as if formed by the action of whirling waters; and, as sinkholes exist in great numbers in the vicinity of the rivers, and possess an outlet {193} at the bottom through a substratum of porous limestone, the idea is abundantly confirmed. In the State of Missouri these peculiar springs are also observed. Some of them in Greene county burst forth from the earth and the fissures of the rocks with sufficient force to whirl a _run_ of heavy buhrstones, and the power of the fountains seems unaffected by the vicissitudes of rain or drought. These same sinkholes, circular ponds, and gushing springs are said to constitute one of the most remarkable and interesting features of the peninsula of Florida. There, as here, the substratum is porous limestone; and it is the subsidence of the layers which gives birth to the springs. The volume of water thrown up by these boiling fountains is said to be astonishingly great; many large ones, also, are known to exist in the beds of lakes and rivers. From the circumstance of the existence of these numerous springs originated, doubtless, the tradition which Spanish chroniclers aver to have existed among the Indians of Porto Rico and Cuba, that somewhere among the Lucayo Islands or in the interior of Florida there existed a fountain whose waters had the property of imparting _rejuvenescence_ and perpetuating perennial youth. Only twenty years after the discoveries of Columbus, and more than three centuries since, did the romantic Juan Ponce de Leon, an associate of the Genoese and subsequent governor of Porto Rico, explore the peninsula of Florida in search of this traditionary fountain; of the success of the enterprise we have no account. Among the other poetic founts of the "Land of {194} Flowers," we are _told_ of one situated but a few miles from Fort Gaines, called "Sappho's Fount,"[139] from the idea which prevails that its waters impart the power of producing sweet sounds to the voices of those who partake of them.