several hours before using, so that the sulphur may be volatilized and the temperature reduced.
Florida is a well watered country. Lakes, streams and springs are extremely numerous. The underlying limestone is full of caverns containing water. Every one knows about the Silver Spring in Marion County. It starts as a full-grown river from a spring 25 to 30 feet deep, perfectly clear, with an outlet GO feet wide, 10 to 14 feet deep. It is the Oclawaha River, navigable for steamers from its very source. The water is probably the rainfall of the region filtering through miles of sand, with a temperature of 72° and perceptibly calcareous to the taste.
The water in the lakes is purer than that from the springs, probably because on exposure the compounds break up, and the gases, sulphur and hydrogen, carbonic acid, oxygen and nitrogen (common air) are eliminated. The Everglades and Lake Okeechobee illustrate this fact. The steamers plying down the Kissimmee River, across Okeechobee and down the Caloosahatchee River to Fort Myers obtain their drinking-water from far out in the lake, because nowhere else can it be found so palatable, or so well fitted for use in the boilers of the steamers.
The source of the sulphuretted hydrogen must be the various sulphates decomposed by the action upon them of organic matter. The mineral compounds arise naturally from the solubility of the various salts, either from the original strata or from their dissemination through the soil.
Fresh-water Springs in the Ocean.
Many of these underground streams proved to exist by the artesian bore-holes are of great volume, and hence must pass to some distance under the ocean. This fact is further corroborated by the small degree of salinity even in the deeper wells. Statements made by residents claim the existence of fresh-water springs miles away from the land opposite St. Augustine, Matanzas and Ormond. The first of these is also mentioned by T. C. Mendenhall, formerly superintendent of the United States Coast Survey, in a letter to J. W. Gregory, in charge of Artesian Well Investigations, Department of Agriculture.
Mr. M. L. Fuller furnishes me with the following additional localities. Dr. Mendenhall mentions the reported occurrence of freshwater springs off the mouth of the Mississippi River. In 'The Island of Cuba,' by Lieutenant A. S. Rowan and M. M. Ramsey (Henry Holt & Co., 1896), page 18, it is stated that the water is often forced by hydrostatic pressure to the surface far out at sea. Elisée Reclus remarked that 'in the Jardines (east of the Isle of Pinos), so named from the verdure-clad islets strewn like gardens amid the blue waters, springs of fresh water bubble up from the deep, flowing probably in subterranean galleries from the mainland.'
Mr. Fuller also adds the following quotation from a paper by
