Food and Drink 89 



germs of disease, sickness may follow its use. Without 

 doubt the most important factor in the spread of disease 

 is, with the exception of impure air, impure water. It is the 

 chief agent in the spread of typhoid fever. The evidence 

 is likewise overwhelming that filthy water is an all-powerful 

 agent in the spread of that terrible disease cholera. 



136. Tea and Coffee. It has been estimated that one- 

 half of the human race now use tea, either habitually or 

 occasionally. Its immoderate use is a prolific source of 

 indigestion, palpitation of the heart, persistent wakeful- 

 ness, and of other disorders. Persons who cannot use it 

 without feeling its hurtful effects should leave it alone. It 

 should not.be taken on an empty stomach, nor sipped after ^ 

 every mouthful of food. 



Coffee often disturbs the rhythm of the heart and causes 

 palpitation. Taken at night it often causes wakefulness. 

 This effect is so well known that it is often employed to 

 prevent sleep. Immoderate use of strong coffee may pro- 

 duce other harmful effects, such as muscular tremors, sick 

 headache, palpitation, and various uncomfortable feelings 

 in the cardiac region. Some persons cannot drink even a 

 small amount of tea or coffee without these unpleasant 

 effects. These beverages are unsuitable for young people. 



137. Cooking. The art of cooking plays a very important 

 part in the matter of health, and thus of comfort and hap- 

 piness. Badly cooked and ill-assorted foods are often the 

 cause of serious digestive disorders. Mere cooking is not 

 enough, but good cooking is essential. Cooking enables 

 food to be more readily chewed and more easily digested. 

 Thus, a piece of meat when raw is tough and tenacious, 

 but if cooked it loses much of its toughness, because the 

 connective tissues are changed into a soft and jelly-like 

 mass. Besides, the meat is more readily acted upon by the 



