20th of September 1880. He made his way back to Herat, where | inspector of the public library at Avignon, and from 1812 to he remained for some time unmolested. In the summer of 1881 he again invaded Afghanistan, and on the anniversary of the battle of Maiwand obtained a signal victory over Abdur Rahman's lieutenants, mainly through the defection of a Durani regiment. Kandahar fell into his hands, but Abdur Rahman now took the field in person, totally defeated Ayub, and expelled him from Herat. He took refuge in Persia, and for some time lived quietly in receipt of an allowance from the Persian governIn 1887 internal troubles in Afghanistan tempted him to make another endeavour to seize the throne. Defeated and driven into exile, he wandered for some time about Persia, and in November gave himself up to the British agent at Meshed. He was sent to India to live as a state prisoner. ment. 1815 he held the same position at Nancy. The Restoration government at first suspected him as a Bonapartist, but at length granted him a pension. From that time he occupied himself in lecturing and the publication of philosophical works. In the Compensations he sought to prove that, on the whole, happiness and misery are equally balanced, and therefore that men should accept the government which is given them rather than risk the horrors of revolution. "Le principe de l'inégalité naturelle et essentielle dans les destinées humaines conduit inévitablement au fanatisme révolutionnaire ou au fanatisme religieux." The principles of compensation and equilibrium are found also in the physical universe, the product of matter and force, whose cause is God. Force, naturally expansive and operating on the homogeneous atoms which constitute elemental matter, is subject to the law of equilibrium, or equivalence of AYUNTAMIENTO, the Spanish name for the district over which a town council has administrative authority; it is used also for a town council, and for the town-hall. The word is de-action and reaction. The development of phenomena under rived from the Latin adjungere, and originally meant "meeting." In some parts of Spain and in Spanish America the town council was called the cabildo or chapter, from the Latin capitulum. The ayuntamiento consisted of the official members, and of regidores or regulators, who were chosen in varying proportions from the "hidalgos" or nobles (hijos de algo, sons of somebody) and the "pecheros," or commoners, who paid the pecho, or personal tax; pecho (Lat. pectus) is in Spanish the breast, and then by extension the person. The regidores of the ayuntamientos, or lay cabildos, were checked by the royal judge or corregidor, who was in fact the permanent chairman or president. The distinction between hidalgo and pechero has been abolished in modern Spain, but the powers and the constitution of ayuntamientos have been subject to many modifications. AYUTHIA, a city of Siam, now known to the Siamese as Krung Kao or "the Old Capital," situated in 100° 32′ E., 14° 21′ N. Pop. about 10,000. The river Me Nam, broken up into a network of creeks, here surrounds a large island upon which stand the ruins of the famous city which was for more than four centuries the capital of Siam. The bulk of the inhabitants live in the floating houses characteristic of lower Siam, using as thoroughfares the creeks to the edges of which the houses are moored. The ruins of the old city are of great archaeological interest, as are the relics, of which a large collection is housed in the local museum. Outside the town is an ancient masonry enclosure for the capture of elephants, which is still periodically used. Ayuthia is on the northern main line of the state railways, 42 m. from Bangkok. Great quantities of paddi are annually sent by river and rail to Bangkok, in return for which cloth and other goods are imported to supply the wants of the agriculturist peasantry. There is no other trade. Ayuthia is the chief town of one of the richest agricultural provincial divisions of Siam and is the headquarters of a high commissioner. The government offices occupy spacious buildings, once a royal summer retreat; the government is that of an ordinary provincial division (Monton). Historically Ayuthia is the most interesting spot in Siam. Among the innumerable ruins may be seen those of palaces, pagodas, churches and fortifications, the departed glories of which are recorded in the writings of the early European travellers who first brought Siam within the knowledge of the West, and laid the foundations of the present foreign intercourse and trade. The town was twice destroyed by the Burmese, once in 1555 and again in 1767, and from the date of the second destruction it ceased to be the capital of the country. AZAÏS, PIERRE HYACINTHE (1766-1845), French philosopher, was born at Sorèze and died at Paris. He spent his early years as a teacher and a village organist. At the outbreak of the Revolution he viewed it with favour, but was soon disgusted at the violence of its methods. A critical pamphlet drew upon him the hatred of the revolutionists, and it was not until 1806 that he was able to settle in Paris. In 1809 he published his great work, Des Compensations dans les destinées humaines (5th ed. 1846), which pleased Napoleon so much that he made its author professor at St Cyr. In 1811 he became this law may be divided into three stages-the physical, the physiological, the intellectual and moral. The immaterial in man is the expansive force inherent in him. Moral and political phenomena are the result of the opposing forces of progress and preservation, and their perfection lies in the fulfilment of the law of equilibrium or universal harmony. This may be achieved in seven thousand years, when man will vanish from the world. In an additional five thousand, a similar equilibrium will obtain in the physical sphere, which will then itself pass away. In addition to his philosophical work, Azaïs studied music under his father, Pierre Hyacinthe Azais (1743-1796), professor of music at Sorèze and Toulouse, and composer of sacred music in the style of Gossec. He wrote for the Revue musicale a series of articles entitled Acoustique fondamentale (1831), containing an ingenious, but now exploded, theory of the vibration of the air. His other works are: Système universel (8 vols., 1812); Du Sort de l'homme (3 vols., 1820); Cours de philosophie (8 vols., 1824), reproduced as Explication universelle (3 vols., 1826-1828); Jeunesse, maturité, religion, philosophie (1837); De la phrénologie, du magnétisme, et de la folie (1843). AZALEA, a genus of popular hardy or greenhouse plants, belonging to the heath order (Ericaceae), and scarcely separable botanically from Rhododendron. The beautiful varieties now in cultivation have been bred from a few originals, natives of the hilly regions of China and Japan, Asia Minor, and the United States. They are perhaps unequalled as indoor decorative plants. They are usually increased by grafting the half-ripened shoots on the stronger-growing kinds, the shoots of the stock and the grafts being in a similarly half-ripened condition, and the plants being placed in a moist heat of 65°. Large plants of inferior kinds, if healthy, may be grafted all over with the choicer sorts, so as to obtain a large specimen in a short time. They require a rich and fibrous peat soil, with a mixture of sand to prevent its getting water-logged. The best time to pot azaleas is three or four weeks after the blooming is over. The soil should be made quite solid to prevent its retaining too much water. To produce handsome plants, they must while young be stopped as required. Specimens that have got leggy may be cut back just before growth commences. The lowest temperature for them during the winter is about 35°, and during their season of growth from 55° to 65° at night, and 75° by day, the atmosphere being at the same time well charged with moisture. They are liable to the attacks of thrips and red spider, which do great mischief if not promptly destroyed. The following are some well-known species:-A. arborescens (Pennsylvania), a deciduous shrub 10-20 ft. high; A. calendulacea (Carolina to Pennsylvania), a beautiful deciduous shrub 2-6 ft. high, with yellow, red, orange and copper-coloured flowers; A. hispida, a North American shrub, 10-15 ft. high, flowers white edged with red; A. indica (China), the so-called Indian azalea, a shrub 3-6 ft. or more high, the original of numerous single and double varieties, many of the more vigorous of which are hardy in southern England and Ireland; A. nudiflora, a North American shrub, 3-4 ft. high, which hybridizes freely with A. calendulacea, A. pontica and others, to produce single and double forms of a great variety of shades; A. pontica (Levant, | of the faithful. 'I will show thee a better way,' replied the Caucasus, &c.), 4-6 ft. high, with numerous varieties differing stranger; let a crier cry aloud "God most great, &c." " On in the colour of the flowers and the tint of the leaves; A. sinensis awaking, Abdallah went to Mahomet and told him his dream," (China and Japan), a beautiful shrub, 3-4 ft. high, with orange- and Azan was thereupon instituted. red or yellow bell-shaped flowers, hardy in the southern half of England, large numbers of varieties being in cultivation under the name of Japanese azaleas. AZAMGARH, or AZIMGARH, a city and district of British India, in the Gorakhpur division of the United Provinces. The town is situated on the river Tons, and has a railway station. It is said to have been founded about 1665 by a powerful landholder named Azim Khan, who owned large estates in this part of the country. Pop. (1901) 18,835. The area of the district is 2207 sq. m. It is bounded on the N. by the river Gogra, separating it from Gorakhpur district; on the E. by Ghazipur district and the river Ganges; on the S. by the districts of Jaunpur and Ghazipur; and on the W. by Jaunpur and Fyzabad. The portion of the district lying along the banks of the Gogra is a low-lying tract, varying considerably in width; south of this, however, the ground takes a slight rise. The slope of the land is from north-west to south-east, but the general drainage is very inadequate. Roughly speaking, the district consists of a series of parallel ridges, whose summits are depressed into beds or hollows, along which the rivers flow; while between the ridges are low-lying rice lands, interspersed with numerous natural reservoirs. The soil is fertile, and very highly cultivated, bearing magnificent crops of rice, sugar-cane and indigo. There are several indigo factories. A branch of the Bengal & North-Western railway to Azamgarh town was opened in 1898. In 1901 the population was 1,529,785, showing a decrease of 11% in the decade. The district was ceded to the Company in 1801 by the wazirs of Lucknow. In 1857 it became a centre of mutiny. On the 3rd of June 1857 the 17th Regiment of Native Infantry mutinied at Azamgarh, murdered some of their officers, and carried off the government treasure to Fyzabad. The district became a centre of the fighting between the Gurkhas and the rebels, and was not finally cleared until October 1858 by Colonel Kelly. AZAN (Arabic for "announcement "), the call or summons to public prayers proclaimed by the Muezzin (crier) from the mosque twice daily in all Mahommedan countries. In small mosques the Muezzin at Azan stands at the door or at the side of the building; in large ones he takes up his position in the minaret. The call translated runs: "God is most great!" (four times), "I testify there is no God but God!" (twice), "I testify that Mahomet is the apostle of God!" (twice), "Come to prayer!" (twice), "Come to salvation!" (twice), "God is most great!" (twice), "There is no God but God!" To the morming Azan are added the words, "Prayer is better than sleep!" (twice). The devout Moslem has to make a set response to each phrase of the Muezzin. At first these are mere repetitions of Azan, but to the cry "Come to prayer!" the listener must answer, "I have no power nor strength but from God the most High and Great." To that of "Come to salvation!" the formal response is, "What God willeth will be: what He willeth not will not be." The recital of the Azān must be listened to with the utmost reverence. The passers in the streets must stand still, all those at work must cease from their labours, and those in bed must sit up. The Muezzin, who is a paid servant of the mosque, must stand with his face towards Mecca and with the points of his forefingers in his ears while reciting Azān. He is specially chosen for good character, and Azan must not be recited by any one unclean, by a drunkard, by the insane, or by a woman. The summons to prayers was at first simply "Come to prayer!" Mahomet, anxious to invest the call with the dignity of a ceremony, took counsel of his followers. Some suggested the Jewish trumpet, others the Christian bell, but according to legend the matter was finally settled by a dream:-" While the matter was under discussion, Abdallah, a Khazrajite, dreamed that he met a man clad in green raiment, carrying a bell. Abdallah sought to buy it, saying that it would do well for bringing together the assembly | AZARA, DON JOSE NICHOLAS DE (1731-1804), Spanish diplomatist, was born in 1731 at Barbunales, Aragon, and was appointed in 1765 Spanish agent and procurator-general, and in 1785 ambassador at Rome. During his long residence there he distinguished himself as a collector of Italian antiquities and as a patron of art. He was also an able and active diplomatist, took a leading share in the difficult and hazardous task of the expulsion of the Jesuits from Spain, and was instrumental in securing the election of Pius VI. He withdrew to Florence when the French took possession of Rome in 1798, but acted on behalf of the pope during his exile and after his death at Valence in 1799. He was afterwards Spanish ambassador in Paris. In that post it was his misfortune to be forced by his government to conduct the negotiations which led to the treaty of San Ildefonso, by which Spain was wholly subjected to Napoleon. Azara was friendly to a French alliance, but his experience showed him that his country was being sacrificed to Napoleon. The First Consul liked him personally, and found him easy to influence. Azara died, worn out, in Paris in 1804. His end was undoubtedly embittered by his discovery of the ills which the French alliance must produce for Spain. Several sympathetic notices of Azara will be found in Thiers, Consulat et Empire. See also Reinado de Carlos IV, by Gen. J. Gomez de Arteche, in the Historia General de España, published by the R. Acad. de la Historia, Madrid, 1892, &c. There is a Notice historique sur le Chevalier d'Arara by Bourgoing (1804). His younger brother, DON FELIX DE AZARA (1746-1811), spent twenty years in South America as a commissioner for delimiting the boundary between the Spanish and Portuguese territories. He made many observations on the natural history of the country, which, together with an account of the discovery and history of Paraguay and Rio de la Plata, were incorporated in his principal work, Voyage dans l'Amérique méridionale depuis 1781 jusqu'en 1801, published at Paris in 1809 in French from his MS. by C. A. Walckenaer. AZARIAH, the name of several persons mentioned in the Old Testament. (1) One of Solomon's " princes," son of Zadok the priest (1 Kings iv. 2), was one of several Azariahs among the descendants of Levi (1 Chron. vi. 9, 10, 13, 36; 2 Chron. xxvi. 17). (2) The son of Nathan, a high official under King Solomon (1 Kings iv. 5). (3) King of Judaḥ, son of Amaziah by his wife Jecholiah (2 Kings xv. 1, 2), also called Uzziah (2 Chron. xxvi. 1). (4) Son of Ethan and great-grandson of Judah (1 Chron. ii. 8). (5) Son of Jehu, of the posterity of Judah (1 Chron. ii. 38). (6) A prophet in the reign of Asa, king of Judah (2 Chron. xv. 1). (7) Two sons of Jehoshaphat, king of Judah (2 Chron. xxi. 2). (8) King of Judah, also called Ahaziah and Jehoahaz, son of Jehoram (2 Chron. xxi. 17; xxii. 1, 6). (9) The son of Jeroham, and (10) the son of Obed, were made "captains of hundreds " by Jehoiada the priest (2 Chron. xxiii. 1). (11) Son of Hilkiah and grandfather of Ezra the Scribe (Ezra vii. 1; Neh. vii. 7, viii. 7, x. 2). (12) Son of Maaseiah, one of those who under the commission of Artaxerxes restored the wall of Jerusalem (Neh. iii. 23). (13) Son of Hoshaiah, an opponent of the prophet Jeremiah (Jer. xliii. 2). (14) One of the companions in captivity of the prophet Daniel, called Abednego by Nebuchadrezzar, by whom with two companions he was cast into a "burning fiery furnace " for refusing to worship the golden image set up by that monarch (Dan. i. 6, iii. 8-30). AZAY-LE-RIDEAU, a town of western France, in the department of Indre-et-Loire, on the Indre, 16 m. S.W. of Tours by rail. Pop. (1906) 1453. The town has a fine Renaissance château, well restored in modern times, with good collections of furniture and pictures. AZEGLIO, MASSIMO TAPARELLI, MARQUIS D' (1798–1866), Italian statesman and author, was born at Turin in October 1798, descended from an ancient and noble Piedmontese family. His father, Cesare d'Azeglio, was an officer in the Piedmontese army and held a high position at court; on the return of Pope war between Piedmont and Austria appeared inevitable he returned to Italy, and was sent as royal commissioner by Cavour to Romagna, whence the papal troops had been expelled. After the peace of Villafranca, d'Azeglio was recalled with orders to withdraw the Piedmontese garrisons; but he saw the danger of allowing the papal troops to reoccupy the province, and after a severe inner struggle left Bologna without the troops, and interviewed the king. The latter approved of his action, and said that his orders had not been accurately expressed; thus Romagna was saved. That same year he published a pamphlet in French entitled De la Politique et du droit chrétien au point de vue de la question italienne, with the object of inducing Napoleon III. to continue his pro-Italian policy. Early in 1860 Cavour appointed him governor of Milan, evacuated by the Austrians after the battle of Magenta, a position which he held with great ability. But, disapproving of the government's policy with regard to Garibaldi's Sicilian expedition and the occupation by Piedmont of the kingdom of Naples as inopportune, he resigned office. Pius VII. to Rome after the fall of Napoleon, Cesare d'Azeglio, general congress of the powers on the Italian question. When was sent as special envoy to the Vatican, and he took his son, then sixteen years of age, with him as an extra attaché. Young Massimo was given a commission in a cavalry regiment, which he soon relinquished on account of his health. During his residence in Rome he had acquired a love for art and music, and he now determined to become a painter, to the horror of his family, who belonged to the stiff and narrow Piedmontese aristocracy. His father reluctantly consented, and Massimo settled in Rome, devoting himself to art. He led an abstemious life, maintaining himself by his painting for several years. But he was constantly meditating on the political state of Italy. In 1830 he returned to Turin, and after his father's death in 1831 removed to Milan. There he remained for twelve years, moving in the literary and artistic circles of the city. He became the intimate of Alessandro Manzoni the novelist, whose daughter he married; thenceforth literature became his chief occupation instead of art, and he produced two historical novels, Niccolò dei Lapi and Ettore Fieramosca, in imitation of Manzoni, and with pronounced political tendencies, his object being to point out the evils of foreign domination in Italy and to reawaken national feeling. In 1845 he visited Romagna as an unauthorized political envoy, to report on its conditions and the troubles which he foresaw would break out on the death of Pope Gregory XVI. The following year he published his famous pamphlet Degli ultimi casi di Romagna at Florence, in consequence of which he was expelled from Tuscany. He spent the next few months in Rome, sharing the general enthusiasm over the supposed liberalism of the new pope, Pius IX:; like V. Gioberti and Balbo he believed in an Italian confederation under papal auspices, and was opposed to the Radical wing of the Liberal party. His political activity increased, and he wrote various other pamphlets, among which was I lutti di Lombardia (1848). On the outbreak of the first war of independence, d'Azeglio donned the papal uniform and took part under General Durando in the defence of Vicenza, where he was severely wounded. He retired to Florence to recover, but as he opposed the democrats who ruled in Tuscany, he was expelled from that country for the second time. He was now a famous man, and early in 1849 Charles Albert, king of Sardinia, invited him to form a cabinet. But realizing how impossible it was to renew the campaign, and 'not having the heart to sign, in such wretched internal and external conditions, a treaty of peace with Austria" (Correspondance politique, by E. Rendu), he refused. After the defeat of Novara(23rd of March 1849), Charles Albert abdicated and was succeeded by Victor Emmanuel II. D'Azeglio was again called on to form a cabinet, and this time, although the situation was even more difficult, he accepted, concluded a treaty of peace, dissolved the Chamber, and summoned a new one to ratify it. The treaty was accepted, and d'Azeglio continued in office for the next three years. While all the rest of Italy was a prey to despotism, in Piedmont the king maintained the constitution intact in the face of the general wave of reaction. D'Azeglio conducted the affairs of the country with tact and ability, improving its diplomatic relations, and opposing the claims of the Roman Curia. He invited Count Cavour, then a rising young politician, to enter the ministry in 1850. Cavour and Farini, also a member of the cabinet, made certain declarations in the Chamber (May 1852) which led the ministry in the direction of an alliance with Rattazzi and the Left. Of this d'Azeglio disapproved, and therefore resigned office, but on the king's request he formed a new ministry, excluding both Cavour and Farini. In October, however, owing to ill-health and dissatisfaction with some of his colleagues, as well as for other reasons not quite clear, he resigned once more and retired into private life, suggesting Cavour to the king as his successor. For the next four years he lived modestly at Turin, devoting himself once more to art, although he also continued to take an active interest in politics, Cavour always consulting him on matters of moment. In 1855 he was appointed director of the Turin art gallery. In 1859 he was given various political missions, including one to Paris and London to prepare the basis for a The death of his two brothers in 1862 and of Cavour in 1861 caused Massimo great grief, and he subsequently led a comparatively retired life. But he took part in politics, both as a deputy and a writer, his two chief subjects of interest being the Roman question and the relations of Piedmont (now the kingdom of Italy) with Mazzini and the other revolutionists. In his opinion Italy must be unified by means of the FrancoPiedmontese army alone, all connexion with the conspirators being eschewed, while the pope should enjoy nominal sovereignty over Rome, with full spiritual independence, the capital of Italy being established elsewhere, but the Romans being Italian citizens (see his letters to E. Rendu and his pamphlet Le questioni urgenti). He strongly disapproved of the convention of 1864 between the Italian government and the pope. The last few years of d'Azeglio's life were spent chiefly at his villa of Cannero, where he set to work to write his own memoirs. He died of fever on the 15th of January 1866. Massimo d'Azeglio was a very attractive personality, as well as an absolutely honest patriot, and a characteristic example of the best type of Piedmontese aristocrat. He was cautious and conservative; in his general ideas on the liberation of Italy he was wrong, and to some extent he was an amateur in politics, but of his sincerity there is no doubt. As an author his political writings are trenchant and clear, but his novels are somewhat heavy and old-fashioned, and are interesting only if one reads the political allusions between the lines. Besides a variety of newspaper articles and pamphlets, d'Azeglio's chief works are the two novels Ettore Fieramosca (1833)and Niccolò dei Lapi(1841), and a volume of autobiographical memoirs entitled I Miei Ricordi, a most charming work published after his death, in 1866, but unfortunately incomplete. See in addition to the Ricordi, L. Carpi's Il Risorgimento Italiano, vol. i. pp. 288 sq. and the Souvenirs historiques of Constance d'Azeglio, Massimo's nicce (Turin, 1884). (L. V.•) AZERBAÏJĀN (also spelt ADERBIJAN; the Azerbadegan of medieval writers, the Athro patakan and Atropateneof the ancients), the north-western and most important province of Persia. It is separated from Russian territory on the N. by the river Aras (Araxes), while it has the Caspian Sea, Gilan and Khamseh (Zenjan) on the E., Kurdistan on the S., and Asiatic Turkey on the W. Its area is estimated at 32,000 sq. m.; its population at 1 to 2 millions, comprising various races, as Persians proper, Turks, Kurds, Syrians, Armenians, &c. The country is superior in fertility to most provinces of Persia, and consists of a regular succession of undulating eminences, partially cultivated and opening into extensive plains. Near the centre of the province the mountains of Sahand rise in an accumulated mass to the height cf 12,000 ft. above the sea.. The highest mountain of the province is in its eastern part, Mount Savelan, with an elevation of 15,792 ft., and the Talish Mountains, which run from north to south, parallel to and at no great distance from the Caspian, have an altitude of 9000 ft.. The principal rivers are the Aras and Kizil Uzain, both receiving numerous tributaries and flowing into the Caspian, and the Jaghatu, Tatava, Murdi, Aji and others, which that there is a free para position in the amine or phenol. They may also be obtained by the molecular rearrangement of the diazoamines, when these are warmed with the parent base and its hydrochloride. This latter method of formation has been studied by H. Goldschmidt and R. U. Reinders (Ber., 1896, 29, p. 1369), who found that the reaction is monomolecular, and that the velocity constant of the reaction is proportional to the amount of the hydrochloride of the base present and also to the temperature, but is independent of the concentration of the diazoamine. The azo compounds are intensely coloured, but are not capable of being used as dyestuffs unless they contain salt-forming, acid or basic groups (see DYEING). By oxidizing agents they are converted into azoxy compounds, and by reducing agents into hydrazo compounds or amines. Azo-benzene, CH1N:NCH, discovered by E. Mitscherlich in 1834, may be prepared by reducing nitrobenzene in alcoholic solution with zinc dust and caustic soda; by the condensation of nitrosobenzene with aniline in hot glacial acetic acid solution; or by the oxidation of aniline with sodium hypobromite. It crystallizes from alcohol in orange red plates which melt at 68° C. and boil at 293° C. It does not react with acids or alkalis, but on reduction with zinc dust in acetic acid solution yields aniline. drain into the Urmia lake. The country to the west of the lake, with the districts of Selmas and Urmia, is the most prosperous part of Azerbaijan, yet even here the intelligent traveller laments the want of enterprise among the inhabitants. Azerbaijan is one of the most productive provinces of Persia. The orchards and gardens in which many villages are embosomed yield delicious fruits of almost every description, and great quantities, dried, are exported, principally to Russia. Provisions are cheap and abundant, but there is a lack of forests and timber trees. Lead, copper, sulphur, orpiment, also lignite, have been found within the confines of the province; also a kind of beautiful, variegated, translucent marble, which takes a high polish, is used in the construction of palatial buildings, tanks, baths, &c., and is known as Maragha, or Tabriz marble. The climate is healthy, not hot in summer, and cold in winter. The cold sometimes is severely felt by the poor classes owing to want of proper fuel, for which a great part of the population has no substitute except dried cowdung. Snow lies on the mountains for about eight months in the year, and water is everywhere abundant. The best soils when abundantly irrigated yield from 50- to 60-fold, and the water for this purpose is supplied by the innumerable streams which intersect the province. The natives of Azerbāîjân make excellent soldiers, and about a third of the Persian army is composed of them. The province is divided into a number of administra- Amino-azo Compounds may be prepared as shown above. tive sub-provinces or districts, each with a hâkim, governor They are usually yellowish brown or red in colour, the presence or sub-governor, under the governor-general, who under the of more amino groups leading to browner shades, whilst the Kajár dynasty has always been the heir-apparent to the throne introduction of alkylated amino groups gives redder shades. of Persia, assisted by a responsible minister appointed by the They usually crystallize well and are readily reduced. When shah. The administrative divisions are as follows:-Tabriz heated with aniline and aniline hydrochloride they yield induand environs; Uskuh; Dch-Kharegan; Maragha; Miandoab; lines (q.v.). Amino-azo-benzene, C6H5 N2 CH,NH2, crystallizes Saújbulagh; Sulduz; Urmia; Selmas; Khoi; Maku; Gerger; in yellow plates or needles and melts at 126° C. Its constituMerend; Karadagh; Arvanek; Talish; Ardebil; Mishkin; tion is determined by the facts that it may be prepared by Khalkhäl; Hashtrud; Garmrud; Afshar; Sain Kalch; Ujan; reducing nitro-azo-benzene by ammonium sulphide and that Sarab. The revenue amounts to about £200,000 per annum in by reduction with stannous chloride it yields aniline and cash and kind, and nearly all of it is expended in the province meta-phenylene diamine. Diamino-azo-benzene (chrysoidine), for the maintenance of the court of the heir-apparent, the salaries C&Hs N2·C&H2(NH2)2, first prepared by O. Witt (Bcr., 1877, and pay to government officials, troops, pensions, &c. (A.H.-S.) 10, p. 656), is obtained by coupling phenyl diazonium chloride AZIMUTH (from the Arabic), in astronomy, the angular with meta-phenylene diamine. It crystallizes in red octadistance from the north or south point of the horizon to the foot hedra and dyes silk and wool yellow. Triamino-azo-benzene of the vertical circle through a heavenly body. In the case of a (meta-aminobenzene-azo-meta-phenylene diamine or Bismarck horizontal line the azimuth is its deviation from the north or brown, phenylene brown, vesuvine, Manchester brown), south direction. AZO (c. 1150-1230), Italian jurist. This Azo, whose name is sometimes written Azzo and Azzolenus, and who is occasionally described as Azo Soldanus, from the surname of his father, is to be distinguished from two other famous Italians of the same name, viz. Azo Lambertaccius, a canonist of the 13th century, professor of canon law at the university of Bologna, author of Questiones in jus canonicum, and Azo de Ramenghis, a canonist of the 14th century, also a professor of canon law at Bologna, and author of Repetitiones super libro Decretorum. Few particulars are known as to the life of Azo, further than that he was born at Bologna about the middle of the 12th century, and was a pupil of Joannes Bassianus, and afterwards became professor of civil law in the university of his native town. He also took an active part in municipal life, Bologna, with the other Lombard republics, having gained its municipal independence. Azo occupied a very important position amongst the glossators, and his Readings on the Code, which were collected by his pupil, Alessandro de Santo Aegidio, and completed by the additions of Hugolinus and Odofredus, form a methodical exposition of Roman law, and were of such weight before the tribunals that it used to be said, " Chi non ha Azzo, non vada a palazzo." Azo gained a great reputation as a professor, and numbered amongst his pupils Accursius and Jacobus Balduinus. He died about 1230. AZO COMPOUNDS, organic substances of the type R-N:N-R' {where R = an aryl radical and R' = a substituted alkyl, or aryl radical). They may be prepared by the reduction of nitro compounds in alkaline solution (using zinc dust and alkali, or a solution of an alkaline stannite as a reducing agent); by oxidation of hydrazo compounds; or by the coupling of a diazotized amine and any compound of a phenolic or aminic type, provided III. 2* NH2 C&H N2 C6H3(NH2)2, is prepared by the action of nitrous acid on meta-phenylene diamine. It forms brown crystals which are readily soluble in hot water, and it dyes mordanted cotton a dark brown. On the composition of the commercial Bismarck brown see E. Täuber and F. Walder (Ber., 1897, 30, pp. 2111, 2899; 1900, 33, p. 2116). Alkylated amino-azo-benzenes are also known, and are formed by the coupling of diazonium salts with alkylated amines, provided they contain a free para position with respect to the amino group. In these cases it has been shown by H. Goldschmidt and A. Merz (Ber., 1897, 30, p. 670) that the velocity of formation of the amino-azo compound depends only on the nature of the reagents and not on the concentration, and that in coupling the hydrochloride of a tertiary amine with diazobenzene sulphonic acid the reaction takes place between the acid and the base set free by the hydrolytic dissociation of its salt, for the formation of the amino-azo compound, when carried out in the presence of different acids, takes place most rapidly with the weakest acid (H. Goldschmidt and F. Buss, Ber., 1897, 30, p. 2075). Methyl orange (helianthin, gold orange, Mandarin orange), (CH3)2N·C&H1·N CH,SO,Na, is the sodium salt of paradimethylaminobenzene-azo-benzene sulphonic acid. It is an orange crystalline powder which is soluble in water, forming a yellow solution. The free acid is intensely red in colour. Methyl orange is used largely as an indicator. The constitution of methyl orange follows from the fact that on reduction by stannous chloride in hydrochloric acid solution it yields sulphanilic acid and para-aminodimethyl aniline. Oxyazo Compounds.-The oxyazo compounds are prepared by adding a solution of a diazonium salt to a cold slightly alkaline solution of a phenol. The diazo takes up group the para position la with regard to the hydroxyl group, and if this be prevented it | obtained by P. Griess (Ann., 1862, 121, p. 258). It crystallizes in then goes into the ortho position. It never goes directly into the meta position. The constitution of the oxyazo compounds has attracted much attention, some chemists holding that they are true azophenols of the type R-N2 R, OH, while others look upon them as having a quinonoid structure, i.e. as being quinone hydrazones, type R-NH N: R1:0. The first to attack the purely chemical side were Th. Zincke (Bcr., 1883,16, p. 2929; 1884, 17, p. 3026; 1887, 20, p. 3171) and R. Meldola (Jour. Chem. Soc., 1889, 55, pp. 114, 603). Th. Zincke found that the products obtained by coupling a diazonium salt with a-naphthol, and by condensing phenylhydrazine with a-naphthoquinone, were identical; whilst Meldola acetylated the azophenols, and split the acetyl products by reduction in acid solution, but obtained no satisfactory results. K. Auwers (Zeit. f. phys. Chem., 1896, 21, p. 355; Ber., 1900, 33, p. 1302)examined the question from the physico-chemical standpoint by determining the freezing-point depressions, the result being that the para-oxyazo compounds give abnormal depressions and the ortho-oxyazo compounds give normal depressions; Auwers then concluded that the para compounds are phenolic and the ortho compounds are quinone hydrazones or act as such. A. Hantzsch (Ber., 1899, 32, pp. 590, 3089) considers that the oxyazo compounds are to be classed as pseudoacids, possessing in the free condition the configuration of quinone hydrazones, their salts, however, being of the normal phenolic type. J. T. Hewitt (Jour. Chem. Soc., 1900, 77, pp. 99 et seq.) nitrated para-oxyazobenzene with dilute nitric acid and found that it gave a benzene-azo-ortho-nitrophenol, whereas quinones are not attacked by dilute nitric acid. Hewitt has also attacked the problem by brominating the oxyazobenzenes, and has shown that when the hydrobromic acid produced in the reaction is allowed to remain in the system, a brombenzene-azo-phenol is formed, whilst if it be removed (by the addition of sodium acetate) bromination takes place in the phenolic nucleus; consequently the presence of the mineral acid gives the azo compound a pseudo-quinonoid character, which it does not possess if the mineral acid be removed from the sphere of the reaction. Para-oxyazobenzene (benzene-azo-phenol), CH2N: N(1) CH4 OH(4), is prepared by coupling diazotized aniline with phenol in alkaline solution. It is an orange-red crystalline compound which melts at 154° C. Ortho-oxyazobenzene, C.H、N: N(1)CH OH(2), was obtained in small quantity by E. Bamberger (Ber., 1900, 33, p. 3189) simultaneously with the para compound, from which it may be separated by distillation in a current of steam, the ortho compound passing over with the steam. It crystallizes in orange-red needles which melt at 82.5-83° C. On reduction with zinc dust in dilute salammoniac solution, it yields ortho-aminophenol and aniline. Meta-oxyazobenzene, CH ̧N: N(1)CH1·OH(3), was obtained in 1903 by P. Jacobson (Ber., 1903, 36, p. 4093) by condensing ortho-anisidine with diazo benzene, the resulting compound being then diazotized and reduced by alcohol to benzene-azometa-anisole, from which meta-oxyazobenzene was obtained by hydrolysis with aluminium chloride. It melts at 112-114° C. and is easily reduced to the corresponding hydrazo compound. Diazo-Amines. The diazo-amines, RN: N NHR1, are obtained by the action of primary amines on diazonium salts; by the action of nitrous acid on a free primary amine, an isodiazohydroxide being formed as an intermediate product which then condenses with the amine; and by the action of nitrosamines on primary amines. They are crystalline solids, usually of a yellow colour, which do not unite with acids; they are readily converted into amino-azo compounds (see above) and are decomposed by the concentrated halogen acids, yielding haloid benzenes, nitrogen and an amine. Acid anhydrides replace the imino-hydrogen atom by acidyl radicals, and boiling with water converts them into phenols. They combine with phenyl isocyanate to form urea derivatives (H. Goldschmidt, Ber., 1888, 21, p. 2578), and on reduction with zinc dust (preferably in alcoholic acetic acid solution) they yield usually a hydrazine and an amine. Diazoamino benzene, CH-N: N-NHCH, was first yellow laminae, which melt at 96° C. and explode at slightly higher temperatures. It is readily soluble in alcohol, ether and benzene. Diazoimino benzene, CH,N1, is also known. It may be prepared by the action of ammonia on diazobenzene perbromide; by the action of hydroxylamine on a diazonium sulphate (K. Heumann and L. Oeconomides, Ber., 1887, 20, p. 372); and by the action of phenylhydrazine on a diazonium sulphate. It is a yellow oil which boils at 59° C. (12 mm.), and possesses a stupefying odour. It explodes when heated. Hydrochloric acid converts it into chloraniline, nitrogen being eliminated; whilst boiling sulphuric acid converts it into aminophenol. Azoxy Compounds, R-N-ON-R', are usually yellow or red crystalline solids which result from the reduction of nitro or nitroso compounds by heating them with alcoholic potash (preferably using methyl alcohol). They may also be obtained by the oxidation of azo compounds. When reduced (in acid solution) they yield amines; distillation with reduced iron gives azo compounds, and warming with ammonium sulphide gives hydrazo compounds. Concentrated sulphuric acid converts azoxybenzene into oxyazobenzene (O. Wallach, Ber., 1880, 13, p. 525). Azoxybenzene, (CH,N),O, crystallizes from alcohol in yellow needles, which melt at 36° C. On distillation, it yields aniline and azobenzene. Azoxybenzene is also found among the electro-reduction products of nitrobenzene, when the reduction is carried out in alcoholic-alkaline solution. The mixed azo compounds are those in which the azo group N: N is united with an aromatic radical on the one hand, and with a radical of the aliphatic series on the other. The most easily obtained mixed azo compounds are those formed by the union of a diazonium salt with the potassium or sodium salt of a nitroparaffin (V. Meyer, Ber., 1876, 9, p. 384): CH2N2-NO+CH,·CH(NC2)K = KNO1+C&H2N2-CH(NO2)CH,. Benzene-azo-nitro-ethane. Those not containing a nitro group may be prepared by the oxidation of the corresponding mixed hydrazo compounds with mercuric oxide. E. Bamberger (Ber., 1898, 31, p. 455) has shown that the nitro-alkyl derivatives behave as though they possess the constitution of hydrazones, for on heating with dilute alkalies they split more or less readily into an alkaline nitrite and an acid hydrazide: CH,NH-N: C(NO)CH,+NaOH=NaNO2+C2H2NH-NH-CO-CH,. Benzene-azo-methane, CH,-N-CH,, is a yellow oil which boils at 150° C. and is readily volatile in steam. Benzene-azoethane, CH, N1⁄2·C¿H、, is a yellow oil which boils at about 180° C. with more or less decomposition. On standing with 60 % sulphuric acid for some time, it is converted into the isomeric acetaldehyde-phenylhydrazone, CH,NH-N: CH-CH2 (Ber., 1896, 29, p. 794). The diazo cyanides, CHÂN, CN, and carboxylic acids, CH N, COOH, may also be considered as mixed azo derivatives. Diazobenzenecyanide, CH,N, CN, is an unstable oil, formed when potassium cyanide is added to a solution of a diazonium salt. Phenyl-azo-carboxylic acid, CH, N2-COOH, is obtained in the form of its potassium salt when phenylsemicarbazide is oxidized with potassium permanganate in alkaline solution (J. Thiele, Ber., 1895, 28, p. 2600). It crystallizes in orange-red needles and is decomposed by water. The corresponding amide, phenyl-azo-carbonamide, CH,N, CONH2, also results from the oxidation of phenylsemicarbazide (Thiele, loc. cit.), and forms reddish-yellow needles which melt at 114° C. When heated with benzaldehyde to 120° C. it yields diphenyloxytriazole, (C&Hs)2CN,C(OH). AZOIMIDE, or HYDRAZOIC ACID, N,H, a compound of nitrogen and hydrogen, first isolated in 1890 by Th. Curtius (Berichte, 1890, 23, p. 3023). It is the hydrogen compound corresponding to P. Greiss' diazoimino benzene, CH,Na, which is prepared by the addition of ammonia to diazobenzene perbromide. Curtius found that benzoyl glycollic acid gavebenzoyl hydrazine with hydrazine hydrate: CH2OCO CH2COOH+2N2H1·H2O=H2O+C2H ̧CONH-NH2+ NH,NHÁCH, COOH. |