See Jerez.


Xexocrates, a Greek philosopher, born in Chalcedon in 396 B. 0., died in 314. He attached himself successively to ^Eschines the Socratic and to Plato, whom he accompanied to Syracuse. After the death of Plato he was repeatedly sent on embassies to Philip of Macedon, and during the Lamian war to Antipater. In 339 he succeeded Speusippus as director of the academy, and held that post till his death. He wrote several metaphysical treatises, two works on physics, and several on ethics and political economy. Aristotle and Theophrastus wrote upon his doctrines, but our knowledge of them is very incomplete. He identified ideas with numbers, and founded upon these a mystical theology, defining the soul as a self-moving number. He taught that the value of everything besides virtue is conditional, and that happiness results from its possession and practice.


See Jokullo.


See Engraving.


Xyloidine, an explosive compound, having the formula C6H9NO7, discovered by Braconnot in 1863, and prepared by the action of strong nitric acid upon starch. The starch is triturated in a strong porcelain mortar with five to eight parts of fuming nitric acid till it is reduced to a transparent semi-fluid mass, without evolution of gas. From 20 to 30 parts of water are then added, by which the xyloidine is precipitated as a white, granular mass, a small quantity of starch remaining in solution. The xyloidine is purified by washing and drying, and then dissolving in 10 parts of glacial acetic acid and one part of dihydrated acid, and the solution filtered and evaporated. When struck, xyloidine detonates, but not so violently as gun cotton.


See Yellow-eyed Grass.


Yakima, a S. county of Washington territory, on the E. slope of the Cascade mountains and extending into the valley of the Columbia; area, about 5,000 sq. m.; pop. in 1870, 432. It embraces the valley of the Yakima river, and contains excellent grazing lands, fertile and productive tracts, and abundant timber. The chief productions in 1870 were 1,250 bushels of wheat, 1,270 of oats, 3,973 lbs. of wool, and 513 tons of hay. There were 429 horses, 104 mules and asses, 1,621 milch cows, 2,547 other cattle, 1,361 sheep, and 87 swine. Capital, Yakima City.


Yalobusha, a N. county of Mississippi, watered by tributaries of the Yalobusha and Tallahatchie rivers; area, 450 sq. m.; pop. in 1870, 13,254, of whom 7,052 were colored. The surface is generally level and the soil highly fertile. It is intersected by the Mississippi Central and the Mississippi and Tennessee railroads. The chief productions in 1870 were 241,138 bushels of Indian corn, 3,772 of Irish and 11,880 of sweet potatoes, 5,901 lbs. of butter, and 5,167 bales of cotton. There were 841 horses, 1,140 mules and asses, 1,851 milch cows, 3,821 other cattle, 3,002 sheep, and 8,232 swine; 1 manufactory of agricultural implements, 1 of sash, doors, and blinds, 1 of cars, 2 of iron castings, 5 flour mills, 4 saw mills, and 2 railroad repair shops. Capital, Coffeeville.