As an evidence of the widespread and far-reaching influences set in motion by the eruptions of Vesuvius it should be noted that Father Odenbach of St. Ignatius' college in Cleveland, O., the noted authority on seismic disturbances, reported that his microseismograph, the most delicate instrument known for detecting the presence of earthquakes in any part of the globe, had plainly recorded the disturbances caused by the eruption of Vesuvius. The lines made by the recorder, he said, had shown a wavy motion for several days, indicating a severe agitation in the earth's surface at a remote point. CHAPTER XXIII. VOLCANOES AND EARTHQUAKES EXPLAINED. BY TRUMBULL WHITE. =The Theories of Science on Seismic Convulsions--Volcanoes Likened to Boils on the Human Body through Which the Fires and Impurities of the Blood Manifest Themselves--Seepage of Ocean Waters through Crevices in the Rock Reach the Internal Fires of the Earth--Steam is Generated and an Explosion Follows--Geysers and Steam Boilers as Illustrations--Views of the World's Most Eminent Scientists Concerning the Causes of Eruption of Mount Pelee and La Soufriere.= The earth, like the human body, is subject to constitutional derangement. The fires and impurities of the blood manifest themselves in the shape of boils and eruptions upon the human body. The internal heat of the earth and the chemical changes which are constantly taking place in the interior of the globe, manifest themselves outwardly in the form of earthquakes and volcanoes. In other words, a volcano is a boil or eruption upon the earth's surface. Scientists have advanced many theories concerning the primary causes of volcanoes, and many explanations relating to the igneous matter discharged from their craters. Like the doctors who disagree in the diagnosis of a human malady, the geologists and volcanists are equally unable to agree in all details concerning this form of the earth's ailment. After all theories relating to the cause of volcanoes have been considered, the one that is most tenable and is sustained by the largest number of scientific men is that which traces volcanic effects back to the old accepted cause of internal fires in the center of the earth. Only in this way can the molten streams of lava emitted by volcanoes be accounted for. The youngest student of familiar science knows that heat generates an upward and outward force, and like all other forces that it follows the path of least resistance. This force is always present in the internal regions of the earth, which for ages upon ages has been gradually cooling from its poles toward its center. When conditions occur by which it can outwardly manifest itself, it follows the natural law and escapes where the crust of the earth is thinnest.