FOODS AND THEIR USES 257 



is diminished. Contrasted with stimulants there are 

 other substances called narcotics which have a quieting 

 effect, often associated with pleasurable feeling. Common, 

 narcotics are tobacco, opium, chloroform and cocaine, 

 whose influences will be discussed in a later section. 

 Tea and coffee have a mild stimulating influence which 

 they owe to alkaloids (thein and caffein) of similar if not 

 identical composition. Both of these beverages, and 

 especially tea, contain tannin which is extracted if water 

 is allowed to stand too long on the grounds. Both tea and 

 coffee are better when freshly made, not only because they 

 contain less tannin, but because they retain more of their 

 delicate aroma which soon disappears if either beverage 

 is allowed to stand. Tannin is especially injurious to the 

 stomach, and tea and coffee should be so prepared that 

 most of this substance is not extracted. Tea and coffee 

 may produce bad effects if used to excess, and there are 

 some individuals in whom coffee, especially, produces 

 disturbances of digestion, but perhaps the majority of 

 people experience little harm from the use of these drinks. 

 Chocolate, likewise a mild stimulant, is more nutritious 

 than tea or coffee. 



The most widely used of the beverages taken to gratify 

 the sense of taste are the various drinks which contain 

 alcohol; such as beer, wine, whisky, brandy and numerous 

 others in almost endless variety. While it has been shown 

 experimentally that alcohol is a food i.e., it may be 

 oxidized in the body with the production of energy 

 it has practically little nutritive value as compared with 

 other foods, and its other effects more than outweigh 

 whatever nutritive value it may possess. The effect of 

 alcohol on digestion when taken in large quantities is bad, 

 as it gives rise to cirrhosis of the liver, inflammation of the 

 stomach, dyspepsia, and a variety of other disturbances. 



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