STALACTITES AND STALAGMITES are found in caves and other places where water charged with carbonate of lime is subject to evaporation. Water impregnated with car bonic acid is able to dissolve lime, and as all rain and surface water contains more or less carbonic acid, it takes up in its passage through the earth to the roofs of caves a certain amount of lime. When the water is exposed on the roof or floor of the cave, evapora tion takes place, and so both the bulk of the water and its solvent power are reduced, and a thin pellicle of solid carbonate of lime is deposited. When this takes place on the roof of the cave; long icicle-like pendants are.formed, which are called stalactites; and when the water drops upon the floor, a stalaginitic layer is formed, which rises at the points where the largest supply of material exists, in the form of pillars to meet the overhang ing stalactites. In some caves, the descending points have met and formed a series of natural columns as if supporting the roof. The color of the limestone
thus formed is affected by the superineumbent strata, but it is generally white or yellow ish. The stalactites have a rich submystalline structure, being composed of acicular radiating crystals, arranged in concentric layers from their exogenous growth Some times, frcm metamorphic changes that have taken place subsequent to their formation, they become more truly crystalline. The amount of the deposition is very great in some caves, and the wondertul variety and singular groupings of the stalactites give them a peculiar beauty. The caves most remarkable in this way are the cave of Adelsberg in Styria, the grotto of Antiparos in the Grecian Archipelago, Wyver's cave in the United States, and the caves_ of the peak in Derby-shire The remains of primeval man found in the caves in France, and the fossils from the bone caves in Britain and elsewhere, are generally cemented together into a stalaginitie deposit on the floor of the cave.