones or bricks, bits of slag, gravel, or other hard material, is called a concrete. The hard lumps are termed the aggregate, and the mortar in which they are embedded is called the matrix. The mixture varies with the nature and quality of the materials, but it often consists of 1 part of quicklime, 2 of sand, and 3 of gravel. It is better to use such a material as broken stone rather than water-rolled gravel, which has often too smooth a surface. Lime concrete, as the kind above described may be termed, is used principally for foundations, that is, a thick bed of it is formed below the lowest course of stones or bricks in walls, in cases where the ground itself is not sufficiently firm and solid. Not unfrequently, in some countries, walls themselves are formed of concrete, by laying a foot or two of it in height at a time between boards, and giving it some time to harden. It then forms an,

CONCRETION

artificial stone. Other methods of building walls of concrete are in use (see BUILDING).

Portland cement concrete is made either by mixing it with gravel alone, or more generally by using the cement along with sand and broken stones. The concrete used at Portland Breakwater Fort and at Cork Harbour have nearly the same composition. The cubic yard of it at the former place was made by using of Portland cement 5 cubic feet, of sand 10 cubic feet, and of broken stones (not more than 34-inch gauge) 28 cubic feet, along with 23 gallons of water. A concrete with these materials in much the same proportion has been used at other places, but different proportions are also employed. Portland cement being the binding material in this concrete, the question arises whether there is sufficient experience of its durability, especially where it is exposed to the action of sea-water, to warrant its employment in structural works of great or even of moderate size. See CEMENTS.

Concrete made of the hydraulic lime from Teil in France, which contains 66 per cent. of silicate of lime, has been employed in the construction of breakwaters and similar works at Cherbourg, Marseilles, and other places. The Teil hydraulic lime is one of the strongest known, and the concrete made with it has resisted the action of seawater for many years. Ordinary lime concrete does not set under water.

A concrete is made of broken stones and tar, about 12 gallons of the latter being used for every cubie yard of concrete. Bitumen or asphalt is better than gas-tar for this purpose, and either may be hardened by the introduction of dried and pounded lime, clay, or brick-dust. The materials should be heated before being mixed with the tar or bitumen. For backing armour-plates in forts a concrete of cast-iron turnings, asphalt, and pitch has been used. Gravel mixed with rather more than a thirtieth part, by bulk, of iron borings, was successfully used as a concrete at Stranraer pier.

Concrete, a term in logic opposed to abstract. A concrete notion is the notion of an object as it exists in nature, invested with all its qualities, as any particular flower, leaf, or tree; an abstract notion is the notion of any attribute of that flower, leaf, or tree, such as its colour, form, or height; qualities which may be thought of independently of the objects in which they inhere, though they cannot so exist.-The abstract method of handling a subject is adapted to speculation and reasoning: the concrete, to poetic effect and impressive illus tration.

Concretion, in Medicine, a formation of solid unorganised masses within the body, either by chemical precipitation from the fluids, or by the accidental aggregation of solids introduced into the system from without. In the former case, a concretion is termed a Calculus (q.v.); in the latter, the concretion may be either wholly com posed of solids foreign to the body, or these may be mingled with the elements of the secretions, as with mucus, or calculous matter. Thus beans, peas, needles, &c., introduced into the cavities of the body, have become the nuclei of concretions, by attracting around them mucus, or crystalline deposits from the urine. The most remarkable forms of concretion, however, are perhaps those formed in the stomach and intestines of man and the lower animals, from the more solid and indigestible parts of the food, or of substances improperly swallowed. Thus, young women have been known to acquire the habit of swallowing their own hair to a great extent; and very large con cretions have been thus formed, which have proved fatal, by obstructing the passage of food.

The