BIOLOGY APPLIED TO HEALTHFUL LIVING 553 



sive use of tea or coffee ; and disturbances of other organs may 

 follow. One who uses even small amounts of tea and coffee 

 and who does not " feel well " for no apparent reason, should 

 try the effect of complete abstaining for a few days occa- 

 sionally. By so experimenting with themselves, many people 

 have learned that tea and coffee harm them. Other people 

 are certainly benefited by a limited use of these beverages. 



Tea and coffee should never be given to young children. 

 They may be easily harmed by such stimulants. 



Cocoa and chocolate are made from the seeds of the cacao- 

 or chocolate-tree, a native of tropical America. The seeds 

 are rich with 50 per cent of fat, some of which is extracted in 

 the process of making commercial cocoa or chocolate. Both 

 of these contain a substance similar to the caffein of tea and 

 coffee, but milder in its effects. However, one who has 

 difficulty from the use of tea and coffee will do well to experi- 

 ment with himself and thus learn whether chocolate or 

 cocoa produces marked effects. 



481. Effect of Narcotic Drugs. We are here concerned 

 with the effect of such drugs as opium, morphine, cocaine, 

 laudanum, chloroform, chloral hydrate, and various patent 

 or secret preparations, all of which are habitually used by 

 some people. In most cases, such drugs are used first to 

 narcotize the nerves and thus relieve pain, and their frequent 

 use finally becomes a habit even more powerful than the 

 alcoholic habit. It is unnecessary to go into an extensive 

 discussion of narcotic drugs, for most intelligent people now 

 understand that only on a physician's advice is it safe to use 

 any drug to relieve pain ; and also that no drug should be 

 used so frequently as to offer the grave risk of establishing a 

 habit. 



It should be noted that the narcotic drugs do not cure 

 diseases. For example, patent headache powders and pills 

 simply dull the sensory nerves. The headache may be due 

 to a disordered stomach, eye-strain, constipation, or other 



