temporary or permanent. Water is temporarily hard when it contains
soluble lime, which is precipitated, that is, separated from it, upon
boiling. Every housewife who uses a teakettle is familiar with this
condition. The lime precipitated day after day clings to the sides of
the vessel in which the water is boiled, and in time they become very
thickly coated. Permanent hardness is caused by other compounds of lime
that are not precipitated by boiling the water. The only way in which to
soften such water is to add to it an alkali, such as borax, washing
soda, or bicarbonate of soda.

36. USES OF WATER IN COOKING.--It is the solvent, or dissolving, power
of water that makes this liquid valuable in cooking, but of the two
kinds, soft water is preferable to hard, because it possesses greater
solvent power. This is due to the fact that hard water has already
dissolved a certain amount of material and will therefore dissolve less
of the food substances and flavors when it is used for cooking purposes
than soft water, which has dissolved nothing. It is known, too, that the
flavor of such beverages as tea and coffee is often greatly impaired by
the use of hard water. Dried beans and peas, cereals, and tough cuts of
meat will not cook tender so readily in hard water as in soft, but the
addition of a small amount of soda during the cooking of these foods
will assist in softening them.

Water is used in cooking chiefly for extracting flavors, as in the
making of coffee, tea, and soups; as a medium for carrying flavors and
foods in such beverages as lemonade and cocoa; for softening both
vegetable and animal fiber; and for cooking starch and dissolving sugar,
salt, gelatine, etc. In accomplishing much of this work, water acts as a
medium for conveying heat.