STALACTITE and STALAGMITE, de posits of lime hanging from the roof (stalac tites) or rising from the floor (stalagmites) of a cavern. Stalactitic formations occur chiefly in long and more or less fantastic masses suspended from the roofs of caverns in limestone rocks. Stalactites appear to be continually forming; water containing car bonate of lime held in solution by carbonic acid, trickling through crevices in the roofs of the caverns, gradually during its exposure to the air loses its carbonic acid and conse quently deposits its carbonate of lime; the water passing over the portion first deposited gradually adds to it, and eventually gives the carbonate of lime its great length and stalac titic character. The flatter deposits, called stalagmites, are formed on the floor of the cavern by the water there depositing that por tion of its carbonate of lime which is not separated during the formation of the stalac tite. They sometimes occur as cones rising to meet the stalactites in the form of large pil lars, and sometimes form flat crusts over the bottoms or sides of a cave. Stalactitic car
bonate of lime is met with in the veins of lead ore in Durham and Northumberland, England. Caverns are sometimes nearly filled with these deposits, which in some cases are of very large dimensions. Oriental alabaster (q.v.) and Mexican onyx are formed as stalag mitic crusts, and consist of calcium car bonate. Among striking examples of stalac tites and stalagmites are those of the Luray and Mammoth caves (qq.v.) in the United States; those in the cavern at Castleton, Derby shire, England, and in the Isle of Skye; in the grotto of Antiparos in the Grecian Archi pelago; in the Woodman's Cave in the Harz, Germany; at Auxelle, France; and the most important of those at Adelsberg, Austria Hungary. Stalactites of iron sulphide, mar casite, are also known. By oxidation of the sulphide, they may be altered to limonite, forming the so-called pipe ore of certain Mis souri iron deposits.