Component parts, when pure: 39.4 parts of sodium and 60.6 chlorine.
Salt is absolutely required for the support of health. Upwards of half the saline matter of the blood consists of common salt; the necessity of supplying its daily waste is therefore obvious. It has been known for ages past that without salt man would perish, and in former periods of history barbarous punishment (entailing certain death) was that of feeding a culprit on food destitute of salt. It is required in the bile and for the cartilages of the body; the digestion would be impaired unless it were supplied, and the cartilages cannot be rebuilt as fast as they waste without its aid.
Table salt is obtained by the evaporation of water from brine springs; it is also dug out of salt mines.
Salt is of great value for the preservation of meat; it prevents the decomposition of flesh at a temperature below 6o°, but above that heat it cannot control putrefaction. It is therefore scarcely safe to salt beef or pork in very hot weather unless ice be used in the pickling. But even in the height of summer meat may be safely cured if ice enough is added to the pickle to keep it as cool as 55 degrees.
Meat is salted either by rubbing salt into it with the hand, or by immersing it in pickle or brine. The flesh absorbs the salt and gives out its watery particles in return, which form brine. Sugar is used in addition to salt, and is no doubt a valuable agent in pickling, for this reason - Oxygen is the great decomposing agent, that is, it is oxygen which causes decay. Now carbon absorbs oxygen, and as sugar contains a great deal of carbon it absorbs the oxygen, and thus helps the salt to preserve the meat. These would be about the ingredients of a good pickle: Four and a half pounds of common and fine salt, three gallons of water, one pound of moist sugar, one ounce of saltpetre, half an ounce of salteratus. For many varied and all good modes of making pickle we refer the reader to Warne's "Model Cookery Book".
Salt in store must be kept in a dry place.