YSENPURG-YUCATAN. 



153 



1770, with a comedy (Hacer que Hacemos). This 

 was followed by several translations of French 

 plays for the royal theatre, and a few original dra- 

 matic compositions. But they are forgotten ; and 

 his literary fame is founded on his Fables. Before 

 the publication of these, he produced a didactic 

 poem, in five cantos, On Music {La Musica}, the 

 first edition of which (Madrid, 1779) is distinguished 

 by typographical beauty. This poem is written in 

 elegant language, but is deficient in poetical con- 

 ception. Grainville translated it, in 1800, into 

 French. In his Literary Fables (Fabulas Liter- 

 arias), which first appeared in 1782, Yriarte at- 

 tacked what he considered the faults and errors of 

 literary men. They are the productions of an un- 

 poetical period, in which the French manner was 

 predominant in Spain. They are, therefore, cold, 

 and without humour; but the language is easy, 

 and there is much variety and elegance in the 

 metres. They have been translated into French 

 and German. In 1787, he collected his works in 

 prose and verse, at Madrid, in six volumes, of which 

 the first contains the Fables and La Musica. In 

 the second are eleven Epistles, mostly satirical, also 

 chiefly directed against the errors of scholars. The 

 other volumes contain, besides, a number of imita- 

 tions and original poems, also a metrical translation 

 of the Epistles of Horace to the Pisos, with expla- 

 natory notes. One of his enemies, Juan Pablo 

 Forner, irritated by his satires, wrote a bitter at- 

 tack on him under the title of Li Asno erudito (The 

 Learned Ass). Yriarte replied with his Para Ca- 

 ses tales suelen tener los Maestros oficiales. In 

 1788, he published a comedy, La Senorita mal Cri- 

 ada, in which, as in a former, El Senorito mimado, 

 the Spanish critics praise jthe strict observance of 

 the three unities. Yriarte died in 1794. See En- 

 sayo de una Biblioteca Espanola de los mejores Es- 

 critores del Reynado de Carlos III., par Sempere 

 y Guarinos (Madrid, 1789, 6 vols.). 



YSENPURG. See Isenburg. 



YTHAN, OR ITHAN, a river in Aberdeenshire, 

 which rises in the hills of the parish of Forgue ; 

 after a south-easterly course of about thirty miles, 

 being augmented about twelve miles from its mouth 

 by the Gight, it falls into the sea at the small vil- 

 lage of Newburgh. The parish of Foveran is on its 

 south bank, and that of Slains on the north at its 

 3stuary. It is navigable for three miles, as far as 

 Ellon; and vessels of 100 or 150 tons burden can 

 proceed a mile up. It possesses a valuable salmon 

 fishery. 



YTTRIA is the name of a very rare earth, dis- 

 covered in the composition of a mineral found at 

 Ytterby, in Sweden ; hence its name. The name 

 of the mineral is gadolinite. The earth may be ob- 

 tained by fusing the gadolinite with two parts of 

 caustic potash, washing the mass with boiling 

 water, and filtering the liquor, which is of a fine 

 green. This liquor is to be evaporated till no 

 more oxide of manganese falls down from it in a 

 black powder ; after which the liquid is to be sa- 

 turated with nitric acid. At the same time, digest 

 the sediment that was not dissolved in very dilute 

 nitric acid, which will dissolve the earth with 

 much heat, leaving the silex and the highly-oxidized 

 iron undissolved. Mix the two liquors, evaporate 

 them to dryness, redissolve and filter, which will 

 separate any silex or oxide of iron that may have 

 been left. A few drops of a solution of carbonate 

 of potash will separate any lime that may be pre- 

 sent; and a cautious addition of hydrosulphuret cf 



potash will throw down the oxide of manganese 

 that may have been left ; but if too much be em- 

 ployed, it will throw down the yttria also. Lastly, 

 the yttria is to be precipitated by pure ammonia, 

 well washed and dried. It is perfectly white. Its 

 specific gravity is 4-842. It has neither taste nor 

 smell. It is infusible alone, but with borax, melts 

 into a transparent glass, or opaque-white, if the 

 borax is in excess. It is insoluble in water, and in 

 caustic fixed alkalies ; but it dissolves in caibonat 

 of ammonia, though it requires five or six times as 

 much as glucine. It is soluble in most of the acids. 

 The salts have the following general characters: 

 Many of them are insoluble in water. Precipitates 

 are occasioned in those which dissolve, by phosphate 

 of soda, carbonate of soda, oxalate of ammonia, 

 tartrate of potash, and ferroprussiate of potash. If 

 we except the sweet-tasted, soluble sulphate of 

 yttria, the other salts of this earth resemble those 

 with a base of lime in their solubility. When 

 yttria is treated with potassium in the same man- 

 ner as the other earths, similar results are obtained. 

 The potassium becomes potash, and the earth as- 

 sumes the appearance of a metal. Its texture is 

 scaly ; its colour gray-black, and lustre perfectly 

 metallic. This scaly texture distinguishes it from 

 aluminum and glucinum. Yttrium for this is the 

 name of the metallic base is not oxidized either 

 in air or water, at common temperatures ; but when 

 heated to redness, it burns with splendour, and be- 

 comes yttria. 



YTTRO-CERITE ; a massive mineral, of a red- 

 dish, grayish-white, or violet-blue colour. It occurs 

 in crusts, sometimes having an indistinct cleavage ; 

 opaque; yields to the knife ; specific gravity 3-447. 

 Its constituents are oxide of cerium 13-15, yttria 

 14-6, lime 47'77, fluoric acid 24-45. It has hitherto 

 been found only at Finbo, near Fahlun, in Sweden, 

 imbedded in quartz. 



YTTRO-TANTALITE occurs massive, has a 

 degree of hardness above apatite, a specific gravity 

 of 5'3 or 5'8, a metallic lustre, and a blackish- 

 brown colour. It is opaque. Under the blow-pipe 

 it decrepitates at first, but melts, by an increase of 

 heat, into a greenish-yellow slag. It consists, ac- 

 cording to Vauquelin, of 45 oxide of columbium, 

 55 of yttria and oxide of iron. It is found, along 

 with gadolinite, at Ytterby, in Sweden, but is ex- 

 ceedingly rare. 



YUCATAN; the most easterly state of the 

 Mexican confederacy, in the form of a peninsula, 

 jutting out into the gulf of Mexico, bounded north- 

 west by the gulf of Mexico, south-east by the bay 

 of Honduras, south by Guatamala, south-west by 

 the state of Vera Cruz. The isthmus which con- 

 nects it with the continent of North America is 

 about 120 miles wide. Square miles, 30,000 ; po- 

 pulation, 496;990 ; chief towns, Merida, the capital, 

 Campeachy, and Valladolid. The soil is very fer- 

 tile, and, when under proper cultivation, produces 

 great crops of cotton, tobacco, pepper, the sugar- 

 cane, indigo, maize, and other kinds of grain. The 

 scarcity of water in the central parts of the state 

 renders the crops variable ; and years occur in 

 which the poorer classes are driven to seek subsis- 

 tence from roots. Cattle, fowls, and bees, are very 

 numerous ; wax and honey plentiful ; but there are 

 no mines. The forests abound with wild beasts. 

 The principal article of commerce is logwood. The 

 climate is hot, the summer beginning in April, and 

 ending in September; but January and February 

 are also warm. The British have some small set- 



