224 GENERAL SCIENCE 



other reasons, as five-sevenths carbohydrates, one-seventh 

 fats and oils, one-seventh proteins. In cases of illness, and 

 of convalescence afterward, the maintenance of this balance, 

 or a departure from it under direction of a physician, becomes 

 a matter of greatest importance. The amount of water per 

 day taken as drink should be from three to five pints and is 

 best taken between meals. Water with meals is beneficial, 

 but food should never be "washed down" in place of being 

 thoroughly masticated and mixed with saliva before swallow- 

 ing. To habitually follow the practice of drinking a half 

 pint of water or more the last thing before retiring at night 

 and the first thing after rising in the morning is an excellent 

 rule for health. 



Though we may not always know the proportions of food 

 required to supply bodily needs, for people in good health an 

 approximation to a balanced ration is to serve at a meal 

 (a) one dish that is largely starch, such as potato, rice, or 

 cereal; (b) one rich in protein, such as meat, eggs, cheese, or 

 beans; (c) some fats, such as butter^ or fat meat, and some 

 sugar (perhaps in fruit jellies and preserves, or as molasses). 



SUMMARY 



Chief- among the protein foods are albumen in eggs, gluten in the 

 various grains, legumen in peas and beans, myosin in meat, and casein 

 in milk. These are composed chiefly of hydrogen, oxygen, carbon, 

 with some nitrogen, and in the egg a little sulphur. Other chemical 

 elements are present in small quantities only. 



Some minerals in solution in drinking waters, and in the cereals and 

 other foods, serve to keep the organs of digestion active and the diges- 

 tive fluids abundant. Three to five pints of water daily contributes 

 toward maintaining a normal condition of Digestion and circulation, 

 and the elimination of waste from the body. 



The introduction into milk of some acid coagulates the casein. 

 The rennet used in cheese-making is a dried portion of the stomach 

 from a calf, and it contains some of the acid secreted there for use in 

 digestion. The gastric fluid in the human stomach contains a little 



