5. KINDS OF WATER.--Inasmuch as water is so important an element in the composition of beverages, every one should endeavor to become familiar with the nature of each of its varieties.
SOFT WATER is water that contains very little mineral matter. A common example of soft water is rainwater.
HARD WATER is water that contains a large quantity of lime in solution. Boiling such water precipitates, or separates, some of the lime and consequently softens the water. An example of the precipitation of lime in water is the deposit that can be found in any teakettle that has been used for some time.
MINERAL WATER is water containing a large quantity of such minerals as will go in solution in water, namely, sulphur, iron, lime, etc.
DISTILLED WATER is water from which all minerals have been removed. To accomplish this, the water is converted into steam and then condensed. This is the purest form of water.
CARBONATED WATER is water that has had carbon-dioxide, or carbonic-acid, gas forced into it. The soda water used at soda fountains is an example of this variety. Carbonated water is bottled and sold for various purposes.
6. NECESSITY FOR PURE WATER.--The extensive use made of water in the diet makes it imperative that every effort be exerted to have the water supply as pure as possible. The ordinary city filter and the smaller household filter can be depended on to remove sand, particles of leaves, weeds, and such foreign material as is likely to drop into the water from time to time, but they will not remove disease germs from an unclean supply. Therefore, if there is any doubt about water being pure enough to use for drinking purposes, it should be boiled before it is used. Boiling kills any disease germs that the water may contain, but at the same time it gives the water a very flat taste because of the loss of air in boiling. However, as is mentioned in Essentials of Cookery, Part 1, the natural taste may be restored by beating the boiled water with an egg beater or by partly filling a jar, placing the lid on, and shaking it vigorously.
RELATION OF BEVERAGES TO MEALS
7. About one-third of all the water required each day is taken in the form of beverages with the meals. It was formerly thought that liquids dilute the gastric juice and so should be avoided with meals. However, it has been learned that beverages, either warm or cold, with the exception of an occasional case, may be taken with meals without injury. The chief point to remember is that it is unwise to drink beverages either too hot or too cold. For the best results, their temperature should be rather moderate.