Lava

la'va, the molten material poured out of volcanoes. As volcanoes are widely distributed, the lava poured out by them represents different parts of the interior of the earth and varies accordingly. When lava cools slowly it forms crystalline rocks; when it cools quickly it forms a glassy rock, of which obsidium is the best type. Characteristic rocks are basalt and porphyry, tufa and pumice. Disintegrating volcanic rock forms a fertile soil. The fertility of the slopes of the European volcanoes, as Vesuvius and Etna, tempts villagers within the zone of danger. In 1812 a volcanic eruption of St. Vincent covered the Barbadoes Islands with several inches, not of snow, but of fertile, fluffy black dust. The rich sugar-cane fields of Hawaii are of volcanic formation. During what is known as the tertiary geologic age a vast outflow of lava flooded the Pacific coast from Idaho to the ocean. It covered southern Idaho, the greater portion of Washington, eastern Oregon, and northeastern California. In cooling, it formed basaltic rock. The plains of the Snake and the Columbia are volcanic. Extensive areas near Flagstaff, Arizona, are covered with coarse black soil resembling crushed coke. Lava soil of high fertility covers large areas in Java, Japan, Italy, Sicily, and Hungary. Wherever rainfall is sufficient or water can be had, the valleys are exceedingly fertile. Some say that basaltic soil forms the best wheat land known. See Volcanoes; Soil; Basalt; Fingal'S Cave