[AS. lim.] An alkaline earth, found as a carbonate in chalk, marble and limestone. Quick lime is obtained by heating pure carbonate of lime to full redness in limekilns, when the carbonic acid is expelled and lime is left. When lime is moistened with water it swells up, gives off much heat and steam, and changes into a soft white powder, commonly called slaked lime {calcium hydrate). In this form it is used for purifying coal gas, in making mortar and plaster for building purposes, for removing the hair from skins in tanning, making paper pulp, and as a manure for land. When slaked lime is put in cold water and allowed to settle, the clear water is lime-water. In addition to the uses already mentioned, lime is used in the manufacture of washing-soda, bleaching-powder, and ammonia-water; in refining sugar, and also in iron-furnaces, lead-smelting, and glass-making. Bleaching-powder, commonly called chloride of lime, is a dry white powder, with a slight acid smell. It is largely used as a disinfectant. Carbonate of lime exists in great abundance in nature, and when crystallized is known as Iceland spar.