"The latter are dispersed through a district of country consisting of limestone, several miles in circumference. They are of considerable number, and force themselves upwards through apertures in the rocks with some violence and ebullition. The waters are strongly impregnated with muriate of soda, and yield upon evaporation very good salt for culinary purposes (not less than 200 tons in the year). "About the centre of this limestone district is found an extraordinary volcanic phenomenon. On approaching the spot from a distance, it is first discovered by a large volume of smoke rising and disappearing at intervals of a few seconds, resembling the vapors arising from a violent surf, whilst a dull noise is heard like that of distant thunder. Having advanced so near that the vision was no longer impeded by the smoke, a large hemispherical mass was observed, consisting of black earth mixed with water, about sixteen feet in diameter, rising to the height of twenty or thirty feet in a perfectly regular manner, and, as it were, pushed up by a force beneath, which suddenly exploded with a dull noise, and scattered about a volume of black mud in every direction. After an interval of two or three, or sometimes four or five seconds, the hemispherical body of mud or earth rose and exploded again. "In the same manner this volcanic ebullition goes on without interruption, throwing up a globular mass of mud, and dispersing it with violence through the neighboring places. The spot where the ebullition occurs is nearly circular and perfectly level; it is covered with only the earthy particles impregnated with salt water, which are thrown up from below; its circumference may be estimated at about half an English mile. In order to conduct the salt water to the circumference, small passages or gutters are made in the loose muddy earth, which lead it to the borders, where it is collected in holes dug in the ground for the purpose of evaporation. "A strong, pungent, sulphurous smell, somewhat resembling that of earth-oil (naphtha), is perceived on standing near the site of the explosion, and the mud recently thrown up possesses a degree of heat greater than that of the surrounding atmosphere. During the rainy season these explosions are more violent, the mud is thrown up much higher, and the noise is heard at a greater distance. "This volcanic phenomenon is situated near the centre of the large plain, which interrupts the great series of volcanoes, and owes its origin to the same general cause as that of the numerous eruptions met with in this island."