CHAPTEK IY. 



DEINKS. QUANTITY AND QUALITY OF FOOD. 



Water Alcohol Distilled liquors Wines, malt liquors, etc. Coffee Tea 

 Chocolate Quantity and variety of food necessary to nutrition Necessity 

 of a varied diet. 



Water. 



WATEK, one of the most important of the proximate 

 principles of the organism, and found in every tissue and 

 part without exception, is introduced with all kinds of 

 food, and is the basis of all drinks. Its functions in the 

 economy have already been fully considered. As a rule, it is 

 taken in greater or less quantity in nearly a pure state. 

 Although, as a drink, water should be colorless, odorless, 

 and nearly tasteless, it always contains more or less of saline 

 and other matters in solution, with a certain quantity of air. 

 The air and gases may be evolved by boiling or removing 

 the atmospheric pressure. Pure water (HO) does not exist 

 in nature. Even rain-water always contains salts, and fre- 

 quently a little ammonia and organic matter. The Croton 

 water supplied to the city of New York, contains 4*16 grains 

 of solid matter to the gallon. 1 The waters of the mineral 

 springs, which are so abundant in parts of this country, are 

 very rich in saline constituents, and generally contain a no- 

 table quantity of carbonic acid ; but the consideration of their 

 properties does not belong to physiology. Water charged 

 with carbonic acid under pressure, called soda water, or in 



*Dr. LEE, in PEREIRA, on Food and Diet, p. 43, note. 



