Salt

[AS.] A substance found in the earth, and very abundant in sea-water, used for season¬ ing and preserving food. It is composed of sodium combined with chlorine. Salt is imp or¬ tant as an article of food, and the lower animals like it; farmers place lumps of rock-salt in their fields for the sheep and the cows to lick. I11 North America there are certain places where the rocks contain much salt, and w7ild animals flock in great numbers to these places, which are known as “ salt-licks.” Salt forms solid beds in the crust of the earth, just as coal does and in this state it is known as rock-salt. Rain-water, sinking into the ground, di olves much of the rock-salt; and if a well be dug down to this salt water, it can be pumped up, and the salt obtained from it by evaporation crystallizes in cube shapes. The salt water is called brine. Salt can also be obtained by evaporating sea-water. In the Car¬ pathian Mountains there are beds of salt from 600 to 700 feet thick. Near Cracow there is a wonderful salt-mine over a you sand feet deep, divided into floors, galleries, and pa ages, all ot salt. One division is so like a church that it is called St. Anthony’s Chapel. It has an altar, pulpit, and statues. Another room has a tomb made of salt. The pa ages are estimated to extend 300 miles. Rock salt is abundant in many parts of the United States, and great quantities of brine are pumped up and evaporated in New York. Rarge deposits exist in Michigan, Louisiana, Utah, Nevada, and elsewhere. Petra, a rock.] A kind of white salt made up of nitric acid and potash, often found oozing from rocks. It is Litter in taste, and is called other compounds formed by the union of an acid ami a base. shore or in deserts, made by the wearing out of rocks, especially of quartz, silica, or flint. Rivers and and sand from pits are usually sharper than sea-sand. The colors of sand are made by various oxides of iron. Sand is used in, making gla , mortar, cement, sand-paper, molds for casting, and in sawing stones and grinding cutlery.— Sand-blast is a stream of sharp sand let fall from a high box on a plate of gla to cut it and make it look like ground gla . Metals and stones may also be cut by the sand-blast. The parts not requiring to be cut or engraved are covered with leather, paper, or wax. yellowish heart wood of trees in the East Indies and the Hawaiian and South Sea islands. It has a pleasant smell. living on the sea-shore. The European kinds include the common sandpiper, called also sum¬ mer-snipe, the dunlin, the knot, and the ruff. Some small plovers are called sandpipers. In North America are the pectoral, the purple, the red-breasted, and the spotted sandpipers. Old and New Red Sandstone are two extensive series of British rocks, the one below and the other above the coal-measures. The terms Permian and Tria ic have taken the place of the name New Red Sandstone. Flexible sandstone is a fine-grained variety of itacolumite, which, . owing to scales of mica, is quite flexible.