Page:Food and cookery for the sick and convalescent.djvu/81

Rh in water is by boiling the same. Boiled water is a valuable antiseptic, and will not ferment.

There are many charged, carbonated, and mineral spring waters bottled and put upon the market. Some are used as table beverages, others for medicinal purposes.

Ordinary water, artificially charged with carbon dioxid (CO2), is called soda water, and may be purchased by the glass, usually in combination with fruit syrups or in syphons. Such water, when sold at the druggist's, contains a larger per cent of CO2than carbonated (naturally charged) waters, which renders it cooler to the taste, as the gas in passing off withdraws heat.

Plain soda water, taken in moderation, assists gastric digestion. It is a bad practice to indulge too freely in soda water with fruit syrups, as it causes a tendency to flatulency and indigestion. Almost all so-called fruit syrups are chemically prepared in the laboratory.

Among the most common carbonated table waters may be mentioned, Poland (uneffervescing), and Vichy, Johannis, Apollinaris, and Seltzer (effervescing). These often tempt people to drink who would otherwise neglect to do so, and in cases of fever they may be freely given. They are useful to dilute alcoholic liquors, and they are quite apt to relieve nausea and vomiting.

The alkaline mineral waters are all carbonated. Their most important ingredient is alkaline carbonates, and sodium chloride, sometimes sodium sulphates being present. Examples: Saratoga, Vichy, White Sulphur Spring, Hot Sulphur Spring, Hunyadi, and Londonderry Lithia Waters. Lithia water is often recommended in cases of rheumatism or gout; Hunyadi for liver troubles and indiscretions in diet.

Where patients are advised by physicians to visit water cures the good results obtained are due as much to change, rest, treatment, and quantity of water ingested, as to any especial value that the water itself contains.