Camping and woodcraft - Scoutmastercg.com

CAVE EXPLORATION 353rial product of caves, up to date, Is the so-called*' Mexican Onyx," which is a fine-grained, translucent,and beautifully colored variety of dripstone.Occasionally the "cave pearls" found in shallowpools, where they have been polished by attrition,have been set as gems. In olden times nearly allthe niter used by our forefathers in making gun^powder was procured from caverns. Guano, ochre,and the sulphates of soda and of magnesia arefound in caves. The chance of discovering mineralveins is lessened by the incrustation of dripstone thatcoats the walls; there is no "bloom" to attract theeye.The animal life of caverns is peculiar. It includestransparent fish, white crayfish, cave lizards,white mice and rats, cave crickets, and minor species—all blind, and some of them quite eyeless—besidesthe usual colonies of bats. Snakes are nevermet inside of caverns, but sometimes may be encounteredin sink-holes, or in the "rock-houses" previouslymentioned.Digging in the floors of caves for relics of prehistoricman has long been a favorite branch ofscience in Europe, but comparatively little of thi^work has been done in America. Sometimes humanskeletons of our own era are found encased in thedripstone, as at Luray, at Mammoth Cave, In theAdelsberg, and in the Cave of MelidonI, wherethe remains of three hundred Cretans, who were-smoked to death by the Turks in 1822, are graduallydisappearing in a stony shroud.