HC = N
N = CH		\
/		O.

They may be prepared by converting nitriles into amidoximes by the action of hydroxylamine, the amidoximes so formed being then acylated by acid chlorides or anhydrides. From these acyl derivatives the elements of water are removed, either by simple heating or by boiling their aqueous solution; this elimination is accompanied by the formation of the azoxime ring. Thus

C6H5CN NH2OH
———>
 C6H5·C//
\		N·OH

NH2 		boil with
———>
propionic anhydride		[C6H5C//
\		N·O·COC2H5

NH2		>[——> C6H5·C//
\		N·O

N		\
//		C·C2H5

Azoximes can also be produced from α-benzil dioxime by the "Beckmann" change. Most of the azoximes are very volatile substances, sublime readily, and are easily soluble in water, alcohol and benzene.

For detailed descriptions, see F. Tiemann (Ber., 1885, 18, p. 1059), O. Schulz (Ber., 1885, 18, pp. 1084, 2459), and G. Müller (Ber., 1886, 19, p. 1492); also Annual Reports of the Chemical Society).

AZTECS (from the Nahuatl word aztlan, "place of the Heron," or "Heron" people), the native name of one of the tribes that occupied the tableland of Mexico on the arrival of the Spaniards in America. It has been very frequently employed as equivalent to the collective national title of Nahuatlecas or Mexicans. The Aztecs came, according to native tradition, from a country to which they gave the name of Aztlan, usually supposed to lie towards the north-west, but the satisfactory localization of it is one of the greatest difficulties in Mexican history. The date of the exodus from Aztlan is equally undetermined, being fixed by various authorities in the 11th and by others in the 12th century. One Mexican manuscript gives a date equivalent to A.D. 1164. They gradually increased their influence among other tribes, until, by union with the Toltecs, who occupied the tableland before them, they extended their empire to an area of from 18,000 to 20,000 square leagues. The researches of Humboldt gave the first clear insight into the early periods of their history. See Mexico; Nahuatlan Stock.

AZUAGA, a town of western Spain, in the province of Badajoz, on the Belmez-Fuente del Arco railway. Pop. (1900) 14,192. Azuaga is the central market for the live-stock of the broad upland pastures watered by the Matachel, a left-hand tributary of the Guadiana, and by the Bembézar, a right-hand tributary of the Guadalquivir. Coarse woollen goods and pottery are manufactured in the town.

AZUAY (sometimes written Assuay), a province of Ecuador, bounded N. by the province of Cañar, E. by Oriente, S. by Loja, and W. by El Oro. It was formerly called Cuenca, and formed part of the department of Azuay, which also included the province of Loja. Azuay is an elevated mountainous district with a great variety of climates and products; among the latter are silver, quicksilver, wheat, Indian corn, barley, cattle, wool, cinchona and straw hats. The capital is Cuenca.

AZUNI, DOMENICO ALBERTO (1749-1827), Italian jurist, was born at Sassar, in Sardinia, in 1749. He studied law at Sassari and Turin, and in 1782 was made judge of the consulate at Nice. In 1786-1788 he published his Dizionario Universale Ragionato della Giurisprudenza Mercantile. In 1795 appeared his systematic work on the maritime law of Europe, Sistema Universale dei Principii del Diritto Maritimo dell' Europa, which he afterwards recast and translated into French. In 1806 he was appointed one of the French commission engaged in drawing up a general code of commercial law, and in the following year he proceeded to Genoa as president of the court of appeal. After the fall of Napoleon in 1814, Azuni lived for a time in retirement at Genoa, till he was invited to Sardinia by Victor Emmanuel I., and appointed judge of the consulate at Cagliari, and director of the university library. He died at Cagliari in 1827. Azuni also wrote numerous pamphlets and minor works, chiefly on maritime law, an important treatise on the origin and progress of maritime law (Paris, 1810), and an historical, geographical and political account of Sardinia (1799, enlarged 1802).