Table waters, as Apollinaris, Vichy, or others containing carbon dioxid are refreshing and wholesome and may be used in nausea and vomiting for their quieting effect. Those who are unable to take milk will often find its digestion will be aided if the milk be mixed with Vichy or seltzer water.
When water is used as a hot drink it should be freshly drawn, brought to a boil, and used at once. This sterilizes it and develops a better flavor.
Cold water should be thoroughly cooled, but not iced. Water is best cooled by placing the receptacle on ice rather than by putting ice in the water. Impure or contaminated ice will contaminate water.
The theory has long been held that water drinking at meals is injurious, the objection being that the food is not so thoroughly masticated if washed down with water, and that it dilutes the digestive juices. But this theory is now rejected by the best authorities.
When water drinking at meals is allowed to interfere with mastication and is used to wash down the food, the objection is well taken, but one need rarely drink while food is in the mouth; the water should be taken at rest periods between mouthfuls.
Thorough mastication and a consequent free mixing of the food with saliva is one of the most essential steps in digestion, and the flow of gastric juice, as the flow of saliva, is stimulated by the water.
It is singular that the use of water at meals has long been considered unwise when the free use of milk, which is about seven-eighths water, has been recommended.
The copious drinking of cool water from a half hour to an hour before a meal will cleanse the stomach and incite the flow of saliva and gastric juice, thus aiding digestion.
Moreover, the digestive cells secrete their juices more freely and the sucking villi absorb more readily when the stomach and intestines are moderately full, either of food or water, and to fill the stomach with food requires too much digestive and eliminative activity.
Water taken before meals passes through the stomach before the food, washes away any mucus that may have collected over the mouths of the gastric glands, stimulates them to activity, and prepares the stomach to receive the food.