Chapter XIII: Part 13

CUVILLES, FRANCOIS DE (1698-c. 1767), French architect and engraver. He helped to carry the French rococo taste to Germany--he was summoned about 1720 to Cologne by the elector James Clement; in 1738 he became architect to the elector of Bavaria, and afterwards occupied the same position towards the emperor Charles VII. His style, while essentially thin, is often painfully elaborate and bizarre. He designed mirrors and consoles, balustrades for staircases, ceilings and fireplaces, and in furniture, beds and commodes especially. He also laid out parks and gardens. He wrote several treatises on artistic and decorative subjects, which were edited by his son, Francois de Cuvilles the younger, who succeeded his father at the court of Munich.

CUXHAVEN, or KUXHAVEN, a seaport town of Germany, belonging to the state of Hamburg, and situated at the extremity of the west side of the mouth of the Elbe, 71 m. by rail N.W. from Hamburg. Pop. (1900) 6898. The harbour is good and secure, and is much frequented by vessels delayed in the Elbe by unfavourable weather. A new harbour was made in 1891-1896, having a depth of 26(1/4) ft., with a fore port 1000 ft. long by 800 ft. wide; and it is now the place of departure and arrival of the mail steamers of the Hamburg-American Steamship Company, who in 1901 transferred here a part of their permanent staff. The port is free, i.e. outside the customs union (_Zollverein_), the imports being principally coals, bricks and timber, and the exports fish. There is a fishing fleet, for which a new harbour was opened in 1892. Though lying on a bare strand, the town is much frequented as a bathing place by Hamburgers. It is strongly fortified, and there are a lighthouse, and lifeboat and pilot stations. The town only dates from 1873, having been formed by uniting the villages of Ritzebuttel and Cuxhaven, which had belonged to Hamburg since 1394.

CUYABA, or CUIABA, capital of the inland state of Matto Grosso, Brazil, about 972 m. N.W. of Rio de Janeiro, on the Cuyaba river near its discharge into the Sao Lourenco, the principal Brazilian tributary of the Paraguay. Pop. (1890) 14,507; of the municipality, 17,815. The surrounding country is thickly populated. Cuyaba has uninterrupted steamer communication with Montevideo, about 2500 m. distant, but has no land communication with the national capital, except by telegraph. The climate is hot and malaria is prevalent. Cuyaba was founded in 1719 by Paulista gold hunters, and its gold-washings, now apparently exhausted, yielded rich results in the 18th century. It is the see of a bishopric and headquarters of an important military district, having an arsenal and military barracks.

CUYAPO, a town of the province of Nueva Ecija, Luzon, Philippine Islands, 28 m. N.N.W. of San Isidro, the capital. Pop. (1903) 16,292. Rice is grown here. In 1907 the town of Nampicuan was formed from part of Cuyapo.

CUYP, the name of a Dutch family which produced two generations of painters. The Cuyps were long settled at Dordrecht, in the neighbourhood of which they had a country house, where Albert Cuyp (the most famous) was born and bred.

The eldest member of the family who acquired fame was JACOB GERRITSZ CUYP, born it is said at Dordrecht in 1575, and taught by Abraham Bloemaert of Utrecht. He is known to have been alive in 1649, and the date of his death is obscure. J. G. Cuyp's pictures are little known. But he produced portraits in various forms, as busts and half-lengths thrown upon plain backgrounds, or groups in rooms, landscapes and gardens. Solid and clever as an imitator of nature in its ordinary garb, he is always spirited, sometimes rough, but generally plain, and quite as unconscious of the sparkle conspicuous in Frans Hals as incapable of the concentrated light-effects peculiar to Rembrandt. In portrait busts, of which there are signed examples dated 1624, 1644, 1646 and 1649, in the museums of Berlin, Rotterdam, Marseilles, Vienna and Metz, his treatment is honest, homely and true; his touch and tone firm and natural. In portraying children he is fond of introducing playthings and pets--a lamb, a goat or a roedeer; and he reproduces animal life with realistic care. In a family scene at the Amsterdam Museum we have likenesses of men, women, boys and girls with a cottage and park. In the background is a coach with a pair of horses. These examples alone give us a clue to the influences under which Albert Cuyp grew up, and explain to some extent the direction which his art took as he rose to manhood.

ALBERT CUYP (1620-1691), the son of Jacob Gerritsz by Grietche Dierichsdochter (Dierich's daughter), was born at Dordrecht. He married in 1658 Cornelia Bosman, a rich widow, by whom he had an only daughter. By right of his possessions at Dordwyck, Cuyp was a vassal of the county of Holland, and privileged to sit in the high court of the province. As a citizen he was sufficiently well known to be placed on the list of those from whom William III., stadtholder of the Netherlands, chose the regency of Dordrecht in 1672. His death, and his burial on the 7th of November 1691 in the church of the Augustines of Dordrecht, are historically proved. But otherwise the known facts concerning his life are few. He seldom dates his pictures, but it appears probable that he ceased to paint about 1675. It has been said that Albert was the pupil of his father. The scanty evidence of Dutch annalists to this effect seems confirmed by a certain coincidence in the style and treatment of father and son. That he was a pupil of van Goyen has been surmised on the strength of the style of his early works. It has been likewise stated that Albert was skilled, not only in the production of portraits, landscapes and herds, but in the representation of still life. His works are supposed to be divisible into such as bear the distinctive marks C. or A. C. in cursive characters, the letters A. C. in Roman capitals, and the name "A. Cuyp" in full. A man of Cuyp's acknowledged talent may have been versatile enough to paint in many different styles. But whether he was as versatile as some critics have thought is a question not quite easy to answer. It is to be observed that pieces assigned to Cuyp representing game, shell-fish and fruit, and inscribed A. C. in Roman capitals (Rotterdam, Amsterdam and Berlin museums), though cleverly executed, are not in touch or treatment like other pictures of less dubious authenticity, signed either with C. or A. C. or "A. Cuyp" in cursive letters. The panels marked C. and A. C. in cursive are portraits or landscapes, with herds, and interiors of stables or sheds, in which there are cows, horses and poultry. The subjects and their handling are akin to those which strike us in panels bearing the master's full signature, though characterized, as productions of an artist in the first phase of his progress would naturally be, by tones more uniform, touch more flat, and colour more deep than we find in the delicate and subtle compositions of the painter's later time. Generally speaking, the finished examples of Cuyp's middle and final period all bear his full signature. They are all remarkable for harmonies attained by certain combinations of shade in gradations with colours in contraposition.

Albert Cuyp, a true child of the Netherlands, does not seem to have wandered much beyond Rotterdam on the one hand or Nijmwegen on the other. His scenery is that of the Meuse or Rhine exclusively; and there is little variety to notice in his views of water and meadows at Dordrecht, or the bolder undulations of the Rhine banks east of it, except such as results from diversity of effect due to change of weather or season or hour. Cuyp is to the river and its banks what Willem Vandevelde is to calm seas and Hobbema to woods. There is a poetry of effect, an eternity of distance in his pictures, which no Dutchman ever expressed in a similar way. His landscapes sparkle with silvery sheen at early morning, they are bathed in warm or sultry haze at noon, or glow with heat at eventide. Under all circumstances they have a peculiar tinge of auburn which is Cuyp's and Cuyp's alone. Burger truly says van Goyen is gray, Ruysdael is brown, Hobbema olive, but Cuyp "is blond." The utmost delicacy may be observed in Cuyp's manner of defining reflections of objects in water, or of sight from water on ship's sides. He shows great cleverness in throwing pale-yellow clouds against clear blue skies, and merging yellow mists into olive-green vegetation. He is also very artful in varying light and shade according to distance, either by interchange of cloud-shadow and sun-gleam or by gradation of tints. His horses and cattle are admirably drawn, and they relieve each other quite as well if contrasted in black and white and black and red, or varied in subtler shades of red and brown. Rich weed-growth is expressed by light but marrowy touch, suggestive of detail as well as of general form. The human figure is given with homely realism in most cases, but frequently with a charming elevation, when, as often occurs, the persons represented are meant to be portraits. Whatever the theme may be it remains impressed with the character and individuality of Cuyp. Familiar subjects of the master's earlier period are stables with cattle and horses (Rotterdam, Amsterdam, Petersburg and Brussels museums). Occasionally he painted portraits in the bust form familiar to his father, one of which is dated 1649, and exhibited in the National Gallery, London. More frequently he produced likenesses of ladies and gentlemen on horseback, in which the life and dress of the period and the forms of horses are most vividly represented (Buckingham Palace, Bridgewater Gallery, Louvre and Dresden Museum). Later on we find him fondest of expansive scenery with meadows and cattle and flocks, or rivers and barges in the foreground and distances showing the towers and steeples of Dordrecht. Cuyp was more partial to summer than to winter, to noon than to night, to calm than to storm. But some of his best groups are occasionally relieved on dark and gusty cloud (Louvre and Robarts's collection). A few capital pieces show us people sledging and skating or netting ice-holes (Yarborough, Neeld and Bedford collections). A lovely "Night on the Banks of a River," in the Grosvenor collection, reminds us that Cuyp's friend and contemporary was the painter of moonlights, Aart van der Neer, to whom he was equal in the production of these peculiar effects and superior in the throw of figures. Sometimes Cuyp composed fancy subjects. His "Orpheus charming the Beasts," in the Bute collection, is judiciously arranged with the familiar domestic animals in the foreground, and the wild ones, to which he is a comparative stranger, thrown back into the distance. One of his rare gospel subjects is "Philip baptizing the Eunuch" (Marchmont House, Berwickshire), described as a fine work by Waagen. The best and most attractive of Cuyp's pieces are his Meuse and Rhine landscapes, with meadows, cattle, flocks and horsemen, and occasionally with boats and barges. In these he brought together and displayed--during his middle and final period--all the skill of one who is at once a poet and a finished artist; grouping, tinting, touch, harmony of light and shade, and true chords of colours are all combined. Masterpieces of acknowledged beauty are the "Riders with the Boy and Herdsman" in the National Gallery; the Meuse, with Dordrecht in the distance, in three or four varieties, in the Bridgewater, Grosvenor, Holford and Brownlow collections; the "Huntsman" (Ashburton); "Herdsmen with Cattle," belonging to the marquess of Bute; and the "Piper with Cows," in the Louvre. The prices paid for Cuyp's pictures in his own time were comparatively low. In 1750, 30 florins was considered to be the highest sum to which any one of his panels was entitled. But in more recent times the value of the pictures has naturally risen very largely. At the sale of the Clewer collection at Christie's in 1876 a small "Hilly Landscape in Morning Light" was sold for L5040, and a view on the Rhine, with cows on a bank, for L3150. (J. A. C.)

John Smith's _Catalogue raisonne_ of the Dutch and Flemish painters,
in 9 vols. (1840), enumerated 335 of Albert Cuyp's works, of which in
1877 Sir J. A. Crowe wrote in this encyclopaedia that "it would be
difficult now to find more than a third of them." In C. Hofstede de
Groot's _Catalogue raisonne_, vol. ii. (1909), revising Smith's, the
number is extended to nearly 850, but he accepts too readily the
attributions of sale catalogues; the work is, however, the best modern
authority on the painter.

CUZA (or COUZA), ALEXANDER JOHN [_Alexandru Joan_] (1820-1873), first prince of Rumania, was born on the 20th of March 1820, at Galatz in Moldavia, and belonged to an ancient _boiar_, or noble, family. He was educated at Jassy, Pavia, Bologna and Athens; and, after a brief period of military service, visited Paris from 1837 to 1840 for a further course of study. In 1845 he married the daughter of another boiar, Elena Rosetti, who in 1862 founded the Princess Elena refuge for orphans, at Bucharest. Cuza was imprisoned by the Russian authorities for taking part in the Rumanian revolution of 1848, but escaped to Vienna. On his return, in 1850, he was appointed prefect of Galatz. In 1857 he rejoined the army, and within a few months rose to the rank of colonel. He became minister of war in 1858, and represented Galatz in the Assembly which was elected in the same year to nominate a prince for Moldavia. Cuza was a prominent speaker in the critical debates which ensued when the assembly met at Jassy, and strongly advocated the union of the two Danubian principalities, Moldavia and Walachia. In default of a foreign prince, he was himself elected prince of Moldavia by the assembly at Jassy (17th Jan. 1859), and prince of Walachia by the assembly at Bucharest (5th Feb.). He thus became ruler of the united principalities, with the title Prince Alexander John I.; but as this union was forbidden by the congress of Paris (18th Oct. 1858), his authority was not recognized by his suzerain, the sultan of Turkey, until the 23rd of December 1861, when the union of the principalities under the name of Rumania was formally proclaimed. For a full account of Cuza's reign see Rumania. The personal vices of the prince, and the drastic and unconstitutional reforms which he imposed on all classes, alienated his subjects, although many of these reforms proved to be of lasting excellence. Financial distress supervened, and the popular discontent culminated in revolution. At four o'clock on the morning of the 22nd of February 1866, a band of military conspirators broke into the palace, and compelled the prince to sign his abdication. On the following day they conducted him safely across the frontier. Prince Alexander spent the remainder of his life chiefly in Paris, Vienna and Wiesbaden. He died at Heidelberg on the 15th of May 1873.

CUZCO, an inland city of southern Peru, capital of an Andean department of the same name, about 360 m. E.S.E. of Lima, in lat. 13 deg. 31' S., long. 73 deg. 03' W. The population, largely composed of Indians and _mestizos_, was estimated at 30,000 in 1896, but according to the official estimate of 1906, it was then about 25% less. The city stands at the head of a small valley, 11,380 ft. above sea-level, and is nearly enclosed by mountains of considerable elevation. The valley itself is 9 m. in length and extends S.E. to the valley of Vilcamayu. Overlooking the city from the N. is the famous hill of Sacsahuaman, crowned by ruins of the cyclopean fortress of the Incas and their predecessors, and separated from adjacent heights by the deep ravines of two streams, called the Huatenay and Rodadero. The principal part of the city lies between these two streams, with its great _plaza_ in the centre. On the W. side of the Huatenay are two more fine squares, called the Cabildo and San Francisco. The houses of the city are built of stone, their walls commonly showing the massive masonry of the Incas at the bottom, crowned with a light modern superstructure roofed with red tiles. The streets cross each other at right angles and afford fine vistas on every side. The principal public buildings are the cathedral, which is classed among the best in South America, the convent of San Domingo, which partly occupies the site of the great Temple of the Sun of the Incas, the _cabildo_ or government-house, a university founded in 1598, a college of science and arts, a public library, hospital, mint and museum of Incarial antiquities. Cuzco was made the see of a bishopric soon after it was occupied by the Spaniards. The Church has always exercised a dominating influence in this region, and the city has many churches and religious establishments. There are a number of small manufacturing industries in Cuzco, including the manufacture of cotton and woollen fabrics, leather, beer, embroidery and articles of gold and silver. Its trade is not large, however, owing to the costs of transportation. The climate is cool and bracing, and the products of the vicinity include many of the temperate zone. A railway from Juliaca (a station on the line from Mollendo to Puno) to Cuzco was virtually completed early in 1908. This railway gives Cuzco an outlet to the coast, and also direct connexion with La Paz, the Bolivian capital. A branch of the Callao & Oroya railway is also projected southward to Cuzco, and reached Huancayo in 1908. Cuzco was the capital of a remarkable empire ruled by the Incas previous to the discovery of Peru, and it was one of the largest and most civilized of the native cities of the New World. It was captured by Pizarro in 1533, and it is said that its size and the magnificence of its principal edifices filled the Spaniards with surprise. It was for many years an object of contention among the Spanish factions, but ultimately the greater attractions of Lima and its own isolation diminished its importance.

The department of Cuzco is the second largest in Peru, having an area of 156,317 sq. m., and a population, according to a reduced official estimate of 1906, of only 328,980. It occupies an extremely mountainous region on the frontier of Bolivia, E. of the departments of Junin, Ayacucho and Apurimac, and extends from Loreto on the N. to Puno and Arequipa on the S. Its area, however, includes a large district E. of the Andes which is claimed by Bolivia, and the settlement of the dispute may materially diminish its size. The elevation of a large part of the department gives it a temperate climate and permits the cultivation of cereals and other products of the temperate zone. Cattle and sheep are produced in large numbers in some of the provinces, while in others mining forms the chief industry. On the eastern forested slopes and in the lower valleys tropical conditions prevail. The population is chiefly composed of Indians who form a sturdy, docile labouring class, but are in great part strongly disinclined to accept the civilization of the dominant white race.

CYANAMIDE, NC.NH2, the amide of normal cyanic acid, obtained by the action of ammonia on cyanogen chloride, bromide or iodide, or by the desulphurization of thio-urea with mercuric oxide; it is generally prepared by the latter process. It forms white crystals, which melt at 40 deg. C., and are readily soluble in water, alcohol and ether. Heated above its melting point it polymerizes to di-cyandiamide (CN2H2)2, which at 150 deg. C. is transformed into the polymer _n_-tri-cyantriamide or melamine (CN2H2)3, the mass solidifying. Nascent hydrogen reduces cyanamide to ammonia and methylamine. It gives mono-metallic salts of the type NC.NHM when treated with aqueous or alcoholic solutions of alkalis. Di-metallic salts are obtained by heating cyanates alone, e.g. calcium, or cyanides in a current of nitrogen, e.g. barium.

Calcium cyanamide has assumed importance in agriculture since the discovery of its economic production in the electric furnace, wherein calcium carbide takes up nitrogen from the atmosphere to form the cyanamide with the simultaneous liberation of carbon. It may also be produced by heating lime or chalk with charcoal to 2000 deg. in a current of air. The commercial product (which is known in Germany as "_Kalkstickstoff_") contains from 14 to 22% of nitrogen, which is liberated as ammonia when the substance is treated with water; to this decomposition it owes its agricultural value. It appears that with soils which are not rich in humus or not deficient in lime, calcium cyanamide is almost as good, nitrogen for nitrogen, as ammonium sulphate or sodium nitrate; but it is of doubtful value with peaty soils or soils containing little lime, nor is it usefully available as a top-dressing or for storing.

CYANIC ACID AND CYANATES. Cyanic acid, CN.OH, was discovered by F. Wohler in 1824, and may be obtained by distilling its polymeride, cyanuric acid, in a current of carbon dioxide (F. Wohler and J. v. Liebig, _Berzelius Jahresberichte_, 1827, 11, p. 84), the vapours which distil over being condensed in a freezing mixture. It is a very volatile liquid of strong acid reaction, and is only stable below 0 deg. C. It has a smell resembling that of acetic acid. At 0 deg. C. it is rapidly converted into a mixture of cyanuric acid, C3N3O3H3, and another polymer, cyamelide (CNOH)x; this latter substance is a white amorphous powder, insoluble in water. An aqueous solution of cyanic acid is rapidly hydrolysed (above 0 deg. C.) into a mixture of carbon dioxide and ammonia. Cyanogen chloride, CNCl, may be regarded as the chloride of cyanic acid. It may be prepared by the action of chlorine on hydrocyanic acid or on mercury cyanide. It is a very poisonous volatile liquid, which boils at 15.5 deg. C. It polymerizes readily to cyanuric chloride, C3N3Cl3. Caustic alkalis hydrolyse it readily to the alkaline chloride and cyanate.

The salts of cyanic acid are known as the cyanates, the two most important being potassium cyanate (KOCN) and ammonium cyanate (NH4OCN). Potassium cyanate may be prepared by heating potassium cyanide with an oxidizing agent, or by heating potassium ferrocyanide with manganese dioxide, potassium carbonate or potassium dichromate (J. v. Liebig, _Ann._, 1841, 38, p. 108; C. Lea, _Jahresb._, 1861, p. 789; L. Gattermann, _Ber._, 1890, 23, p. 1224), the fused mass being extracted with boiling alcohol. It crystallizes in flat plates and is readily soluble in cold water. It is a somewhat important reagent, and has been used by Emil Fischer in various syntheses in the uric acid group (see PURIN). Ammonium cyanate possesses considerable theoretical importance since the first synthetical production of an organic from inorganic compounds was accomplished by warming its aqueous solution for some time, urea being formed (F. Wohler, _Berzelius Jahresberichte_, 1828, 12, p. 266). J. Walker and J. K. Wood (_Jour. Chem. Soc._, 1900, 77, p. 24) prepared pure ammonium cyanate by the union of gaseous ammonia and cyanic acid, special precautions being taken to keep the temperature below the point at which the salt is transformed into urea. It crystallizes in fine needles, which melt suddenly at about 80 deg. C., then resolidify, and melt again at about 128 deg. to 130 deg. C. (this temperature being that of the melting point of urea). Substituted ammonias were also made to combine with cyanic acid, and it was found that the substituted ammonium cyanates produced pass much more readily into the corresponding ureas than ammonium cyanate itself. (On the constitution of cyanic acid see F. D. Chattaway and J. M. Wadmore, _Jour. Chem. Soc._, 1902, 81, p. 191.)

Esters of normal cyanic acid are not known, but those of isocyanic acid (HN.CO) may be prepared by the action of alkyl halides on silver cyanate, or by oxidizing the isonitriles with mercuric oxide. They are volatile liquids which boil without decomposition, and possess a nauseating smell. When hydrolysed with caustic alkalis, they yield primary amines (this reaction determines their constitution). C2H5NCO + H2O = C2H5NH2 + CO2. When heated with water they yield carbon dioxide and symmetrical dialkyl ureas; with ammonia and amines they form alkyl ureas; and with acid anhydrides they yield tertiary amides.

Ethyl isocyanate, C2H5NCO, was first prepared by A. Wurtz (_Ann. chim._, 1854 (3), 42, p. 43) by distilling a mixture of potassium ethyl sulphate and potassium cyanate. It is a colourless liquid which boils at 60 deg. C.

_Cyanuric acid_, H3C3N3O3, was obtained by Wohler and Liebig by heating urea, and by A. Wurtz by passing chlorine into melting urea. It forms white efflorescent crystals. Treatment with phosphorus pentachloride gives cyanuric chloride, C3N3Cl3, which is also formed by the combination of anhydrous chlorine and prussic acid in the presence of sunlight. These substances contain a ring of three carbon and three nitrogen atoms, i.e. they are symmetrical triazines.

CYANIDE, in chemistry, a salt of prussic of hydrocyanic acid, the name being more usually restricted to inorganic salts, i.e. the salts of the metals, the organic salts (or esters) being termed nitriles. The preparation, properties, &c., of cyanides are treated in the article PRUSSIC ACID; reference should also be made to the articles on the particular metals. The most important cyanide commercially is potassium cyanide, which receives application in the "cyanide process" of gold extraction (see GOLD).

CYANITE, a native aluminium silicate, Al2SiO5, crystallizing in the anorthic system. It has the same percentage chemical composition as andalusite and sillimanite, but differs from these in its crystallographic and physical characters. P. Groth writes the formula as a metasilicate (AlO)2SiO3. The name cyanite was given by A. G. Werner in 1789, from [Greek: kyanos], blue, in allusion to the characteristic colour of the mineral; the form kyanite is also in common use, and the name disthene, proposed by R. J. Hauy in 1801, is used by French writers.

Distinctly developed crystals with terminal planes are rare, the mineral being commonly found as lamellar cleavage masses or long blade-shaped crystals embedded in crystalline rocks. The colour is usually a pale sky-blue, but may be white, greenish or yellowish; it varies in intensity in different bands, so that the crystals usually present a more or less striped appearance. There is a perfect cleavage parallel to the broad face m (100), and a less perfect one parallel to t (010): the basal plane p (001), oblique to the prism zone, is a gliding plane on which secondary twinning is produced by pressure, giving rise to characteristic horizontal striations on the cleavage face m. The accompanying figure represents a crystal twinned on the plane m (100). A negative biaxial optic figure is seen in convergent polarized light through the cleavage plane m, the axial plane being inclined at about 30 deg. to the edge between m and t. A remarkable feature of cyanite is the great difference in hardness on different faces of the same crystal and in different directions on the same face: on the face m in a direction parallel to the edge between m and p the hardness is 7, whilst in a direction parallel to the edge between m and t it is 4(1/2). The name disthene, from [Greek: dis], two, and [Greek: sthenos], strong, has reference to these differences in hardness.

Analyses of cyanite often show the presence of a small amount (usually less than 1%) of ferric oxide and sometimes traces of copper, and to these constituents the blue or green colour of the mineral is doubtless due. The mineral is infusible before the blowpipe, and is not decomposed by acids. At a high temperature, about 1350 deg. C., it becomes transformed into sillimanite, changing in specific gravity from 3.6 to 3.2.

Cyanite is a characteristic mineral of the metamorphic crystalline rocks--gneiss, schist, granulite and eclogite--and is often associated with garnet and staurolite. A typical occurrence is in the white, fine-scaled paragonite-schist of Monte Campione, near St Gotthard in Switzerland, where long transparent crystals of a fine blue colour are abundant. In the gneiss of the Pfitscher Tal near Sterzing in Tirol a white variety known as rhaetizite is found. It occurs at several places in Scotland, for instance, at Botriphnie in Banffshire, with muscovite in a quartz-vein. Fine specimens are found in mica-schist at Chesterfield in Massachusetts, and at several other localities in the United States. It is found in the gold-washings of the southern Urals and in the diamond-washings of Brazil. As minute crystal fragments it is met with in many sands and sandstones.

When of sufficient transparency and depth of colour (deep cornflower-blue) the mineral has a limited application as a gem-stone; it is usually cut _en cabochon_. (L. J. S.)

CYANOGEN (Gr. [Greek: kyanos], blue [Greek: gennan], to produce), C2N2, in chemistry, a gas composed of carbon and nitrogen. The name was suggested by Prussian blue, the earliest known compound of cyanogen. It was first isolated in 1815 by J. Gay-Lussac, who obtained it by heating mercury or silver cyanide; this discovery is of considerable historical importance, since it recorded the isolation of a "compound radical." It may also be prepared by heating ammonium oxalate; by passing induction sparks between carbon points in an atmosphere of nitrogen (see H. von Wartenburg, _Abs. J.C.S._, 1907, i. p. 299), or by the addition of a concentrated solution of potassium cyanide to one of copper sulphate, the mixed solutions being then heated. It also occurs in blast-furnace gases. When cyanogen is prepared by heating mercuric cyanide, a residue known as para-cyanogen, (CN)_x, is left; this is to be regarded as a polymer of cyanogen. It is a brownish amorphous solid, which is insoluble in water. Cyanogen is a colourless gas, possessing a peculiar characteristic smell, and is very poisonous. It burns with a purple flame, forming carbon dioxide and nitrogen; and may be condensed (by cooling to -25 deg. C.) to a colourless liquid, and further to a solid, which melts at -34.4 deg. C. (M. Faraday, _Ann._, 1845, 56, p. 158). It dissolves readily in water and the aqueous solution decomposes on standing; a dark-brown flocculent precipitate of azulmic acid, C4H5N5O, separating whilst ammonium oxalate, urea and hydrocyanic acid are found in the solution. In many respects it resembles chlorine in its chemical behaviour, a circumstance noted by Gay-Lussac; it combines directly with hydrogen (at 500 deg. to 550 deg. C.) to form hydrocyanic acid, and with chlorine, bromine, iodine and sulphur, to form cyanogen chloride, &c.; it also combines directly with zinc, cadmium and iron to form cyanides of these metals. It combines with sulphuretted hydrogen, in the presence of water, to form the compound C2N2.H2S, and in the presence of alcohol, to form the compound C2N2.2H2S. Concentrated hydrochloric acid converts it into oxamide. Potash solution converts it into a mixture of potassium cyanide and cyanate. When heated with hydriodic acid (specific gravity 1.96) it forms amino-acetic acid, and with tin and hydrochloric acid it yields ethylene diamine.

CYAXARES (Pers. _Uvakhshatra_), king of Media, reigned according to Herodotus (i. 107) forty years, about 624-584 B.C. That he was the real founder of the Median empire is proved by the fact that in Darius's time a Median usurper, Fravartish, pretended to be his offspring (Behistun inscr. 2. 43); but about his history we know very little. Herodotus narrates (i. 103 ff.) that he renewed the war against the Assyrians, in which his father Phraortes had perished, but was, while he besieged Nineveh, attacked by a great Scythian army under Madyas, son of Protothyes, which had come from the northern shores of the Black Sea in pursuit of the Cimmerians. After their victory over Cyaxares, the Scythians conquered and wasted the whole of western Asia, and ruled twenty-eight years, till at last they were made drunk and slain by Cyaxares at a banquet (cf. another story about Cyaxares and a Scythian host in Herod, i. 73). As we possess scarcely any contemporary documents it is impossible to find out the real facts. But we know from the prophecies of Jeremiah and Zephaniah that Syria and Palestine were really invaded by northern barbarians in 626 B.C., and it is probable that this invasion was the principal cause of the downfall of the Assyrian empire (see MEDIA and PERSIA: _Ancient History_).

After the destruction of the Scythians Cyaxares regained the supremacy, renewed his attack on Assyria, and in 606 B.C. destroyed Nineveh and the other capitals of the empire (Herod. i. 106; Berossus _ap._ Euseb. _Chron._ i. 29, 37, confirmed by a stele of Nabonidus found in Babylon: Scheil in _Recueil de travaux_, xviii.; Messerschmidt, "Die Inschrift der Stele Nabonaids," in _Mitteilungen der vorderasiatischen Gesellschaft_, i., 1896). According to Berossus he was allied with Nabopolassar of Babylon, whose son Nebuchadrezzar married Amyitis, the daughter of the Median king (who is wrongly called Astyages). The countries north and east of the Tigris and the northern part of Mesopotamia with the city of Harran (Carrhae) became subject to the Medes. Armenia and Cappadocia were likewise subdued; the attempt to advance farther into Asia Minor led to a war with Alyattes of Lydia. The decisive battle, in the sixth year, was interrupted by the famous solar eclipse on the 28th of May 585 predicted by Thales. Syennesis of Cilicia and Nebuchadrezzar (in Herodotus named Labynetus) of Babylon interceded and effected a peace, by which the Halys was fixed as frontier between the two empires, and Alyattes's daughter married to Cyaxares's son Astyages (Herod. i. 74). If Herodotus's dates are correct, Cyaxares died shortly afterwards.

In a fragmentary letter from an Assyrian governor to King Sargon (about 715 B.C.) about rebellions of Median chieftains, a dynast Uvakshatar (i.e. Cyaxares) is mentioned as attacking an Assyrian fortress (Kharkhar, in the chains of the Zagros). Possibly he was an ancestor of the Median king. (Ed. M.)

CYBELE, or CYBEBE (Gr. [Greek: Knbele], [Greek: Knbebe]), a goddess native to Asia Minor and worshipped by most of the peoples of the peninsula, was known to the Romans most commonly as the GREAT MOTHER OR THE GODS (q.v.), or the Great Idaean Mother of the Gods--_Magna Deum Mater, Mater Deum Magna Idaea_. She was known by many other names, such as _Mater Idaea_, Dindymene, Sipylene, derived from famous seats of worship, and Mountain Mother, &c., in token of her character, but Cybele is the name by which she is most frequently known in literature. Her cult became centralized in Phrygia, had found its way into Greece, where it never flourished greatly, as early as the latter 6th century B.C., and was introduced at Rome in 204 B.C. Under the Empire it attained to great importance, and was one of the last pagan cults to die. Cybele was usually worshipped in connexion with Attis (q.v.), as Aphrodite with Adonis, the two being a duality interpreted by the philosophers as symbolic of Mother Earth and her vegetation. (G. Sn.)

CYCLADES, a compact group of islands in the Greek Archipelago, forming a cluster around the island of Syra (Syros), the principal town of which, now officially known as Hermoupolis, is the capital of a department. Population of the group (1907) 130,378. The islands, though seldom visited by foreigners, are for the most part highly interesting and picturesque, notwithstanding their somewhat barren appearance when viewed from the sea; many of them bear traces of the feudal rule of Venetian families in the middle ages, and their inhabitants in general may be regarded as presenting the best type of the Greek race. To the student of antiquity the most interesting are: Delos (q.v.), one of the greatest centres of ancient religious, political and commercial life, where an important series of researches has been carried out by French archaeologists; Melos (q.v.), where, in addition to various buildings of the Hellenic and Roman periods, the large prehistoric stronghold of Phylakopi has been excavated by members of the British school at Athens; and Thera (see SANTORIN), the ancient capital of which has been explored by Baron Hiller von Gaertringen. Thera is also of special interest to geologists owing to its remarkable volcanic phenomena. Naxos, the largest and most fertile island of the group, contains the highest mountain in the Cyclades (Zia, 3290 ft.); the island annually exports upwards of 2000 tons of emery, a state monopoly the proceeds of which are now hypothecated to the foreign debt. The oak woods of Ceos (Zea) and Ios furnish considerable supplies of valonia. Kimolos, which is absolutely treeless, produces fuller's-earth. The famous marble quarries of Paros have been practically abandoned in modern times; the marble of Tenos is now worked by a British syndicate. The mineral wealth of the Cyclades has hitherto been much neglected; iron ore is exported from Seriphos, manganese and sulphur from Melos, and volcanic cement (pozzolana) from Santorin. Other articles of export are wine, brandy, hides and tobacco. Cythnos, Melos and other islands possess hot springs with therapeutic qualities. The prosperity of Syra, formerly an important distributing centre for the whole Levant, has been declining for several years.

Population (1907):--Syra 31,939 (communes, Hermoupolis 18,132, Mykonos
4589, Syra 9218); Andros 18,035 (Andros 8536, Arni 2166, Gaurio 2897,
Corthion 4436); Thera 19,597 (Thera 4226, Egiale 1513, Amorgos 2627,
Anaphe 579, Emporium 2172, Therasia 679, Ios 2090, Kalliste 3519, Oea
2192); Ceos 11,032 (Ceos 3817, Dryopis 1628, Cythnos 1563, Seriphos
4024); Melos, 12,774 (Melos 4864, Adamas 529, Siphnos 3777, Kimolos
2015, Pholegandros 962, Sikinos 627); Naxos 25,185 (Naxos 2064,
Apiranthe 2421, Vivlos 4343, Coronis 3205, Marpessa 1313, Naoussa
1670, Paros 3586, Tragea 4661, Hyrie 1922); Tenos 11,816 (Tenos 4697,
Panorme 2658, Peree 2801, Sosthenion 1660).

CYCLAMEN, in botany, a genus belonging to the natural order Primulaceae, containing about ten species native in the mountains of central Europe and the Mediterranean region. _C. europaeum_ (Sow-bread) is found as an introduced plant in copses in Kent and Sussex. The plants are low-growing herbs with large tuberous rootstocks, from the surface of which spring a number of broad, generally heart-shaped or kidney-shaped, long-stalked leaves, which in cultivated forms are often beautifully marbled, ribbed or splashed. The flowers are nodding, and white, pink, lilac or crimson in colour. The corolla has a short tube and five large reflexed lobes. After flowering the stalk becomes spirally coiled, drawing the fruit down to the soil. Cyclamen is a favourite winter and spring flowering plant. _C. persicum_ is probably the best known. It is a small-growing kind bearing medium-sized leaves and numerous flowers. _C. giganteum_ is a large, strong-growing species; not quite so free flowering as _C. persicum_, but in all other respects superior to it when well grown. _C. papilio_ differs in the fringed character of the petals. It has been obtained by selection from _C. persicum_. There is also a very beautiful crested race, probably derived from _C. giganteum_.

The plants are raised from seed, and, with good cultivation, flower in fifteen to eighteen months from date of sowing. Seed should be sown as soon as ripe, in July or August, in pots or pans, filled up to 2(1/2) in. of the rim with broken crocks for drainage. The soil should consist of fibrous yellow loam, leaf-mould in flakes, and coarse silver-sand, in equal parts. Sow the seed thinly--1/4 in. to 1/2 in. apart--and cover with a very thin sprinkling of the soil. Protect with a square of glass covered with a piece of brown paper for shade, and place on a shelf in a warm greenhouse. The soil should never be allowed to get dry.

When the seedlings appear, remove the covering, care being taken that they do not suffer for want of shade, water or a moist atmosphere. As soon as the third leaf appears, repot singly into thumb-pots in slightly coarser soil, so that the crowns of the little plants are just above the level of the soil. In December transfer into a little richer soil, consisting of two parts fibrous loam broken into small bits by hand and the fine particles rejected, one part flaked leaf-mould, passed through a half-inch sieve, half a part of plant ash from the burnt refuse heap and half a part of coarse silver-sand. Keep through the winter in a moist atmosphere at a temperature not below 50 deg. Fahr., and as near the glass as possible. In March they should be ready for their next shift into 5-in. pots. The potting compost should be the same as for the last shift, with the addition of half a part of well-sweetened manure, such as a spent mushroom bed. Keep in a warm moist atmosphere and shade from strong sunlight. In June remove to cold frames and stand them on inverted pots well clear of one another. Slugs show a marked partiality for the succulent young leaves and should be excluded by dusting round the frames occasionally with newly slaked lime. The inverted pots serve as traps. The frames may thus be frequently syringed without keeping the plants unduly wet. Shade heavily from direct sunlight, but afford as much diffused light as practicable. Ventilate on all favourable occasions, and close the frames early after copious syringing.

By the end of the month they will be ready for the final shift into 7-in. pots. Much care must be used in handling them, the leaves being large, tender and numerous. The soil is as for the last potting. The frames should be kept close and heavily shaded for a few days after potting; then gradually reduce shade and increase ventilation. By the end of July the elegance of the foliage alone should well repay the care bestowed on them. From this time onwards very little shading will be needed, the object of the cultivator being to harden the growth already made. With the advent of cool weather in September, remove to flowering quarters in a warm greenhouse. Flowering will begin in November and will continue through the winter and spring. The damping off of the flower-buds may occasionally prove troublesome during winter. This may generally be traced to checks, such as sudden changes in temperature, too low a temperature, careless watering, &c. During spring plants that are flowering freely will require weak manure water about twice a week.

Plants selected to bear seed should be set aside for that purpose, and as soon as the capsules are found to be developing properly they should be reduced to six or seven per plant, and all flower-buds picked off as soon as they are large enough to handle. The production of strong seeds is of the utmost importance.

Plants grown for market purposes, either for decoration or for seed, are sown later than the above, are kept cooler, and during summer receive more ventilation and less shade. This results in the production of plants with much smaller and more erect leaves, which travel well. They are flowered in spring and early summer. The species grown for this purpose is _C. persicum_.

A few species are hardy in dry sheltered positions, such as rockeries, under walls and old trees, provided the positions are well drained. Such are _C. europaeum_, with reddish-purple flowers in summer; _C. hederifolium_ in autumn; and _C. neapolitanum_, with large leaves marbled with silver and rosy-pink flowers.

CYCLE (Gr. [Greek: kuklos], a circle), in astronomy, a period of time at the end of which some aspect or relation of the heavenly bodies recurs. The more important cycles are discussed in the articles CALENDAR and ECLIPSE. In physics, the term is applied to a series of operations which, performed upon a system, brings it back to its original state; "Carnot's Cycle" is an example (see THERMODYNAMICS). From the use of the word for any period at the end of which the same events recur in the same order or for any complete series of phenomena, it is used loosely of any long period of time. The name [Greek: ho epikos kuklos], the epic cycle, was given to the poems which complete the Homeric account of the Trojan War (see below). It is this use which has given rise to the application of the term "cycle" to a series of prose or poetical romances which have for a centre one subject, whether a person, as in the Alexander, Arthurian or Charlemagne cycles, or an object, such as the ring of the Nibelungenlied. In music "Song-cycle" (Ger. _Liederkreis_) is similarly used of a series of songs written round one subject or set to poems by the same author. Beethoven's _An die ferne Geliebte_ (Op. 98), published in 1816, is the earliest instance. Schubert's _Die schone Mullerin_, Schumann's _Dichterliebe_ and Brahms's _Magelone-Lieder_ are well-known instances.

_Epic Cycle._--This is a collection or corpus of lays written about 776-580 B.C. by poets of the Ionian School, introductory or complementary to the Homeric poems, dealing with the legends of the Trojan and Theban wars. At a later date they were arranged so as to form a continuous narrative (the _Iliad_ and the _Odyssey_ included), perhaps after certain alterations had been made, to fill up gaps and remove inconsistencies and repetitions. By whom, and when, they were so arranged, cannot be decided; it is possible that it was the work of Zenodotus of Ephesus, who had the care of the epic section of the Alexandrian library. In order to furnish the general reader with a comprehensive sketch of mythological history, Proclus--according to Welcker and Valesius (Valois), not the neo-Platonist, but an unknown 2nd or 3rd century grammarian, perhaps Eutychius Proclus of Sicca[1] in Africa, one of the tutors of Marcus Aurelius (see PROCLUS)--compiled a prose summary ([Greek: Grammatke chrestomatheia]) of the contents of the poems, to serve as a sort of primer to Greek literature. Extracts from this are preserved in the Codex Venetus of Homer and Photius (cod. 239), according to which the epic cycle began with the union of Uranus and Ge and ended with the death of Odysseus on his return to Ithaca at the hands of his son Telegonus. The cycle was in existence in his (Proclus's) time, and was in request not so much for its artistic merit, as for the "sequence of the events described in it." Further light is thrown on the subject by pictorial representations, intended for school use during the Roman imperial period, the most famous of which is the _Tabula Iliaca_ in the Capitoline museum.

The expression "epic cycle" in the sense of a poetical collection does not occur before the Christian era; the word [Greek: kyklos] ("cycle," "circle") is used of a special kind of short poem and also of a prose abstract of mythological history; the adjective has the general sense of "hackneyed," "conventional," and is applied contemptuously (by Callimachus and Horace) to a particular Alexandrian school of poetry.

The most important poems of the Trojan legendary cycle are the _Cypria of Stasinus_ (q.v.); the _Aethiopis_ and _Iliou Persis_ (Sack of Troy) of Arctinus (q.v.); the _Little Iliad_ of Lesches (q.v.); the _Nosti_ of Hagias or Agias; the _Telegonia_ of Eugammon. To the Theban cycle belong: the _Thebais_ or _Expedition of Amphiaraus_ and the _Epigoni_ of Antimachus. The _Oechalias Halosis_ (capture of _Oechalia_) of Creophylus (q.v.); the _Phocais_ (or _Minyas_) of Prodicus; and the _Danais_ of Cercops, although belonging to the old Homeric epos, cannot with certainty be included in the epic cycle. The names of the authors are in several cases exceedingly doubtful.

BIBLIOGRAPHY.--The standard work on the subject is F. G. Welcker, _Der
epische Cyclus_ (1865-1882); see also T. W. Allen, "The Epic Cycle,"
in _Classical Quarterly_, Jan. and April 1908 (summary of sources and
authorities); Wilamowitz-Mollendorff, _Homerische Untersuchungen_
(1884), who regards the traditional names and personalities of the
poets of the cycle with great scepticism; D. B. Monro, _Journal of
Hellenic Studies_, iv. (1883), appendix to his edition of the
_Odyssey_, xiii.-xxiv. (1900), and on the Codex Venetus fragment of
Proclus; J. E. Sandys, _Hist. of Class. Schol._ (2nd ed., 1906), vol.
i. ch. 2; J. B. Bury, _Ancient Greek Historians_ (1909), pp. 2-8 on
the epics as history; articles by H. Flach in Ersch and Gruber,
_Allgemeine Encyklopadie_, and by E. Schwartz and others in
Pauly-Wissowa, _Realencyclopadie_.

FOOTNOTE:

[1] An objection to this view is that according to the Augustan
historian Capitolinus (_Antoninus_, 2) Eutychius of Sicca was a Latin
not a Greek grammarian.

CYCLING, the clipped term now given comprehensively to the sport or exercise of riding a bicycle (q.v.) or tricycle (q.v.).

History.

Suggestions of vehicles having two or more wheels and propelled by the muscular effort of the rider or riders are to be found in very early times, even on the bas-reliefs of Egypt and Babylon and the frescoes of Pompeii; but though sporadic examples of such contrivances are recorded in the 17th and 18th centuries, it was apparently not till the beginning of the 19th century that they were used to any considerable extent. A "velocipede" invented by Blanchard and Magurier, and described in the _Journal de Paris_ on the 27th of July 1779, differed little from the _celerifere_ proposed by another Frenchman, de Sivrac, in 1690; it consisted of a wooden bar rigidly connecting two wheels placed one in front of the other, and was propelled by the rider, seated astride the bar, pushing against the ground with his feet. The next advance was made in the _draisine_ of Freiherr Karl Drais von Sauerbronn (1785-1851), described in his _Abbildung und Beschreibung seiner neu erfundenen Laufmaschine_ (Nuremberg, 1817). In this the front wheel was pivoted on the frame so that it could be turned sideways by a handle, thus serving to steer the machine (figs. 1 and 2). A similar machine, the "celeripede," also with a movable front wheel, is said to have been ridden by J. N. Niepce in Paris some years before. In England the draisine achieved a great, though temporary, vogue under various names, such as velocipede, patent accelerator, bivector, bicipedes, pedestrian curricle (patented by Dennis Johnson in 1818), dandy horse, hobby horse, &c., and for a time it was popular in America also. The propulsion of the draisine by pushing with the feet being alleged to give rise to diseases of the legs, arrangements were soon suggested, as by Louis Gompertz in England in 1821, by which the front wheel could be rotated by the hands with the aid of a system of gearing, but the idea of providing mechanical connexions between the feet and the wheels was apparently not thought of till later. Pedals with connecting rods working on the rear axle are said to have been applied to a tricycle in 1834 by Kirkpatrick McMillan, a Scottish blacksmith of Keir, Dumfriesshire, and to a draisine by him in 1840, and by a Scottish cooper, Gavin Dalzell, of Lesmahagow, Lanarkshire, about 1845. The draisine thus fitted had wooden wheels, with iron tires, the leading one about 30 in. in diameter and the driving one about 40 in., and thus it formed the prototype, though not the ancestor, of the modern rear-driven safety bicycle.