ON VOLCANOES AND EARTHQ.UAKES. 377 and the sea swells and roars, generally undulating in an unusual manner, even without wind. During the commotion, the shocks are generally numerous, suc ceeding each other with various degrees of rapidity. The earth undulates, heaving and alternately subsiding ; or, in slighter cases, is merely in a tremulous state. In violent earthquakes, it opens ; and, in these fis sures, which are often of great size, towns and animals are ingulfed. The fissures sometimes emit smoke and flame, sometimes water; and flame and smoke are also often seen to issue out of the earth, without visible openings, as they do sometimes out of the sea also. The effect of the shocks on the water is remarkable; ships sometimes feeling the same sensation as if they had struck the ground, or received the blow of a wave. The proofs of the connexion between earthquakes and volcanoes are innumerable ; and the latter indeed often appear to give vent to that elastic matter which, being pent up, is the cause of the motion and the tremors of the earth. An earthquake extending to a distance of fifty miles, accompanied the eruption of flames in the sea of Azof which attended the forma tion of an island; and the ejection of Sabrina off the Azores, was also marked by the same circumstance. The same occurred when the volcanic islands arose out of the sea on the coast of Iceland. The great earth quakes of Sicily and Calabria were accompanied by eruptions of the Lipari Isles ; and those of iEtna, Vesuvius, and other volcanoes, have equally been attended by earthquakes. Those of Cumana were connected with similar phenomena in the West Indies ; and are supposed to have been dependent on the erup tions of the Andes. The earthquake of Quito in 1797 was marked by an eruption in Guadaloupe; and the